10 October 2008

How Lie Detectors Work

For more than 15 years, Robert Hanssen led a double life. In one life he was a 25-year veteran with the Federal Bureau of Investigation (FBI) who had access to some of the nation's most-classified information. In his other life, he allegedly was spying for the Russian government. Hanssen's deception was finally discovered, and in February 2001 he was arrested and later pled guilty to 15 espionage-related charges. Spies are probably the world's best liars, because they have to be, but most of us practice deception on some level in our daily lives, even if it's just telling a friend that his horrible haircut "doesn't look that bad."

People tell lies and deceive others for many reasons. Most often, lying is a defense mechanism used to avoid trouble with the law, bosses or authority figures. Sometimes, you can tell when someone's lying, but other times it may not be so easy. Polygraphs, commonly called "lie detectors," are instruments that monitor a person's physiological reactions. These instruments do not, as their nickname suggests, detect lies. They can only detect whether deceptive behavior is being displayed.

Photo courtesy Lafayette Instrument
An analog polygraph instrument
Most analog polygraphs are being replaced by digital devices.


Do you think you can fool a polygraph machine and examiner? In this article, you'll learn how these instruments monitor your vital signs, how a polygraph exam works and about the legalities of polygraph testing.

A polygraph instrument is basically a combination of medical devices that are used to monitor changes occurring in the body. As a person is questioned about a certain event or incident, the examiner looks to see how the person's heart rate, blood pressure, respiratory rate and electro-dermal activity (sweatiness, in this case of the fingers) change in comparison to normal levels. Fluctuations may indicate that person is being deceptive, but exam results are open to interpretation by the examiner.

Source: Lafayette Instrument
Physiological responses recorded by a polygraph

Polygraph exams are most often associated with criminal investigations, but there are other instances in which they are used. You may one day be subject to a polygraph exam before being hired for a job: Many government entities, and some private-sector employers, will require or ask you to undergo a polygraph exam prior to employment.

Polygraph examinations are designed to look for significant involuntary responses going on in a person's body when that person is subjected to stress, such as the stress associated with deception. The exams are not able to specifically detect if a person is lying, according to polygrapher Dr. Bob Lee, former executive director of operations at Axciton Systems, a manufacturer of polygraph instruments. But there are certain physiological responses that most of us undergo when attempting to deceive another person. By asking questions about a particular issue under investigation and examining a subject's physiological reactions to those questions, a polygraph examiner can determine if deceptive behavior is being demonstrated.

Photo courtesy Lafayette Instrument
Today, most polygraph exams are administered with digital equipment like this.

The polygraph instrument has undergone a dramatic change in the last decade. For many years, polygraphs were those instruments that you see in the movies with little needles scribbling lines on a single strip of scrolling paper. These are called analog polygraphs. Today, most polygraph tests are administered with digital equipment. The scrolling paper has been replaced with sophisticated algorithms and computer monitors.

Photo courtesy Lafayette Instrument
Parts of a polygraph that monitor physiological responses

When you sit down in the chair for a polygraph exam, several tubes and wires are connected to your body in specific locations to monitor your physiological activities. Deceptive behavior is supposed to trigger certain physiological changes that can be detected by a polygraph and a trained examiner, who is sometimes called a forensic psychophysiologist (FP). This examiner is looking for the amount of fluctuation in certain physiological activities. Here's a list of physiological activities that are monitored by the polygraph and how they are monitored:

  • Respiratory rate - Two pneumographs, rubber tubes filled with air, are placed around the test subject's chest and abdomen. When the chest or abdominal muscles expand, the air inside the tubes is displaced. In an analog polygraph, the displaced air acts on a bellows, an accordion-like device that contracts when the tubes expand. This bellows is attached to a mechanical arm, which is connected to an ink-filled pen that makes marks on the scrolling paper when the subject takes a breath. A digital polygraph also uses the pneumographs, but employs transducers to convert the energy of the displaced air into electronic signals.

  • Blood pressure/heart rate - A blood-pressure cuff is placed around the subject's upper arm. Tubing runs from the cuff to the polygraph. As blood pumps through the arm it makes sound; the changes in pressure caused by the sound displace the air in the tubes, which are connected to a bellows, which moves the pen. Again, in digital polygraphs, these signals are converted into electrical signals by transducers.

  • Galvanic skin resistance (GSR) - This is also called electro-dermal activity, and is basically a measure of the sweat on your fingertips. The finger tips are one of the most porous areas on the body and so are a good place to look for sweat. The idea is that we sweat more when we are placed under stress. Fingerplates, called galvanometers, are attached to two of the subject's fingers. These plates measure the skin's ability to conduct electricity. When the skin is hydrated (as with sweat), it conducts electricity much more easily than when it is dry.

Some polygraphs also record arm and leg movements. As the examiner asks questions, signals from the sensors connected to your body are recorded on a single strip of moving paper. You will learn more about the examiner and the test itself later.

Detractors of the polygraph call lie detection a voodoo science, saying that polygraphs are no more accurate at detecting lies than the flip of a coin. "Despite claims of 'lie detector' examiners, there is no machine that can detect lies," reads a statement from the American Civil Liberties Union (ACLU). "The 'lie detector' does not measure truth-telling; it measures changes in blood pressure, breath rate and perspiration rate, but those physiological changes can be triggered by a wide range of emotions."

Take the Quiz
Think you're an expert on lie detectors? Test your knowledge with this quiz­ from Investigation Discovery:

Lee, who has been performing ­polygraph exams for 18 years, agrees that polygraphs do not detect lies. "What has happened over the years is that the media has dubbed this lie detection, and that's what's clicked, but from a scientific perspective, absolutely not. There's no such thing as lie detection. I couldn't tell you what a lie looks like."

He does assert that polygraphs can detect deceptive behavior even through the stress brought on by the exam itself. "If the (forensic psychophysiologist) is properly trained and has the experience, he can penetrate that. Through the specific procedure that the FP will employ, anxiety will not penetrate into it."

Polygraph Examiners

There are only two people in the room during a polygraph exam -- the person conducting the exam and the subject being tested. Today, some polygraph examiners prefer to be called forensic psychophysiologists (FPs). Because polygraph examiners are alone in the room with a test subject, his or her behavior greatly influences the results of the exam.

"It's a very serious factor when someone is being accused of a crime," Lee said. "See, I don't care about the deceptive person. I'm looking for the innocent person. I'm their advocate. I'm totally unbiased and neutral when that person comes walking in. But as soon as I make that assessment that there's no deception indicated, I immediately become their advocate."

The forensic psychophysiologist has several tasks in performing a polygraph exam:

  • Setting up the polygraph and preparing the subject being tested
  • Asking questions
  • Profiling the test subject
  • Analyzing and evaluating test data

How the question is presented can greatly affect the results of a polygraph exam. There are several variables that an FP has to take into consideration, such as cultural and religious beliefs. Some topics may, by their mere mention, cause a specific reaction in the test subject that could be misconstrued as deceptive behavior. The design of the question affects the way the person processes the information and how he or she responds.

There are approximately 3,500 polygraph examiners in the United States, 2,000 of which belong to a professional organization, according to Dr. Frank Horvath, a Michigan State University professor of criminal justice and a member of the American Polygraph Association.

Who Uses Polygraphs?
Polygraphs are limited in their use in the private sector, but they are frequently used by the U.S. government. Here are some entities and occasions that may call for the use of a polygraph:
Horvath is concerned about the credentials and qualifications of many polygraph examiners in the United States who do not belong to some sort of professional organization. Laws regarding polygraph licensing vary from state to state, and there is no government or private entity that controls polygraph licensing. Horvath also feels that training of polygraph examiners is inadequate.

"I just do not think the field is at the state where we would say that any polygraph examiner is the equal of all other polygraph examiners. That's just not so," Horvath said. "We have a number of standardization problems in terms of examiner qualifications that concern me enormously. You could buy a polygraph [instrument] tomorrow and come to Michigan and you wouldn't be able to practice here because we have a rigorous licensing law, but you could move down to Ohio and open a business tomorrow."

Today, some polygraph examiners take classes and work an internship in order to become an accredited examiner with national associations. Some states also require examiners to be trained. There are many schools around the United States that have been set up to train people to conduct polygraph exams. One of these schools is the Axciton International Academy, which was started by Lee. The school is accredited by the American Polygraph Association and certified by the American Association of Police Polygraphists.

Here are the steps that students at the Axciton Academy must complete before becoming licensed forensic pyschophysiologists:

  • Prior to enrolling in the school, students must possess a baccalaureate degree or have five years of investigative experience and an associates degree.
  • Students must attend and pass a 10-week intensive course. Curriculum includes psychology, physiology, ethics, history, question construction, psychological analysis of speech, chart analysis and test-data analysis.
  • Students must enter an internship program and conduct a minimum of 25 exams for actual cases. These exams are faculty reviewed. This internship can take anywhere from eight months to one year.

Following the completion of these requirements, the student becomes a polygrapher and may obtain a license in his or her state if that state requires one. There is no standardized test that all polygraph examiners must pass in order to practice.

Going on the Box
Undergoing a lie detector test can be an intimidating experience that can challenge the nerves of even the most stoic person. You are sitting there with wires and tubes attached to and wrapped around your body. Even if you have nothing to hide, you could be afraid that the metal-box instrument sitting next to you will say otherwise. Fittingly, undergoing the uncomfortable experience of a polygraph test is often referred to as "going on the box."

Mouse-over the wire colors to see where they lead.

A polygraph exam is a long process that can be divided up into several stages. Here's how a typical exam might work:

  • Pretest - This consists of an interview between the examiner and examinee, where the two individuals get to learn about each other. This may last about one hour. At this point, the examiner gets the examinee's side of the story concerning the events under investigation. While the subject is sitting there answering questions, the examiner also profiles the examinee. The examiner wants to see how the subject responds to questions and processes information.

  • Design questions - The examiner designs questions that are specific to the issue under investigation and reviews these questions with the subject.

  • In-test - The actual exam is given. The examiner asks 10 or 11 questions, only three of four of which are relevant to the issue or crime being investigated. The other questions are control questions. A control question is a very general question, such as "Have you ever stolen anything in your life?" -- a type of question that is so broad that almost no one can honestly respond with a "no." If the person answers "no," the examiner can get an idea of the reaction that the examinee demonstrates when being deceptive.

  • Post-test - The examiner analyzes the data of physiological responses and makes a determination regarding whether the person has been deceptive. If there are significant fluctuations that show up in the results, this may signal that the subject has been deceptive, especially if the person displayed similar responses to a question that was asked repeatedly.

There are times when a polygraph examiner misinterprets a person's reaction to a particular question. The human factor of a polygraph exam and the subjective nature of the test are two reasons why polygraph exam results are seldom admissible in court. Here are the two ways that a response can be misinterpreted:

  • False positive - The response of a truthful person is determined to be deceptive.
  • False negative - The response of a deceptive person is determined to be truthful.
"If we look at laboratory-based studies, false-positive errors occur somewhat more often than false-negative errors," Horvath said.

Critics of polygraph exams say that even more false-positive errors occur in real-world scenarios, which biases the system against the truthful person. These errors are likely to occur if the examiner has not prepared the examinee properly or if the examiner misreads the data following an exam.

Countermeasures and Legalities

Often, people who are being given a polygraph exam will employ certain countermeasures in an attempt to beat the instrument. There are Web sites and books that instruct you on how to fool the polygraph. Here are just a few examples of how people try to trick the device:
  • Sedatives
  • Antiperspirant on fingertips
  • Tacks placed in the shoe
  • Biting tongue, lip or cheek

The idea of countermeasures is to cause (or curtail) a certain reaction that will skew the test's result. A subject may attempt to have the same reaction to every question so that the examiner cannot pick out the deceptive responses. For example, some people will place a tack in their shoe and press their foot down on the tack after each question is asked. The idea is that the physiological response to the tack may overpower the physiological response to the question, causing the response to each question to seem identical.

Whether you pass or fail a polygraph exam will often have very little legal ramification. Often, defense lawyers brag that their client has passed a polygraph. Of course, you will rarely hear of a defendant taking a polygraph if he or she failed it.

Polygraphs are rarely admissible in court. New Mexico is the only state in the United States that allows for open admissibility of polygraph exam results. Every other state requires some type of stipulation to be met prior to admitting polygraph exams into record. In most cases, both sides of a legal case have to agree prior to the trial that they will allow polygraphs to be admitted. On the federal level, the admissibility criteria are much more vague and admission typically depends on the approval of the judge.

The main argument over the admissibility of polygraph tests is based on their accuracy, or inaccuracy, depending on how you want to view it. The level of accuracy of a lie detector depends on who you talk to about it, Horvath said. Both sides of the argument have the same research to look at, but they come to very different conclusions.

"We have people in the scientific community who look at the same research that I look at and they reach a conclusion that is quite different," Horvath said. "From their point of view, they allege that polygraph testing is probably only around 70 percent accurate, and it has a great bias against truthful people. Then, what the proponents say, looking at the same research, they reach a quite different conclusion, and that is that polygraph testing is around 90 percent accurate."

Employee Polygraph Protection Act of 1988
Employees in the private sector are not subjected to polygraph exams like employees of the federal government. The U.S. federal government is the largest consumer of polygraph exams. Private sector employees are protected by the Employee Polygraph Protection Act of 1988 (EPPA). This law only affects commercial businesses. It does not apply to schools, prisons, other public agencies or some businesses under contract with the federal government.

EPPA provides that a business cannot require a pre-employment polygraph and cannot subject current employees to polygraph exams. A business is allowed to request an exam, but cannot force anyone to undergo a test. If an employee refuses a suggested exam, the business is not allowed discipline or discharge that employee based on his or her refusal.

At the federal level, there have been specific legal cases that have shaped the admissibility of polygraphs. The results of these cases are mixed: There have been some federal circuits that have admitted polygraph results, while others have flatly denied them. Here are just a few of the legal cases that have shaped how polygraphs are viewed by the U.S. courts:
  • Frye v. United States (1923) - U.S. Court of Appeals of District of Columbia - This is the original decision dealing with scientific evidence and its admissibility in court. Frye was accused of murdering a doctor. At the time, he took a unigraph, a precursor to the polygraph. The unigraph measured only the cardiovascular activities of the body. The examiner reported Frye to be truthful, and Frye moved to have that evidence admitted in court. The court ruled that before any scientific evidence could be admitted into the court of law it must first be accepted by the scientific community. At that time, there were no studies done on unigraphs or polygraphs, so the evidence was not admitted.

  • United States v. Piccinonna (1989) - U.S. Court of Appeals, 11th Circuit - This decision allowed for polygraph results to be admitted in court, but only if one of two requirements is met: Either the two parties in the case agree to allow it, or the judge decides to allow it based on criteria established by the 11th Circuit.

  • Daubert v. Merrell Dow Pharmaceuticals (1993) - U.S. Supreme Court - The court opened the door for scientific evidence, and gave judges broader discretion as to whether or not to admit polygraphs. This applies to all federal courts but does not apply in state courts, although particular states do accept this ruling.

  • United States v. Scheffer (1998) - U.S. Supreme Court - Moving beyond the broader topic of scientific evidence, this military case directly involved polygraphs. The court ruled that the U.S. president has the prerogative to deny polygraph results in military tribunals because polygraph testing is so controversial.

It seems clear that no final decision has been made on the federal level. At the state level, polygraph admissibility is generally handled on a case-by-case basis. The courts' ambiguity stems from the questionable validity of polygraph exams. Interestingly, the biggest opponent to polygraph admission in court is the U.S. federal government, which happens to be the largest consumer of polygraphs exams.

There are still many questions that must be answered before polygraphs are accepted by the courts and the public at large. Of course, we may never see this broad acceptance. No matter if you agree or disagree with the use of polygraphs, thousands of people undergo these tests every year, and many people's lives are changed forever by their results.

Read More......

09 September 2008

How Satellite Radio Works

We all have our favorite radio stations that we preset into our car radios, flipping between them as we drive to and from work, on errands and around town. But when you travel too far away from the station, the signal breaks up and fades into static. Most radio signals can only travel about 30 or 40 miles from their source. On long trips, you might have to change radio stations every hour or so as the signals fade in and out. And it's not much fun scanning through static trying to find something -- anything -- to listen to.

Photo courtesy XM Satellite Radio
Satellite radio broadcasters promise crystal-clear music transmitted from thousands of miles into space.
See more pictures of satellite radio.

Now, imagine a radio station that can broadcast its signal from more than 22,000 miles (35,000 kilometers) away and then come through on your car radio with complete clarity. You could drive from Tacoma, Wash., to Washington, D.C., without ever having to change the radio station! Not only would you never hear static interfering with your favorite tunes, but the music would be interrupted by few or no commercials.

XM Satellite Radio and Sirius Satellite Radio both launched such a service at the beginning of the 21st century. Satellite radio, also called digital radio, offers uninterrupted, near CD-quality music beamed to your radio from space.

In February 2007, XM Radio and Sirius Radio announced that they planned to merge into a single satellite radio company. XM and Sirius are both in debt, and a merger could quickly solve that problem. The merger could also lead to lower prices and more programming choices for consumers. Some people are skeptical about the two companies joining, though, fearing a monopoly would only reduce competition, raise prices and affect consumers poorly. XM and Sirius currently must convince the FCC that a merger wouldn't violate anti-trust laws.

Even though XM and Sirius have had financial trouble, satellite radio still has a fairly strong fan base. About 8 million people subscribe to XM Radio, and more than 6 million people tune into Sirius Radio. ­Car manufacturers have been installing satellite radio receivers in some models for a few years now, and several models of portable satellite radio receivers are available from a variety of electronics companies. In this article, you'll learn what separates satellite radio from conventional radio and what you need to pick up satellite radio signals.

The Basics

Satellite radio is an idea over a decade in the making. In 1992, the U.S. Federal Communications Commission (FCC) allocated a spectrum in the "S" band (2.3 GHz) for nationwide broadcasting of satellite-based Digital Audio Radio Service (DARS). Only four companies applied for a license to broadcast over that band. The FCC gave licenses to two of these companies in 1997. CD Radio (now Sirius Satellite Radio) and American Mobile Radio (now XM Satellite Radio) paid more than $80 million each to use space in the S-band for digital satellite transmission.

At this time, there are three space-based radio broadcasters:

  • Sirius Satellite Radio
  • XM Satellite Radio
  • WorldSpace
Satellite radio companies are comparing the significance of their service to the impact that cable TV had on television 30 years ago. Listeners won't be able to pick up local stations using satellite radio services, but they will have access to hundreds of stations offering a variety of music genres. Each company has a different plan for its broadcasting system, but the systems do share similarities. Here are the key components of the three satellite radio systems:
  • Satellites
  • Ground repeaters
  • Radio receivers

Satellite radio works a lot like satellite TV -- you purchase a receiver and pay a monthly subscription fee for a certain number of channels. For the moment, there are slight variances in the three satellite radio companies' systems. In the next three sections, we will profile each of the companies and their current satellite radio services.

The XM/Sirius Merger
Both XM and Sirius offer about 100 channels under their current plans. If both the FCC and the Department of Justice approve their proposed merger, though, things might change a little. According to the two companies, the merged company will offer a few options. You could subscribe to 50 channels from either XM or Sirius for $6.99, or you could get a "best-of" package of 100 channels selected from both networks for $14.99. If you're already an XM or Sirius customer, you wouldn’t have to replace your old radio. However, if you wanted to pick and choose your own channels from both networks, you would have to pay a little extra and purchase a new receiver. This all depends on whether the merger is approved, and as of October 2007 there have been no decisions. ­­

XM Satellite Radio

XM Radio uses two Boeing HS 702 satellites, appropriately dubbed "Rock" and "Roll," placed in parallel geostationary orbit, one at 85 degrees west longitude and the other at 115 degrees west longitude. Geostationary Earth orbit (GEO) is about 22,223 miles (35,764 km) above Earth, and is the type of orbit most commonly used for communications satellites. The first XM satellite, "Rock," was launched on March 18, 2001, with "Roll" following on May 8. XM Radio has a third HS-702 satellite on the ground ready to be launched in case one of the two orbiting satellites fails.

Photo courtesy XM Satellite Radio
This graphic illustrates how the XM Radio system works.

XM Radio's ground station transmits a signal to its two GEO satellites, which bounce the signals back down to radio receivers on the ground. The radio receivers are programmed to receive and unscramble the digital data signal, which contains up to 100 channels of digital audio. In addition to the encoded sound, the signal contains information about the broadcast. The song title, artist and genre of music are all displayed on the radio. In urban areas, where buildings can block out the satellite signal, XM's broadcasting system is supplemented by ground transmitters.

Photo courtesy XM Satellite Radio
An XM Satellite Radio receiver

Each receiver contains a proprietary chipset. XM began delivering chipsets to its XM radio manufacturing partners in October 2000. The chipset consists of two custom integrated circuits designed by STMicroelectronics. XM has partnered with Pioneer, Alpine, Clarion, Delphi Delco, Sony and Motorola to manufacture XM car radios. Each satellite radio receiver uses a small, car-phone-sized antenna to receive the XM signal. General Motors has invested about $100 million in XM, and Honda has also signed an agreement to use XM radios in its cars. GM began installing XM satellite radio receivers in selected models in early 2001.

Currently, subscribers can receive the XM signal for $12.95 per month. For that price, listeners get up to 100 channels of music, talk and news. They also get access to XM Radio online, a streaming audio service with over 70 channels. Many of the channels have no commercials, with none of the channels having more than seven minutes of ads per hour. XM's content providers include USA Today, BBC, CNN, Sports Illustrated and The Weather Channel. The service bolsters that lineup with its own music channels.

Sirius Satellite Radio

Sirius originally used three SS/L-1300 satellites, instead of GEO satellites, to form an inclined elliptical satellite constellation. Sirius says the elliptical path of its satellite constellation ensures that each satellite spends about 16 hours a day over the continental United States, with at least one satellite over the country at all times. Sirius completed its three-satellite constellation on Nov. 30, 2000. A fourth satellite will remain on the ground, ready to be launched if any of the three active satellites encounters transmission problems. ­In 2006, Sirius purchased a GEO satellite because of its superior signal delivery. The GEO satellite will supplement the elliptical satellites, not replace them. It is currently under construction, and a launch is planned for fall 2008.

The Sirius system is similar to that of XM. Programs are beamed to one of the three Sirius satellites -- the satellites then transmit the signal to the ground, where your radio receiver picks up one of the channels within the signal. Signals are also be beamed to ground repeaters for listeners in urban areas where the satellite signal can be interrupted.

Just like XM Radio, Sirius currently offers a monthly subscription for $12.95 per month. Sirius produces car radios and home entertainment systems, as well as car and home kits for portable use. The Sirius receiver includes two parts: the antenna module and the receiver module. The antenna module picks up signals from the ground repeaters or the satellite, amplifies the signal and filters out any interference. The signal is then passed on to the receiver module. Inside the receiver module is a chipset consisting of eight chips. The chipset converts the signals from 2.3 gigahertz (GHz) to a lower intermediate frequency. Sirius also offers an adapter that allows conventional car radios to receive satellite signals.


So far, WorldSpace has been the farthest-reaching company in the satellite radio industry. It put two of its three satellites, AfriStar and AsiaStar, in geostationary orbit before either of the other two companies launched one. AfriStar and AsiaStar were launched in October 1998 and March 2000, respectively. AmeriStar, which will offer service to South America and parts of Mexico, has not yet been launched. Each satellite transmits three signal beams, carrying more than 40 channels of programming, to three overlapping coverage areas of about 5.4 million square miles (14 million square km) each. Each of the WorldSpace satellites' three beams can deliver over 50 channels of crystal-clear audio and multimedia programming via the 1,467- to 1,492-megahertz (MHz) segment of the L-Band spectrum, which is allocated for digital audio broadcasting.

The United States is not currently part of WorldSpace's coverage area, although the company has invested in XM Radio and has an agreement with XM to share any technological developments. WorldSpace is going beyond one nation and eyeing world domination of the radio market. That might be overstating the company's intent a bit, but WorldSpace does plan to reach the corners of our world that most radio stations can't. There are millions of people living in WorldSpace's projected listening area who can't pick up a signal from a conventional radio station. WorldSpace says it has a potential audience of about 4.6 billion listeners spanning five continents.

Photo courtesy WorldSpace
WorldSpace will be able to broadcast to the majority of the world's population when its AmeriStar satellite is launched.

WorldSpace broadcasters uplink their signal to one of the three satellites through a centralized hub site or an individual feeder link station located within the global uplink beam. The satellite then transmits the signal in one, two or all three beams on each satellite. Receivers on the ground then pick up the signal and provide CD-quality sound through a detachable antenna.

Photo courtesy WorldSpace
Two of the WorldSpace satellite radio receivers

WorldSpace satellite receivers are capable of receiving data at a rate of 128 kilobits per second (Kbps). The receivers use the proprietary StarMan chipset, manufactured by STMicroelectronics, to receive digital signals from the satellites.

Read More......

03 July 2008


Surrounded by strong currents and fortified by steel and concrete, Alcatraz federal prison was meant to be the highest-security prison in America, a place no one could escape from. The island on which it rests shuns even plant life. Alcatraz is essentially a rock surrounded by water -- hence its forbidding nickname, "The Rock." The only creatures that don't mind being around are the great white sharks that troll the chilly water. Beyond the prison's security measures, the island itself provided a strong deterrent to escape.

Paul Giamou/Aurora/Getty Images
Welcome to Alcatraz

The name Alcatraz at one time represented the worst side of American life, home of the hardest criminals guilty of the worst crimes. It gained such mystique that some gangsters actually wanted to go there to enhance their reputation among other criminals.

The mystique grew further when Hollywood got hold of it. Movies depicted Alcatraz as haunted, dramatized life inside the prison and glorified the criminals that were sent there, giving Alcatraz a larger-than-life image. Escapees, kingpins and the most famous inmate of all, the Birdman of Alcatraz, continued to inflate the prison's reputation in the public eye.

Reality at the prison was sometimes stranger than fiction -- there were several daring escapes, complete with a few missing bodies and an account of chipping away at walls with spoons. In general, however, the story was often more mundane, because conditions at Alcatraz probably weren't much worse than at other prisons at the time.

Alcatraz has a history much greater than the almost 30 years it spent as a federal penitentiary. As a fort, a lighthouse, the site of a Native American occupation and a national park, Alcatraz has changed through the centuries, often reflecting changes in American society. In this article, we'll learn about the infamous federal prison, some of the notable people who were sent there and famous incidents in the prison's history. We'll also find out how Alcatraz became a prison and why it's an important location in the movement for greater Native American rights.

The Escape-proof Alcatraz Prison

Alcatraz Island is actually the top of a mountain, a rough spit of sandstone jutting from San Francisco Bay. The bay was once a valley, but at some point tens of thousands of years ago, sea levels rose and the valley filled in with water. Very little soil covers the island, and as a result, very little plant life grows there naturally (some trees and bushes were brought there by construction crews in the past).

Map of Alcatraz

­ The waters around Alcatraz are especially treacherous. They're usually very cold, below 60 degrees Fahrenheit (16 degrees Celsius), and the currents are strong. When the tide recedes, the current tends to draw out toward the Pacific Ocean, rather than toward San Francisco. To make matters worse, let's not forget the great whites.

Perched on this island rock is a concrete and steelprison. It was first built as a military prison in 1912. In 1934, it was completely remodeled, making it the most high-tech prison in the U.S. at the time.

An aerial view of Alcatraz Island
Juan Silva/Iconica/Getty Images
An aerial view of Alcatraz Island

The prison was built to accommodate about 600 prisoners, although as a federal prison, Alcatraz only held a maximum of 300 inmates (some of the cell blocks from the military prison era were closed off with wire grating). The initial 1912 design was innovative -- the island provided one barrier to escape, and the thick concrete walls and barred windows of the prison building created another. Within the prison building were cell blocks, rows of iron cells that had no point of contact with any outer walls. Each cell block was like a prison inside a prison. The 1934 remodeling replaced all the iron bars with hardened steel, called "tool-resistant" steel because it could withstand cutting with a hacksaw. It cost more to install the new steel bars in 1934 than it cost to build the entire prison in 1912: more than $200,000 [source: Barter].

New steel wasn't the only new technology on the island. A mechanical locking system that allowed guards to open certain cell doors or groups of cell doors remotely, by pulling levers at a control panel, replaced the old system of a single key for each cell. Metal detectors, a relatively new technology in 1934, were also placed on prison grounds.

A re-creation of the cell once occupied by Alcatraz escapee Frank Morris
Justin Sullivan/Getty Images
A re-creation of the cell once occupied by Alcatraz escapee Frank Morris

There were three cell blocks, A, B and C, all running parallel to each other. A Block was the shortest, while B and C ran the length of most of the main building. Each cell block was three tiers high. Each cell was 5 feet (1.5 m) wide by 9 feet (2.7 m) deep, and contained a bed, a sink, a toilet and a small desk for writing. Two shelves for personal items ran along the back wall. Three of the cell walls were solid concrete, while the front "wall" was made of the hardened steel bars. Only one prisoner lived in each cell.

Next, we'll see what life was like inside Alcatraz.

D Block
What do you do when inmates in a jail misbehave? Put them in a more restrictive part of the jail. At Alcatraz, this purpose was served by D Block, where prisoners spent almost every minute in their cells, with only one hour per week for exercise. Repeat rule breakers might end up in "the Hole," one of five special cells with an iron door that blocked all light. One final cell was for the worst of the worst. It had no toilet, just a hole in the floor. Prisoners were often left in this cell naked and without any blankets, and the food was meager.

Prior to D Block's construction, troublesome prisoners were sent to "the dungeon," a series of old cells in the basement, left over from the original building upon whose foundation the prison was built.

Life on Alcatraz Island

For the prisoners living in Alcatraz prison, life was similar to life in other American prisoners of the era. That is to say, not especially pleasant, but neither was Alcatraz the brutal hellhole many blockbuster films make it out to be. In the mornings, each prisoner swept his cell clean, dressed and stood ready for a head count. Then they all marched to the mess hall for breakfast before moving on to work at the docks, in the laundry area or at one of the industrial buildings on the island. They could also spend time studying in the library. After dinner, inmates returned to their cells -- "lights out" was at 9:30 p.m.

A National Park Service ranger walks down
A National Park Service ranger walks down "Broadway."

The prisoners nicknamed the long concrete walkways between the cell blocks. The central walkway was Broadway, and the others were named Park Avenue and Michigan Avenue. The area in between the mess hall and the cell blocks was called Times Square. At either end of the main cell block area was a "gun gallery," a multilevel walkway enclosed in bars and mesh and patrolled by armed guards who had a clear view (and a straight shot) at any point on the cell block.

An empty guard house near the Alcatraz prison recreation yard
An empty guard house near the prison recreation yard as the sun sets on Alcatraz

There were some key differences at Alcatraz, however. The first warden, James Johnston, upheld absolute discipline and a very rigid routine. For the first few years of operation, the prisoners weren't allowed to talk at all except for brief periods, even at meals. Speaking out loud resulted in a stay in the dungeon or on D Block. This enforced silence was one aspect of life at Alcatraz that really grated on the inmates. Eventually, they began talking out en masse, realizing that there weren't enough isolation cells to hold them all, and the talking ban was relaxed [source: Barter].

It's true that the treatment of prisoners in the isolation cells was inhumane, and there were protests regarding prisoner treatment at Alcatraz at the time. These led to gradual reforms that removed some of the harshest punishments. On the other hand, many Alcatraz prisoners were happy to be there instead of another prison. The intense discipline and routine meant the prison was kept very clean, and it was relatively safe compared to other places.

Convicts weren't the only ones living on the island. The guards and their families lived there too. The children took a boat off the island to attend school every day. In fact, nothing was produced or grown on the island, so a boat ride was required for every shopping trip. The island did have a movie theater and other recreational opportunities. But life was also a bit strange. Children weren't allowed to have toy guns, because a prisoner could get a hold of one and use it to bluff a guard and escape. Magazines had to be carefully destroyed, because the prisoners weren't allowed to receive news of the outside world and definitely weren't allowed to read about sex or crime. Razors, knives and silverware had to be thrown into the bay [source: Babyak].

Next: inmates who tried to escape the escape-proof prison.

No Special Treatment Here
Robert Stroud, the Birdman of Alcatraz
American Stock/Getty Images
Robert Stroud, the Birdman of Alcatraz

All inmates at Alcatraz were treated the same, even if they were famous. Crime boss Al Capone, who had it easy at his prior prison and ran his criminal empire from behind bars, came to Alcatraz expecting the same deal. He received no special treatment and spent most of his time at Alcatraz sick with syphilis.

The legendary Birdman of Alcatraz, Robert Stroud, was known for breeding and studying dozens of birds in his cell at his former prison. No birds were allowed in his cell at Alcatraz, despite his growing fame outside prison walls. In fact, when his own biography was published, he wasn't allowed to read it because it had chapters about his criminal life [source: Oliver].

Escape from Alcatraz

Despite the intense security, things didn't always run smoothly at Alcatraz Federal Penitentiary. There were several escape attempts from the escape-proof prison, including one that might have been successful.

Nat Farbman/Time Life Pictures/Getty Images
Alcatraz may not have been escape-proof, but that doesn't mean it was easy to break out.

Joseph Bowers was shot and killed while climbing a fence in 1936. Two prisoners managed to escape in 1937, but it's generally believed that they drowned, although their bodies were never found. The next year, three inmates attacked and killed a guard during an escape attempt. One was killed by another guard, a second was wounded and the third gave up.

A 1939 escape attempt was the seed of a fictionalized film,"Murder in the First," starring Kevin Bacon as Henri Young. In real life, Young tried to escape along with three others. They were found on the beach, where one escapee was shot and killed, another wounded, while Young and Rufus McCain were nearly incapacitated by the cold water. A year later, Young stabbed McCain to death in the prison workshop. Young's trial brought attention to the miserable conditions of the solitary confinement cells, where he was kept for extended periods. This eventually resulted in a conviction on a reduced charge, but Young wasn't quite the sympathetic character portrayed in the movie.

It's a 1962 escape that is perhaps the most famous. Brothers Clarence and John Anglin and Frank Morris spent long months patiently working at their plan. They chipped away with spoons at the rotted concrete around the ventilation grates in their cells, using cardboard painted to look like the original grate to disguise the work. When the holes were large enough, they could move into an open maintenance space, reserved for pipes and conduits. There, they constructed life vests and a raft out of raincoats they accumulated. Their absence from their cells at night was disguised by clever papier-mâché heads left on each pillow. Finally, the trio climbed ventilation shafts to the roof, hopped a fence and escaped into San Francisco Bay. Later, some personal items belonging to one of the Anglin brothers were found floating in a plastic bag, leading prison officials to declare the men drowned. They were never seen or heard from again, but the legend persists that they successfully made their way to nearby Angel Island or were picked up by a waiting boat.

In the first season of the TV show MythBusters, the show's crew tested the Anglin/Morris escape strategy, attempting to paddle across the bay on a similar makeshift raft. They successfully made it to shore after a difficult, unpleasant journey. While the experiment doesn't prove that the 1962 escape succeeded, it shows that such an escape was technically possible.

Flag flying at half mast during Alcatraz prison riots, May 1946
Charles E. Steinheimer/Time & Life Pictures/Getty Images
Alcatraz during the prison riots of May 1946

There were also several riots and protests by prisoners at Alcatraz, many due to the general conditions in the prison. In the 1950s, racist white prisoners rioted because of the presence of black prisoners in the same cell blocks. But the bloodiest incident in Alcatraz history happened in 1946. A band of six prisoners overpowered a guard and launched an effort to take over the entire prison. Several more guards were locked up (and later shot). Guards from nearby San Quentin prison joined with military troops to retake Alcatraz by force. Two guards were killed and three of the prisoners who had started the incident also died. Two of the surviving three were later killed in San Quentin's gas chamber.

In the next section, we'll find out how a nondescript island became a notorious prison.

The Worst of the Worst
Alcatraz's status as a federal prison led to the presence of some inmates who weren't the hardened crooks one might imagine. The concept of a federal prison was relatively new, and anyone convicted of a federal offense might be sent there. As a result, some of the cons at Alcatraz were convicted of lesser crimes, like shoplifting from a store that had a post office branch inside it or transporting bootlegged alcohol into another state.

History of Alcatraz

Gulls flying around Alcatraz
Mark Oatney/Digital Vision/Getty Images
Alcatraz: for the birds
We don't know much about the early days of Alcatraz Island, because no one called it home. There is speculation that Native Americans used it as a place of exile for those who broke tribal law. More likely, local tribes visited the island to gather eggs, since birds were the only creatures who lived there. In fact, the name Alcatraz comes from a Spanish word for gannets or pelicans: alcatraces.

In 1847, the first official survey of the island took place. Lieutenant William H. Warner of the U.S. Army noted that the island overlooks the entrance to San Francisco Bay and would make a perfect location for a fortification to guard the area [source: Oliver]. The army built a dock and reshaped the island to construct defensive positions. Several buildings had been constructed by the 1860s, when dozens of artillery pieces were placed to help defend against possible Confederate incursions during the Civil War. A large building called the Citadel was erected to house the troops stationed there -- the prison at Alcatraz would later be built on the Citadel's foundations.

No major military events occurred at Alcatraz, although the island's guns were fired several times, always due to a misunderstanding or misidentification of a ship. As the years passed, the military began shipping prisoners to the island, usually soldiers who had deserted or committed other crimes. The commanding officers would stick these prisoners wherever they would fit (in the Citadel's basement, at first), building new places for them almost haphazardly. At the end of the Civil War, it was decided officially to convert the island into a military prison. The Citadel was converted and expanded in the 1870s.

By the dawning of the 20th century, the old military prison was overflowing and outdated. The massive earthquake that struck San Francisco in 1906 shunted almost 200 city prisoners to Alcatraz, proving once and for all that a modern prison was needed. The Citadel was torn down, and the United States Military Prison, Pacific Branch, Alcatraz Island was completed in 1912.

By the 1930s, military officials had begun to question the need for a prison like Alcatraz. The military wasn't in the business of running prisons, and it was creating a drain on their budget. At the same time, Prohibition and other factors had led a high crime rate nationwide. J. Edgar Hoover, head of the FBI, was spearheading efforts to crack down on criminals. He needed a fearsome prison to send criminals to, and Alcatraz fit the bill. The change of ownership and renovation of the prison took place between 1933 and 1934, when the first prisoners arrived under a shroud of secrecy.

Sioux tribesmen on Alcatraz
Jon Brenneis/Time Life Pictures/
­Getty Images

Sioux tribesmen staking claim to live and farm on Alcatraz.

Alcatraz's life as a federal prison ended for many of the same reasons it stopped being a military prison. Everything on Alcatraz had to be shipped in -- every meal, magazine and pack of cigarettes -- which made running Alcatraz far more expensive than a mainland prison. In addition, the old concrete building was deteriorating due to the constant contact with saltwater. It would cost millions to repair. The final nail in the coffin was the escape of 1962. If the prison wasn't truly escape-proof, what purpose did it serve? In 1963, it was closed down permanently.

The history of Alcatraz wasn't over, however. In the late 1960s and 1970s, the island was occupied by a band of Native Americans from several tribes who demanded that they be given ownership of the island. Ultimately, their demands weren't met and the takeover failed, but it brought a great deal of attention to the inequalities suffered by Native Americans. In the aftermath, government policies changed to allow tribes to determine their own fates and exist as political and commercial entities [source: Johnson].

In 1973, Alcatraz Island became part of Golden Gate National Recreation Area. The prison still stands, and millions of visitors have taken tour boats to the island to experience a small piece of U.S. history.

For more articles on prisons and other history stuff you might like, try the next page.

Read More......

What was the Prison Project?

Back in the early 1990s, most of us weren't yet savvy Internet surfers. We still got all our news from the paper rather than Web sites, and e-mail hadn't yet taken over faxes and letters in our business and personal lives. Many of us were still years away from learning about the possibilities of the Internet -- that is, if we'd heard of it at all. However, Bill Burrall, a computer instructor for Moundville Junior High School in West Virginia, was ahead of us. He'd already been steeped in the Internet world for over a decade, and was not only thoroughly familiar with it, but recognized its educational potential for students.

State Penitentiary inmates participated in the prison project
iStockPhoto/Tom Mc Nemar
Burrall's prison project coordinated with several inmates inside this facility, the West Virginia State Penitentiary.

Using the AT&T Learning Network, a worldwide educational Internet community, Burrall and his middle school classes participated in a valuable telecommunications project where kids got the chance to correspond with other classes from around the country and around the world. After realizing the success of these projects, Burrall decided to take advantage of the same system in a new way that later put him in the national spotlight.

As it happened, Moundsville Junior High was situated merely a few blocks from West Virginia's State Penitentiary. Where most teachers would have found this close proximity a source of concern, Burrall saw opportunity. The school would serve as a focal point for Burrall's revolutionary prison project, which used telecommunications to connect kids from around the world to the prison's inmates. After a year of struggle to get his idea approved by the school board and eventually the governor, Burrall was finally able to launch his prison project in 1992, later known as the "Inmates and Alternatives Project."

Read the next page to find out how Burrall used telecommunications to offer students life-altering experiences.

Another Look Inside
In a vastly different approach to gain inmate insight, Bill Geerhart, a pop-culture historian, mailed letters to notorious murderers posing as a conflicted 10 year old with questions about whether to stay in school. He later published what he claimed were actual responses from such people as Charles Manson, Richard Ramirez and Ted Kacynski -- some disturbing, some unintelligible [Source: RADAR].

Prison Pen Pals: How the Prison Project Worked

­As an authority on educational telecommunications, Burrall had the advantage of being one of eight coordinators in the AT&T Learning Network, which consisted of 50,000 students in 22 foreign countries [source: Burrall]. This helped him orchestrate a system where he could communicate with other middle-school teachers from such places as Louisiana, Alaska and the Netherlands.

Meanwhile, Burrall partnered with the education department at the West Virginia State Penitentiary. There, several inmates volunteered to become "pen pals" (pun intended) with students. Of the twelve participants, six were "lifers," meaning they had been sentenced to life in prison. To kick things off, Burrall asked these inmates to assume pseudonyms (fake names) and write short biographies of themselves. Taking names from the J.R.R. Tolkien Lord of the Rings trilogy, such as "Frodo" and "Pippin," many listed their hobbies and described their families and what life was like before prison.

The inmates would submit their letters to the prison's electronic bulletin board, known as the "Play Pen." The educational director at the prison, who would read over them, then sent them to Burrall at Moundsville. Burrall would look them over before disseminating them to the appropriate schools.

Burrall assigned one inmate to each of the participating schools including his own, so that each class could serve as a consistent pen pal to a particular inmate. After reading the inmate's biography, the teacher helped students to come up with a set of 10 questions for their pen pal having to do with "society's problems." Students submitted these questions onto an electronic bulletin board (anonymously) under the teachers' supervision. They commonly asked about the inmate's relationship with his family or what life was like in prison. The inmates responded to these questions, and the kids were then allowed to ask more questions. This correspondence went on for about 15 weeks.

prisoner reading letter behind bars
iStockPhoto/Andrejs Zemdega
For the prison project, inmates received a printout of the children's questions so that they could respond.­

Although there was concern about the prisoners' responses, the inmates' answers were better than even Burrall hoped. Amazingly, Burrall asserts that neither he nor the prison's educational director ever needed to censor inappropriate material in the inmates' letters [source: Burrall]. Instead, the prisoners were quick to warn the students about how easy it is to go down the wrong path and described the despair they felt in prison. Burrall claims that the "virtual bond" formed during the correspondence challenged the students' misconceptions [source: Burrall]. Prisoners also showed their appreciation of the project, claiming that it helped them to gain personal insight [source: Burrall].

After a few successful semesters of working with many different schools, the project ended -- partly because the prison closed, and partly because Burrall was chosen as IBM's National Teacher of the Year for Technology and as a result of this honor took several years to tour the country and give talks about the project to other educators. The project has even been given the distinction of being archived in the Smithsonian.

Since then, some educators have been able to replicate the project, such as one known as the Harlem Valley Project in New York, which also ran for a few semesters.

For more information on prison life and telecommunications technology, explore the links on the next page.

Prison Project vs. "Scared Straight"
Although they are often compared, Bill Burrall's Prison Project is drastically different from "Scared Straight" programs, where adolescents personally visit prisons to learn about life inside. For instance, Burrall's program let kids in remote areas (such as the kids in one Alaskan school) have the opportunity to connect with prisoners. In addition, the anonymity allowed inmates to open up more, ensuring the emotional efficacy of the program, as well as the safety of the kids.

Read More......

16 May 2008


The theory of evolution is one of the best-known scientific theories around. Try to make it through a day without using or hearing the word "evolution" and you'll see just how widespread this theory is.

Evolution is fascinating because it attempts to answer one of the most basic human questions: Where did life, and human beings, come from? The theory of evolution proposes that life and humans arose through a natural process. A very large number of people do not believe this, which is something that keeps evolution in the news.

In this article, we will explore the theory of evolution and how it works. We will also examine several important areas that show holes in the current theory -- places where scientific research will be working in the coming years in order to complete the theory. The holes are considered by many to be proof that the theory of evolution should be overthrown. As a result, quite a bit of controversy has surrounded evolution ever since it was first proposed.

Let's start off by taking a look at the basic principles of the theory of evolution, look at some examples and then examine the holes.

The Basic Process of Evolution

The basic theory of evolution is surprisingly simple. It has three essential parts:
  • It is possible for the DNA of an organism to occasionally change, or mutate. A mutation changes the DNA of an organism in a way that affects its offspring, either immediately or several generations down the line.

  • The change brought about by a mutation is either beneficial, harmful or neutral. If the change is harmful, then it is unlikely that the offspring will survive to reproduce, so the mutation dies out and goes nowhere. If the change is beneficial, then it is likely that the offspring will do better than other offspring and so will reproduce more. Through reproduction, the beneficial mutation spreads. The process of culling bad mutations and spreading good mutations is called natural selection.

  • As mutations occur and spread over long periods of time, they cause new species to form. Over the course of many millions of years, the processes of mutation and natural selection have created every species of life that we see in the world today, from the simplest bacteria to humans and everything in between.

Billions of years ago, according to the theory of evolution, chemicals randomly organized themselves into a self-replicating molecule. This spark of life was the seed of every living thing we see today (as well as those we no longer see, like dinosaurs). That simplest life form, through the processes of mutation and natural selection, has been shaped into every living species on the planet.

Can such a simple theory explain all of life as we know it today? Let's start by understanding how life works and then look at some examples.

How Life Works: DNA and Enzymes

Evolution can be seen in its purest form in the daily evolution of bacteria. If you have read How Cells Work, then you are familiar with the inner workings of the E. coli bacteria and can skip this section. Here's a quick summary to highlight the most important points in How Cells Work:
  • A bacterium is a small, single-celled organism. In the case of E. coli, the bacteria are about one-hundredth the size of a typical human cell. You can think of the bacteria as a cell wall (think of the cell wall as a tiny plastic bag) filled with various proteins, enzymes and other molecules, plus a long strand of DNA, all floating in water.

  • The DNA strand in E. coli contains about 4 million base pairs, and these base pairs are organized into about 1,000 genes. A gene is simply a template for a protein, and often these proteins are enzymes.

  • An enzyme is a protein that speeds up a particular chemical reaction. For example, one of the 1,000 enzymes in an E. coli's DNA might know how to break a maltose molecule (a simple sugar) into its two glucose molecules. That is all that that particular enzyme can do, but that action is important when an E. coli is eating maltose. Once the maltose is broken into glucose, other enzymes act on the glucose molecules to turn them into energy for the cell to use.

  • To make an enzyme that it needs, the chemical mechanisms inside an E. coli cell make a copy of a gene from the DNA strand and use this template to form the enzyme. The E. coli might have thousands of copies of some enzymes floating around inside it, and only a few copies of others. The collection of 1,000 or so different types of enzymes floating in the cell makes all of the cell's chemistry possible. This chemistry makes the cell "alive" -- it allows the E. coli to sense food, move around, eat and reproduce. See How Cells Work for more details.

You can see that, in any living cell, DNA helps create enzymes, and enzymes create the chemical reactions that are "life."

In the next section, we'll discuss how bacteria reproduce.

How Life Works: Asexual Reproduction

Bacteria reproduce asexually. This means that, when a bacteria cell splits, both halves of the split are identical -- they contain exactly the same DNA. The offspring is a clone of the parent.

As explained in How Human Reproduction Works, higher organisms like plants, insects and animals reproduce sexually, and this process makes the actions of evolution more interesting. Sexual reproduction can create a tremendous amount of variation within a species. For example, if two parents have multiple children, all of the children can be remarkably different. Two brothers can have different hair color, different heights, different blood types and so on. Here's why that happens:

  • Instead of a long loop of DNA like a bacterium, cells of plants and animals have chromosomes that hold the DNA strands. Humans have 23 pairs of chromosomes, for a total of 46 chromosomes. Fruit flies have five pairs. Dogs have 39 pairs, and some plants have as many as 100.

    The human chromosomes hold the DNA of the human genome. Each parent contributes 23 chromosomes.

  • Chromosomes come in pairs. Each chromosome is a tightly packed strand of DNA. There are two strands of DNA joined together at the centromere to form an X-shaped structure. One strand comes from the mother and one from the father.
  • Because there are two strands of DNA, it means that animals have two copies of every gene, rather than one copy as in an E. coli cell.

    Photo courtesy U.S. DOE, Human Genome Project

  • When a female creates an egg or a male creates a sperm, the two strands of DNA must combine into a single strand. The sperm and egg from the mother and father each contribute one copy of each chromosome. They meet to give the new child two copies of each gene.
  • To form the single strand in the sperm or egg, one or the other copy of each gene is randomly chosen. One or the other gene from the pair of genes in each chromosome gets passed on to the child.
Because of the random nature of gene selection, each child gets a different mix of genes from the DNA of the mother and father. This is why children from the same parents can have so many differences.

A gene is nothing but a template for creating an enzyme. This means that, in any plant or animal, there are actually two templates for every enzyme. In some cases, the two templates are the same (homozygous), but in many cases the two templates are different (heterozygous).

Here is a well-known example from pea plants that helps understand how pairs of genes can interact. Peas can be tall or short. The difference comes, according to Carol Deppe in the book "Breed your own Vegetable Varieties":

...in the synthesis of a plant hormone called gibberellin. The "tall" version of the gene is normally the form that is found in the wild. The "short" version, in many cases, has a less active form of one of the enzymes involved in the synthesis of the hormone, so the plants are shorter. We refer to two genes as alleles of each other when they are inherited as alternatives to each other. In molecular terms, alleles are different forms of the same gene. There can be more than two alleles of a gene in a population of organisms. But any given organism has only two alleles at the most. Shorter plants usually cannot compete with the taller forms in the wild. A short mutant in a patch of tall plants would be shaded out. That problem isn't relevant when a human plants a patch or field with nothing but short plants. And short plants may be earlier than tall ones, or less subject to lodging (falling over) in the rain or wind. They also may have a higher proportion of grain to the rest of the plant. So shorter plants can be advantageous as cultivated crops. Specific mutations or alleles are not good or bad in and of themselves, but only within a certain context. An allele that promotes better growth in hot weather may promote inferior growth in cold weather, for example.

One thing to notice in Deppe's quote is that a mutation in a single gene may have no effect on an organism, or its offspring, or its offspring's offspring. For example, imagine an animal that has two identical copies of a gene in one allele. A mutation changes one of the two genes in a harmful way. Assume that a child receives this mutant gene from the father. The mother contributes a normal gene, so it may have no effect on the child (as in the case of the "short" pea gene). The mutant gene might persist through many generations and never be noticed until, at some point, both parents of a child contribute a copy of the mutant gene. At that point, taking the example from Deppe's quote, you might get a short pea plant because the plant does not form the normal amount of gibberellin.

Another thing to notice is that many different forms of a gene can be floating around in a species. The combination of all of the versions of all of the genes in a species is called the gene pool of the species. The gene pool increases when a mutation changes a gene and the mutation survives. The gene pool decreases when a gene dies out.

One of the simplest examples of evolution can be witnessed in an E. coli cell. To get a better grip on the process, we'll take a look at what happens in this cell.

The Simplest Example of Evolution

The process of evolution acts on an E. coli cell by creating a mutation in the DNA. It is not uncommon for the DNA strand in an E. coli bacterium to get corrupted. An X-ray, a cosmic ray or a stray chemical reaction can change or damage the DNA strand. In most cases, a particular E. coli cell with mutated DNA will either die, fix the damage in the strand or fail to reproduce. In other words, most mutations go nowhere. But every so often, a mutation will actually survive and the cell will reproduce.

Imagine, for example, a bunch of identical E. coli cells that are living in a petri dish. With plenty of food and the right temperature, they can double every 20 minutes. That is, each E. coli cell can duplicate its DNA strand and split into two new cells in 20 minutes.

Now, imagine that someone pours an antibiotic into the petri dish. Many antibiotics kill bacteria by gumming up one of the enzymes that the bacteria needs to live. For example, one common antibiotic gums up the enzyme process that builds the cell wall. Without the ability to add to the cell wall, the bacteria cannot reproduce, and eventually they die.

When the antibiotic enters the dish, all of the bacteria should die. But imagine that, among the many millions of bacteria living in the dish, one of them acquires a mutation that makes its cell-wall-building enzyme different from the norm. Because of the difference, the antibiotic molecule does not attach properly to the enzyme, and therefore does not affect it. That one E. coli cell will survive, and since all of its neighbors are dead, it can reproduce and take over the petri dish. There is now a strain of E. coli that is immune to that particular antibiotic.

In this example, you can see evolution at work. A random DNA mutation created an E. coli cell that is unique. The cell is unaffected by the antibiotic that kills all of its neighbors. This unique cell, in the environment of that petri dish, is able to survive.

E. coli are about as simple as living organisms can get, and because they reproduce so rapidly you can actually see evolution's effects on a normal time scale. In the past several decades, many different types of bacteria have become immune to antibiotics. In a similar way, insects become immune to insecticides because they breed so quickly. For example, DDT-resistant mosquitoes evolved from normal mosquitoes.

In most cases, evolution is a much slower process.

The Speed of Mutations

As mentioned in the previous section, many things can cause a DNA mutation, including: Therefore, mutations are fairly common. Mutations happen at a steady rate in any population, but the location and type of every mutation is completely random. According to Carl Sagan in "The Dragons of Eden":

Large organisms such as human beings average about one mutation per ten gametes [a gamete is a sex cell, either sperm or egg] -- that is, there is a 10 percent chance that any given sperm or egg cell produced will have a new and inheritable change in the genetic instructions that make up the next generation. These mutations occur at random and are almost uniformly harmful -- it is rare that a precision machine is improved by a random change in the instructions for making it.

According to "Molecular Biology of the Cell":

Only about one nucleotide pair in a thousand is randomly changed every 200,000 years. Even so, in a population of 10,000 individuals, every possible nucleotide substitution will have been "tried out" on about 50 occasions in the course of a million years, which is a short span of time in relation to the evolution of species. Much of the variation created in this way will be disadvantageous to the organism and will be selected against in the population. When a rare variant sequence is advantageous, however, it will be rapidly propagated by natural selection. Consequently, it can be expected that in any given species the functions of most genes will have been optimized by random point mutation and selection.

According to the book "Evolution," by Ruth Moore, it is possible to speed up mutations with radiation:

So Muller put hundreds of fruit flies in gelatin capsules and bombarded them with X-rays. The irradiated flies were then bred to untreated ones. In 10 days thousands of their offspring were buzzing around their banana-mash feed, and Muller was looking upon an unprecedented outburst of man-made mutations. There were flies with bulging eyes, flat eyes, purple, yellow and brown eyes. Some had curly bristles, some no bristles...

Mutations fuel the process of evolution by providing new genes in the gene pool of a species.

Then, natural selection takes over.

Natural Selection

As you saw in the previous section, mutations are a random and constant process. As mutations occur, natural selection decides which mutations will live on and which ones will die out. If the mutation is harmful, the mutated organism has a much decreased chance of surviving and reproducing. If the mutation is beneficial, the mutated organism survives to reproduce, and the mutation gets passed on to its offspring. In this way, natural selection guides the evolutionary process to incorporate only the good mutations into the species, and expunge the bad mutations.

The book "Extinct Humans," by Ian Tattersall and Jeffrey Schwartz, puts it this way:

...in every generation, many more individuals are produced than ever survive to maturity and to reproduce themselves. Those that succeed -- the "fittest" -- carry heritable features that not only promote their own survival but are also passed along preferentially to their offspring. In this view, natural selection is no more than the sum of all those factors that act to promote the reproductive success of some individuals (and its lack in others). Add the dimension of time, and over the generations natural selection will act to change the complexion of each evolving lineage, as advantageous variations become common in the population at the expense of those less advantageous.

Let's look at an example of natural selection from How Whales Work.

The ancestors of whales lived on land -- there is evidence of the evolution of the whale from life on land to life in the sea (read How Whales Work for details), but how and why did this happen? The "why" is commonly attributed to the abundance of food in the sea. Basically, whales went where the food was. The "how" is a bit more perplexing: Whales are mammals, like humans are, and like humans, they lived and walked on solid ground, breathing air into their lungs. How did whales become sea creatures? One aspect of this evolution, according to Tom Harris, author of How Whales Work, is explained as follows:

To make this transition, whales had to overcome a number of obstacles. First of all, they had to contend with reduced access to breathable air. This led to a number of remarkable adaptations. The whale's "nose" moved from the face to the top of the head. This blowhole makes it easy for whales to breathe in air without fully surfacing. Instead, a whale swims near the surface, arches its body so its back briefly emerges and then flexes its tail, propelling it quickly to lower depths.

Photo courtesy Sea World Orlando

Odd as it seems that the whale's "nose" actually changed positions, the theory of evolution explains this phenomenon as a long process that occurs over perhaps millions of years:

  • Random mutation resulted in at least one whale whose genetic information placed its "nose" farther back on its head.
  • The whales with this mutation were more suited to the sea environment (where the food was) than "normal" whales, so they thrived and reproduced, passing on this genetic mutation to their offspring: Natural selection "chose" this trait as favorable.
  • In successive generations, further mutations placed the nose farther back on the head because the whales with this mutation were more likely to reproduce and pass on their altered DNA. Eventually, the whale's nose reached the position we see today.

Natural selection selects those genetic mutations that make the organism most suited to its environment and therefore more likely to survive and reproduce. In this way, animals of the same species who end up in different environments can evolve in completely different ways.

Creating a New Species

Imagine that you take a group of Saint Bernards and put them on one island, and on another island you put a group of Chihuahuas. Saint Bernards and Chihuahuas are both members of the species "dog" right now -- a Saint Bernard can mate with a Chihuahua (probably through artificial insemination) and create normal puppies. They will be odd-looking puppies, but normal puppies nonetheless.

Given enough time, it is possible to see how speciation -- the development of a new species through evolution -- could occur among the Saint Bernards and the Chihuahuas on their respective islands. What would happen is that the Saint Bernard gene pool would acquire random mutations shared by all of the Saint Bernards on the island (through interbreeding), and the Chihuahuas would acquire a completely different set of random mutations shared by all of the Chihuahuas on their island. These two gene pools would eventually become incompatible with one another, to the point where the two breeds could no longer interbreed. At that point, you have two distinct species.

Because of the huge size difference between a Saint Bernard and a Chihuahua, it would be possible to put both types of dogs on the same island and have the exact same process occur. The Saint Bernards would naturally breed with only the Saint Bernards and the Chihuahuas would naturally breed with only the Chihuahuas, so speciation would still occur.

If you put two groups of Chihuahuas on two separate islands, the process would also occur. The two groups of Chihuahuas would accumulate different collections of mutations in their gene pools and eventually become different species that could not interbreed.

The theory of evolution proposes that the process that might create a separate Chihuahua-type species and Saint Bernard-type species is the same process that has created all of the species we see today. When a species gets split into two (or more) distinct subsets, for example by a mountain range, an ocean or a size difference, the subsets pick up different mutations, create different gene pools and eventually form distinct species.

Is this truly how all of the different species we see today have formed? Most people agree that bacteria evolve in small ways (microevolution), but there is some controversy around the idea of speciation (macroevolution). Let's take a look at where the controversy comes from.

Holes in the Theory

The theory of evolution is just that -- a theory. According to "The American Heritage Dictionary," a theory is:

A set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena.

Evolution is a set of principles that tries to explain how life, in all its various forms, appeared on Earth. The theory of evolution succeeds in explaining why we see bacteria and mosquitoes becoming resistant to antibiotics and insecticides. It also successfully predicted, for example, that X-ray exposure would lead to thousands of mutations in fruit flies.

Many theories are works in progress, and evolution is one of them. There are several big questions that the theory of evolution cannot answer right now. This is not unusual. Newtonian physics worked really well for hundreds of years, and it still works well today for many types of problems. However, it does not explain lots of things that were eventually answered by Einstein and his theories of relativity. People create new theories and modify existing ones to explain the unexplained.

In answering the open questions that still remain unsolved, the theory of evolution will either become complete or it will be replaced by a new theory that better explains the phenomena we see in nature. That is how the scientific process works.

Here are three common questions that are asked about the current theory of evolution:

  • How does evolution add information to a genome to create progressively more complicated organisms?
  • How is evolution able to bring about drastic changes so quickly?
  • How could the first living cell arise spontaneously to get evolution started?
Let's look at each of these questions briefly in the following sections.

Question 1: How Does Evolution Add Information?

The theory of evolution explains how strands of DNA change. An X-ray, cosmic ray, chemical reaction or similar mechanism can modify a base pair in the DNA strand to create a mutation, and this modification can lead to the creation of a new protein or enzyme.

The theory of evolution further proposes that billions of these mutations created all of the life forms we see today. An initial self-replicating molecule spontaneously formed. It evolved into single-cell organisms. These evolved into multi-cell organisms, which evolved into vertebrates like fish, and so on. In the process, DNA structures evolved from the asexual single-strand format found in bacteria today into the dual-strand chromosomal format found in all higher life forms. The number of chromosomes also proliferated. For example, fruit flies have five chromosomes, mice have 20, humans have 23 and dogs have 39.

Evolution's mutation mechanism does not explain how growth of a genome is possible. How can point mutations create new chromosomes or lengthen a strand of DNA? It is interesting to note that, in all of the selective breeding in dogs, there has been no change to the basic dog genome. All breeds of dog can still mate with one another. People have not seen any increase in dog's DNA, but have simply selected different genes from the existing dog gene pool to create the different breeds.

One line of research in this area focuses on transposons, or transposable elements, also referred to as "jumping genes." A transposon is a gene that is able to move or copy itself from one chromosome to another. The book "Molecular Biology of the Cell" puts it this way:

Transposable elements have also contributed to genome diversity in another way. When two transposable elements that are recognized by the same site-specific recombination enzyme (transposase) integrate into neighboring chromosomal sites, the DNA between them can become subject to transposition by the transposase. Because this provides a particularly effective pathway for the duplication and movement of exons (exon shuffling), these elements can help create new genes.

Another area of research involves polyploidy. Through the process of polyploidy, the total number of chromosomes can double, or a single chromosome can duplicate itself. This process is fairly common in plants, and explains why some plants can have as many as 100 chromosomes.

The amount of research in this area is truly remarkable and is teaching scientists amazing things about DNA. The following links give you a taste of that research, and are interesting if you would like to learn more about these topics:

you create a very large cage and put a group of mice into it. You let the mice live and breed in this cage freely, without disturbance. If you were to come back after five years and look into this cage, you would find mice. Five years of breeding would cause no change in the mice in that cage -- they would not evolve in any noticeable way. You could leave the cage alone for a hundred years and look in again and what you would find in the cage is mice. After several hundred years, you would look into the cage and find not 15 new species, but mice.

The point is that evolution in general is an extremely slow process. When two mice breed, the offspring is a mouse. When that offspring breeds, its offspring is a mouse. When that offspring breeds... And the process continues. Point mutations do not change this fact in any significant way over the short haul.

Carl Sagan, in "The Dragons of Eden," put it this way:

The time scale for evolutionary or genetic change is very long. A characteristic period for the emergence of one advanced species from another is perhaps a hundred thousand years; and very often the difference in behavior between closely related species -- say, lions and tigers -- does not seem very great. An example of recent evolution of organ systems in humans is our toes. The big toe plays an important function in balance while walking; the other toes have much less obvious utility. They are clearly evolved from fingerlike appendages for grasping and swinging, like those of arboreal apes and monkeys. This evolution constitutes a respecialization -- the adaptation of an organ system originally evolved for one function to another and quite different function -- which required about ten million years to emerge.

The fact that it takes evolution 100,000 or 10 million years to make relatively minor changes in existing structures shows just how slow evolution really is. The creation of a new species is time consuming.

On the other hand, we know that evolution can move extremely quickly to create a new species. One example of the speed of evolution involves the progress mammals have made. You have probably heard that, about 65 million years ago, all of the dinosaurs died out quite suddenly. One theory for this massive extinction is an asteroid strike. For dinosaurs, the day of the asteroid strike was a bad one, but for mammals it was a good day. The disappearance of the dinosaurs cleared the playing field of most predators. Mammals began to thrive and differentiate.

Example: The Evolution of Mammals
65 million years ago, mammals were much simpler than they are today. A representative mammal of the time was the species Didelphodon, a smallish, four-legged creature similar to today's opossum.

In 65 million years, according to the theory of evolution, every mammal that we see today (over 4,000 species) evolved from small, four-legged creatures like Didelphodon. Through random mutations and natural selection, evolution has produced mammals of striking diversity from that humble starting point:

  • Humans
  • Dogs
  • Moles
  • Bats
  • Whales
  • Elephants
  • Giraffes
  • Panda bears
  • Horses
Evolution has created thousands of different species that range in size and shape from a small brown bat that weighs a few grams to a blue whale that is nearly 100 feet (30.5 m) long.

Let's take Carl Sagan's statement that "A characteristic period for the emergence of one advanced species from another is perhaps a hundred thousand years, and very often the difference in behavior between closely related species -- say, lions and tigers -- does not seem very great." In 65 million years, there are only 650 periods of 100,000 years -- that's 650 "ticks" of the evolutionary clock.

Imagine trying to start with an opossum and get to an elephant in 650 increments or less, even if every increment were perfect. An elephant's brain is hundreds of times bigger than an opossum's, containing hundreds of times more neurons, all perfectly wired. An elephant's trunk is a perfectly formed prehensile appendage containing 150,000 muscle elements (reference). Starting with a snout like that of an opossum, evolution used random mutations to design the elephant's snout in only 650 ticks. Imagine trying to get from an opossum to a brown bat in 650 increments. Or from an opossum to a whale. Whales have no pelvis, have flukes, have very weird skulls (especially the sperm whale), have blow holes up top, have temperature control that allows them to swim in arctic waters and they consume salt water rather than fresh. It is difficult for many people to imagine that sort of speed given the current theory.

Example: The Evolution of the Human Brain
Here is another example of the speed problem. Current fossil evidence indicates that modern humans evolved from a species called Homo erectus. Homo erectus appeared about 2 million years ago. Looking at the skull of Homo erectus, we know that its brain size was on the order of 800 or 900 cubic centimeters (CCs).

Modern human brain size averages about 1,500 CCs or so. In other words, in about 2 million years, evolution roughly doubled the size of the Homo erectus brain to create the human brain that we have today. Our brains contain approximately 100 billion neurons today, so in 2 million years, evolution added 50 billion neurons to the Homo erectus brain (while at the same time redesigning the skull to accommodate all of those neurons and redesigning the female pelvis to let the larger skull through during birth, etc.).

Let's assume that Homo erectus was able to reproduce every 10 years. That means that, in 2 million years, there were 200,000 generations of Homo erectus possible. There are four possible explanations for where the 50 billion new neurons came from in 200,000 generations:

  • Every generation, 250,000 new neurons were added to the Homo erectus brain (250,000 * 200,000 = 50 billion).
  • Every 100,000 years, 2.5 billion new neurons were added to the Homo erectus brain (2,500,000,000 * 20 = 50 billion).
  • Perhaps 500,000 years ago, there was a spurt of 20 or so closely-spaced generations that added 2.5 billion neurons per generation.
  • One day, spontaneously, 50 billion new neurons were added to the Homo erectus brain to create the Homo sapiens brain.
* In an absolutely fascinating experiment first reported in July 2002, scientists modified a single mouse gene and created mice with brains 50% larger than normal. This experiment shows that a point mutation can, in fact, have an immense effect on brain size. It is still unknown whether the larger brains make the mice smarter or not, but it is easy to imagine later mutations refining the wiring of these millions of new neurons.

In another fascinating study, researches have identified minimal changes in an amino acid on a single gene that have a profound effect on speech processing in humans.

It does appear that tiny changes in single genes can have very large effects on the species.

None of these scenarios is particularly comfortable. We see no evidence that evolution is randomly adding 250,000 neurons to each child born today, so that explanation is hard to swallow. The thought of adding a large package of something like 2.5 billion neurons in one step is difficult to imagine, because there is no way to explain how the neurons would wire themselves in. What sort of point mutation would occur in a DNA molecule that would suddenly create billions of new neurons and wire them correctly?* The current theory of evolution does not predict how this could happen.

One line of current research is looking at the effect of very small changes in DNA patterns during embryonic development. Any new animal, be it a mouse or a human, starts life as a single cell. That cell differentiates and develops into the complete animal. A tremendous amount of signaling happens between cells during the development process to ensure that everything ends up in the right place. Tiny changes in these signaling processes can have very large effects on the resulting animal. This is how the human genome, with at most 60,000 or so genes, is able to specify the creation of a human body containing trillions of cells, billions of carefully wired neurons and hundreds of different cell types all brilliantly sculpted into organs as diverse as the heart and the eyes. The book "Molecular Biology of the Cell" puts it this way:

Humans, as a genus distinct from the great apes, have existed for only a few million years. Each human gene has therefore had the chance to accumulate relatively few nucleotide changes since our inception, and most of these have been eliminated by natural selection. A comparison of humans and monkeys, for example, shows that their cytochrome-c molecules differ in about 1 percent and their hemoglobins in about 4 percent of their amino acid positions. Clearly, a great deal of our genetic heritage must have been formed long before Homo sapiens appeared, during the evolution of mammals (which started about 300 million years ago) and even earlier. Because the proteins of mammals as different as whales and humans are very similar, the evolutionary changes that have produced such striking morphological differences must involve relatively few changes in molecules from which we are made. Instead, it is thought that the morphological differences arise from differences in the temporal and spatial pattern of gene expression during embryonic development, which then determine the size, shape and other characteristics of the adult.

In other words, there just are not that many differences in the DNA of a human and a whale, yet humans and whales look totally different. Small collections of DNA mutations can have a very big effect on the final result.

Right now, the signaling mechanisms that wire up the 100 billion cells in the human brain are something of a mystery. How can the mere 60,000 genes in the human genome tell 100 billion neurons how to precisely wire themselves in the human brain? No one right now has a clear understanding of how so few genes can meticulously wire so many neurons. In a developing fetus in the womb, DNA is correctly creating and wiring up millions of cells per minute. Given that DNA does wire up a working human brain every time a baby is born, it may be the case that DNA has special properties that make evolution work more efficiently. As the mechanisms become better understood, the effects of DNA mutations during development will become better understood as well.

Question 3: Where Did the First Living Cell Come From?

In order for the principles of mutation and natural selection in the theory of evolution to work, there have to be living things for them to work on. Life must exist before it can to start diversifying. Life had to come from somewhere, and the theory of evolution proposes that it arose spontaneously out of the inert chemicals of planet Earth perhaps 4 billion years ago.

Could life arise spontaneously? If you read How Cells Work, you can see that even a primitive cell like an E. coli bacteria -- one of the simplest life forms in existence today -- is amazingly complex. Following the E. coli model, a cell would have to contain at an absolute minimum:

  • A cell wall of some sort to contain the cell
  • A genetic blueprint for the cell (in the form of DNA)
  • An enzyme capable of copying information out of the genetic blueprint to manufacture new proteins and enzymes
  • An enzyme capable of manufacturing new enzymes, along with all of the building blocks for those enzymes
  • An enzyme that can build cell walls
  • An enzyme able to copy the genetic material in preparation for cell splitting (reproduction)
  • An enzyme or enzymes able to take care of all of the other operations of splitting one cell into two to implement reproduction (For example, something has to get the second copy of the genetic material separated from the first, and then the cell wall has to split and seal over in the two new cells.)
  • Enzymes able to manufacture energy molecules to power all of the previously mentioned enzymes

Obviously, the E. coli cell itself is the product of billions of years of evolution, so it is complex and intricate -- much more complex than the first living cells. Even so, the first living cells had to possess:

  • A cell wall
  • The ability to maintain and expand the cell wall (grow)
  • The ability to process "food" (other molecules floating outside the cell) to create energy
  • The ability to split itself to reproduce
Otherwise, it is not really a cell and it is not really alive. To try to imagine a primordial cell with these capabilities spontaneously creating itself, it is helpful to consider some simplifying assumptions. For example:
  • Perhaps the original energy molecule was very different from the mechanism found in living cells today, and the energy molecules happened to be abundant and free-floating in the environment. Therefore, the original cell would not have had to manufacture them.
  • Perhaps the chemical composition of the Earth was conducive to the spontaneous production of protein chains, so the oceans were filled with unimaginable numbers of random chains and enzymes.
  • Perhaps the first cell walls were naturally forming lipid spheres, and these spheres randomly entrapped different combinations of chemicals.
  • Perhaps the first genetic blueprint was something other than DNA.
These examples do simplify the requirements for the "original cell," but it is still a long way to spontaneous generation of life. Perhaps the first living cells were completely different from what we see today, and no one has yet imagined what they might have been like. Speaking in general terms, life can only have come from one of two possible places:
  • Spontaneous creation - Random chemical processes created the first living cell.
  • Supernatural creation - God or some other supernatural power created the first living cell.

And it doesn't really matter if aliens or meteorites brought the first living cell to earth, because the aliens would have come into existence through either spontaneous creation or supernatural creation at some point -- something had to create the first alien cells.

Most likely, it will be many years before research can completely answer any of the three questions mentioned here. Given that DNA was not discovered until the 1950s, the research on this complicated molecule is still in its infancy, and we have much to learn.

The Future of Evolution

One exciting thing about the theory of evolution is that we can see its effects both today and in the past. For example, the book "Evolution" mentions this:

The earliest known reptiles are so amphibian-like that their assignment to one category or the other is largely a matter of opinion. In this area of life, however, there was no missing link; all the gradations from amphibian to reptile exist with a clarity seldom equaled in paleontology.

In other words, there is plenty of evidence, past and present, for some sort of evolutionary process. We see it in bacteria and insects today, and we see it in the fossil record through the development of millions of species over millions of years.

After thinking about questions like the three mentioned in the previous sections, different people come to different conclusions. In the future, there are three possible scenarios for the theory of evolution:

  • Scientists will come to a complete understanding of DNA and show how mutations and natural selection explain every part of the development of life on this planet.
  • Scientists will develop a new theory that answers the questions posed above to almost everyone's satisfaction, and it will replace the theory of evolution that we have today.
  • Scientists will observe a completely new phenomenon that accounts for the diversity of life that we see today. For example, many people believe in creationism. In this theory, God or some other supernatural power intervenes to create all of the life that we see around us. The fossil record indicates that hundreds of millions of new species have been created over hundreds of millions of years -- Species creation is an intense and constant process with an extremely long history. If scientists were to observe the creation process occurring the next time a major new species comes into existence, they could document it and understand how it works.

Let's assume that the theory of evolution as currently stated is the process that did bring about all of the life that we see today. One compelling question is: "What happens next?" Evolution must be at work right now. Our species, Homo sapiens, only appeared about 40,000 years ago. What does evolution have in store for human beings, and how will the change manifest itself?

  • Will a child appear one day whose brain is twice as big as any normal human brain? If so, what will be the capabilities of that brain, and how will it differ from the brain seen today? Or are our brains slowly evolving right now?
  • Will children appear one day who have more than 23 chromosomes? If so, what will be the effects of the new chromosomes?
  • Will man learn how to control or accelerate evolution through genetic engineering? Once we completely understand different genomes, will we be able to engineer evolutionary steps that lead to new species on a much faster schedule? What would those species look like? What would we design them to do?
These are all fascinating questions to think about. They reveal just how big an effect evolution can have. Given enough time, evolution could completely alter life on this planet by disposing of the species we see today and creating new ones.

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