Friday, May 23, 2014

Understanding the Evolution of Flightless Birds

Source: National Geographic News Report 5/13/14

One of the stronger evidences for evolution is the existence of such creatures as flightless birds.  If one were creating creatures willy-nilly all at once, as creationists assert, why create a creature with wings and feathers but without the ability to fly?  It makes no sense from a creationist perspective, but it makes perfect sense in an evolutionary perspective. 

Scientists, however, are always interested in the details of evolution.  Where does each known creature, past or present, fit in the evolution of life?  This article focuses on a puzzle that evolutionary biologists have been pondering for 150 years: where to place the creatures known as tinamous, a South American bird that has limited ability to fly.  It shares some similarities with flightless birds such as emus, ostriches, and kiwis.  Did it evolve from creatures like these, redeveloping the ability to fly?  Such a scenario is unlikely.  But it is equally unlikely that they would independently evolve other similar features to the flightless birds, known collectively as ratites.

In the past, such questions could not be answered conclusively because the evidence of morphology (body features of existing creatures) and fossil evidence can only suggest possible avenues of evolution.  The ability to sequence DNA now provides an independent means of analyzing ancestry and a new study has done just that with the DNA of flightless birds and the tinamous.

Science advances using the scientific method.  This method tests a hypothesis by stipulating what results would be expected in an experiment if the hypothesis were true.  Then if the tests show the expected results, it supports the hypothesis.  Results that are at odds with what is expected cast doubt on the hypothesis.

This study produced evidence from DNA that supports the hypothesis that the flightless birds and tinamous share a common ancestor that could fly.  The fact that DNA evidence allows us to confirm a connection suggested by morphology and fossils adds to the existing mountain of evidence that evolution is a fact, not a hypothesis still being tested, as anti-evolution critics would have us believe.

Is Evolution Predictable?

Source: news report 5/15/14

This report highlights something that anti-evolutionists need to recognize: scientists no longer debate whether evolution happens or not; they instead are interested in how evolution works.  Furthermore, the science has developed to the point where experiments can shed light on whether or not evolution is predictable.  The report describes research into the mechanism of evolution using an insect that evolved to resemble a leaf on a plant. 
So Patrik Nosil, an evolutionary biologist at the University of Sheffield in the United Kingdom, turned to a stick insect called Timema cristinae. In many places in California, this species has split into two forms, or ecotypes, on a hillside. One form is wide and lives on a wide-leaf plant; the other is narrow, with a stripe down its back, and lives on a plant with narrow leaves. Nosil and his colleagues sequenced the genomes of dozens of individuals of each ecotype from multiple hillsides to assess the genetic differences that arose to make them specialized for their particular host plant.
The report goes on to describe the following experiment:
Nosil’s team transplanted hundreds of individual stick insects onto the plant they weren’t adapted to and collected the offspring a year later. They checked the offspring’s DNA to see how the frequency of different versions of their genes shifted compared with those frequencies in the parents. Such shifts represent places where one version provides a better survival advantage than another, enabling the insects with that version to reproduce. Dozens of those shifts coincided with the DNA differences between the ecotypes, signaling that those differences were due to selection, not chance.
Experiments such as this are common in biology today.  They contradict the commonly repeated assertion by anti-evolutionists that evolution cannot be tested.  In fact, thousands of experiments have been conducted which, like this one, show the process of evolution in experiments.  The ability to sequence DNA adds another layer to the understanding of evolution, since the DNA is the physical link that makes evolution possible. 

Did the Evolution of Animal Intelligence Begin With Tiktaalik?

Source: Smithsonian Magazine June 2014

Another of the notorious (to the anti-evolution crowd) gap in the fossil record gets filled.  As discussed in earlier posts, fossil gaps are not evidence of any alleged failure of evolutionary theory.  Gaps are to be expected because fossils only form in special environments.  We also haven't found all the fossil beds that do exist.  So we should expect to find fossils which fill gaps.  In this case we have an important link between land and sea creatures.

Quoting from the Smithsonian Magazine article:
In 2004, when the fossil bones of Tiktaalik roseae were dug from the ground of Ellesmere Island, in the Canadian Arctic, the discovery was hailed as a breakthrough not just for paleontology, but for beleaguered science teachers trying to keep creationism out of their classrooms. A fish (with scales and gills) clearly resembling a tetrapod (with a flat head, a neck and prototypes of terrestrial limb bones in its lobelike fins), it precisely filled one of the gaps in the fossil record that creationists cited as evidence against Darwinian evolution.
The article goes on to show how science always learns from new data such as this. 
 The hip and pelvis were surprisingly robust, suggesting more powerful rear limbs than previously believed. Although almost certainly still encased in fleshy lobes, appendages could have helped support or even propel the animal in shallow water or mud flats. If so, it changes our view of the evolution of tetrapods, whose ancestors were believed to drag themselves by their forefins, only developing useful hind legs once ensconced on land.
The article also comments on the underlying assumption of evolution, that new species evolve when there is a new environment to exploit.  At the time the ocean had large carnivorous predators a-plenty, such as Taktaalik.  But the land had a diverse range of plants and some animals such as mollusks and insects with no predators of any size.  Getting out of the ocean also put a creature out of reach of the predators of the sea. 
As for what drove this epochal migration, “it’s extremely bloody obvious: There were resources on land, plants and insects, and sooner or later something would evolve to exploit them,” says vertebrate paleontologist Mike Benton of the University of Bristol. It’s also possible, says Shubin, that fear played a part. “If you look at the other fish in the water at the time, they’re big monstrous predators,” he says. Some exceeded 20 feet in length. Even for Tiktaalik, a toothy carnivore itself, this was a “predator-rich, competitive environment.” If you can’t be the biggest fish in the pond, maybe it’s better to get out of the water altogether.

In 2004, when the fossil bones of Tiktaalik roseae were dug from the ground of Ellesmere Island, in the Canadian Arctic, the discovery was hailed as a breakthrough not just for paleontology, but for beleaguered science teachers trying to keep creationism out of their classrooms. A fish (with scales and gills) clearly resembling a tetrapod (with a flat head, a neck and prototypes of terrestrial limb bones in its lobelike fins), it precisely filled one of the gaps in the fossil record that creationists cited as evidence against Darwinian evolution.

Read more:
Give the gift of Smithsonian magazine for only $12!
Follow us: @SmithsonianMag on Twitter
In 2004, when the fossil bones of Tiktaalik roseae were dug from the ground of Ellesmere Island, in the Canadian Arctic, the discovery was hailed as a breakthrough not just for paleontology, but for beleaguered science teachers trying to keep creationism out of their classrooms. A fish (with scales and gills) clearly resembling a tetrapod (with a flat head, a neck and prototypes of terrestrial limb bones in its lobelike fins), it precisely filled one of the gaps in the fossil record that creationists cited as evidence against Darwinian evolution.

Read more:
Give the gift of Smithsonian magazine for only $12!
Follow us: @SmithsonianMag on Twitter

Saturday, May 15, 2010

Study of Evolution Needed to Understand and Control Plant Diseases, Scientists Argue

A strong argument for the validity of evolution is the fact that our research into diseases and medical treatments assumes that evolution accounts for the divergence of both organisms such as ourselves and disease pathogens. Without this assumption, our medical research would grind to a halt.

An article in Red Orbit, an Internet journal for news on science, space, and technology, Emergence Of Fungal Plant Diseases Linked To Ecological Speciation, discusses the reasoning behind a commentary published by Tatiana Giraud, Pierre Gladieux, and Sergey Gavrilets that argues for the need for funding for general research on evolution. Without understanding evolution, they argue, we would not be able to understand how new diseases emerge, since a new species may provide a new and better host for certain portions of a pathogen community. Pathogens themselves also tend to evolve rapidly.

So when we hobble efforts to teach evolution, we are undercutting the ability of our society to generate scientists capable of studying the one group of nature's organisms which still poses a serious threat to human life. Anti-evolutionary crusaders are also the loudest voices for cutting government and private funding of evolutionary research. A citizenry unaware of the value of understanding evolution will be less likely to object when funding for evolution is cut.

So the next time you come down with a disease and the good doctors at your local hospital quickly identify and treat your disease, say a prayer of thanks for the scientists who have devoted their lives over the past 15o years understanding the nature of evolution! Then next time you hear someone suggest we cut funding for evolution research, ask him or her how Intelligent Design advocates would approach the control of infectious diseases.

This leads me to think about the theology of Creationism and Intelligent Design, which would have us believe that all the diversity of species is purely the result of recent creation of all species by God. Ian Anderson, the driving creative force behind the rock group Jethro Tull, wrote a lyric that goes, "The jungles are full of crocodile nasties/ and he who made kittens put snakes in the grass."

The comedy group Monty Python wrote a parody of the song "All Things Bright and Beautiful," called "All Things Dull and Ugly." Here are the lyrics of the original song (which I remember singing in my church's children's choir):

All things bright and beautiful,
All creatures great and small,
All things wise and wonderful:
The Lord God made them all.

Each little flow’r that opens,
Each little bird that sings,
He made their glowing colors,
He made their tiny wings.

The purple-headed mountains,
The river running by,
The sunset and the morning
That brightens up the sky.

The cold wind in the winter,
The pleasant summer sun,
The ripe fruits in the garden,
He made them every one.

The tall trees in the greenwood,
The meadows where we play,
The rushes by the water,
To gather every day.

He gave us eyes to see them,
And lips that we might tell
How great is God Almighty,
Who has made all things well.

Here is Monty Python's version:

All things dull and ugly,
All creatures short and squat,
All things rude and nasty,
The Lord God made the lot.

Each little snake that poisons,
Each little wasp that stings,
He made their brutish venom.
He made their horrid wings.

All things sick and cancerous,
All evil great and small,
All things foul and dangerous,
The Lord God made them all.

Each nasty little hornet,
Each beastly little squid--
Who made the spiky urchin?
Who made the sharks? He did!

All things scabbed and ulcerous,
All pox both great and small,
Putrid, foul and gangrenous,
The Lord God made them all.

In theological circles, these songs highlight the problem of theodicy, the name given to the question, "If God is a loving God, why do we have such a multitude of evils in the world?" A theology that embraces the findings of science has no need of this question. The evolution of all the things we value most, including ourselves, strawberries, bluebirds, ladybugs, goldfish, and kittens, also produced all the nasty, ugly parts of nature. In Unitarian Universalism, this is referred to as the interconnectedness of all life. Embracing this leads in a very different theological direction than a Creationist theology.

It also means that when we study evolution, we are studying life, ourselves, and--I would assert--God. Other religions, such as Buddhism and Taoism, also embrace the plurality of nature, pointing out that the distinctions between good and bad, beautiful and ugly, medicine and poison, are human inventions, not a part of the natural order. The sooner we recognize this, the more quickly we can approach an understanding of the whole which is both wholesome and healthy.

Thursday, May 13, 2010

Filling in the Gaps

Anti-evolutionists will not be trumpeting this news to their faithful fundies, I don't think. Irish study fills gap in evolution describes a new fossil find, not just a single fossil, but a site that is providing thousands of fossils documenting a stretch early evolution that has not been studied before. As the article reports, fossils of soft-bodied animals are extremely rare. This is because the conditions that will preserve a soft body are extremely rare. Only when the soft bodies are captured in some kind of muck which stops decay and then the muck turns into something like shale do we get to see what these ancient creatures looked like.

Those critical of evolution like to claim that the fossil record is incomplete. They say that as if it were not completely expected and explainable. As described in my previous post, the fossil record shows steady, slow evolution of many species, as well as relatively fast spurts of evolution. What gaps exist are not because intermediate creatures did not exist, but because they were not preserved in fossils or because we have yet to discover where they are preserved.

When new fossils are found, they provide a kind of lab in which to test evolutionary theory (not that more tests are needed, but that is what science always does with new information). We look at what we find and ask if it is consistent with theory. In this case, the fossils found in Morocco show life about 480 million years ago. Another site preserving such soft-bodied species dates back 510 million years ago. If evolution is correct we expect to find some creatures essentially unchanged even over 30 million years. But we also expect some creatures to have evolved to take advantage of new ecological niches.

That is exactly what is being found in the Fezouata Formations in the Draa Valley north of Zagora in southeastern Morocco.

“We know the fossil record is an important record of life, but it is an incomplete record,” says [Dr. Patrick] Orr. It makes interpretation of the progress of evolution very difficult, akin to trying to assemble the plot of a film using only intermittent still images, he suggests.

There was an explosion of new life forms during the Cambrian Period, with the shales revealing soft-bodied animals, according to Orr, “and then the record went blank.”

Now the evolutionary story continues with the Moroccan fossils showing that many of these Cambrian animals survived and multiplied into the next period, the Ordovician. The original animals were there but the Ordovician Period saw a rapid diversification of related species and so the mix is much more varied, Orr says.

This kind of filling in of gaps has been going on since scientists began hunting for fossils. Sometimes a new fossil location forces revision of the story that scientists had developed based on the then existing evidence. But this is a natural part of science. Such revisions are not to the theory of evolution, but to the details of what we are understanding evolution to have entailed.

Friday, April 30, 2010

"A 95 million-year-old fossilized jaw discovered in Texas has been identified as a new genus and species of flying reptile, Aetodactylus halli, says paleontologist Timothy S. Myers, who identified and named Aetodactylus halli. The rare pterosaur -- literally winged lizard -- is also one of the youngest members of the pterosaur family Ornithocheiridae in the world. It’s only the second ornithocheirid ever documented in North America, says Myers, a postdoctoral fellow at Southern Methodist University, Dallas."

Another fossil find. The fossil record is an important part of the reason evolution is considered a fact, not a hypothesis in need of more evidence. There are two aspects to using fossils to document evolution. One is the fossil itself, the things it tells us about the creature captured in stone for us to find millions of years later. The second is the dating of the fossil, to understand when it lived. Since the flow of time allows evolution to play out, we need the date to update the timeline of evolution.

The methods for dating fossils are various, but all are based in solidly established sciences like geology and nuclear physics. Geologists initially received as much grief from the fundamentalists as evolution would later receive. They were estimating the age of mountain ranges, seabeds, and other geologic formations by estimating the time it would take for things like erosion to whittle away at the hards surfaces of the earth. These preliminary estimates quickly placed the history of the earth thousands and even millions of years in the past, well past the six thousand years which the early Bible would indicate.

But this criticism eventually died out. One reason was that the evidence for an old earth continued to mount until there was no reasonable way to claim the earth was actually six thousand years old. Today, some fundamentalists hold onto the idea of a young earth, but they have absolutely no way to support this in the face of such a huge amount of evidence placing the earth approximately 4 billion years old.

When nuclear radiation was discovered and understood, this provided an independent way to test the dates which geology had proposed. The heaviest elements in the universe are often unstable, changing into other elements as they emit protons and neutrons from the nucleus. Some of these take a very long time to decay and so the amount of certain isotopes can lead to estimates of the age of the materials tested. The well-known carbon-14 dating process is just one example. But Carbon-14 is only valid for formerly living material which died no more than about 100 thousand years ago. Other elements, however, can be used to date rocks, sediments, and other parts of the earth's crust. The physics of nuclear decay and half-life determination is highly precise and beyond question as an accurate understanding of the basic building blocks of matter. Radioactive dating allowed more precise determination of the age of various parts of the earth's crust.

Even more confirmation of the earth's age came with the discovery of tectonic plates. Now geologists had a strong theory to explain all the things they had been documenting, such as fossils of fish at the tops of mountains, sections of one continent which fit perfectly into sections of other continents (Africa and S. America, for examle), and the ages of different parts of the crust. There is no question about the validity of plate tectonics. It has allowed us to know roughly how the planet looked at various times in the past. The continent of Antarctica, for example, was once along the equator and covered with tropical plants.

One aspect of plate tectonics which gave further confirmation to evolution was the correlation between when various continents broke apart, and when various species diverged from a common ancestor. Similar mammals exist in South America and Africa, which were once part of the same super continent. The estimates for when certain species diverged corresponds well to when geology says the continents split.

Between the fossil record and continental drift and geology, we can describe the various plants and animals which populated the earth and on which continents they lived and where those continents were and what kind of climate they experienced. This has given us a remarkable ability to "see" the earth as it has existed over the course of its 4 billion years.

When the big picture is seen in this way, it should be clear that no more fossils are needed to prove evolution. New fossils provide only more details allowing us to understand the manner in which evolution has shaped the populations of life on the planet.

For more information, I recommend the following site for a good overview of the evidence for evolution and the place fossils play in understanding evolution:

For a detailed (thought still merely an overview) of transitional fossils, go to this site:

2-million-year-old fossils offer look at human evolution

Not much has been studied of this new fossil discovery, but each new hominid fossil fills in a little more of the evolution of humans from earlier forms of apes. Contrary to popular understanding of human evolution, there is no missing link that would clinch the evidence for human evolution. We don't have anything like a detailed collection of fossils that show every stage of our evolution, but we have enough to show that it happened. This will undoubtedly lead to many new insights into the process.

Wednesday, April 28, 2010

Dinosaurs outgrow their baby feathers

This little article describes a fossil find that demonstrates a transition state between dinosaurs and birds. Critics of evolution often suggest that the fossil record is incomplete and has missing links. This is a bogus argument, however, because the fossil record is expected to be incomplete, not because of any shortcoming of evolution, but for geologic reasons. Fossils only form when an animal is quickly buried in something that excludes the usual chemicals that promote tissue degeneration. The majority of animals and plants that have lived have died in mundane ways that do not lead to fossils.

More significant is the strong evolutionary trends that can be seen in the fossils we have found. The dinosaur to bird transition is just one. New fossils are being unearthed every day and over the centuries that fossils have been collected and studied, nothing in the millions of fossils strongly contradicts the theory of evolution.

Sunday, April 25, 2010

A recent incident in Connecticut illustrates a serious problem in public education in America: the fear of controversy when teaching evolution. A science teacher presented a lesson plan for approval which would compare the accomplishments of Charles Darwin and Abraham Lincoln. The plan was not approved because, according to an e-mail from the principal, the principal did not want to present potentially controversial information to grade school children. An appeal to reverse this decision made to a higher level of the administration was also turned down.

You can read details of the incident here: and

The official excuse was that evolution is “a philosophically unsatisfactory explanation for the diversity of life,” and is “not age appropriate, is not part of our existing curriculum, is not part of the state frameworks at this point in a student’s education, nor a topic in which you [teacher Mark Tangarone] have particular expertise.”

The claim that it was not part of the state frameworks turned out to be false ( The principal and teacher have since resigned and the principal later apologized for his decision.

The anti-evolution extremists have gotten administrators so terrorized that they are afraid to teach evolution. The idea that young children will be traumatized by learning about evolution is propaganda and refusal to teach evolution on this basis will produce the exact result it allegedly tries to avoid. Children are naturally curious and curiosity about human origins is a natural and expected development. When this curiosity is not satisfied with facts that explain the prevailing consensus, they fill the void with whatever other explanation is offered. This is usually the pseudo science of intelligent design or blatantly religious creationism put forward by adults with religious motivations for their ideas and little knowledge of biology. Children grow up accepting these ideas, and when they are later presented with evidence for evolution, they are forced to reject the authorities they've trusted in order to assimilate the information. This leads confused children who complain to their parents, who then complain to the school boards, who respond by watering down text books and "teaching the controversy".

A stand must be taken and school boards need to teach the community, not just the students, about how science works and the preponderance of evidence for evolution. If parents still don't want to face these facts, they are free to home school their children or send them to private schools which cater to their prejudices. Public education needs to stick to the facts and let children know what scientists already know, that evolution is fact, not speculation.
I have not had the time to update this as I intended. The point of this blog was to show how commonly the theory of evolution explains the details of the diversity of life on earth. As a scientist, I'm aware of the role of evidence in developing theories. Everyone who examines the evidence for evolution with an open mind should be impressed by how thoroughly they theory explains the living world. The fact that so many doubt the theory indicates how poor a job our education system does of presenting this evidence.

I have been casting about in my mind for an analogy that does justice to the mountain of evidence for evolution placed next to the feeble examples presented by the anti-evolution scientists of what they think are features of life which could not have evolved. I think I've got something that may begin to hint at this difference.

Imagine the following hypothetical situation. The Pope is giving his annual Easter address to the assembled masses in St. Peter's Square. Film crews line the outer perimeter. In the midst of the address, a man pulls a rocket propelled grenade launcher from hiding and fires at the balcony where the Pope is speaking. Miraculously (some will say) the rocket misses the balcony and the Pope is not injured. The man attempts to load another grenade but is wrestled to the ground and apprehended by security forces.

A trial is held for the man on charges of attempted murder of the Pope. The evidence supporting the charges is massive. The event was witnessed by millions of people. Thousands of these people had digital cameras with which they documented the event from all sides. News media from countries around the world captured the events on high quality video equipment. The rocket launcher had his fingerprints on it. When authorities searched his house, they found evidence that he bought the weapon and stored it at his house. They also found detailed notes in his handwriting explaining how he planned to assassinate the Pope. In addition, the man readily confessed to the attempt.

Despite all this evidence, imagine that a small group of people maintains that the man is innocent. They don't have an alternative suspect. In support of the their claim, they point out that some of the pictures taken of the incident in St. Peter's Square do not clearly show the man's face. The say that the material in his house could have been planted, although they have no idea who that might be or why they would do that. Finally, they quote the man's mother as saying that she did not believe her boy was capable of such an act.

When the weakness of their "evidence" is pointed out, they have no rebuttals except to claim that the authorities are prejudiced against the man and are conspiring to frame the man.

The evidence for evolution is everywhere. First of all, the mechanism of evolution is not hypothetical but real and easily explained and demonstrated. Biological reproduction relies on the genetic material to accurately guide every organism into a close replica of the parents. Some variation in the particular genetic code is naturally present. Individuals with traits that hinder their survival will make them statistically less likely to pass on their genetic code to offspring, while individuals with traits that enhance their survival have an increased chance of passing on their genes. With thousands, millions, even billions of generations over which the statistics can operate, evolution is inevitable.

There is the fossil record showing the progression of traits. While some of the record is understandably incomplete (fossils only form in certain geological conditions), there are many examples of detailed step-by-step evidence of evolution, such as the horse, the transition from reptile to mammal, from reptile to bird, and fish to amphibian, to name but the most dramatic.

There is the close match between the family trees generated by the fossil record and trees suggested by the degree of genetic difference between modern species and the length of time since various differences occurred. The variation in species also follows predicable lines when we examine species from different island and continents separated by oceans, such as Australia, Madagascar, North and South America. Similar environments have produced similar species, such as the dingo on Australia and the wild dogs of the rest of the world.

Then there is the evidence in vestigial organs and bones, such as the hip joints in snakes and eye sockets in blind-from-birth moles. There is also plenty of evidence of evolution happening in the past two hundred years, including laboratory tests on species such as fruit flies and bacteria. There is the example of domesticated animal breeding which shows just how widely a given species can diverge just by the power of selective breeding.

There is the close fit between the evidence for evolution and the other sciences which demonstrate key features of the evolutionary theory, such as the age of the earth (geology), the age of the sun (astrophysics) and the age of the universe (particle physics). There is evidence from such sciences as anthropology, archaeology, and paleontology showing the evolution of the human species over millions of years. There is evidence of cultural evolution, evolution of ethics (cooperation), evolution of language, writing, and many other technical arts.

Finally, the big picture of the universe from the time of the Big Bang shows various kinds of evolution in the sense of simpler things combining to form more complex systems which in turn generate more complex systems. In the beginning was energy that evolved as it cooled to form protons, neutrons, and electrons, which combined to form hydrogen and helium, which combined at the hearts of stars to form larger elements, with the heaviest elements forming in super nova explosions of stars. Elements combined into planets that evolved complex compounds from the basic elements. Some of these compounds formed complex self-replicating forms, and life was off and running. Over time, single cells evolved cooperatives which formed multi-celled organisms. Groups of organisms combined over time to form even more complex organisms, such as fish and plants. In some of these, family groups evolved into simple societies and some of these evolved into complex societies of cooperating individuals. One of these evolved intelligence and once that reached a certain level, evolution of culture and technology followed.

So the amount of evidence is truly a mountain range, while the best the anti-evolutionists can offer are a few feeble aspects of a few organisms which they say could not have evolved. They offer a religious text from 3 or 4 thousand years ago which gives us a creation myth, the details of which do not even closely resemble the picture developed by modern science. They offer egotistical indignation that we humans could have evolved from more lowly forms. They offer no alternative to explain what evolution can explain. Their most basic argument is flawed with the logical error that attempts to prove one theory by showing that the prevailing theory is not adequate. Even if evolution were wrong, it would not support the creationist/intelligent design alternative the anti-evolutions espouse.

So please don't let anti-evolutionists determine what gets taught in public schools. Children need to know the facts in order to judge the facts. The evidence is overwhelming. People uncomfortable with the consequences must deal with this rather than try to hide the mountain with a religious myth.

Sunday, March 08, 2009

When I started this blog, my goal was to provide support for the theory of evolution by demonstrating that, contrary to statements by anti-evolutionists, new evidence of evolution is continually being reported. This includes new findings from fields such as cell biology, ecology, morphology (the study of the forms organisms take), ethology (the study of animal behavior), medicine, and neurology. Oh, and let's not forget fossils, which continue to turn up new examples of intermediate forms. Time has not allowed me to carry through with this agenda.

But there is an argument that needs to be made that relates to the question of evidence and evolution. Anti-evolutionists, who with a few exceptions are not biological scientists, claim that current text books and biology curiculla need to reflect an alleged abundance of evidence that calls evolution into serious question. Now this "evidence" has been refuted by competent scientists, but the idea that such evidence could exist is refuted by a proper understanding of the way science works.

If the evidence existed which seriously challenges evolution, and if biological science is operating by the same rules as other sciences, then it would be leading biological scientists who would be insisting on debate about the validity of the theory. Scientists make their mark on the history of science by seeking out such evidence as cannot be explained with current theories. That is what science does. Yet no such fight is being fought, at least not by scientists.

A good example of how this works can be seen in the history of phyics around the turn of the 20th Century. A famous anecdote illustrates the attitude of established physicists at this time. A recent college graduate asked a physics professor if he recommended a student seek an advanced degree in physics. The professor discouraged the student, saying that all the important theories had been established and the only work that remained for physicists was to calculate the known constants to greater and greater accuracy. One student at the time, who thankfully did not receive and follow that advice, was Albert Einstein. In 1905, working as a patent clerk, published papers that exploded the complancy of physicists and established whole new fields of study, such as relativity and quantum mechanics.

How did the scientists of the day respond? Did they ignore this evidence, attempt to cover it up, try to stiffle criticism of the established theories? No. Physicists were energized and zestfully set to work to find the theory that would explain the evidence coming to light better than the established theories. This is not to say that every physicist of the day was persuaded that new theories were needed. In some ways, the new theories did not really take off until the old theorists died off and were replaced by students who did not have any emotional stake in maintaining the status quo.

This is how the system is supposed to work. Science invites the reporting of evidence that calls theories into question. It thrives on them. If the new theories proposed by physicists such as Einstein, Bohr, Heisenberg, and others did not explain the evidence in hand better than the established theories, no changes would have been made. Science is inately conservative, requiring a lot of evidence before changing its collective mind.

My point is that if the evidence that seriously challenged evolution existed, we would not need non-scientists to lead the charge to change the acceptance of evolution in the scientific community or the lay community. The scientists themselves would be fighting over whose theories would replace evolution. No such fight has ever occured in the case of evolution. Most of the evidence that seemed to call evolution into question has turned out to be improperly interpreted. Sometimes later discoveries shed new light on the evidence.

For example, some anti-evolutionists have made much of a bed of rock with fossil footprints that appeared to show footprints of humans along-side footprints of dinosaurs. If this were good evidence, it would indeed throw the field of evolution into a dither; according to orthodox evolution theory dinosaurs were extinct long before primates, much less humans, had evolved. But the evidence was being misinterpreted. A closer examination of the footprints by qualified paleontologists demonstrated that what appeared to be human footprints were prints of a dinosaur which left prints which, at first glance appeared human.

Likewise, anti-evolutionists have insisted that a complex structure like an eye could not evolve because it does not work if any part did not do its job. But scientists have shown that a wide range of organisms have eyes ranging in simplicity from mere light sensitive spots to the eyeball with a lens. Each is but a small change from a simpler example, demonstrating that evolution can produce complex structures.

These attempts to discredit evolution are dead-ends that evolutionary biologists have already considered and rejected, not because they don't want to see the theory discredited, but because evidence supports the conclusions. If this is not yet convincing you, let me give you an analogy that might clarify it.

There are some who claim that the Nazi holocaust of Jews and others undesirables never happened. Knowledgable historians do not discuss these claims, citing this as an alternative interpretation of the evidence, nor are these theories taught in history classes. This is because the evidence for the Holocaust is so extensive that it would be irrational to claim it never happened. Historians don't consider the Holocaust a theory which deserves to be viewed as inconclusive because the evidence is so extensive and so clear that no qualifiers need be made. The Holocaust, unfortunately, happened; it is a fact of history, not a theory.

If we consider what could cause people to question the Holocaust, we cannot but conclude that they choose to believe this in spite of the evidence based on bigotry, not evidence. In a like manner, I conclude that those who believe in intelligent design and creationism do so in spite of the massive weight of evidence based on religious beliefs. To suggest that such ideas have a place in science class is as irrational as to assert that anti-Holocaust texts be introduced in history classes. The only reason to even mention these topics in science or history classes would be to demonstrate antithesis of science and history.