Tuesday, October 30, 2012

Religion vs. Science the Vast Gulf Part Five: Weather and Climate

I just uploaded a YouTube video about Darwin visiting the Petrified Forest in Arizona. The petrified wood comes only from ancient conifers, none from modern trees, proving that it could not have been produced by a big Flood. See other videos here.

This is the fifth in a series of entries about the vast difference between the modern scientific view of the world and the view that people had of the world at the time the Bible was written.

To the Biblical worldview, the climate of the Earth is directly controlled by God. And there are many, many religious people who believe this today. Their proof? Genesis 8:22, in which God makes a promise: while the Earth remains, seedtime and harvest, cold and heat, summer and winter, day and night, shall not cease. I have several students each semester who quote this verse in their supposedly scientific papers on the subject of what I now try to call global climate disruption. In this, they are imitating their great Christian hero, Senator James Inhofe, who quotes Genesis 8:22 whenever the subject of climate comes up in the Senate.

Modern science has demonstrated that Earth’s climate is controlled by many complex factors. In any given year, it is affected by changes in the angle of the sunlight, by the amount of greenhouse gases in the atmosphere, by the amount of energy coming from the sun, by ENSO patterns, rain shadows, etc. Long-term changes are caused by periodic oscillations in Earth’s orbit, movements of the continents, etc. A religious person could claim that God works through these natural laws; but we are not talking about that kind of religious person. We are talking about people who believe God is forbidden to use figures of speech. Forbidden, I presume, by them.

That is, we know what causes the seasons. The Earth moves, and is tilted, and as a result a lower angle of sunlight creates winter, and a greater angle of sunlight creates summer. Psalm 93:1 clearly states that the Earth does not move, and it was this verse that got Galileo in trouble with the Catholic Church. Creationists no longer claim that the Earth does not move, but they do so mainly by arbitrarily assigning a figurative meaning to the psalm.

We also know what causes wind and rain. Air blows from high to low pressure areas, and rain results from the condensation of water vapor. In contrast, the Bible says that rains caused Noah’s flood because the windows of heaven were opened. Job referred to the storehouses of the wind. These are perfectly good figures of speech, and are apparently accepted as such even by creationists. But they have to violate their own assumptions by doing so.

There is a dark side to creationist beliefs that God has made sure that global warming has not occurred. At the moment, creationists are denying that global warming is happening (step one), or if so, that humans are causing it (step two). They deny that we should be doing anything right now to reduce carbon emissions. God put all that coal in the ground during the Flood (thoughtfully picking out just the conifers and keeping out the flowering plants) so that we could burn it right now. Not slowly, over centuries, but right now. This is because many of them think Armageddon is right around the corner, so why wait?

But at some point even creationists will have to admit that global warming is a reality. However, when they do so, they will go directly from steps one and two to step three: It is too late and there is nothing we can do about it. They circumvent the entire process of trying to bring our carbon emissions under control. And they will give their own religious twist to step three: they will say that global warming, which in upcoming decades will be greater than most of us have even been able to imagine, is God’s punishment upon the world. Punishment for what? Probably for homosexuality. After all, God said that while the Earth remains, seedtime and harvest, cold and heat, summer and winter, day and night, shall not cease. Creationist stage three belief concerning global climate disruption is that it will in fact occur while God is carrying out His end-time Apocalypse.

By the way, why did God make the Genesis 8:22 promise? One might think there is a lofty reason, based upon Jesus’ version of God. But according to verse 21, the reason is that Noah offered a sacrifice of clean meat on an altar, and when God “smelled the pleasing odor,” he made the promise. So if you ever want anything from God, invite Him to a barbecue. Yeehaw!

Friday, October 26, 2012

Religion vs. Science, the Vast Gulf Part Four: You Are What You Eat

I continue the series of posts about the many ways religion, especially Christianity, differs from science. The first entry was about the scientific method. The second was about the sky. I posted part two before I had heard about Bill Nye and the creationists in 2006. Bill was giving a lecture in Waco, Texas, in which he mentioned that the moon does not create its own light, but reflects the light of the sun. Some creationists walked out, since Genesis describes the moon as “the lesser light,” which to them meant that it emits its own light. My guess is that this viewpoint does not represent most creationists.

In the previous essay, I wrote about how carbon-based life forms cannot be made from the dust of the Earth, taken literally. But there is a temporal dimension to this also. Your atoms are in a state of continual turnover. You are losing some, and gaining some, from the food that you eat, which is carbon-based. There is a reason Captain Kirk did not share a sandwich with the silicon-based Horta.

Which brings up the important subject of what we should eat. While Jesus considered it to be of secondary importance (It is what comes out of a man, not what goes into a man, which defiles him, he said), there are nevertheless laws of food and health. And the Biblical dietary laws contrast with the scientific dietary laws. The U.S. government guidelines for nutrition look pretty different from Leviticus 11.

The Old Testament Jews were very concerned about clean vs. unclean foods. Leviticus has quite a list of unclean foods. Many of them seem arbitrary. But modern scientists have figured out some likely reasons for some of these laws. For example, why did Jews hate pigs so much? And they have hated pigs for a long time. Archaeologist Israel Finkelstein has unearthed evidence that the Jews were not very different from surrounding tribes even during the heyday of Solomon, and that Jerusalem of Solomon was not the glorious city that the Old Testament describes. But even in the sites of their earliest villages was the remarkable absence of pig bones. We all know pigs are dirty. Of course, the reason they are dirty is we keep them dirty. Wild pigs are no dirtier than other wild animals. Pigs spread parasites, but so do cows. Smallpox apparently evolved from cowpox early in human village life.

One possible reason that the Jews proscribed pork is one I heard from José Lutzenberger, former Secretary of the Environment in Brazil. He spoke at the Prairie Festival at the Land Institute in Salina, Kansas. (He didn’t keep his job too long. As someone pointed out, he was serious about environmentalism, and appointing “Lutz” as Secretary of the Environment in Brazil was like appointing Wes Jackson as Secretary of Agriculture in the USA.) He said that cows, horses, sheep, and goats did not compete with humans for food; they ate grass and other things that humans cannot digest. But pigs eat some of the same things we do, and therefore may compete with humans for food. A rich man could fatten his pigs while poor people starve in the ancient, or not so ancient, world. Pigs were, to Lutz, a symbol of poor environmental stewardship in ancient times. I’m not sure if he had any scientific evidence, but his statement has stayed with me for many years.

The Old Testament laws also proscribe shellfish. The reason was obvious: spoiled shellfish can make you very sick. They knew this back in ancient times. There was a good chance that any shellfish, by the time it reached the hills of central Judah, would be spoiled. A more recent custom is to eat shellfish that have been harvested only in the months with the letter R in them (that is, not May, June, July, or August). Today we know that shellfish that have fed upon dinoflagellates (“red tide”) can have neurotoxin. So this made sense.

But the modern view of nutrition is totally unlike that of the Old Testament (and New). We can eat fat foods, but only a little bit, and most of our fats should be unsaturated, e.g. from olives and nuts. We need to eat a lot of vegetables and fruits, and get lots of exercise during the ordinary course of a day. This was not so important in the old days when food was often scarce, and when people walked everywhere—there was no stair-vs.-elevator decision for them to make. Their laws worked for them, imperfectly, and our laws work for us. (I’m about to eat some chicken thigh meat, because my cravings are prehistoric in origin.)

This may seem like a small matter, and Biblical literalists do not, to my knowledge, attack nutritionists. I have not heard creationists say, while engulfing fat steaks, “God guarantees my health because I avoid pork and shellfish.” But modern nutrition science does show, just as clearly as modern evolutionary science, that our scriptures were the products of their time, reflecting the best understanding that people had back then, rather than inspired and infallible scientific truths.

Friday, October 19, 2012

Religion vs. Science, the Vast Gulf Part Three: Dust of the Ground

Last night, a big dust storm blew across Oklahoma. It was visible from outer space, and brought precious topsoil from Nebraska. It has been about seventy years since Hugh Hammond Bennett convinced the Senate to establish what was then called the Soil Conservation Service. Have we learned anything?

I now continue my series about the many ways in which modern science differs from the Biblical worldview--a series that does not include any discussion of evolution. The first essay is here and the second is here.

Most biology courses begin with atoms and molecules. Organisms are mostly made of carbon, hydrogen, oxygen, nitrogen, and phosphorus, organized mostly into carbohydrates, lipids, proteins, and nucleic acids. You don’t usually hear any religious people objecting to this. But they should, if they are Biblical literalists.

Genesis 2 describes the creation of man (and later of woman, after he created the animals). And God made man from the dust of the ground. One time, back when I was a theistic evolutionist but a Christian believer, I taught in a Sunday class that this could include organic molecules. A creationist in the class said that this was not so; dust is dust, that is, very fine soil particles blowing in the wind. Not DNA, proteins, and such.

Well guess what. The dust of the ground consists of very different atoms from organic sources. The dust of the ground consists mostly of silicon and oxygen. You cannot take a handful of dust and turn it into an organism without changing the atoms.

And then there is the breath of life. Genesis 2 says that God breathed the breath of life into the lump of clay and made it a living soul. Now, both of the main Hebrew words (ruach for breath, and nephesh for soul) are broadly interpretable. Ruach (Greek: pneuma) can mean breath, wind, or spirit. Nephesh can mean body or soul. But to a literalist, it should be disturbing to realize that life results from the production of ATP by mitochondria. “Breath of life” and “metabolism by mitochondria” can be forced to reconcile, but this is not how the ancient mind thought of life.

One could say that Genesis 2 says that God made humans from pre-existing organic matter—actually, from pre-existing hominins. Many religious people use this as a way of reconciling Genesis with human evolution. But this is not satisfactory to a literalist creationist. How can a creationist accept biochemistry?

Friday, October 12, 2012

Religion vs. Science, the Vast Gulf Part Two: The Heavens

In a previous blog entry, I wrote about the vast gulf between science and religion with how to determine what is true. I now continue this series about how different science and religion are from one another.

Before Copernicus and Galileo, most people viewed the sky as some kind of sphere or series of spheres on which the stars rotated around the Earth, and each planet (as well as the sun and moon) had its own sphere. Either that or they thought the sun, moon, and stars were gods. This was certainly the view of the writer of Genesis 1, who used the term “raqia” for what is usually translated “firmament.” Did you ever wonder why Genesis called the sky “firmament,” which sounds like “firm”? Because “raqia” is derived from “raqa,” which means “to beat out,” or stamp out, often used for metal beat into a thin sheet. This is the way the word is used in Exodus 39:3, Numbers 16:39, Isaiah 40:19, and Jeremiah 10:9. It refers to trampling or stamping with the foot in 2 Samuel 22:43, Ezekiel 6:11 and 25:6. Figuratively, this can mean “an expanse,” but literally it refers to a metal dome. (See here.)

This does not mean, of course, that the Biblical authors were somehow anti-scientific. They shared the view that nearly everyone had until recently. Copernicus believed in the heavenly spheres; he just made the sun the center, and Earth was on a sphere. Nobody accuses Copernicus of being anti-scientific. It was not until the twentieth century that scientists understood that many of the “nebulae” were faraway galaxies. But the Bible certainly cannot be used as a literally accurate basis for astronomy. Many scientific Christians simply point out that this was not the purpose of Genesis in the first place.

The Bible refers to stars falling from the sky. Isaiah said it (Is. 34:4), Jesus said it (Matthew 24), and Revelation uses the phrase at least twice, in chapters 6 and 8. Of course this cannot literally happen. We all use the term “falling star” figuratively for meteors. No problem, unless you base your science on the Bible. The Biblical view of the universe, like all views of the universe before Kepler and Newton, is vastly different from the modern view shared by everyone, even most creationists.

Sunday, October 7, 2012

Oklahoma Teachers Evolution Workshop, Part Seven

As the Teachers' Evolution Workshop sponsored by Oklahomans for Excellence in Science Education drew to a close on October 9, we had presentations and discussions by high school teachers about how to teach evolution, usually in interesting laboratory settings.

Andrea Blair, high school teacher in Broken Arrow, Oklahoma, and a graduate student at the University of Tulsa (where she spends time studying the anatomical structure of amphibians), told the participants about some of the lab activities she has devised or adapted. Some were versions of the natural selection simulations that have been used in many classes for decades; for example, to simulate natural selection of light vs. dark moths against light vs. dark bark, based on the twentieth-century studies by H. B. D. Kettlewell. But the greatest amount of discussion came in response to Andrea's investigation of radiometric dating. Students begin with a box of coins, all heads-up, which represent radioactive atoms. Then the students shake the box just once, count and remove the tails-up, which represent atoms that decayed. The students repeat this over and over, and generate a graph of radiometric decay. But they do so by stimulating a random process (actually a quantum process). I, for one, have never heard about this activity from anyone else.

Andrea also described how to use different colors of beans to represent alleles in a population. Students randomly draw pairs of beans that represent diploid individuals in a population. Then, natural selection can be simulated on the simulated diploids. The advantage of this activity is that students can see the effect of natural selection not on phenotypes but on allele frequencies in a population. This activity can be modified to simulate genetic drift and founder effect.

One thing that Andrea emphasized is that these activities are cheap and easy. You don't need a budget for prepared teaching materials or for computer simulation software. Best of all, students are learning about the processes of evolution, without feeling like "evolution" is being pressed upon them.

And with this, the workshop ended. The participants were, we hope, inspired and equipped to teach evolution in creative ways and to deal constructively with inevitable conflicts. The setting, the University of Oklahoma Biological Station on the shore of Lake Texoma, was restful and beautiful.

Oklahoma Evolution Workshop, Part Six

Early on Sunday morning, the clouds blew away. The Teachers' Evolution Workshop, sponsored by Oklahomans for Excellence in Science Education, began with a presentation by Bob Melton, curriculum specialist for the Putnam City schools. Both Oklahoma and Texas have repeatedly received a grade of "F" from the Fordham Foundation for science education, because the Oklahoma state standards (and until recently those in Texas also) do not include the word "evolution." The Fordham Foundation has actually indicated that this is the reason for their low rating. However, Bob pointed out, all of the components of evolutionary science (such as natural selection and change in populations) are present. This is simply because state legislators and administrators hate evolution but do not know what it is, so that in the absence of the actual word these state officials do not realize that evolutionary concepts are being taught. Meanwhile, in what I consider a supreme irony, the very same government officials who refuse to include evolution in the state education standards have turned around and criticized science teachers for doing such a bad job and getting Oklahoma an F.

Bob reviewed the legal cases which, in every case, confirmed that evolution, and not creationism (including intelligent design), must be taught in biology courses. In some cases, some teachers have claimed that their First Amendment right by requiring them to teach evolution, but the courts have not agreed with these teachers. Moreover, schools may limit the extent to which students can disrupt classes, nor opt out of sections of classes, because of religious objections. This would be like saying, "For religious reasons, we do not want our children to learn about the Civil War in American history class." On the other hand, science instructors cannot ridicule religious beliefs in class. If teachers encounter resistance from administrators to teaching evolution, they can take some comfort in the fact that major scientific and educational societies (such as National Association of Biology Teachers and American Association for the Advancement of Science) have issued statements in support of teaching evolution.

It is doubtful, however, that any teachers in Oklahoma and Texas would have time to fight local officials for the right to teach evolution. One of our participants is a high school teacher who has to, on a Sunday, to grade 454 papers, after her three-hour return drive from this workshop. It is, perhaps, better to avoid conflict as much as possible. But one way to do this, modeled by Kansas high school teacher Ken Bingman, is to get the students to investigate evolution for themselves, rather than to just tell them the scientific truth.

Bob also got the participants to think of new ways to make teaching more fun, for example with songs such as "It's a Long Ways from Amphioxus."

The second presentation was by Dr. Joseph Maness, a biology professor at Southwestern Oklahoma State University. Jody gave the participants ideas about how to deal with the religion/evolution conflict. In Oklahoma, many students have been raised to believe that if they accept evolution, they will literally go to hell. What should we do? We can get some help from the American Association for the Advancement of Science's Dialogue on Science, Ethics, and Religion (DoSER). Their book The Evolution Dialogues explains that students do not need to choose between science and faith. For one thing, there is not just two positions (creation vs. evolution) but a whole continuum of viewpoints, as I mentioned in an earlier blog. There is a whole continuum of views. Eugenie Scott of the National Center for Science Education has published a diagram of this continuum, which was modified from one developed by a Christian geologist, Davis Young, who taught at Calvin College in Michigan.

While I admit that ther does not have to be a conflict between science and faith, I think we should be honest with students about what I call the "vast gulf" between science and religion, which I have begun and will continue to discuss in entries to this blog. Therefore, science and religion can be reconciled, but you have to decide to make them reconcile. For example, DoSER claims that science and religion both have "reason" as a shared value. Of course, this is not true of many religions, even in America. In most cases, the process of reconciliation has resulted from the advance of science and retreat of religion. Jody told us that in Biblical times, "faith" meant "trust" rather than "doctrine." I admit that the "trust" definition of faith makes the "vast gulf" between science and religion not quite as wide as I had indicated in my earlier blog entry. Nevertheless, most people today equate "faith" with "doctrine" handed down by religious leaders.

Several conference participants expressed the view that an overview of the potential compatibilities between science and religion would have been a good way to begin, not end, the workshop. These participants, religious beleivers, wondered if their faith was being attacked at the workshop, when to their surprise this was not the case.

Saturday, October 6, 2012

Oklahoma Evolution Workshop, Part Five

For the late afternoon and evening sessions, the workshop focused on educational and religious issues related to evolution.

Dr. Mary Kay Johnston is a new young professor at Concordia University in Austin TX, which is associated with the Lutheran Church. That is, the Missouri Synod of the Lutheran Church, which officially endorses young-earth creationism but tolerates some diversity of opinions within the academy. She has not experienced trouble from her colleagues or church leaders for teaching evolution, but does have to deal with students coming to college with misconceptions of and hostility toward evolution. This quickly turned into a lively discussion about how to deal with religious issues popping up in science classes.

To avoid some of these problems, Dr. Johnston suggested, we could do some of the following things. For example, talk with students about what science really is. Also, let them know how evolution works before you begin talking with them about the products of evolution, especially humans. And use examples of evolution that are less likely to elicit a negative reaction; students (and their parents and preachers) are unlikely to get bent out of shape over the evolution of diatoms. You don't even have to call it evolution at first. Dr. Johnston encouraged us to deal with Intelligent Design, and to point out the flaws in its fundamental argument: that the parts of a complex system cannot work by themselves. The creationists' favorite example is the bacterial flagellum; but the basis of the flagellum is the same as that of a secretory apparatus.

Rich Broughton also told participants about some excellent teaching resources that are available online, such as Understanding Evolution, the National Center for Science Education, the Howard Hughes Medical Institute Cool Science site, and the Talk Origins Archive.

You can't get a lively group like this to not keep talking about religion-science issues. Dinner conversations got serious, in a constructive and friendly way. Those of us involved in this discussion got to know and appreciate each other more, in my view.

For the evening session, Dr. Victor Hutchison, retired from a distinguished professorship at the University of Oklahoma, told us about how creationism and intelligent design are not science, but are politics and religion using science as a disguise, and demonstrated this to us by quotations from the creationists. For example, to Phillip Johnson, the removal of evolution will be the "salvation of western civilization." This is clearly a conflict between science and religion, fueled from the religion side. The militant atheists fuel the attack from the atheist side, especially the "Gnu Atheists." I had never heard this term before; this group of atheists invented the term for themselves. The gnu atheists attack "accommodationists" who try to at least defuse some of the religious conflict over evolution. Meanwhile, many churches such as the Catholic Church (under Pope John Paul II) accept the science of evolution, and some scientists (such as Thodosius Dobzhansky, one of the founders of evolutionary science) have been religious. Dr. Hutchison pointed out that there are not just two views of creation vs. evolution; there is a whole range of views.

There is also a problem between intelligent design and science: if you simply say, regarding anything that you think is complex, "the Intelligent Designer created it," this brings scientific inquiry to and end. The creator made it; end of story. Not surprisingly, the intelligent-design creationists have not published their own scientific research. And intelligent design is clearly motivated by politics. When Judge John Jones ruled against the creationists in the Dover trial, Republicans were quick to attack him, even though he was a Republican who had been endorsed by Rick Santorum and appointed by George W. Bush.

The intelligent design side is sometimes dishonest, Vic told us. The creationists, going into the 2005 Dover trial, submitted a pile of scientific papers that they claimed supported their view. When the defenders of evolution contacted the authors, they indicated that the creationists had misconstrued the papers to mean something that contradicted their scientific conclusions.

Vic updated us about the recent history of creationist legislative bills in Oklahoma, which narrowly failed, and only because Oklahomans who cared about science education contacted the legislators. He spoke over an hour with incredible energy, even as he enters his ninth decade. Who can follow him, when he finally becomes too tired to continue his work? There are several of us on the Board of Oklahomans for Excellence in Science Education, sponsor of this workshop, who can try, but it will take all of us to keep his work going.

Oklahoma Evolution Workshop, Part Four

The evolution workshop for Oklahoma teachers continued after lunch. I had the first session. I began by advertising my own website, where you can find essays and photographs, as well as copies of scholarly articles  I have written. It has links to my YouTube channel and to this evolution blog.

Then I began with the story of the Ghosts of Evolution. (I have a recent YouTube video where Darwin discusses this subject.) I held up a big, sticky, green fruit of Maclura pomifera, known as bois d'arc, Osage orange, or horse-apple. The native range of this tree includes Oklahoma. I modeled the kind of questions that they can ask their students. Why do some plants produce juicy sweet fruits? Animals eat them, swallowing the seeds and transporting them to a new location. This is useful to the plant only if the animal swallows undamaged seeds, as we do with strawberry or kiwi seeds, or as raccoons do with persimmon seeds. With their finicky fingers, some raccoons could pick out the persimmon seeds, but this would waste valuable time, during which other raccoons would eat up all the fruits. The concept that students might grasp is coevolution. In this case, juicy fruits evolved in response to animals that eat them and disperse their seeds.

But what eats big, sticky bois d'arc fruits? In Oklahoma, someone will always say, horses. In other parts of the country, nobody may have any idea. But modern horses are not native to North America. There were native horses in North America at the end of the last ice age, but they have become extinct. Perhaps at the end of the last ice age, there were large animals (horses, mammoths, mastodons, gomphotheres, etc.) that ate bois d'arc fruits, but today, there are no native animals that eat them. Thousands of years ago, there was a coevolutionary waltz between bois d'arcs and gomphotheres; today, the bois d'arc is doing a waltz with no partner.

We went outside, into the cold wind. The temperature has dropped 50 degrees in two days. If you want to get kids outside and still teach them about evolution, just take them to an oak tree and ask them what they know about oak trees. The wood is strong. The trees live a long time. Acorns are large, as are the seedlings that emerge from them. Now, think about what kind of environment would benefit trees that have these characteristics. In an old, stable forest, large seeds and large seedlings would be better able to compete with the dense populations of plants that are already there. They invest for the long term in strong wood. Then take the kids to a cottonwood tree. Cottonwoods produce cheap wood and do not live very long. Their seeds are numerous and small. These characteristics make sense for trees that live near rivers, where they have a lot of water but also face a great risk of being destroyed in a flood. It would make no sense for a cottonwood to invest in wood that will last for centuries, since a cottonwood tree would probably get killed in a century or less. This may help students to understand that evolution does not always produce the same "superior" set of adaptations; the "superior" traits for a tree in an old, stable forest are different from those in a young, frequently-disturbed, floodplain forest.

Then Dr. Cecil Lewis had a second session, this time devoted to his specialty: the evolutionary and medical genetics of humans. He explained how population genetics works. A large, old population that has been large for a long time may have a great deal of genetic variation, including a lot of rare variants. Large populations can lose genetic variation if they become small--that is, they go through a population bottleneck. Small populations can lose genetic variation just by chance. If the population then grows rapidly, it retains the genetic makeup that it had while it was small. That is, a newly-large population will have no more genetic variability than it did when it was small. If you find a population that is large but has low genetic variability, this probably means that there was a recent genetic bottleneck. This appears to have happened in the human species. The entire human species, all seven billion of us, has the same amount of genetic variation that one would expect from a mammal population with only twenty thousand individuals. This suggests that (perhaps 70,000 years ago) our species had a brush with extinction--there may have been, at that time, only about twenty thousand of us.

You can make a closer examination of the genetics of human groups. The greatest genetic variation is in Africa. The genetic variation in the Middle East is a subset of African genes. The genetic variation in Europe is a subset of Middle Eastern genes; Asians are a separate subset. North American native genetic variation is a subset of Asian genes; South American native genetic variation is a subset of North American native genes. Each time a migration occurs, only a subset of people leave home, therefore some genes get left behind. Human genes, therefore, are an invisible record of the pattern of human migrations during the last 200,000 years.

Some human genetic patterns have resulted from natural selection. Lewis gave an example: the ALDH2-2 gene, the gene that codes for alcohol dehydrogenase. One variant of this gene is much more common in Asians than in anyone else. The Asian variant is the reason that Asians generally have a lower tolerance of alcohol than other people. However, since refiend alcohol is a recent invention, the Asian variant of the gene was probably selected by exposure to pathogens.

Oklahoma Evolution Workshop, Part Three

The workshop sponsored by Oklahomans for Excellence in Science Education has brought together high school teachers and college faculty from Oklahoma and Texas. It began Friday night, October 5, and continues this morning. A few minutes ago, I blogged about the first two presentations, both of which addressed the scientific way of knowing about the world.

Now, Dr. Richard Broughton, a zoologist at the University of Oklahoma, is discussing how to interpret phylogenetic trees and how the phylogenetic way of thinking has changed our view of life. A millennium ago, scholars all believed that everything from the simplest animals to humans formed a scale of being from lower to higher. After Darwin, most scientists accepted that all organisms were part of a tree of life, rooted in a common ancestor--but they still accepted humans as the top of the tree, as if this is what the tree was meant to produce. But, when you think about real trees, you would never think that the top twig (if you can even identify it) is what the tree is all about. Modern evolutionary thinking identifies all species as being equally "evolved," all of them (us) being twigs on the tree.

Phylogenetic thinking has gotten scientists to think in terms of evolutionary branch points. Mammals, for example, all share a common ancestor (phylogenetic branch point), while all birds share a common (dinosaur) ancestor. Further back in time, birds and mammals shared a common vertebrate ancestor. This ancestor had the same limb bone pattern found in birds and humans, therefore this pattern is homologous. But this ancestor did not fly; bat and bird wings are, therefore, analogous--they evolved separately, despite their similar appearance. Phylogenetic trees can be based on physical characteristics (bones, wings, etc.) or on DNA data.
Rich had the participants figure out a phylogenetic tree based on a set of xerox copies; the ones that have the same shared derived characters (smudges made in copying) have a more recent common ancestor than the other. Therefore phylogenetic analysis can be used to figure out the pedigree of, for example, ancient Biblical manuscripts.

One of the best pieces of genetic evidence for a shared ancestry of chimps and humans is human chromosome 2. The genes of human chromosome 2 line up with those of two chimp chromosomes, but one of them is reversed. Human chromosome 2 has nonfunctional telomeres in the middle, and a nonfunctional centromere--which exactly fits what you would expect if two ancestral chromosomes fused together end to end in the human lineage, but not in chimps. But, as Rich emphasized, there are a lot of other pieces of genetic evidence, including shared noncoding DNA inherited from a shared ancestor. You can construct a phylogenetic tree of primates based on nothing but ERV (endogenous retroviruses; dead viruses that got stuck in the chromosomes) and it matches the phylogenetic trees constructed on the basis of completely different sets of data. The recent availability of whole-genome sequencing has allowed many new examples to be found. A group discussion revealed that no coherent explanations have been offered for these genetic patterns by creationists, who reject shared ancestry.

Even something as easy to understand as vitamin C provides evidence of evolutionary ancestry. The bodies of most mammals can make vitamin C, but primates cannot. Primates must get vitamin C from their food. By chance, the ancestors of mammals lost the ability to produce vitamin C, but it didn't matter, because they ate lots of fruit. We still have the gene for making vitamin C, but it sits unused in our chromosomes.

Scientists study species such as fruit flies--why? Some politicians think this is ridiculous, and boldly say so. But we share a lot of genes with fruit flies, and we can learn a lot about these genes by studying fruit flies. It is evolution that makes sense of this pattern. It confirms what Darwin said, even though he could not have imagined any of these molecular patterns.

Oklahoma Evolution Workshop, Part Two. What is Science?


The first presenter is Dr. Cecil Lewis, an anthropologist at the University of Oklahoma who uses DNA studies to illuminate human evolutionary history. His topic is the nature of science. Creative expression, critical thinking, writing, and math: if you can do these things, he says, you can do science. Science does not destroy the beauty of the natural world by dissecting it, but helps us to appreciate its beauty more deeply because we understand how it works. Reflecting the ideas of Lee Smolin in The Life of the Cosmos, Lewis said that when we look up into the night sky, we see not just pretty stars but the crucibles in which the elements of which life is made were created.

Students are sometimes surprised that we do not know the answers to everything. (I, for one, have gotten comments from students who didn't like me saying "I don't know.") But that is science: it is always investigating new questions, often replacing old ideas with new ones. And there are always things that we will probably never know. Both scientific and religious suppositions can, by trying to quickly fill in the gaps of our understanding, stifle our quest for understanding. Not understanding something is not necessarily a deficit; it can be an opportunity. He pointed out that we should be careful to distinguish such things as scientific fact and scientific theory: the theory explains the facts. The principles of scientific investigation, which many people think they do not understand, are not all that different from the principles of criminal investigation. We have to accept the fact that we all, scientists or not, are susceptible to bias and error.

We got into a detailed discussion of the differences among theory, hypothesis, organizing principles, coalescence, multiple tiers of theory, and even faith, which was valuable for us but which, I suspect we all agreed, we should not necessarily use in our classroom; the students would tune us out and think that we were just being "theoretical," without knowing what they meant by this. Sort of like the cast of Big Bang Theory. I did not dare throw another term into the mix, one that I consider important: consilience. (Evolution has consilience because it is a conclusion that can be arrived at my numerous separate lines of reasoning based on independent sets of facts.)

I offered a summary of my own during the discussion: We are all like cows, prone to wander away from the path of truth; science is a yoke that keeps us on path, while pulling the cart of knowledge forward. I'm not sure if this means anything, but it is a nice sound bite. I used it in the "scientific mthod" entry in my encyclopedias.

What we certainly do not want to do is to create the impression that science has all the answers. In the minds of our students, we scientists will lose the battle of authority if we try to compete with religion. God, even if God does not exist, will always overwhelm the greatest scientist.

So, how can we bring scientific thinking into the classroom? Certainly not by talking about the philosophy of science. Instead, according to Julie Angle (a science education professor at Oklahoma State University), we should do it by having classes do hands-on activities that promote problem-solving skills. "Engage their minds!" she said. She used the "cube activity:" by looking at numbers and colors and fonts on five sides of a cube, we can infer what is on the sixth side--that is, if there is anything on the sixth side. This activity seems simplistic, but exercises scientific thought well enough that the National Academy of Sciences included it in their book Teaching about Evolution and the Nature of Science.

Julie's second activity was one I'd never seen before: the "check it out" module developed at Indiana University. Just from looking at a few checks from an envelope, students can try to reconstruct a story line about what is happening. It is the kind of reasoning that Perry Mason would use to figure out who the murderer is. The participants found out it isn't quite as easy as you might think, because each group of participants drew out a different subset of checks upon which to base their tentative hypotheses. It is also possible that some of the checks were irrelevant to the story line. When scientists gather observations, we cannot be sure that all of the observations will be useful. When a writer puts a whole lot of irrelevant information in a novel to mislead the reader--as Arturo Perez-Reverte did in Club Dumas--I find it infuriating; but nature does it all the time. From these activities, we experienced the fact that scientific reasoning emerges from reasoning abilities our prehistoric ancestors used to, for example, track animals.

In Julie's final activity, the participants looked at fossilized footprints to reconstruct the story of how the footprints formed. At first, they have incomplete information, and modify their hypotheses as more evidence becomes available.

As Shawn Lawrence Otto explained in Fool Me Twice, the attacks on evolution and other major scientific issues by the general public are not due to a deficit of knowledge, but due to attitudes. By getting students to do some simple scientific hypothesis-testing, we can open their minds to science as a way of thinking. It might be worth the time, even in a course (such as general biology) already brimful of information.

Friday, October 5, 2012

Oklahoma Teachers Evolution Workshop Begins

Tonight, the eighth annual Teachers Evolution Workshop in Oklahoma begins. It is sponsored by Oklahomans for Excellence in Science Education. We are meeting at the University of Oklahoma Biological Station on the north shore of Lake Texoma near Durant. The meeting has been organized by Dr. Richard Broughton of the University of Oklahoma. The participants are teachers and graduate students from Oklahoma and Texas. The first presenter is Dr. Ola Fincke of the University of Oklahoma. She is most famous for studying the sexual selection of damselflies in distress.

Dr. Fincke is telling us about how to incorporate evolutionary concepts into high school biology teaching in such a way that they are less likely to resist it. She suggests that we get the students to ask questions about why organisms have the adaptations that they do: why do so many insects have camouflage? Why do some flowers stink? Students can figure out answers to these questions. Throughout her session, Dr. Fincke used the question-and-discussion technique, to show that it can work. Sometimes the discussion got a little confused, but not for long; but that is a risk you have to take to allow students to investigate and understand for themselves. The principles of phylogeny can be illustrated by genealogical patterns, which the students already understand. A frog is more closely related to a human than to a fish because frogs and humans share a more recent common ancestor, just as siblings share a more recent common ancestor with one another than with a cousin.

Evolution is both fact and theory: the fact that it happens, and the theory that explains how it happens. It happens by natural selection. Humans have used a type of applied selection to produce many varieties of crops and livestock and pets. Students may be surprised to realize that natural selection, as proposed by Darwin and Wallace, is a common-sense principle: how could it not happen? Natural selection is not chance; therefore, evolution is not caused by "random chance." Natural selection is undirected, but is not random!

The fact of evolution is demonstrated by such things as the vestigial hips in whales, which have no hind legs. It is also demonstrated by the fact that it happens all the time around us: new strains of HIV evolve within the bodies of HIV-positive people. Why do icefish in Antarctic waters, which have no hemoglobin in their blood, still have hemoglobin genes--this can be explained only by evolutionary ancestry. Geneticists can take a gene that stimulates eye production from a mouse, and swap it out in place of the fly eye-production gene, and it still works in the fly--this is an experiment that confirms shared ancestry.

In the discussion that followed, we talked about whether teachers should call evolution what it is. This opened up a big political can of worms, which created an open argument among the instructors to which there was no resolution. But, as Dr. Fincke showed, you can teach evolution through common sense and evidence.

Tuesday, October 2, 2012








