Friday, February 17, 2012

Teaching Evolution in Oklahoma

I got my student evaluation comments back from the evolution course that I taught last fall. My goal is to teach evolutionary science, and in the process it is necessary to undermine creationist claims. But I also wish to make it clear that many scientists have religious beliefs, including Christian beliefs, that do not prevent them from accepting evolutionary science. So I teach science from neither a creationist nor an atheistic perspective. The science, of course, is consistent with atheism, but not with creationism. I make it clear to students that I am not trying to make them quit being Christians.

I think I am being successful. I am hitting right in the middle of the religion spectrum. I bothered one atheist in the class (yes, there are a few in Oklahoma) and one creationist.

The atheist wrote, “As an atheist I wish for all my professors to keep their beliefs to themselves and as someone whose way of life is often scorned, I understand how some of my fellow classmates felt. The professor had no bad intentions with the comments, but they should be left out of the classroom as they will offend no matter how they are phrased.”

A creationist wrote, “I have been studying claims that falsify evolution along with studying for this class. If such claims were taught at the end of the semester it might make us learn more in depth on this topic and to think for ourselves. A mark of an educated man is to entertain an idea without accepting it.”

So for those of you who think that Oklahoma is filled with raging fundamentalists who hate anyone who presents evolution…well, maybe you are right, but the raging fundamentalists do not generally attend universities. The fundamentalist university students are generally very cordial. I think I know who the creationist was, and if I am right, she actually earned the highest grade in the class.

The creationist comment ended with, “P.S. Christ loves you.”

Check out the new YouTube video at This week, Darwin hangs out on the corner of South Trenton Avenue and South Trenton Avenue in Tulsa, Oklahoma, and explains the process of evolutionary convergence.

As ever, I want to hear your comments and questions and responses. I do not have an absolutely predetermined list of blog entries, and would be happy to follow a discussion thread that you introduce.

Friday, February 10, 2012

Why Evolution Looks like It Has an Overall Direction

When directional selection occurs, evolution has a direction. It rapidly chooses the winners. But directional selection usually does not last very long. One would not expect evolution to take a consistent, overall direction over the course of millions of years. What it takes to be a winner at one place and time is not what it takes at another.

And yet, in the popular imagination, the idea persists that humans are the “most evolved” species and that evolution pushes “upward” toward a human-like state. Worms are inferior to us because they did not evolve as much. Chimpanzees are inferior to us also, but not as inferior as worms. Ask somebody about evolution, and they will probably either say it is a plot of the Devil or else they will tell you a story that puts humans up at the top of the stairs. Literally. When the publisher was designing the cover to the paperback version of my first Encyclopedia of Evolution, the artist depicted stairs, with monkeys at the bottom and humans at the top. One cannot blame the artist, who merely drew what he or she had been taught to believe. The publisher, not the author, decides the cover images of a book, but this publisher immediately changed the image when I told them that it was scientifically wrong. More recently, an editor rejected a book manuscript because, he said, evolution is an inevitable upward progression, and since my book did not say this, I obviously did not know what evolution was.

This up-the-stairs version of evolution is the one that harmonizes most easily with old creationist views. In the Middle Ages, the natural world was depicted as a scala naturae, or ladder of nature. Rocks were at the bottom, simple organisms above the rocks, mammals and birds above the simpler animals, humans above all other animals, angels above humans, God above angels.

To many early evolutionary scientists, and to many people today, the scala naturae still exists, only God and the angels have been lopped off the top, and evolution has been substituted for creation. This is essentially the pre-Darwinian version of evolution that was proposed by French biologist (inventor of the word biology) Jean Baptiste de Lamarck. Simple organisms were continually forming themselves out of the mud, then modifying themselves into ever more complex forms until they became human, or something like a human.

Scientists today understand that there is no single, upward staircase of evolutionary progress. All species are equally evolved. Worms are very good at being worms. They can make a living in ways that humans cannot. Chimpanzees are very good at being chimpanzees. In some ways, bacteria can be seen as the most successful life form on this planet. There are more bacteria, and more kinds of bacteria, than any other group of organisms. They live in a greater range of conditions, and have persisted for three and a half billion years. The human species, in contrast, can live in only a narrow range of conditions, and has done so for only about 100,000 years, about 0.003 percent as long as bacteria have existed.

There is, however, no denying that life has seemed to make progress. Three and a half billion years ago, only bacteria (and probably viruses as well) existed. By a billion years ago, there were complex cells as well. Five hundred million years ago, almost all life forms lived in the oceans. By four hundred million years ago, some life forms lived on land. Bigger and more complex organisms have evolved over time. An evolutionary story is unfolding. If this isn’t progress, what is?

The reason that evolution seems to lead to progress is that evolution accumulates successes. Bacteria were successful. So also were the more complex cells that evolved from them. Natural selection kept both of them. Plants have been successful. So have animals. Natural selection has kept both of them. The Tree of Life gets bigger and bigger. Also, natural selection capitalizes upon whatever works, whether it is greater complexity or greater simplicity, whether it is life on land or life in the sea. Natural selection capitalizes upon opportunity. Each step toward greater complexity opened up new possibilities. Over evolutionary time, successes and complexities have accumulated. Some of the stories have vanished, such as the saga of the dinosaurs. But most of them are still here, to astonish us today as we behold and study them.

Check out the new YouTube video available at (Channel, StanEvolve). This week it is Charles Darwin explaining that humans, bananas, grapes, and chickens all have a common evolutionary ancestor.

Also remember to submit any comments, especially about topics you would like to discuss.

This entry appears in my book Life of Earth: Portrait of a Beautiful, Middle-Aged, Stressed-Out World, published by Prometheus Books.

Friday, February 3, 2012

Memes Are Everywhere

At the end of 2011, I wrote about the cultural and memetic evolution of the economy. Most of you probably understood what I meant. But I would like to include here a summary of the idea of memetic evolution, which I have extracted from Life of Earth: Portrait of a Beautiful, Middle-Aged, Stressed-Out World, published last year.

Humans exist in a sea of memes. For example, music is memes. Somebody invents a new piece of music, and performs it. A successful set of music memes gets performed by others. Because of memetic selection, there are more copies of Dvořák’s New World Symphony on the market than anything written by Johann Ditters von Dittersdorf. The reason that most folk songs are good is that they have endured centuries of memetic selection. Memetic selection appears to have condemned the deliberately atonal academic music of the twentieth century, such as the works of Anton Webern and Witold Lutosławski, to long-term obscurity. (You’ve never heard of them? That is my point.)

To a certain extent, memetic evolution is arbitrary. But memes, like genes, must correspond to underlying reality. In the case of music, harmonic consonance creates more of a feeling of peace and enjoyment than harmonic dissonance. Consonance results when the vibrations of different notes match one another’s overtone series. Humans desire more than just peace and enjoyment from their music, however, and a certain amount of dissonance is necessary to create a flow of musical events; resolution of a dissonance is part of the story of a piece of music. You cannot change the physical basis of consonance and dissonance any more than you can change the law of gravity. Rhythm is also based on the natural world and may be even more primal than harmony. The powerful drum beats of Japanese taiko and Lakota wacipi music bring back fetal memories of your mother’s heartbeat.

Computer programs are memes. Computer programmers commonly use evolutionary algorithms that consciously imitate natural selection. The program begins with a simple set of instructions, then generates slight variations, tries them out, then retains the ones that work the best. The weasel program is a simple example of an evolutionary algorithm. The computer iterates this process over and over, producing complex results that were designed not by the programmer but by memetic evolution within the computer. Old movies with battle scenes required (and boasted of) “a cast of thousands,” but modern movies often have such large-scale scenes generated by computer programs that use evolutionary algorithms.

Literature is memes. The marketplace is an arena of memetic evolution, as people choose some products over others. Science is memes, as scientists try out hypotheses, retaining and propagating the ones that successfully explain the natural world. Everywhere you look, there are memes, memes, and more memes, all of them evolving.

Check out the new YouTube video available soon on my YouTube Channel (StanEvolve). The video may not be available right away. Also remember to submit any comments, especially about topics you would like to discuss for this blog.

For more information about Life of Earth: Portrait of a Beautiful, Middle-Aged, Stressed-Out World, which has now been published in Chinese as well as English, see my website.