Dinosaur Adventure, Part 1

I had three choices of how to spend the weekend of September 23. I could have gone to the field meeting of the Oklahoma Academy of Sciences; I could have gone to the Prairie Festival at the Land Institute; or I could go look at dinosaur footprints in Dinosaur Valley State Park in Texas. I chose the third option. This was the weekend when I had a chance to meet with some of the people who know more about these footprints than anyone else in the world. As an evolution educator, author, and blogger, this was an opportunity I did not want to miss.

I visited Dinosaur Valley State Park last March, as described earlier in this blog (see here and here), but on the previous visit I was by myself and the river was still flowing. Some of the photos I posted from that visit show dinosaur footprints underwater. This time, in addition to my chance to meet the experts, the river was nearly dry. Texas has had a long drought, costing the state economy over $5 billion, and to which the April 21, 2011 day of prayer proclaimed by Governor Rick Perry has not brought an end. Such a drought is a disaster in all ways except one: it exposed the bed of the Paluxy River, which has dinosaur footprints.

They say that you can throw a rock anywhere in Texas and it will hit a barbecue place that is better than anyplace else in the world. I entered a barbecue place, where a sign on the wall said, “Cowboys: No shirt, no service; Cowgirls: No shirt, free beer.” Yep, I’m in Texas all right. In reality, this place had no beer and everyone was clothed. I was with Glen Kuban, who has an expert knowledge of the Paluxy River dinosaur footprints.

As we ate our brisket, Glen told me his story. Our lives were strangely parallel: we are the same age, we graduated the same year, and we made the same migration from creationist fundamentalism to Christian theistic evolution at about the same time. We were both elected as Fellows of the American Scientific Affiliation, a Christian scientific organization, the same year. The difference is that, while my abandonment of creationism involved learning about research done by other people, Glen’s abandonment of creationism resulted directly from his research into one of creationism’s most notorious claims. Also, I am a professor, while Glen sells molds and casts of fossils and fossilized footprints, primarily to museum gift shops. Glen is sort of a latter-day Alfred Russel Wallace or Henry Walter Bates, the nineteenth-century naturalists who funded their travels and work by selling specimens they collected in the tropics. He also maintains a website with lots of Paluxy information.

Here is the notorious creationist claim. In 1982, a creationist named Carl Baugh was looking around at the fossilized dinosaur footprints in the bed of the Paluxy River. He found some impressions that, to him, looked like they might be human footprints. He also obtained some footprints that looked like very flat carved human footprints (see earlier blog entries above). Whether he carved them himself or credulously obtained them from someone else I am not prepared to say. If humans and dinosaurs left footprints in the same mud at the same time, then the entire evolutionary time scale is off. This does not necessarily prove the creationist version of Earth history; after all, why would dinosaurs and humans have been walking leisurely along in the mud in the middle of the Flood of Noah? But, thought a young Glen Kuban, the Paluxy footprints would be a really important thing to study.

So in 1980 Glen began to study the footprints. He quickly discovered that the so-called human footprints that were still in the riverbed were actually dinosaur footprints partially obscured by mud when they were originally made and afterwards. And another discovery surprised him. He found that the creationists, even those who used the “Paluxy man prints” as evidence of creationism, did not seem to be interested in studying the Paluxy prints. They seemed to be satisfied with hearsay and content to accept Baugh’s carved prints as evidence sufficient to overturn all of evolutionary science. Glen may be the only person in the world whose view of creationism was changed by actually studying the Paluxy dinosaur footprints. It appears that some prominent creationist writers and speakers continued to tout the “man-prints” even after they knew, and admitted, that the man-prints were fake. We’re not saying who the creationists are.

I looked forward to the next day, September 24, on which I would work in the dry riverbed with Glen and with another expert, Mike O’Brien. To be continued. This month's blog entries will be about the dinosaur footprints.

I have also posted a YouTube video in which Charles Darwin visits the dinosaur footprints.

I also maintain a religion blog which I have not heavily advertised because I want to keep this evolution blog and my website focused on science.

A Serious Humorous Interlude

Please remember to visit my YouTube site for videos in which I explain evolutionary concepts in the guise of Charles Darwin. You’ll be glad you did!

This is a humorous poem that takes a backward look at human evolution. I first saw it when I was in high school, back when I was a creationist. I enjoyed it then and I enjoy it now.

Darwin’s Mistake
(Evolution—From the Monkey’s Viewpoint)

Three monkeys sat in a coconut tree Discussing things as they are said to be.

Said one to the others, “Now listen, you two, There’s a rumor around that can’t be true, That man descended from our noble race. The very idea is a great disgrace.

“No monkey has ever deserted his wife, Starved her babies and ruined her life. And you’ve never known a mother monk To leave her babies with others to bunk Or pass from one on to another Till they scarcely know who is their mother.

“And another thing you’ll never see, A monk build a fence round a coconut tree, And let the coconuts go to waste, Forbidding all other monks to taste. Why, if I put a fence around a tree, Starvation will force you to steal from me!

“Here’s another thing a monkey won’t do, Go out at night and get on a stew, Or use a gun or club or knife To take some other monkey’s life.

“Yes, man descended, the ornery cuss, But, brother, he didn’t descend from us!”

This poem has appeared in many places on the web, without attribution of authorship. One website, however, identifies the author as Gilliam S. Weaver and tells his story.

Are We the Inevitable Products of Mathematical Equations?

I have just finished reading Martin Nowak’s Super Cooperators, a book written with Roger Highfield. Nowak is a biomathematician at Harvard. He has spent a career designing mathematical models that demonstrate the conditions under which altruism can evolve. Altruism is when one animal is nice to another animal of the same species.

Nowak’s view of the world resonates with my spirit. He sees the natural world as full of cooperation. Cooperation is at least as important as the “survival of the fittest,” which Darwinism is often portrayed to be. I find his viewpoint inspiring just like the viewpoint of Lynn Margulis (whom Nowak hardly mentions). The fact that Nowak is a fellow devotee of the music of Gustav Mahler doesn’t hurt any either.

And some important results have emerged from Nowak’s mathematical models. I cannot summarize all of them, but one that I remember is the following. In simple, direct interactions, when a cooperator and a defector come in contact, the defector always wins. That is, the cooperator becomes a sucker for offering help that is not reciprocated. In large populations in which all the animals are equally likely to come in contact, altruism doesn’t have a chance. But in populations in which small groups can form, where animals can choose their friends, so to speak, altruistic groups can emerge. And when they do, they can beat out the pathetic defectors every time, at least temporarily. This is particularly the case in animal societies where the animals know the reputations of other animals, which is something they can do within small groups. This is, in fact, probably the most important way in which altruism evolved. It is an example of multi-level selection: selection among groups within a larger population.

However, in one sense, I consider Nowak’s work to be unrealistic. He begins the book by expressing his feeling that all of truth can be expressed precisely by mathematics. Toward the end of the book, he claims that his equations would be true anywhere in the universe. He admits that his conclusions are not too different from beliefs, such as the Golden Rule, found in traditional religions. But he still thinks he has made a monumental universal discovery. “Now, for the first time, aspects of these powerful ideas [from religion] have been quantified in experiments, captured in equations, and enshrined in science.” He seems to mean that ideas such as the Golden Rule are really true for the first time in the history of the universe as a result of his mathematical simulations.

Nowak’s mathematical approach is unrealistic because it omits all historical contingency. In Nowak’s models, animals are cooperators or defectors for logical reasons. So maybe his equations would work reliably on the planet Vulcan. But they cannot be relied upon for human behavior. The equations mirror many, but not all, aspects of human behavior. The primary historical contingency is religion. The memes of religion have parasitized the human mind to such an extent that, throughout human history, many people have considered it a religious duty, absent any benefit, and more important than life itself, to bring death and destruction to others. Nowak’s models do not include the thirst for evil that is so common in human motivation, in which loss is reward because it ensures eternal life in a heaven.

Almost Everything Evolves

The following appears in my book, Life of Earth: Portrait of a Beautiful, Middle-Aged, Stressed-Out World, published earlier this year by Prometheus Books. I also just finished lecturing about this subject in my evolution class this morning.

The process of natural selection involves these elements: variation; reproduction; limitation. We usually think of genes in this context: natural selection favors the best genes, which must cooperate with other genes to create the best organisms, within populations. But there is nothing about the process of natural selection that requires that the evolvers be organisms. As it turns out, almost everything evolves.

Evolutionary biologist Richard Dawkins pointed out that it is not just genes, but any kind of information, that evolve. Dawkins called non-genetic pieces of information memes, a counterpart to genes. The result is cultural evolution, the counterpart to biological evolution. Cultural evolution turns out to strongly affect biological evolution, because for most complex animals, the most important part of the environment is the culture of its species.

All that is necessary for something to evolve, according to Dawkins, is a faithful but imperfect copying mechanism for instructions, and a system that is ready to obey those instructions. DNA and the cell fulfill these requirements. So do computer programs and computers. And so do memes and the human mind.

A meme can be as simple as an idea. Somebody thinks of an idea, which is a mutant form of some earlier idea that somebody else had. This is the variation step. In the population of human minds, this new idea contributes to the memetic variation of ideas that is available in the culture. The person then tells the idea to another person, or publishes it or sends it. This is the reproduction step. The human mind has a limited capacity for recalling and using ideas. This is the limitation step. The result is that the most successful ideas get propagated in the culture. The less successful ideas remain rare, the arcane knowledge of a few people, or become extinct. The most successful ideas are not necessarily the best ideas, but just the ones that people like the most. For every good and true idea, there are probably a dozen bad and stupid ideas that rattle around in people’s brains. Many of us try to eradicate the bad ideas from our minds, but with only partial success.

Usually, memes are parts of complex sets. As a result, memetic selection not only favors the memes that are most useful to the animals that think or learn them, but work best as part of a memetic set. Human languages are sets of memes. All humans have an innate capacity for language, but they always learn their particular languages from other humans. The result is that languages evolve.

Evolution is like a branching tree. The branches become separate species when the animals no longer recognize one another as potential mates. Languages have the same pattern. The main Indo-European branch of evolution split into smaller branches, one of which was Latin, which then evolved into smaller branches such as Iberian and French, which evolved into twigs such as when Iberian evolved into Spanish, Portuguese, and Catalan. Mutations accumulate in languages, and memetic selection preserves the variations that are most useful or most appealing to the speakers. After awhile, so much divergence has occurred that the speakers may be mutually unintelligible, as when a speaker of Spanish tries to understand French, or when a Parisian pretends he cannot understand a Frenchman from Dijon. An awareness of the branching evolutionary pattern of languages grew during the nineteenth century at the same time as the awareness of biological evolution. A successful word-meme is one that functions best as part of a language, not necessarily by itself.

Let the Earth Bring Forth Plants

The first chapter of Genesis in the Old Testament is a hymn to an orderly and bountiful cosmos. Surprisingly enough, it begins by describing a universe that existed before God began to create. This universe had two problems: it was chaotic and empty (the old King James English says “formless and void”). During the six days of creation, according to this hymn, God solved these two problems. On the first three days, he brought order into the heavenly, the fluid, and the earthly realms: making light separate from darkness, air separate from water, and land separate from sea. On the last three days, he filled the heavenly, fluid, and earthly realms: filling the heavens with stars, the water and air with fish and birds, and the earth with “creeping things.” It is obvious to everyone except creationists that this chapter was never, even when it was first written, intended as an historical description of the history of the cosmos. It described the work of creation as categories, not as a timeline. Astronomy, geology, and biology now provide explanations for the processes of creation described poetically in Genesis.

As beautiful as it is, however, the first chapter of Genesis reflects the human-centered viewpoint of the time in which it was written (about 500 BCE), a viewpoint to which most modern people still cling, even if they are not particularly religious. This viewpoint puts humans at the pinnacle of creation, something that most people (including those who think they understand evolution) still do. The writer of Genesis did not praise humans as much as you might think, however: humans were created on the same “day” as all of the creeping things. Humans did not even get their own special day of creation. But Genesis clearly states that humans rule all of the creation, and uses terms that imply that humans have the right to conquer and rape the creation.

One example of this domination is the creation of plants. Plants appear on Day 3, along with the dry land. That is, in this hymn, plants are not considered to be living organisms; they are just a part of the landscape. In a sense this is true: any landscape without plants is quickly ravaged by erosion, as I have explained in my book Green Planet. But the God of Genesis does not give plants any role of their own other than to be eaten by animals. Behold, he says on Day 6, I have given you every green plant for food.

But plants are organisms. They’ve got to make a living like everybody else. Plants have populations that evolve. It is not in the interests of the plants to just sit there and allow themselves to be eaten by animals. The plants that natural selection favors are those that can avoid getting eaten by animals.

As a result, the world is not just a big salad bowl. Nearly every wild plant has several or many characteristics that make it unpalatable to animals. In some cases, plant defenses are clearly visible: spines on cactuses, stinging hairs on nettles. In other cases, the defenses are invisible but even more effective. Most plants have leaves that are at least mildly toxic. Plants produce thousands of different kinds of chemicals that are toxic to animals. Some of them accumulate poisonous mineral ions out of the soil and put them in little sacs (vacuoles) in the leaf cells, where the poisons will not harm the leaves but will harm any animal that chews the leaf, breaking open the sacs of poison.

Humans have bred crop and garden plants that are palatable, and this has created for most of us the illusion that plants are just waiting to be eaten. They are like Al Capp’s cartoon shmoos, which fall all over themselves in an attempt to get eaten, with stupid grins on their faces. Be warned: wild plants do not have brains, they are in fact stupid, but evolution has produced in them many defenses that appear to those who study them to be very clever. Wild relatives of crop plants, such as beans, tomatoes, and potatoes, are poisonous. Some tribal peoples subsist on wild cassava. But they have to boil and squeeze the cassava pulp to remove poisons first.

Even the parts of plants that are not poisonous are not simple gifts to feed animals. Many species of plants produce soft, colorful, sweet, fragrant fruits. These fruits make themselves very visible to animals, and reward the animals for eating them. Such fruits, abundant and hanging low, are in fact part of our image of paradise. (The word paradise itself comes from the Persian word pairidaeza, a walled garden.) But the plants have something to gain from this arrangement. The fruits have seeds in them. Animals usually eat the entire fruit, swallowing the seeds. It is just too much work for the animal to pick out the seeds, especially since the pulp clings closely to them. Plants cannot move around and carry their seeds to new locations, nor can the seeds move under their own power. Many plants therefore get animals to carry their seeds to new places by getting the animals to eat them. They pay the animals by feeding them the sweet and nourishing pulp of the fruit. The animals deposit the seeds, along with a pile of fertilizer, far away from the parent tree. Both the plants and the animals benefit. In other cases, plants take advantage of the animals. Seeds with spiky burs entangle the fur of mammals, which carry the seeds to a new location while they are trying to scrape the burs from their fur.

Plants and herbivores are involved in what has been called an arms race. Plants evolve defenses, and herbivores evolve ways of circumventing the defenses. Plants then evolve new defenses, and herbivores evolve ways of circumventing these as well. For both the plants and the animals, this interaction is expensive. The plants have to use their energy and molecules to make poisons rather than using them to grow new leaves and roots. Animals have to use energy and molecules to digest the plants despite their defenses. In human societies, spending more money on defense means spending less on growth (such as infrastructure and education). Plants and animals find themselves in the same predicament as humans do.

This is coevolution: natural selection favors plants that are prickly or poisonous, but not so much that they cannot grow, and animals that can tolerate or avoid the poisons, but not so much that they divert too much energy away from their own metabolism, movement, and growth.

One you have learned about the coevolutionary relationship between herbivores and plants, you can never again look at a serene natural landscape the same way as before. The Lord is my shepherd, said the psalmist, leading sheep into green pastures. The psalmist also said that God prepared a table for him in the presence of his enemies. But the psalmist could not have guessed that, to a certain extent, the green pastures themselves were one of the enemies. There never was a natural Garden of Eden in which all the plants were uncomplicatedly nutritious.

This entry was part of my book Life of Earth: Portrait of a Beautiful, Middle-Aged, Stressed-Out World, published earlier this year by Prometheus Books.