Ten Questions to Ask Your Biology Teacher

The Ten questions were written by Jonathan Wells, author of the creationist book Icons of Evolution. These questions have been going around for awhile and many people have responded. So here's my attempt.

• The origins of life. Why do textbooks claim that the 1953 Miller-Urey experiment shows how life's building blocks may have formed on Earth - when conditions on the early Earth were probably nothing like those used in the experiment, and the origin of life remains a mystery?

The origin of life may be hotly debated, but it has nothing to do with evolution, or with Darwin's theory of natural selection. Go ahead and argue that one all you want.

• Darwin's tree of life. Why don't textbooks discuss the "Cambrian explosion," in which all major animal groups appear together in the fossil record fully formed instead of branching from a common ancestor - thus contradicting the evolutionary tree of life?

*poking around in bookshelves*
Did I really get rid of my biology textbooks? oh well, they were old editions anyway. So, Wells has bad textbooks or has a reading comprehension problem. The major vertebrate groups as we know them, just as an example, are all post Cambrian. Sorry!

• Why do textbooks define homology as similarity due to common ancestry, then claim that it is evidence for common ancestry -- a circular argument masquerading as scientific evidence?

Easy one. They don't. Similarity of structure can be due to common ancestry or convergence, so there is no assumption that similar structure implies common ancestry. Also, Mr. Wells, you have to update your terms a little. The word you want is synapomorphies. Synapomorphies are shared derived traits, which in cladistic analysis are used to define taxonomic groups. Deciding which traits are to be defined as synapomorphies is part of a detailed and methodical process. The traits must be derived (meaning, different from what would be found in a hypothetical ancestor) and it helps if they are complex and specialized, such as a feather. Taxonomists collect many types of evidence, including morphology and genetic evidence, and conduct a complex analysis that yields a diagram of the most likely phylogenetic relationships.

• Vertebrate embryos. Why do textbooks use drawings of similarities in vertebrate embryos as evidence for common ancestry - even though biologists have known for over a century that vertebrate embryos are not most similar in their early stages, and the drawings are faked?

Well, now I know for sure he has crappy textbooks. Maybe the textbooks wouldn't be so crappy if school boards weren't forced to select books with creationist crap in them. Call me crazy. I believe he is referring to Haeckel's drawings of embryos, which were used to teach the idea that "Ontogeny recapitulates phylogeny." His drawings weren't "faked", they were just misinterpreted. Even when I was in high school in a much crappier biology course than you can find even in Kansas, I learned that the ontogeny-recapitulates-phylogeny thing was crap. It wasn't in my high school textbooks twenty years ago. I hope it's not in any textbooks now. All of that being said, I've taken graduate courses in developmental biology, and yes ... the more closely related vertebrates are, the more closely they resemble each other in their early developmental stages.

• The archaeopteryx. Why do textbooks portray this fossil as the missing link between dinosaurs and modern birds - even though modern birds are probably not descended from it, and its supposed ancestors do not appear until millions of years after it?

The idea of the missing link is no longer seriously discussed in evolutionary circles, partly due to the influence of cladistics. To put it in simple terms, the likelihood of finding the fossil of the actual individual that was the common ancestor of different species is infinitesimally small. The "missing link" is now referred to as the "hypothetical ancestor," and we now assume that it is impossible to identify any given fossil as this ancestor. Therefore, you can point to any fossil and claim that it has no living descendants, and no scientist will be able to dispute it. This does not in any way weaken the case for evolution.

As for Archeopteryx, it's a damn beautiful fossil and everyone should look at it and marvel at it.

• Peppered moths. Why do textbooks use pictures of peppered moths camouflaged on tree trunks as evidence for natural selection - when biologists have known since the 1980s that the moths don't normally rest on tree trunks, and all the pictures have been staged?

Did you expect scientists to be out with cameras photographing the event as it happened? Of course the photos were posed. And even creationists admit that evolution happens on this scale. I'll alert the ER that Wells will be arriving with a gunshot wound to his foot.

• Darwin's finches. Why do textbooks claim that beak changes in Galapagos finches during a severe drought can explain the origin of species by natural selection - even though the changes were reversed after the drought ended, and no net evolution occurred?

So what you're saying is, environmental pressures caused beaks to change, then when the environmental pressures changed, the beaks changed back, and this is evidence against evolution because ... why exactly? I think Mr. Wells will be needing a wheelchair.

• Mutant fruit flies. Why do textbooks use fruit flies with an extra pair of wings as evidence that DNA mutations can supply raw materials for evolution - even though the extra wings have no muscles and these disabled mutants cannot survive outside the laboratory?

Because the majority of mutations are either neutral or detrimental. next?

• Human origins. Why are artists' drawings of apelike humans used to justify materialistic claims that we are just animals and our existence is a mere accident - when fossil experts cannot even agree on who our supposed ancestors were or what they looked like?

Once again, Mr Wells has either been paging through textbooks from either the 1950s or from the new batch being ordered for Kansas public schools. In fact, I am not even sure what he is asking. There is a very strong fossil record of early humans. The scientists who discover these fossils fight tooth and nail over ancestry, because of academic politics. However, all agree that in the past, many different hominids wandered the earth, who looked similar to us but were clearly a different species. They also agree that we are descended from creatures like this. They may not agree whether we descended from A. afarensis or another line, but that's splitting hairs. Biologically, we are animals. We are not plants, we are not rocks, we are not fungi. We have brains, hearts, lungs, bones, and muscles, like every other vertebrate on the planet. If you want to put humans in a special category of animal, that's up to you, but to deny we are animals is ludicrous.

• Evolution as a fact. Why are students told that Darwin's theory of evolution is a scientific fact - even though many of its claims are based on misrepresentations of the facts?

The theory of evolution isn't all about Darwin, and hasn't been for many decades. Darwin gave us a mountain of evidence in favor of evolution, and in the following century, additional information, especially from genetics, has turned the mountain into a mountain range. Our job as scientists is to look at the evidence and explain it in the simplest, most logical way. Evolution is far and away the best explanation for the evidence we have. Nitpicking at a stone here and there can't take down the mountain.


So there you are. I think it's great if students want to discuss ideas about evolution in class. It is too bad someone could not come up with better questions. These aren't meant to stimulate honest debate. They're written under the assumption that there is a conspiracy by biologists to dupe naive students with fake evidence. They're written so that students can antagonize teachers, not to help them learn. Then again, if teachers are prepared, maybe they can seize the opportunity to teach actual critical thinking.