Found on this website, “Ten Questions to Ask Your Biology Teacher About Evolution” is meant to be a handy guide for students skeptical of evolution. According to this article at The New York Times, science teachers in the US are increasingly having to deal with similar anti-evolution ploys. Reading through the list gave me a few chuckles, so I thought — with only my knowledge from high school biology — I would go through the list and do my best to respond to the various challenges.

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

It appears to be a favorite tactic of anti-evolutionists to try to tie evolutionary biology with the question of the origins of life. The truth is, biological evolution, natural selection, and common ancestry don’t say anything about how life began. Life could have started any number of ways; evolution is merely the proposed mechanism to explain the diversity and robustness of modern life.

That being said, we aren’t completely in the dark as to how life on Earth began. Unfortunately, we may never be able to prove how life on Earth began, but rather only likely ways that it could have began. While there is some controversy as to whether the Miller-Urey experiment replicated the atmospheric conditions of early Earth¹, it did show us the possibility of creating the building blocks of organic life from non-living materials. In that respect, it is still an important experiment, with implications for our search for the origin of life.

Regardless, this is not a criticism of evolution — it’s a criticism of the Miller-Urey experiment.

2. 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?

Life must reach a certain level of complexity before it can start fossilizing. At the very least, it must form some type of rigid outer-membrane, if it is to leave any sign of its existence². To leave an actual fossil (in the popular sense of the word), it would need some type of developed skeletal system. For the first few million years of life’s development, it is highly unlikely that it would have had any of these things.

One possible explanation for the Cambrian explosion is that an intelligent designer created all of the life on Earth at that one point. However, this doesn’t explain why the fossil records for that period don’t match the animals and plants we find populating the Earth today (unless some type of evolution happened between now and then). This explosion also predates the age of the Earth, as accepted by most creationists.

The second, more plausible, explanation is that early life was simply lacking the complexity required to leave a fossil record behind. There is enough evidence, in the form of genetic similarities, pointing to a common ancestor that the Cambrian explosion doesn’t really pose too big an obstacle.

You can read more about the possible causes of the Cambrian explosion here.

3. HOMOLOGY. 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?

This point tries to confuse the issue at hand by calling it circular reasoning — which it is not. The argument is that all life found on our planet shares certain genetic similarities. Species that are otherwise unrelated share certain genes that we would not expect, unless if they had shared a common ancestor at some point in the past. Furthermore, all life on Earth has the same type of genetic code (our DNA all works in the exact same way)³. Because there’s no specific reason why DNA would have to be structured the same way (or even that hereditary information must be passed on by DNA), this is also evidence pointing to a common ancestor.

Biological life does not share similarities merely by definition (as point 3 asserts), but rather shares certain objective physical similarities.

4. VERTEBRATE EMBRYOS. Why do textbooks use drawings of similarities in vertebrate embryos as evidence for their 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?

I don’t know exactly what a “faked drawing” is, but I know that textbooks are often inaccurate, and don’t necessarily reflect the most up-to-date knowledge of the scientific community — especially in the field of evolutionary biology.

This might be a legitimate point against a bad textbook example, but I don’t have enough knowledge to address this. However, it seems unlikely that this one obscure example would be enough to overturn evolution… especially if, as the question states, the examples are faked.

5. 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?

This is an example of a straw man argument — specifically, an over-simplification of what the archaeopteryx represents. It is not a “missing link between dinosaurs and modern birds”, because it can’t be. There are thousands, if not millions of links between all of the different types of dinosaurs, and different types of modern birds. To claim that there’s a single animal that links all of these would be silly.

The archaeopteryx’s significance is that it is a very old “bird” fossil. It’s a missing link in the sense that it has some characteristics that are very similar to modern birds, and some characteristics that are not similar at all. Like all fossils, it supports evolution by showing how life changes over time. It doesn’t have to be the direct ancestor of any known living creature in order to show how drastically different life used to be hundreds of millions of years ago.

More about the archaeopteryx can be found here.

6. 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?

Because the picture illustrates a key example in the way natural selection works. Through selective pressures, life will (over time) adapt to any given environment. Visual camouflage is one of these adaptations. Camouflage gives animals an advantage when hiding from predators, sometimes making their survival more likely, making it more likely that they will survive to reproduce.

I don’t know enough to say definitively whether this is the case with the peppered moth, but there are enough examples out there to make this point seem stupid.

One such example is the biston betularia caterpillar… which just so happens to be the larval developmental stage of the peppered moth⁴:

7. 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?

The ridiculousness in this question comes from the term “net evolution”. The question admits that evolution occurs, by stating that the beaks changed — each time to match the finches’ environment. The implication is that evolution is necessarily a linear process, and therefore change in one direction can be counter-acted with change in another direction.

In reality, evolution is about life adapting to its environment; and when the environment changes, so do the selective pressures acting on the life. If the environment changes, and then reverts to its original state, then the selective pressures (assuming all else remains constant) will also revert to their original state. The fact that the finches’ beaks changed a second time when the drought ended is further proof for evolution!

8. 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?

Though this question is phrased poorly, it seems to be pointing out that the fruit fly example is one of a negative, as opposed to a positive mutation, and therefore (implies) that it is possible for a beneficial mutation to occur.

First, it’s important to note that natural selection does not rely solely on random mutation in order to function (a lot of change is the result of self-imposed selective breeding). Secondly, a vast majority of mutations are non-beneficial mutations. However, as stated in the question, animals with these negative mutations typically don’t live for very long in nature. This helps ensure that the negative mutation is not passed on from generation to generation, and is therefore short-lived. However, when a positive mutation (i.e. one that confers some type of survival advantage) does occur, it helps ensure that it is more likely for that animal to live long enough to reproduce. If this happens for long enough, then the animals with this mutation will slowly start to outnumber those without, due to the conferred survival advantage.

The example (the mutant fruit fly) could possibly be a response to evolutionary critics who claim that it is impossible for a random mutation to result in a more complex organism. By showing that some fruit flies have a third wing (even if it is a non-functional wing), it demonstrates that mutations are capable of increasing the complexity of an organism.

9. HUMAN ORIGINS. Why are artists’ drawings of ape-like 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?

For starters, we don’t use artist renditions of ape-like humans to justify materialistic claims. We use fossils and ancient human artifacts. Artist renditions of human ancestors (sometimes even computer reconstructions) are used for textbooks and newspapers, but this is usually a technique to augment the text and make it more interesting. It is ludicrous to believe that because a science textbook uses an illustration to accompany an article, that all of the original scientific research was based off the same illustrations. This question illustrates just how much some people fail to understand what the scientific method is.

Additionally, “fossil experts” may dispute how humans spread across the globe (time-scale, order, etc.), and who our more immediate ancestors were (in the past few thousand years, or so), but there aren’t any major disputes as to who are distant ancestors were.

10. EVOLUTION A FACT? Why are we told that Darwin’s theory of evolution is a scientific fact — even though many of its claims are based on misrepresentations of the facts?

Evolution is a scientific theory. It is the best mechanism we have to date that explains the genetic diversity of life on Earth. It is consistent with all empirical evidence, and has immense predictive powers. Until we come up with something better, evolution will be the closest thing we have to a fact about how life on Earth developed.

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I hope that you’ve learned something from this; I know that through doing a bit of basic research for this article, I managed to pick up a few things. It’s important to keep in mind that these are modern criticisms leveled against evolution in our classroom, and it’s easy to see how some of these arguments can convince people of the theory of evolution’s “flaws”. This is exactly why critical thinking skills — the ability to take a step back, and examine these questions one-at-a-time — are so important. All it takes is a bit of time, and the willingness to investigate, to uncover how silly the claims against evolution really are.

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• Iconsofevolution.com: Ten questions to ask your biology teacher about evolution.
• NYTimes.com: A Teacher on the Front Lines as Faith and Science Clash