The folks over at Science and Religion Today were interested in our study on graduate student conceptions of evolution, and asked me to give some thoughts on the question “How detailed an understanding of evolution do we need?” Here is my answer.

If by “we” you mean “scientists,” then it is extremely important that we gain as detailed an understanding of evolutionary mechanisms and the patterns of diversification that they have produced as we can. The question of the origins of biological diversity is a fundamental one, and obtaining as complete an answer as possible is a primary goal of the life sciences. Evolution is to biology what the periodic table is to chemistry: It makes sense of otherwise disconnected pieces of information and provides the framework for further investigation.

If you mean “students enrolled in science programs,” either undergraduates or grad students (as in our study), then I would say that a good working knowledge of evolutionary theory, though not a full understanding of all its nuances, should be a major goal. Again, evolution is the unifying principle of biology, and without grasping how it works, one cannot make sense of the history and current diversity of life on this planet. Most science majors will not go on to become professional evolutionary researchers, but many will become teachers, researchers in industry or government, consultants, doctors, politicians, or any of a wide range of careers in which a working knowledge of evolution is important. As I tell the students in my course when I discuss why they should work hard to understand evolution, if the goal is to have a scientifically literate public, who but the future teachers and other educated citizens can make that happen?

If you mean “members of the public at large,” then I would say that at least a basic understanding of evolution is still important, if not for academic reasons then for pragmatic ones. Evolutionary knowledge informs decisions in medicine, agriculture, resource management, and many other areas. If, as I am sure most biologists feel, an understanding of evolution is important at all levels, then it is important that it be taught—and taught properly—from elementary school to graduate school. A population that recognizes the standing and relevance of evolutionary principles is one that will support this endeavor, whereas one that misunderstands or fears evolutionary biology will seek to undermine science education. There is an inevitable feedback loop in this regard, and effective education is the way to make it a positive one.

How detailed an understanding of evolution do we need? It depends on who “we” are—but “very little” is not the answer in any case.

A commenter on my other blog at ScientificBlogging (basically a subset of posts from this one) seems to have objected to the claim that evolutionary science makes predictions.

gimme 5 examples of predictions, i mean real predictions: not fit the model hogwash

Marilyn

Here’s a list that I put together in around 10 minutes.

1) That a transitional fossil linking fishes and tetrapods would be found in rocks of a specific age (from the Devonian) and formed in freshwater environments. CONFIRMED.

2) That human chromosome 2 would show clear signs of fusion of two chromosomes that are separate in other apes when examined at the level of DNA sequence. CONFIRMED.

3) That genes for producing features thought to have existed in ancestors but absent in descendants will still be found when genomes are examined in detail or even through atavism. CONFIRMED (see also the paper mentioned in the original post).

4) That proteins in the bacterial flagellum will turn out to be similar to proteins with other functions. CONFIRMED.

And a classic…

5) Darwin predicted that the evidence would show that humans evolved in Africa based on similarities to other apes. CONFIRMED.

Others have put together some decent videos about this as well.

Want to share your own favourite examples?

Today I gave my lecture on mammal diversity and evolution in the 4th year vertebrate course. We have been talking a fair bit about paraphyletic groups, common vs. scientific names, and so on. Within this context, we explored the issue of whether we’re “descended from monkeys”, by taking a look at a phylogeny of relevant primates:

The issues that we noted were:

1. “Apes”, as defined as orangutans, gorillas, and chimps, but not humans, is paraphyletic. In other words, either “apes” is not a scientifically defensible term or else it must include humans.
2. “Monkeys” is paraphyletic, and in particular Old World monkeys are more closely related to “apes” than they are to New World monkeys. (Also, humans and Old World monkeys are equally closely related to New World monkeys).
3. We are not descended from any modern “monkeys” or “apes”, rather we share common ancestors with them. (In that sense, the answer is NO to whether we’re descended from monkeys).
4. The last ancestor shared by all apes (including humans) would itself probably have qualified as an ape. (In that sense, the answer is YES we are descended from an ape, but not any of the modern species).
5. For “monkeys” not to be problematic, it would have to include apes. In that sense, we would be apes AND monkeys. (And, for that matter, we’re also lobe-finned fishes). As above, it may very well be that the ancestor of all monkeys and apes (the very bottom node on the phylogeny) would have been considered a monkey, and therefore YES we are descended from a monkey (but again, not any modern species).

After class, one of my students emailed me a link to this video, which explores the issues nicely. The author takes a cladistic approach and concludes that we are descended from monkeys for the reasons listed above.

What do you think?