The scientific evidence for the fact of evolution is overwhelming. Stephen J. Gould, reflecting the attitude that nothing in science is certain and that all conclusions are tentative, characterized the evidence for evolution as “affirmed to such a high degree that it would be perverse to withhold one’s provisional assent.”
When the big-picture conclusions of evolution are challenged on ideological and pseudoscientific grounds, scientists and defenders of science will often emphasize the high degree of confidence that we currently have in evolutionary theory. This leads to the knee-jerk reaction of evolution deniers to call scientists “arrogant” and “dogmatic.” They confuse a high degree of scientific confidence with dogma, whether deliberately or not, but this tactic can be rhetorically effective.
There are so many slam-dunks for evolution that I have not been able to shake the feeling that if I had the time to walk someone through the best lines of evidence for evolution, and they has even the barest sliver of an open mind, I could convince them of its reality. Or at least I could give them a whopping dose of cognitive dissonance that might later nudge their opinions. On rare occasions I have even been able to do this – just often enough to keep this hopeful belief alive.
But I have also often thought that a valuable resource, for scientists, for skeptics, and for the public, would be a resource, accessible to the public, that documented the best cases for evolution. They are out there, in bits and pieces, if you know where to look. Talkorigins.org is perhaps the best single resource on the web. (Their server has been down recently – something about changing hosts – but you can access it at their backup site for now – http://toarchive.org/). There are also sources that provide responses to creationist nonsense.
What I would like, however, is a resource that brings together the home-runs for evolution and lays them out so that anyone literate enough to read can see the evidence for what it is.
Well, Nature magazine has decided to do just that – they have published with free online access 15 Evolutionary Gems, by Henry Gee, Rory Howlett and Philip Campbell. I will definitely be adding this to my list of goto sites about evlolution.
They hit many of the lines of evidence that I have been using as my best examples for evolution. For example, they discuss Ambulocetus and the evolution of whales, and the exploding fossil evidence for feathered dinosaurs and early birds. These were both examples the creationists liked to complain about there being no transitional fossils linking major groups. Then, beautiful transitional fossils were discovered – and then more and more.
Another great example they discuss is Tiktaalik – a link between tetrapod fish and land-dwelling vertebrates.
They discuss more than the fossil evidence for common descent, and also discuss evidence for natural selection, reproductive isolation, and other mechanisms of evolutionary change. And finally they document some of the best evidence from molecular genetics – such as the structure of genes and how small changes can lead to macroscale changes in morphology.
While I find the Nature article an excellent resource, it is not quite the ultimate resource I would hope for. First, the text is a bit dense for the lay reader. Take this final paragraph of the section on natural selection:
The study shows how the introduction of a predator can cause individuals of a prey species to change their behaviour so as to reduce the risk of predation, but also cause an evolutionary response at the level of the population that differs between the sexes according to their ecology.
That’s not quite as punchy as I would like, given that the stated purpose of this article is to spread evolution to the public. Also – how about some pictures? They discuss transitional fossils – well, a picture of a half-way whale, and some examples of half-birds/half-dinosaurs would be extremely effective.
They also don’t emphasize the importance of the evidence they are presenting enough. Why is Tiktaalik such a home-run for evolution?
I applaud Nature magazine for taking the time to address the public understanding of science and put together such a resource. I only give the execution a B, however. The evidence is so much more compelling than these articles would make it seem.