Amusing Recollections from Evolutionary Biology
I took a course in Evolutionary Biology over the summer and kept note of quotes I found amusing as I studied. While most of the course dealt with observable, scientific, change-within-a-created-kind evolution, we did of course cover the whole common-descent evolution thing as well.
While we were studying development across the plant and animals kingdoms, MADS genes and HOX genes were discussed. These genes work in extremely similar ways to direct the differentiation of cells within a young embryo. In plant embryos, MADS genes do the job, whereas in animals, HOX genes get it done. However, according to phylogeny, these genes evolved after plants and animals had already diverged from each other. So despite the fact that MADS genes and HOX genes are very similar, evolutionary biologists believe they evolved separately.
The textbook makes the following remarks about this phenomenon:
"The same combinatorial principle has evolved both in MADS genes and HOX genes through completely independent evolutionary paths - a beautiful example of convergence, and strong evidence for the claim that this method of control must be an extremely good one" (Stearns & Hoekstra, 2005, p. 145).
Not all of our learning was done from a textbook. In one of the videos assigned to us, a biologist reflected with unmistakable awe on the evolution of cetaceans:
"Whales show us the shear creative power of evolution. I mean, from a wolf-life mammal to a whale in ten or so million years, is, is amazing."
That was from a video from PBS entitled "How Do We Know Evolution Happens," by the way.
Late in the course, we discussed coevolution, resulting in complex relationships between species (and often, even kingdoms or domains). One such relationship is symbiosis, and it includes the mutualistic relationship between the inseparable fungus and algae in a lichen (the two even reproduce together), mycorrhizal fungi and plants, and the grouper and wrasse fishes, in which the wrasse plays a dentist who cleans the grouper's teeth. In an even more complex twist on that latter relationship, a fish species called the blenny 'has evolved' to resemble the wrasse, so that it can safely parasitize the grouper by literally biting a chunk out of its flesh. While the grouper and wrasse are symbiotic, the blenny has taken advantage of their relationship and exploited it to his advantage.
Such remarkably complex relationships between organisms are difficult to explain by evolution, so an entire subject - coevolution - is devoted to explaining it. Coevolution is a complex subject, and coevolutionary relationships are defined by four criteria they must match. One of these criteria is described in the textbook as follows:
"The design criterion. We could claim that an interaction coevolved if it were complicated, unusual, and precise, like something an engineer might design - for example, an interaction like that of the grouper, wrasse, and blenny" (Stearns & Hoekstra, 2005, p. 476; emphasis original).
This coming from a textbook that begins and ends with comments on 'unscientific' doubters of evolution! Anyhow, phrases like "a beautiful example," "sheer creative power," and "like something an engineer might design" seem rather out-of-place in this evolutionary context, and sound characteristic of something from creationist literature.
Stearns & Hoekstra. (2005). Evolution: An Introduction. New York, NY: Oxford University Press.
PBS evolution video clip: (skip ahead to 5:58 to watch the wolf-like creature magically transform into a beautiful orca!)