Starting today, posting will be light for a while as I’m embarking on the Great Southern Evolution, Atheism, and Barbecue Tour. I plan to resume regular posting around February 11, but am hoping that Greg and Matthew will step into the breach.
Here’s another from the “true facts” series of videos: “True facts about leaf katydids.” The dialogue is amusing, but the photographs and videos are amazing.
Leaf katydids are, to me, the paradigm of natural selection, for they show how close selection can take an animal toward an “optimum” phenotype. It’s not often that we can see how close selection in nature has taken an animal towards “perfection,” and there are many factors preventing the attainment of that perfection: the availability of the right mutations, constraints on development that prevent perfect mimicry because those genes have other roles in the organism, and so on. And in most cases humans can’t even discern what the “optimum” really is. At least in cases of mimicry like this, we know what the optimum is (precise mimicry of a leaf to protect one from predators) and can see that those other factors haven’t been important.
Some day I’ll do a post on cases in which natural selection has taken organisms almost right to their optimum.