We don’t get to see our granddaughter this morning — she’s getting her pediatric checkup today — so while sitting on my thumbs in my hotel room this morning, I threw together a video on the problem of homology, as misrepresented by Jonathan Wells and Paul Nelson. Seriously, they get it all wrong with tendentious misrepresentations.
There is a real problem of homology, because homology is rendered difficult to see by standard, naturalistic evolutionary processess. Wells and Nelson get it all exactly backwards. That homologies are obscured by the nature of evolutionary change is what we’d expect from evolutionary theory. It’s like how bioinformaticians will talk about the problem of long branch attraction; it’s a real problem, but it doesn’t imply that evolution is wrong, because it’s an expected effect of evolutionary change.
Likewise, evo-devo people will write long papers about the problem of homology, because the action of evolution obscures homologies and we have to struggle to see beyond it. Only a pair of buffoons would argue that it means evolution is false.
I don’t have a script for this one, because it’s just me talking extemporaneously in a dull hotel room, sorry. But I do have a good quote from Mary Jane West-Eberhard, and that’ll have to do if you don’t have the patience to listen to some geezer talking at a camera.
Changing characters do not march ever outward along the branches of a phylogenetic tree. While homology, parallelism, and convergence remain useful conceptual guides, they need to be seen against a background of continual reshuffling with a particulate, mosaic phenotype that renders linear terms like parallelism and convergence only approximate, and potentially misleading, descriptions of evolution.
Does a concept of mixed or partial homology just make a mess of homology? In fact, evolution makes a mess of homology.
Mary Jane West-Eberhard