I’ve been trying to put together my reader for a new unit (class) on human evolution at Macquarie University that I’ll be doing next semester. As usual, I’m doing this at the 11th hour, but this should be my last completely new, never-before-taught-at-my-university class for at least a year (I hope). In the process of checking out the most recent edition of my favorite human evolution journals, I happened across an odd and really thoughtful piece by Prof. Kenneth Weiss, who’s at Penn State. In the past, I’ve remarked about ‘post-neo-Darwinism,’ a term that I’m sure causes grimaces and eye-rolling, but that I think is worth discussing (I can’t take credit for the term; I think I heard it from Prof. Emily Schultz of St. Cloud State University at the last meeting of the American Anthropology Association).
By the way, Daniel posted a great ‘Evolution Round Up’ just recently with a whole lot of interesting material (I especially enjoyed Mo’s piece at Neurophilosophy on ‘Synapse proteomics & brain evolution’). We’re not really an evolution theme website, but it’s obvious how important it is to locate brain development in frameworks consistent with evolution. (I’ll come back to why being overly persuaded by evolutionary frameworks can be pernicious in a second, and it’s broader than my recent rant about memetics.)
Unfortunately, because the Weiss piece is more of an essay, in his recurring column entitled ‘Crotchets & Quiddities,’ there’s really no abstract of it, so I can’t link through to a nice concise summary of the piece. So, more than usual, I’m going to copy blocks of text from his essay, ‘All Roads Lead to… Everywhere?: Is the genetic basis of interesting traits so complex that it loses much of its traditional evolutionary meaning?’, before I get into my own commentary. Obviously, if you have access through a good research library, you should be able to get your hands on the original article. (More on Weiss’s columns can be found here — they’re quite good.)
The set-up for Weiss’s discussion is the idea that it doesn’t make sense to talk about ‘THE road’ to any particular place in a complex systems of highways and secondary roads because there are many routes:
With such choices, it doesn’t make much sense to ask, ‘‘What is the road to Rome?’’ In a somewhat similar way, rapidly growing knowledge about the nature of genomes and what they do suggests that what’s good for the Romans is good for biology as well. Instead of a gene for this and a gene for that, we face the possibility that all genes lead to everywhere, which may have important
implications with regard to our understanding of the genetic basis or evolution of traits like the shape of the skull, a skull, or this skull. If all real roads lead to the Circus Maximus, do all our craniofacial genetic roads lead to the foramen magnum?