EGRU-blog

Arendt, J., and Reznick, D. (2008) Convergence and parallelism reconsidered: what have we learned about the genetics of adaptation? Trends in Ecology and Evolution 23: 26-32. doi:10.1016/j.tree.2007.09.011

Are you ready for some arguing over evolutionary semantics? Bored with the age old ‘how do we define what a ‘species’ is? Please read further… In our quest to define and describe evolution we have come up with descriptive terms to communicate with each other. Two of these are the oft used dichotomy of ‘convergent’ and ‘parallel’ evolution. The idea being that the underlying mechanisms for evolution are different in distantly related species (convergent) but similar in closely related species (parallel). Arendt and Reznick draw on recent research to argue that this dichotomy is more of a figment of our imaginations than anything real. I am usually not a fan of splitting hairs over word meanings, but this article is a fun look at how the genetics behind the evolutionary of phenotypically similar traits can work similarly in distantly related species, and differently in closely related species. I’m sure the climax of the article for EGRUlaiset will be found when the authors focus on pelvis evolution and make connections between sticklebacks and manatees. Perhaps we should get a bit bigger tank and round us up some manatees?

J.L.