Tuesday, May 08, 2007

Really ancient morphs?   posted by Razib @ 5/08/2007 11:59:00 PM

A few years ago Henry Harpending & Greg Cochran published In our genes in PNAS. They focused on the D4 dopamine receptor (DRD4) locus as "a model system for understanding the relationship between genetic variation and human cultural diversity." Check this out, Drd4 gene polymorphisms are associated with personality variation in a passerine bird:
Polymorphisms in several neurotransmitter-associated genes have been associated with variation in human personality traits. Among the more promising of such associations is that between the human dopamine receptor D4 gene (Drd4) variants and novelty-seeking behaviour....Frequencies of the three Drd4 SNP830 genotypes, but not the ID15 genotypes, differed significantly between two P. major lines selected over four generations for divergent levels of 'early exploratory behaviour' (EEB). Strong corroborating evidence for the significance of this finding comes from the analysis of free-living, unselected birds where we found a significant association between SNP830 genotypes and differing mean EEB levels. These findings suggest that an association between Drd4 gene polymorphisms and animal personality variation predates the divergence of the avian and mammalian lineages. Furthermore, this work heralds the possibility of following microevolutionary changes in frequencies of behaviourally relevant Drd4 polymorphisms within populations where natural selection acts differentially on different personality types.