Research published from The University of Queensland indicates that natural selection plays a greater role than genetic drift in SNPs dealing with height, waist-to-hip ratio, BMI, and schizophrenia among European, African, and Asian populations (Does evolution make us or are we just drifting that way?). Led by Professor Jian Yang from UQ’s Institute for Molecular Bioscience and Queensland Brain Institute, the team used more than 400,000 genetic samples from African, East Asian and European populations to determine if the SNPs (pronounced as “snips”) showed a tendency towards randomness, implying genetic drift, or not, and thus natural selection.
The results showed that for SNPs such as height, waist-to-hip, BMI, and schizophrenia, there was a greater frequency for height among Europeans; a greater BMI number for Africans with Europeans having greater than Asians; both Europeans and Africans falling out of the mean for schizophrenia. None of these traits showed the tendency towards a random distribution which indicates that for these SNPs natural selection plays a greater role than genetic drift. In other words, what this study says that rather than in the colloquial debate of Nature versus Nurture it’s more like Selection over Nature and Nurture not having a factor at all. This is important in that it gives hope for the potential to treat certain ailments, such as schizophrenia through treatments such as CRISPR.
It has left me to wonder how much of natural selection over genetic drift influenced hominin traits? Eyebrows/brow ridges, robust/gracile, even “having a chin” how were these more a product of selectivity among groups than randomness among Neandertals, Denisovans, and modern humans? More intriguing, could this be applied to culture as well?
-A. M. Holmes