Evolution
Evolutionary genetics is a sub-branch of population genetics that studies (a) the evolutionary processes that account for changes in gene frequency over time and (b) the causes and consequences of existing genetic variation. Behavioral genetics is the study of genetic variation underlying human psychological traits. Evolutionary behavioral genetics combines these two fields. At IBG, we recognize the importance of taking an evolutionary perspective in understanding the genetic variation that underlies human disorders and other psychological traits. This approach is the flip side of the coin to the standard evolutionary psychology approach, which typically focuses on human universals and adaptations.
We are using whole genome SNP (single nucleotide polymorphism) data to understand the patterns of genetic variation, which in turn provides information on the roles of directional selection, balancing selection, mutation, and genetic drift on the genes that affect mental health traits. These studies overlap considerably with those using statistical genetics techniques, although we are open to using any method that can substantively increase knowledge in this area. We are also comparing human SNP data to SNP data from non-human primates to pinpoint genes that may underlie human-specific traits. In the future, sequencing data (data on every nucleotide in an individual’s genome) will be available, which will dramatically expand our ability to answer fundamental questions about human genetic variation.
Studies:
SNP homozygosity study: Using SNP data, Keller and McQueen are assessing individuals’ degree of homozygosity to understand the role of directional dominance and purifying selection on various mental health traits.
Recent selection on genes underlying mental health: Keller and McQueen are scanning the genome to assess for areas that have been under recent positive selection, and noting which of these areas influence mental health traits.
Evolutionary genomics of human cognition: To gain insights into the evolutionary genomics of human and great ape lineages, Sikela and colleagues are using cDNA aCGH to identify lineage-specific gene duplications or losses that have occurred between these lineages. Of particular interest are those human lineage-specific genes that underlie the cognitive abilities unique to the human brain, and how such genes, when defective, lead to cognitive disability.
Faculty:
The following faculty specialize in Statistical Genetics Research:
Publication Highlights:
- Keller, M. C., & Miller, G. F. (2006). Resolving the paradox of common, harmful, heritable mental disorders: Which evolutionary genetic models work best? Behavioral and Brain Sciences, 29, 385-452.| pubmed abstract |
- Rhesus Macaque Genome Sequencing and Analysis Consortium. Evolutionary and Biomedical Insights from the Rhesus Macaque Genome. Science 316: 222-234, 2007. | pubmed abstract |
- Sikela J.M. The Jewels of Our Genome: The Search for the Genomic Changes Underlying the Evolutionarily Unique Capacities of the Human Brain. PLoS Genet 2(5): e80, 2006. | pubmed abstract |