Natural selection occurs when environmental conditions (“selective pressures”) drive species to adapt by improving either the organism’s ability to survive or reproduce. One impressive example of human adaptation comes from Andean highlanders and Tibetans — two populations living at extremely high altitudes. People living at sea-level elevations find transitions to extremely high altitudes challenging and encounter a suite of symptoms commonly referred to as “altitude sickness.” Highlanders and Tibetans, however, inhabit high elevations without ailment generation after generation. Many such trans-generational adaptations to extreme environmental conditions have been shown to have genetic origins.
Our research hopes to address the broad question: To what extent has natural selection shaped human traits and genetics? To address this, we will test whether parts of the genome have been selected for and then we will determine which medically relevant traits are influenced by selection. Understanding the impact of selection in humans will not only inform us about local adaptive processes but also disease biology.
The specific aims of our proposed work are to:
Aim 1. Identify genomic regions under selection
Aim 2. Characterize impacts of selection on human traits, including disease
Aim 3. Determine sets of genes that influence selected traits