Human Genetics Seminar Series

Nandita Garud, PhD
Assistant Professor, Department of Ecology and Evolutionary Biology, UCLA

"Rapid Adaptation in Natural Populations: Lessons from Drosophila and the Human Microbiome"

The availability of whole genome data from natural populations has challenged many
longstanding assumptions about molecular evolution. For example, it has long been assumed
that natural selection is typically slow and infrequent. Using whole‐genome data from both
Drosophila and the human microbiome, I found evidence that rapid adaptation is much more
pervasive than previously thought. In my talk, I will first describe a method I developed to
detect soft sweeps, a signature of rapid adaptation, and its application to Drosophila and other,
non‐model organism data. Next, I will show that selective sweeps of genes and SNPs in
bacteria in the human microbiome are common on 6‐month time scales, and that these sweeps
likely originate in adaptive introgression from other species and strains in the microbiome.
This suggests that complex ecological communities can play an important role in shaping
evolution on short time scales. In sum, I will describe how we can leverage whole genome data
and novel statistics for uncovering the mode and tempo of adaptation in natural populations.

host: Dr. Janet Sinsheimer