The More Things Change, the More They Stay the Same: Rapid and Dynamic Evolution in Ancient and Essential Traits

Annalise Paaby, Ph.D.
School of Biological Sciences
Georgia Institute of Technology

Livestream via Zoom

ABSTRACT
How do complex traits evolve? Living systems are governed by the interaction of hundreds, if not thousands, of genes encoded in the genome. Relationships between genes affect how mutations are expressed and whether traits are constrained or labile in the face of natural selection. How do these complex dynamics influence the variation we observe in natural populations? Using the model system C. elegans, I describe the role of genetic dependencies in two essential phenomena: RNA interference, a mechanism of gene regulation shared across Eukaryotes and for which C. elegans is the Nobel exemplar... but which nevertheless exhibits dramatic variation in competency; and transfer RNAs, an essential family of molecules required for protein synthesis, but which suffers extreme mutational degradation and gene turnover. In both scenarios, I make the case that uncovering the causes and consequences of natural variation is critical to understanding the biology of even the most well-studied traits.