Biological Sciences Colloquium: Dr. Gabrielle Welsh
Dr. Gabrielle Welsh, postdoctoral researcher in behavioral ecology and genomics at the University of Chicago, will be giving a talk about her work entitled “How parasitoids and relaxed preferences facilitate the evolution of novel signals in a rapidly evolving field cricket.” The abstract is as follows:
The evolution of sexual signals is critical to the generation of biodiversity. How novel signals arise and spread is difficult to envision because new signal or receiver features may disrupt communication, and we can rarely observe the incipient stages of signal evolution. Pacific field crickets, Teleogryllus oceanicus, provide an ideal opportunity to do so. Multiple novel signals that protect males from eavesdropping parasitoid flies have evolved in the past decade in Hawaii. I investigated 1) receiver behavior that facilitates mating by males producing novel signals, 2) how this behavior changes as novel signals spread, and 3) the genomic underpinnings of morphological variation that generates novel signals. To examine how novel signals persist despite not aligning with historical female preferences, I tested the underappreciated hypothesis that relaxed receiver preferences facilitate the earliest stages of novel signal evolution. Using preference trials, I found that females from Hawaii (where the flies are present) were more permissive than females from Australia and French Polynesia (where the flies are absent). Thus, elevated mate searching costs may lead to relaxed preferences that accommodate novel signals. Relaxed preferences persisted in Hawaii even as novel signals spread. Preference relaxation likely allows new signals to spread. Genome-wide association studies show that novel song variants are associated with different genes. Thus, novel signals with a convergent function (attracting mates while avoiding the fly) can have different genomic origins.
The presentation will begin at 3:00 PM in Lapham Hall N101, preceded by an informal reception from 2:45-3:00 PM.