November 5, 2020

5:00pm Zoom

EcoEvoPub Seminar Series
Department of Ecology and Evolutionary Biology, UCLA

" Graduate Student Presentations "

Graham Montgomery

Department of Ecology and Evolutionary Biology, UCLA, Tingley Lab 

 “Insect and insectivorous bird declines: current research in the Appalachians & a roadmap moving forward”

I’ll go over the current state of insect decline research (spoiler: it’s complicated), talk about preliminary results from two field seasons doing bird and insect re-surveys in Great Smoky Mountains National Park, then talk about the need for 1) increased insect monitoring and 2) better standardization of methods among already-existing programs. I can also promise some photos of some pretty insects and landscapes.

 

Ellie Diamant

Department of Ecology and Evolutionary Biology, UCLA, Yeh Lab

 

 “Male-like female morphs in hummingbirds: the evolution of a widespread sex-limited plumage polymorphism”

 

Differences in the way males and females look or behave are common in animals. However, discrete variation within sexes (sex-limited polymorphism) also occurs in several lineages. In birds, female-limited polymorphism in which some females resemble males in coloration is most prominent in hummingbirds — a group known for its morphological and behavioral sexual dimorphism. Yet it remains unclear whether this intrasexual color variation in hummingbirds arises through direct selection on females, or indirectly as a non-adaptive byproduct resulting from selection on males. Here we analyzed specimens from >300 hummingbird species to determine the extent, evolutionary history, and function of female-limited polymorphism. We found that female-limited polymorphism evolved independently in every major clade and occurs in nearly 25% of hummingbird species. Using phylogenetically-informed analyses, we rejected non-adaptive hypotheses that female-limited polymorphism is the result of indirect selection or pleiotropy. Instead, female-limited polymorphism is associated with migratory status and marginally with social dominance, though not with ecology, suggesting that resembling males provides social benefits to females. Ultimately we show that female-limited polymorphism is not only widespread in hummingbirds and likely to provide social benefits, but may also be useful for understanding the evolution of female ornamentation in systems under strong sexual selection.

Thursday, November 5th, 2020 @ 5 PM