MVZ LUNCH SEMINAR - Michael Harvey: Ecology as a driver of evolutionary diversity within Amazonian bird species
Seminar | January 31 | 12-1 p.m. | Valley Life Sciences Building, 3101 VLSB, Grinnell-Miller Library
MVZ Lunch is a graduate level seminar series (IB264) based on current and recent vertebrate research. Professors, graduate students, staff, and visiting researchers present on current and past research projects. The seminar meets every Wednesday from 12- 1pm in the Grinnell-Miller Library. Enter through the MVZ's Main Office, 3101 Valley Life Sciences Building, and please let the receptionist know you are there for the MVZ lunch seminar. The library is located in the rear of the Museum on the north side - follow the orange directional signs.
Species often differ in the degree of phenotypic and genetic diversity observed across their geographic distributions. The geography and landscape history of the region in which they occur is partly responsible, but broad ecological traits of species may also help determine intraspecific diversity. Here, I examine the link between one ecological trait, habitat, and intraspecific diversity using 20 pairs of closely related Amazonian bird species in which one member of the pair occurs primarily in floodplain forest and the other in upland forest. I use standardized geographic sampling across the Amazon Basin and data from the same set of 2,416 genomic markers, both of which permit the comparison of diversity measures across species. I find that species of upland forest have greater genetic diversity and divergence across the landscape than species of floodplain forest. Mechanisms acting at both ecological (e.g., dispersal) and evolutionary (e.g., crown age of populations) timescales appear to be responsible for the trait-dependent disparity in diversity. I conclude that species ecology in the form of habitat association determines intraspecific diversity and suggest that differences in diversity between floodplain and upland avifaunas in the Amazon may be driven by differences in the demographic and evolutionary processes at work in the two habitats. Finally, I outline a recent focus in my Amazonian research program on characterizing the speciation process in a single area representing a suture zone between many pairs of divergent populations the headwaters of the Amazon River in Peru. Replicate population pairs at different stages of divergence can provide a window on the entire speciation process. I am characterizing not only population differentiation, but also the changing architecture of genome divergence, rates of phenotypic differentiation, and rates of behavioral divergence across lineages in this system. I can then evaluate which axes of divergence are most relevant to speciation using estimates of reproductive isolation from genomic data and mate-recognition experiments.