Signatures of selection in convergent feather lice ecomorphs

On-Demand

Presenting Author(s)

Avery Grant (she/her/hers)

Graduate Student
University of Nevada
Reno, Nevada

Co-Author(s)

Stanislav Kolencik (he/him/his)

Postdoctoral Researcher
University of Nevada, Reno
Reno, Nevada
ES

Edward L. Stanley

Florida Museum of Natural History
Gainesville, Florida
DA

David Alvarez-Ponce

University of Nevada
Reno, Nevada
KJ

Kevin P. P. Johnson

Illinois Natural History Survey
Champaign, Illinois
JA

Julie M. M. Allen

University of Nevada
Reno, Nevada

Most often occurring on island-like systems, adaptive radiations result in a broad array of phenotypic differentiation, in part due to niche partitioning. These events provide a unique opportunity to investigate mechanisms resulting in the repeated evolution of similar characteristics by looking into patterns and processes that lead to adaptation and diversification. There are few such studies involving parasites on hosts compared to vertebrate groups. One group of particular interest is avian feather lice (Phthiraptera: Philopteridae). They are found on most bird orders and have repeatedly diversified into ecomorphs specific to areas of the host’s body (head, body, wing, generalist). This is an ideal study system as the bird itself acts as an island and the different body parts as microhabitats. Feather lice ecomorphs are divergent within host groups and convergent across lineages, suggesting that each ecomorph has evolved independently numerous times. While the morphological differences between ecomorphs are well documented, the genetic changes associated with repeated ecomorph evolution are unknown, which is a critical step in investigating the patterns of molecular evolution between and within species. Using a branch-site model in PAML, we inferred events of positive selection in orthologous feather louse genes, in order to identify those that are recurrently under positive selection in certain ecomorphs. In this way, we identify genes responsible for convergent evolution within each ecomorph. This will provide critical information needed for determining gene function and the selective pressures occurring to gain a better understanding of the evolutionary mechanisms involved in ecomorph evolution.