What role does sexual selection play in shaping traits in natural populations?

Mating behaviors usually involve other non-behavioral traits and can be shaped by ecological and environmental factors. Therefore, behaviors often experience complex selection pressures, including strong sexual selection. The lab works on characterizing the interacting roles of morphological traits, mate quality, and environmental factors in mate choice and sexual selection. Focusing on sexual selection facilitates integrative studies that incorporate animal behavior, mating patterns, ecology, and population dynamics.

Sexual selection also provides opportunities to model evolutionary complexity. In 2017, Sarah co-supervised an interdisciplinary group of four undergraduate students who created and analyzed an evolutioanry game theoretic model of how male condition, female density, and female mate choice interact in territorial, migratory animals. We found that sexual conflict emerged in some cases, a surprising result that we plan to publish with the undergraduate students as lead authors. This summer research experience highlighted not only how models can shed new light on biological questions, but also how models of sexual selection can captivate young scientists and engage them in the scientific process.

Most of the empirical work in the lab has been on Syngnathids, the fish family comprised of seahorses, pipefishes, and seadragons. These fish are particularly interesting from a sexual selection point of view because they exhibit male pregnancy, in which the males care for the developing embryos. In many species, the females also have elaborate display traits to attract the males, and research in the lab works towards understanding how sexual selection shapes those traits.

Sarah did her PhD work on the Gulf pipefish, Syngnathus scovelli (pictured below), which is found in the Gulf of Mexico and the Atlantic coast of Florida. That work focused on understanding what evolutionary forces drive population differentiation and how selection impacts the genome.

The Flanagan lab is now focusing on native and endemic species in New Zealand. The lab is continuing to ask questions about the forces shaping differentiation and the role of sexual selection in the evolution of these charismatic fish.

Some relevant papers include:

Flanagan SP, Rosenqvist G, and Jones AG. 2017. Mate quality and timing of reproduction affects sexual selection in a sex-role-reversed pipefish. Behavioral Ecology and Sociobiology. 71(1): 1-10. doi: 10.1007/s00265-016-2255-3 pdf, link to paper, press release, data

Flanagan SP, Johnson JB, Rose E, and Jones AG. 2014. Sexual selection on female ornaments in the sex-role-reversed Gulf pipefish (Syngnathus scovelli). Journal of Evolutionary Biology. 27 (11): 2457-2467. pdf, data

Flanagan SP, and Bevier CR. 2014. Do male activity and territory quality affect female association time in the Brown Anole, Anolis sagrei? Ethology. 120 (4): 365-374. link to paper