Visit and talk on colour evolution in Hawaiian damselflies by Jonathan Brown on November 15 2016

Posted   by Erik Svensson

As for next week's EXEB-meeting, we will have a visitor from outside who will give a small and informal research presentation: Jonathan M. (Jackie) Brown, GrinnellCollege, Iowa, USA. See title and Abstract below. You can also check his website for information about his research on various species of arthropods.

Jackie’s research explores the evolution of ecological interactions in arthropods. He is particularly interested in how changes in these interactions are associated with the formation of new species. Study taxa have included phoretic mites and their beetle hosts, herbivorous moths and flies and their host plants and enemies, and damselflies and their biotic and abiotic environments.  Ongoing projects include:  (1) the evolution of host plant association in Hawaiian tephritids; (2) the evolution of body color and color dimorphisms in Hawaiian damselflies; and (3) the evolution of unicoloniality in North American Formica ant species. Jackie has also been the director of Grinnell’s ConardEnvironmental Research Area, where he has integrated long-term research on fire effects in prairie and woodland ecosystems into undergraduate biology classes.   

Jackie will be in Lund the whole next week (November 14-18), meaning that there is plenty of time to meet and interact with him and discuss your and his research. We also plan to go out for beers on Tuesday evening (November 15). Please contact me (erik.svensson@biol.lu.se) if you are interested in participating or want to set up a meeting with Jackie. 

Time of EXEB-meeting: Tuesday, November 15 at 10.00

Where: "Darwin" seminar room, 2nd floor (Ecology Building)

Evolution of body color and color dimorphisms in Hawaiian damselflies: is there more to color than meets the eye?

Sexual dimorphism in color is common in insects, but some species also display sex-limited dimorphism.  Female-limited dimorphisms in damselflies are most often attributed to sexual interactions, i.e., negative frequency-dependent selection by males targeting the more common female morph.  In contrast, my collaborator Idelle Cooper has proposed that ecological selection, rather than sexual conflict in mating rate, explains female dimorphism in an endemic Hawaiian damselfly (Megalagrion calliphya). Pigments -- here the ommochromes that produce red body color -- can have non-visual functions as well, for example as antioxidants that protect against the oxidative stress produced by exposure to UV radiation.  We are now testing this ecological selection hypothesis across the Megalagrion radiation, which exhibits high interspecific variation in body color, in sexual dimorphism, and in the presence of female dimorphism. Our ongoing studies  (1) identify how body color is correlated with abiotic habitat variables, particularly exposure to solar radiation, during the evolution of species across the archipelago; (2) test whether variation in sexual interactions can explain the habitat/color correlations; (3) connect color with survivorship in different habitats; and (4) test pigment function as an antioxidant.  Early results suggest that the primary function of body color is not visual.