CISAB Speaker| Christine R.B. Boake

C E N T E R F O R T H E I N T E G R A T I V E S T U D Y O F A N I M A L B E H A V I O R

S P E A K E R S E R I E S

Christine (Chris) R.B. Boake

Professor
Department of Ecology & Evolutionary Biology
University of Tennessee

Flying Apart: Sexual Selection and Speciation in Hawaiian Drosophila

29 September Guest Lecture for Fall 2000 Graduate Seminar:
Behavioral Ecology

ABSTRACT:
© 2000 CISAB

If sexual selection can lead to speciation, then it should be possible to identify traits that are both sexually selected within a species and contributing to behavioral isolation with a close relative. Such analyses need to be conducted with species that have not completed divergence. The sympatric species Drosophila silvestris and D. heteroneura show incomplete prezygotic isolation and no postzygotic isolation. They are thus ideal for investigating the mechanisms that influence speciation. The critical stage of behavioral isolation between these species is the first approach: male D. silvestris and female D. heteroneura that approach each other fail to proceed into courtship. Any other pairing, including either sex of hybrid with either parental species, is as successful as a pairing within a species. Thus, traits that influence behavioral isolation between these species must meet two criteria, first differing significantly between the parental species, and second, showing dominance of the D. heteroneura type in the F1 hybrids. One striking difference between the species, the broad head of D. heteroneura, is sexually selected but not involved in behavioral isolation (Boake et al. 1997). More recently my colleagues and I have examined a component of the initial approach, a male abdominal vibration that produces a tremulation termed a "purr." Our results indicate that the pulse rate of the purr could be both sexually selected within at least one species, and involved in behavioral isolation.

RELATED READING:
© 2000 CISAB

Boake, C.R.B., M. DeAngelis, & D. Andreadis. 1997. Is sexual selection and species recognition a continuum? Mating behavior of the stalk-eyed fly Drosophila heteroneura. Proceedings of the National Academy of Sciences USA 94:12442-12445. |ABSTRACT|FULL TEXT|

Boake, C.R.B. 2000. Flying apart: Speciation in Hawaiian Drosophila. BioScience 50(6):501-508.

Readings for Seminar:
Gavrilets, S. & C.R.B. Boake. 1998. On the evolution of premating isolation after a founder event. American Naturalist 152(5):706-716. |ABSTRACT|

Turner, G.F. & M.T. Burrows. 1995. A model of sympatric speciation by sexual selection. Proceedings of the Royal Society of London B 260(1359): 287-292. |ABSTRACT|

ONLINE RESOURCES:
© 2000 CISAB