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New thesis changes evolutionary theory on mating

Pressmeddelande   •   Feb 17, 2011 09:00 CET

The stereotype of over-sexed, aggressive, males competing to mate with coy females predominates for both human and non-human animals. The doctoral thesis by Sandra South at the Department of Ecology and Genetics challenges this stereotype. South defends her thesis at Uppsala University on February 25.

The stereotypical view of males and females has been considered to be largely supported by scientific studies showing elaborate male traits used during combat for access to, or to attract, females. Traditional evolutionary theory predicts that females will be choosy and only mate with males of high quality as females invest more in reproduction (for example during pregnancy); while males will be indiscriminate and eager to mate with any female. Sandra South shows in her thesis a more complex picture.

Sandra South investigates mate choice and the evolution of the elaborate feather-like leg ornaments in a brightly coloured Neotropical mosquito. South finds that males of this species not only compete for mates, but also choose between them. These results and similar findings in many other animals- from primates to fruit flies- provided the motivation for South to build on traditional evolutionary theory using mathematical modelling.

- My thesis shows that there is no reason to assume that “beggars can't be choosers”. Even when males are competing for access to females they should rarely be expected to mate indiscriminately, says Sandra South.

For more information, please contact: Sandra Helen South, mobile number: +46 733 58 02 08, e-mail:

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