(Image by furtwangl via Flickr)
Male fruit flies have super-sized sperm, making them an evolutionary anomaly. Now, researchers have determined why their “little swimmers” aren’t so little. Sexual selection typically favours organisms that produce a large number of small sperm instead of those organisms which invest lots of resources into a small number of large sperm. However, the sperm of the male fruit fly defies that law, as it can measure up to five centimetres in length.
Researchers found this type of sexual ornamentation evolved at the same time as female fruit flies were evolving a longer seminal receptacle. According to a new study out of Syracuse University, sperm production in fruit flies is related to the physical condition of the male, with the healthiest males producing the largest sperm. The team combined genetic analyses of interacting sex-specific traits with a comparative analysis of how male and female reproductive potentials depend on health and nutrition.
Authors:
Stefan Lüpold, Mollie K. Manier, Nalini Puniamoorthy, Christopher Schoff, William T. Starmer, Shannon H. Buckley Luepold, John M. Belote & Scott Pitnick
Corresponding author:
Scott Pitnick, Center for Reproductive Evolution, Department of Biology, Syracuse University, 107 College Place, Syracuse, New York 13244-1270, USA
Original paper, published on May 26, 2016 in Nature.
