40-million-year-old mating mites reveal sex role reversal

Tuesday, March 1, 2011

WASHINGTON - New research from the University of Michigan and the Russian Academy of Sciences describes an extinct mite species in which the traditional sex roles were reversed.

The evidence comes, in part, from 40 million-year-old mating mites preserved in Baltic amber.

“In this species, it is the female who has partial or complete control of mating. This is in contrast to the present-day reproductive behavior of many mite species where almost all aspects of copulation are controlled by males,” said Pavel Klimov.

Harassing reluctant females, guarding females before and after mating and fighting off competing males are typical behaviours.

For females, having control over mating allows them to choose superior males to mate with, while rejecting losers (who may be, however, extremely adept at coercing females), and it spares them the wear and tear of being subjected to harassment, guarding and frequent copulation.

In the extinct mite species Glaesacarus rhombeus, the male lacks the specialized organs for clinging to females that are seen in many present-day mites. The female, however, has a pad-like projection on her rear end that allows her to control the clinging.

“Some lineages have developed female copulatory tubes that function like a penis,” said Klimov.

The study appears on March 1 in the Biological Journal of the Linnean Society. (ANI)

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