MNN - Mother Nature Network

Researchers studying ancient amber deposits have discovered the closest thing in nature to a scandalous mite sex tape. Two members of an extinct, 40-million-year-old species of mite were found trapped in the amber while displaying unusual sexual behavior in which the female dominates the male, according to PhysOrg.com.

 

In most species of modern mite, it's the male that is in control of copulation. Aside from harassing reluctant females by guarding them from engaging with other males, male mites of some species have evolved specialized clinging organs that grapple the females and force them into sex.

 

As the act frozen in amber now suggests, however, mite sex roles weren't always this way. In fact, sex roles appear to have been reversed for the ancient species.

 

"In this species, it is the female who has partial or complete control of mating," said Pavel Klimov, an associate research scientist at the University of Michigan Museum of Zoology. "This is in contrast to the present-day reproductive behavior of many mite species where almost all aspects of copulation are controlled by males."

 

In fact, it's the females from the extinct mite species (Glaesacarus rhombeus) that harbor the specialized, pad-like, clinging sex organs. Klimov even describes some types of these female clinging structures as "copulatory tubes that function like a penis."

 

So what happened to these dominatrix mites? Why did they go extinct? Scientists suggest that a biological battle of the sexes has been raging throughout evolutionary history. Both genders struggle to gain the upper hand in controlling how their genes get passed on to the next generation. It's an evolutionary cycle that occasionally gets played out in extremes, such as with these mites.

 

Scientists have long suspected that sex role reversals have occurred throughout mite evolution, but it wasn't until this discovery that they could confirm it. Finding a fossil is one thing; finding perfectly preserved animal behavior is something rare.

 

Who knows what others kinds of oddball behavior, scandalous or otherwise, scientists may find as they continue to mine these amazing amber deposits for more rare snapshots of biological history?