Female flies are more likely to sleep around in colder climes

CORNWALL, England, Oct. 26 (UPI) -- Those flies up north are just friskier. According to scientists at the University of Exeter, female flies tend to be more promiscuous in colder climates. Intropical climes, females are more apt to settle down.

The discrepancy seems to have little to do with weather and mostly a result of genetics, scientists say.

When British researchers brought different types of fruit flies from Arizona and Montana to their laboratory in Cornwall, England, they found the various species were only marginally influenced by changes in temperature.

After interbreeding flies for 40 generations, in order to preserve their genome, researchers exposed the flies to varying temperatures. Females tended to take on more mates as researchers cranked up the air conditioning, and fewer as the mercury rose. But the most promiscuous and monogamous species tended to remain so, regardless of temperature.

Researchers published their findings in a new paper, published this week in the journal Behavioral Ecology.

"This is a textbook example of the role of genes versus environment," lead study author Michelle Taylor, a researcher at the Center for Ecology and Conservation, said in a press release. "It makes sense biologically for females to have a number of partners as they will produce more offspring that are more genetically diverse and survive better."

"What is interesting, and what needs further research, is the question of why some females stay with one partner," Taylor added. "We don't know what maintains monogamy."

Taylor and her colleagues surmise that promiscuity offers an evolutionary advantage by encouraging genetic variety and increasing a species' ability to adapt to a changing climate. Northern latitudes may be more exposed to climatic changes, where as the tropics remain more stable.

"These results are an important step towards understanding how genes and environment contribute towards behaviour and ultimately how behaviour affects the success or failure of natural populations," Taylor concluded.