Choosing mates using logic

A new study has discovered that fruit flies (Drosophila melanogaster), unlike many of us make rational decisions while choosing partners.

Experiments were conducted by scientists from the University of British Columbia and University of Washington, where, individual male flies were given the choice of choosing between two females as their mates. Male fruit flies were paired with 10 different females flies of different genetic strains. With as many as 2700 trials using different combination of male and female fruit flies, it was found that males were able to pick out females that are most likely to produce the maximum amount of offspring.

The males were also found to be consistent in their choices, choosing females ranking higher in the hierarchy over the others. For example; if female fruit fly A is the highest in rank, followed by B, C, D and so on, males, when given a choice between A and B, always chose A. Similarly when given a choice between B and C, the males chose B. The ranking ranking of a female fruit fly relates to the amount of offspring it is able to produce.

Similar experiments were conducted but, after impairing either the sense of smell or the sight of the male fruit flies, their mate choosing pattern remained unchanged. However, when both their eyesight and sense of smell were impaired, the males failed to detect the ranking hierarchy in females, leading the scientists to conclude that the choices made earlier were based on a combination of visual and olfactory cues.

Making decisions based on logic has always been associated as a trait unique to humans. This study turns out to be among the first of its kind, providing evidence that some species besides humans may also be capable of rational decision making.processes.