Tuesday, 8 March 2016
Darwinian Mechanisms Cannot Improve a Fruit Fly, Study Suggests
Researchers tested whether they could design a fruit fly (Drosophila melanogaster) that would be better than the amazing design we see in the tiny creatures attracted by overripe apples and bananas.
They changed the fly’s wing shape in many ways, hoping to produce a more efficient flier. However, in each case the original turned out to be better than the altered model.
The researchers published their findings the journal Nature Communications.
“Our aerodynamic model shows that all of the wing morphs we have tested show a decrease in aerodynamic efficiency in comparison with the control,” they had to admit.
Alterations always came with a cost. Tweaking a trait to make it more effective resulted in the loss of another trait. The altered flies were less able to evade predators, for instance.
Natural selection cannot vary the fly’s shape indefinitely without actually causing the insect to be worse off than before the alteration.
In other words, the original design is the best. It also suggests that the assumed evolution is not very clever.
Evolution could never match the amazing design that is obvious in all living beings, including us.
Ray, Robert P. 2016. Enhanced flight performance by genetic manipulation of wing shape in Drosophila. Nature Communications 7, 10851. doi:10.1038/ncomms10851 (1 March).