Liat Clark in Wired:
After repeatedly subjecting fruit flies to a stimulus designed to teach numerical skills, the evolutionary geneticists finally hit on a generation of flies that could count — it took 40 tries before the species' evolution occurred. The findings, announced at the First Joint Congress on Evolutionary Biology in Canada, could lead to a better understanding of how we process numbers and the genetics behind dyscalculia — a learning disability that affects a person's ability to count and do basic arithmetic.
“The obvious next step is to see how [the flies'] neuro-architecture has changed,” said geneticist Tristan Long, of Canada's Wilfrid Laurier University, who admits far more research is needed to delve into what the results actually mean. Primarily, this will involve comparing the genetic make-up of an evolved fruit fly with that of a standard test fly to pinpoint the mutation.
The research team, made up of geneticists from Wilfrid Laurier University in Canada and the University of California, repeatedly subjected test flies to a 20-minute mathematics training session. The flies were exposed to two, three or four flashes of light, with two or four flashes coinciding with a shake of the container the flies were kept in. Following a pause, the flies were again subjected to the flashing light, however none prepared themselves for a repeat of the shake since they could not discern a difference between two, three or four flashes. That is, until the key 40th generation of descendants were put to the test.