Geneticists Evolve Fruit Flies with the Ability to CountScience Friday, July 13th, 2012
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.
The findings back-up the theory that numerical skills such as mental arithmetic are ancient constructs. Some of the more unusual natural fans of numeracy include salamanders, newborn chicks and mongoose lemurs, all of which have demonstrated basic skills in the lab. The humble fruit fly — which has been a popular experimental tool for geneticists since the early 1900s, its brief life span making it evolve faster — is the first example of a test subject gaining the skills through evolution, however.