New York: It may still be a quandary - which came first, the chicken or the egg. With a study of the colorful “eyespots” on the wings of some butterflies, scientists have come closer to explaining how one breed of chicken evolved into another.
One theory of “eyespots” origin is that they evolved from simpler, single spots; another theory is that they evolved from a “band” of colour which later separated into spots.
“What we basically conclude is that neither of the existing theories about butterfly `eyespots` is correct,” said Jeffrey Oliver from Oregon State University in the US.
The evidence suggests that a few “eyespots” evolved as a group at about the same time but behaved somewhat as individual entities, Oliver added.
Having appeared as a result of some genetic mutation, however, the “eyespots” then had the capability to move, acquire a function that had evolutionary value, and because of that value were retained by future generations of butterflies.
At all times, they retained the biological capacity for positional awareness - the “eyespots” formed in the same place until a new mutation came along.
"At first, it appears the `eyespots` helped this group of butterflies with one of the most basic aspects of survival value, which is avoiding predators,” Oliver said.
But just as important, Oliver said, the study indicates how through continued mutation, these “eyespots” moved to a completely different place - the other side of the wing.
There, they performed a completely different function - helping the butterfly to attract and be identified by optimal mates.
“If you take this same concept and apply it to other important features like vertebra and a spinal column, it suggests that some small number of bones would form through mutation, and eventually move, join and be perpetuated as they acquired a function with survival value,” Oliver explained.
The study appeared in the journal Proceedings of the Royal Society B.