Zeack News

Washington, Jun 15 : Guess how fast can evolution take place? In less than 10 years, at least in fish, according to a new study.

In their study, researchers at California University introduced guppies (small fresh-water fish) from Yarra River, Trinidad, into the nearby Damier River, in a section above a barrier waterfall that excluded all predators.



Eight years later, they found that the guppies in the low-predation environment above the barrier waterfall had adapted to their new environment by producing larger and fewer offspring with each reproductive cycle.



However, no such adaptation was seen in the guppies which colonised the high-predation environment below barrier waterfall.



"High-predation females invest more resources into current reproduction because a high rate of mortality, driven by predators, means these females may not get another chance to reproduce.



"Low-predation females, on the other hand, produce larger embryos because the larger babies are more competitive in the resource-limited environments typical of low-predation sites.



"Moreover, low-predation females produce fewer embryos not only because they have larger embryos but also because they invest fewer resources in current reproduction," lead researcher Swanne Gordon said. Z