Reemergence of species after collapse possible

Species that disappear through hybridization can reemerge if the disturbance is removed.

Last Updated: May 23, 2011, 21:02 PM IST

Washington: Certain species of stickleback fish have collapsed into hybrid swarms as water clarity in their native lakes has changed, and certain species of tree frogs have collapsed as vegetation has been removed around their shared breeding ponds.

Now, a new study has suggested that species pairs that disappear through hybridization after human-induced changes to the environment can reemerge if the disturbance is removed.

Stimulating environmental disturbances reduces the ability of individuals to identify and select mates from their own species and hybridization can lead to population decline and the loss of biodiversity.

“What is happening isn`t just speciation in reverse. The model shows that populations after collapse are likely to be different from the parental populations in ways that affect the future evolution of the system," said Tucker Gilman, the paper’s author, National Institute for Mathematical and Biological Synthesis.

According to the study, the reemergence of species pairs was more likely when disturbances were strong than when they were weak, and most likely when disturbances were quickly corrected.

However, even temporary bouts of hybridization often led to substantial homogenization of species pairs.

“The encouraging news from an ecosystems service point of view is that, if we act quickly, we may be able to refill ecological niches emptied by species collapse. However, even if we can refill the niches, we probably won``t be able to bring back the same species that we lost,” Gilman added.

The finding was published in the journal ‘Evolution’.

ANI