Washington, May 12 : A new study by biologists has determined that an endangered species of flora or fauna may increase the risk of extinction of other species in its ecological community.
According to a report in Science Daily, a team of theoretical biologists active at Linkoping University in Sweden and the University of Sheffield in the UK conducted the study.
The researchers simulated what happens in a food web when a species dies out, to see which species might die out and what the consequences might be in each case. indings indicate that secondary extinction gives rise to a greater decline in trophic diversity than can be explained by mere chance.
The biologists have used the analogy of jackstraws to explain their theory.
In the game of jackstraws, or spillikins, the players try to pull a stick out of a jumbled pile without moving the other sticks.
The sticks can represent members of an ecological community.
Some species, like some sticks, can easily be moved with no consequences to their neighbors. Others occupy a unique position in the food web and their removal will have a considerable impact on other members.
One instance of this is the sea otter. It lives on mussels and sea urchins, and when it disappeared from the tang forests along the Pacific coastline of the Americas, entire ecosystems collapsed.
The surprising finding was that many other species in the otter's ecosystem became locally extinct.
The new study shows that those species, which disappear in the second wave of extinction, have a trophically unique role.
Once these keystone species are identified, conservation activities can be directed where they will help most.