New mammal species a warning for humanity

February 10, 2009 19:31 IST

A scientist has said that the fact that we're discovering new mammal species in an era of human-caused mass extinctions is not a cause for joy, but only a warning for humanity.

The statement has been made by Paul Ehrlich, the Bing Professor of Population Studies at Stanford University, and co-author of an analysis of the 408 new mammalian species discovered since 1993. Ehrlich conducted the analysis with Gerardo Ceballos, a professor of biology at the National University of Mexico.

The 408 newly discovered species amount to approximately 10 percent of the known species of mammals.

"As a group, mammals have been very well studied, and their size makes them relatively easy to spot compared to insects or microbes. It is not that surprising that multitudes of new insect species are still being discovered, or that the new extremophile species are found in hydrothermal vents on the ocean floor," Ehrlich said.

"But, the new mammals include a small antelope weighing approximately 200 pounds and surprisingly high numbers of primates, more than what would be expected if the discoveries were randomly distributed across higher taxonomic groups," Ehrlich added.

"Our analysis indicates how much more varied biodiversity is than we thought and how much bigger our conservation problems are if we're going to maintain the life-support services that we need from biodiversity," the professor said.

Among those ecosystem services is disease control.

"There's an important set of diseases called hantaviruses that infects human beings and quite frequently kills them. And it turns out that if you reduce the diversity of the different species of rodents, say, in a forest, the rodents that carry hantaviruses can become more common. And the results for human beings are more death and disease," Ehrlich said.

"So, by reducing the diversity of mouse-like creatures in a forest, you can make that forest more dangerous for people," he added.

"Many of the newly discovered species have small populations or limited geographic ranges, making them particularly vulnerable to extinction. The rarer of the species and the smaller of the populations often disappear without us even knowing that they are going," Ehrlich said.