Thaindian News

Washington, Dec 3 (IANS) What sets humankind’s closest relatives — monkeys, apes and other primates — apart from other animals?

One answer is that primates are less affected by seasonal ups and downs — particularly rainfall — that take their toll on other animals. The findings may also help explain the evolutionary success of early humans, scientists say.

“Wild animals deal with a world that’s unpredictable from year to year,” said study lead author Bill Morris, biologist at Duke University, US.

“The weather can change a lot; there can be years with plenty of food and years of famine,” he was quoted as saying by the journal American Naturalist.

Researchers working at the National Evolutionary Synthesis Centre (NESCent) in Durham, US, analysed decades of birth and survival data for seven species of primates in the wild, according to a Duke statement.

They are muriqui monkeys and capuchin monkeys in Central and South America, yellow baboons, blue monkeys, chimpanzees and gorillas in Africa, and sifakas (lemurs) in Madagascar.

Collecting this data was no small effort. Nearly every day for more than 25 years, seven research teams working around the world have monitored the births, lives and deaths of thousands of individual primates.

Thanks to a new database developed at NESCent, the scientists were able to pool their painstakingly-collected data and look for similarities across species.

When they compared year-to-year fluctuations in primate survival to similar data for other animals — namely, two dozen species of birds, reptiles and mammals — they found that primate survival remained more stable despite seasonal variation in rainfall.

“Primates appear to be well buffered against fluctuations in weather and food availability relative to a lot of other animals,” said co-author Susan Alberts, biologist at Duke University and associate director at NESCent.