London, Dec 11 (UNI) It is certainly a good news for all carrier-oriented women -- you can think of having babies in late 30's and 40's as today's humans are more resistant to diseases impeding fertility than our ancestors.
According to a new reserach, humankind has evolved more rapidly in the past 5,000 years, at a rate roughly 100 times higher than any other period of human evolution resulting in more disease resistant genes and thus helping women to remain fertile for longer.
The research suggests that evolutionary pressure could help erase chronic diseases like obesity, cardiovascular disease, and type 2 diabetes, which can impede later fertility, the Daily Telegraph reported ''The trend has been toward later reproduction, many people wait to have kids until they are in their late 30s to 40s,'' said the lead author Prof John Hawks from the University of Wisconsin-Madison.
''But very few people lived into their 40's more than 50,000 years ago. That's a big biological change. So genes that impede fertility at later ages must be experiencing stronger selection pressure,'' he said.
By examining more than 3 million variants of DNA in 269 people, researchers identified about 1,800 genes that have been widely adopted in relatively recent times because they offer some evolutionary benefit.
The findings may lead to a broad rethink of human evolution, Prof Hawks said: ''We are more different genetically from people living 5,000 years ago than they were different from Neanderthals.'' ''In evolutionary terms, cultures that grow slowly are at a disadvantage, but the massive growth of human populations has led to far more genetic mutations,'' Prof Hawks added.
''And every mutation that is advantageous to people has a chance of being selected,'' he concluded.
Their claim counters a common theory that human evolution has slowed to a crawl or even stopped in modern humans, since in modern society the survivors no longer have to be the fittest, and is based on data from an international genetics project that can chart how evolution has shaped mankind over the past 40,000 years.