London:  They not only pamper their grandchildren with cuddles and cakes, and offer good advice,
but grandparents are also the key to the evolution of human civilisation, say researchers.

A number of recent studies have highlighted how helpful it was to have older people around during early human development -- in fact, grandparents are able to babysit, make tools, teach skills and most importantly pass on vital wisdom on human relationships.

Studies carried out by London's Natural History Museum emphasised the importance of experience in food gathering. Professor Chris Stringer, author of 'The Origin of Our Species', said elders pass on knowledge of poisonous food, the location of water supplies and important skills such as tool-making.

Most importantly they know the distant relationships with other tribes so it is easier to negotiate rules around access to water holes or to land rich in game.

Kristen Hawkes of the University of Utah, carried out studies of the Hadza hunter gatherers of Tanzania. She said grandmothers have an important role in foraging food and teaching the skill so that children are healthier and the tribe can flourish.

Prof Rachel Caspari of Central Michigan University traced back a connection between the population explosion in human beings around 30,000 years ago and longevity.

She looked at bones from all over the world to analyse age at the time when the population became more successful. She found that when humans began living beyond 30, it was much easier for the tribe to expand.

"Living to an older age had profound effects on the population sizes, social interactions and genetics of
early modern human groups and may explain why they were more successful than other archaic humans, such as Neanderthals," she said.

(Agencies)