Mammoths 'developed anti-freeze blood'

A form of ''anti-freeze blood'' may have helped woolly mammoths survive life in the Arctic, research suggests.

Ancestors of both the extinct mammoth and modern elephants originated in equatorial Africa, scientists believe. But mammoths migrated north between 1.2 and two million years ago just as climate change caused temperatures to plunge.

The move is surprising since elephants are not adapted to the cold.

Scientists investigated whether changes to haemoglobin may have been part of the mammoth's cold climate secret.

Their hunch was confirmed when they analysed preserved DNA from a 43,000 year-old mammoth whose body had been frozen in ice.

The researchers, led by Dr Kevin Campbell, from the University of Manitoba in Winnipeg, Canada, compared genes for haemoglobin from the mammoth with those of modern African and Asian elephants.

They found mutations in the mammoth genes which would have enabled haemoglobin to release oxygen at low temperatures.