Saturday, August 25, 2007

History rewritten by skulls

THE discovery of two fossils has challenged the belief our ancestor homo erectus evolved from homo habilis, according to an article in the British magazine Nature.

The finds, on the eastern bank of Lake Turkana in Kenya, suggested the species may have co-existed for some 500,000 years in East Africa.

The team that found the remains was led by mother-daughter team Mary and Meave Leakey of the famed Kenyan anthropological family who have uncovered a host of critical human and hominid remains in east Africa.

One of the fossils was an upper jaw bone of homo habilis that dated back 1.44 million years.

It was nevertheless more recent than any of the previously found fossils of its kind.

The second was a remarkably well preserved skull of homo erectus, which, paradoxically dates back even further, to some 1.55 million years ago.

"What is truly striking about this fossil is its size," said Fred Spoor of London's University College, one of the paper's lead authors. "It's the smallest homo erectus found anywhere in the world."

This suggests male and female skulls were different sizes -- challenging current thinking.

The discoveries have created a stir among academics tracing humankind's roots, because it challenges the presumed evolutionary timeline of the species: homo habilis to homo erectus to homo sapiens.

"Their co-existence makes it unlikely that homo erectus evolved from homo habilis," said Meave Leakey, one of the lead authors of the paper.

"The fact that they stayed separate as individual species for a long time suggests that they had their own ecological niche, thus avoiding direct competition."

Homo habilis is thought to have lived from about 2.5 million to 1.8 million years ago.

Homo erectus is important because it is believed to be the first hominid to leave Africa.

Meat back on menu

Australian families are turning back to "meat and three veg" as staple fare, according to a new study published in the Nutrition and Dietetics journal.

The study, funded by Meat and Livestock Australia, reveals 88 per cent of Australian households eat red meat at least once a week, while 96 per cent put meat on the table every month.

Meat and Livestock Australia managing director David Thompson says the figure represents a small but significant change in eating habits, and there are a number of reasons behind it.

"People are becoming more aware of the health benefits of fresh food," Mr Thompson said.
"They're becoming disenchanted with processed food. They're responding by going back to more traditional food.

The study found that red meat plays a vital role in child development.

"The nutrients in red meat are so important for childhood development, particularly early childhood," Mr Thompson said.

"Red meat is the major deliverer of iron, zinc and vitamin B12 in our diets, and a little known fact is that it's also second only to seafood in omega-3."

Federal Health Minister Tony Abbott lent his support to the study. "I have always enjoyed red meat," Mr Abbott said. "It's important to rehabilitate red meat as part of the Australian diet. Apart from anything else, red meat is an important Australian industry."

Australians consume 35 per cent of domestic production of red meat.

Japan and the United States are our biggest meat export destinations.