what's in a tooth?

[Guest guest]

Meat eating is an old human habit

Humans evolved beyond their vegetarian roots and became meat-eaters at the

dawn of the genus Homo, around 2.5 million years ago, according to a study

of our ancestors' teeth.

In 1999, researchers found cut marks on animal bones dated at around 2.5

million years old. But no one could be sure that they were made by

meat-eating hominids, because none appeared to have suitable teeth.

Now an analysis by Ungar of the University of Arkansas has revealed

that the first members of Homo had much sharper teeth than their most likely

immediate ancestor, Australopithecus afarensis, the species that produced

the famous fossil Lucy.

Eating meat requires teeth adapted more to cutting than to grinding. The

ability to cut is determined by the slope of the cusps, or crests. " Steeper

crests mean the ability to consume tougher foods, " Ungar says. He has found

that the crests of teeth from early Homo skeletons are steeper than those of

gorillas, which consume foods as tough as leaves and stems, but not meat

Ripe fruit

But the crests of teeth from A. afarensis are not only shallower than those

of early Homo, they are also shallower than those of chimpanzees, which

consume mostly soft foods such as ripe fruit, and almost no meat.

" Ungar shows that early Homo had teeth adapted to tougher food than A.

afarensis or [chimpanzees]. The obvious candidate is meat, " says

anthropologist Wrangham of Harvard University.

Ungar used a laser to scan each tooth and mapped the surface as though it

were a landscape, using a geographic information system, he told a symposium

on diet and evolution at the University of Arkansas in August.

He had to find a way to compare teeth already worn by use, because unworn

teeth are extremely rare in fossils. In a previous study on the teeth of

gorillas and chimps, he validated the technique by showing that the

differences between species' teeth remain constant however much they are

worn down (Proceedings of the National Academy of Sciences, vol 100, p

3874).

Suze Fisher

Lapdog Design, Inc.

Web Design & Development

http://members.bellatlantic.net/~vze3shjg

Weston A. Price Foundation Chapter Leader, Mid Coast Maine

http://www.westonaprice.org

----------------------------

" The diet-heart idea (the idea that saturated fats and cholesterol cause

heart disease) is the greatest scientific deception of our times. " --

Mann, MD, former Professor of Medicine and Biochemistry at Vanderbilt

University, Tennessee; heart disease researcher.

The International Network of Cholesterol Skeptics

<http://www.thincs.org>

----------------------------

[Guest guest]

oops! forgot to provide the link for that article:

http://www.newscientist.com/news/news.jsp?id=ns99994122

Suze Fisher

Lapdog Design, Inc.

Web Design & Development

http://members.bellatlantic.net/~vze3shjg

Weston A. Price Foundation Chapter Leader, Mid Coast Maine

http://www.westonaprice.org

----------------------------

" The diet-heart idea (the idea that saturated fats and cholesterol cause

heart disease) is the greatest scientific deception of our times. " --

Mann, MD, former Professor of Medicine and Biochemistry at Vanderbilt

University, Tennessee; heart disease researcher.

The International Network of Cholesterol Skeptics

<http://www.thincs.org>

----------------------------