You Are What You Eat? Maybe Not the Case for Ancient
By Audrey Huang
Johns Hopkins Medicine
Careful analysis of microscopic abrasions on the teeth
of early human "cousins" by researchers
at Johns Hopkins, University of Arkansas, University of
Cambridge and Stony Brook University show
that although equipped with thick enamel, large jaws and
powerful chewing muscles, this ancient
species may not have eaten the nuts, seeds or roots their
anatomy suggests. Instead, the tooth wear
suggests a more general diet, as reported April 30 in
Public Library of Science One.
"For so many years we've operated under the assumption
that the shape of something's teeth,
jaws and skull tells us what they habitually ate," said
Mark Teaford, a professor of anatomy at Johns
for Functional Anatomy and Evolution. "But it seems
like we had the wrong idea. Just
because they're capable of eating hard foods doesn't mean
that they did. It really makes us rethink
some of our basic assumptions."
Using high-powered microscopy to scan tooth surfaces,
and computer programs that measure
imperfections on the surfaces of teeth, the researchers
analyzed tooth surfaces from Paranthropus
boisei from eastern Africa. According to most researchers,
P. boisei's jaw and tooth structure was so
specialized and extreme it must have had a very specialized
diet. In fact, its anatomy gave it the
nickname "Nutcracker Man."
Measuring the microwear from permanent molars of P.
boisei from Ethiopia, Kenya and Tanzania
dating from 2.27 million years ago to about 1.4 million
years ago, the team compared its results with
microwear from living primates and other fossils. The
researchers found that P. boisei teeth had very
little pitting indicative of eating hard foods.
"It seems that while they were perhaps capable of
eating harder foods, they generally didn't,"
Teaford said. "We see similar situations in modern
primates, who often like soft fruit. But they can't
find that all the time, so occasionally they'll eat harder
or tougher foods if they have to."
"Looking at P. boisei, you think, 'Wow, it's a chewing
machine,' but that's really an
oversimplification. It may not have been so specialized,"
The research was funded by the National Science
Authors on the paper are Peter Ungar, of the
University of Arkansas; Frederick Grine, of Stony
Brook University and the University of Cambridge; and
Teaford of Johns Hopkins.
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