Charles Q. Choi, LiveScience (May 2, 2011)
"The strong-jawed human relative nicknamed "Nutcracker Man" likely didn't crack nuts at all, preferring to graze on grass like a cow instead, scientists find.
"These findings could dramatically alter conventional wisdom regarding what the earliest members of the human lineage and their relatives ate.
"The extinct hominid, officially called Paranthropus boisei, ranged across East Africa 1.2 million to 2.3 million years ago, living side-by-side with the direct ancestors of humanity. It earned its nickname because of its massive jaw and huge molars...."
"...It was long assumed that because of its powerful jaw, P. boisei lived up to its nickname and ate nuts, seeds and other hard items. Still, a recent study of its teeth did not turn up the kind of pitting one would expect from hard meals, hinting that it actually dined on softer fare.
Now scientists investigating carbon isotope ratios in Nutcracker Man's teeth found 'it most likely was eating grass, and most definitely was not cracking nuts,' Cerling said...."
"...'...No living ape feeds mostly on grass, and the practice is rare among primates. "There is one primate that is primarily a grass-eater, the gelada baboon in Ethiopia,' Cerling told LiveScience, and Ungar noted the wear and tear seen on P. boisei teeth 'looks very similar to that of the gelada baboon.'..."
Eating grass seems to be a sort of good news-bad news situation.
On the one hand, grass grows like - well, like grass. It's a very common plant.
On the other hand, back when Paranthropus boisei was around, ancestors of zebras, pigs, warthogs and hippos were in the neighborhood: also eating grass.
Maybe that's why P.b. is extinct, and we're not. There's probably more to it than that: in the Lemming's opinion.
That LiveScience article gives a little of the technical side of how researchers worked out what isotopes were in those big teeth:
"...The researchers drilled enamel off 24 teeth collected in central and northern Kenya from 22 P. boisei that lived between 1.4 million and 1.9 million years ago. They pulverized approximately 2 milligrams of enamel per tooth to look at the carbon isotopes within. All carbon isotopes have six protons in their atoms, but they differ from each other in how many neutrons they have in their nuclei -- for instance, carbon-12 has six, while carbon-13 has seven.
"By looking at the carbon isotope ratios in tooth enamel, scientists can decipher the past diet. The method relies on the type of carbon used in photosynthesis, the process in which carbon dioxide and water, with energy from the sun, are turned into food for certain plants. For instance, trees and the leaves, nuts and fruits they produce, as well as shrubs, herbs and cool-season grasses, all rely on C3 photosynthesis, which prefers carbon-12, while tropical grasses and sedges such as papyrus rely on C4 photosynthesis, where both carbon-12 and the heavier carbon-13 isotope are used...."
(LiveScience)
Fascinating stuff, in the Lemming's opinion: although your experience may vary.
Somewhat-related posts:
- "New Clue in Human Evolution: It's All in the Wrist"
(January 28, 2011) - "Growing Up Neanderthal: Another New Look"
(November 15, 2010) - "Homo Gautengensis: Big Teeth, Tiny Brain, Fire, Stone Tools; and a New Puzzle"
(May 21, 2010) - "Neanderthals and Me: New Data About Old Relatives"
(May 7, 2010) - "Homo Erectus, Kitchens, and Human (Pre)History"
(December 21, 2009)
How the Lemming sees science, religion, and all that:
- "God's Creation: He Seems to Think Big"
A Catholic Citizen in America (September 23, 2010) - "Copernicus, Galileo, Science and a Reality Check"
A Catholic Citizen in America (October 26, 2009) - "Faith and Reason, Religion and Science"
A Catholic Citizen in America (March 20, 2009)
Particularly - "Catholic Church, Creationism, Evolution, Facts and Faith"
A Catholic Citizen in America (March 5, 2009)
No comments:
Post a Comment