Stephanie Pappas, LiveScience (August 11, 2010)
"The timeline of early human evolution needs another revision with the discovery that human ancestors used tools 800,000 years earlier than previously realized.
"The finding in Ethiopia, a pair of mammalian fossil bones marred by tool marks, pushes tool use back into the age of Australopithecus afarensis, an early human ancestor that lived in east Africa 3 million to 4 million years ago.
"Archaeologists previously believed that early human ancestors, or hominins, [not a typo1] started using tools 2.5 million years ago. That's when evidence shows one of the first Homo species, Homo habilis, began butchering meat with sharpened stones. (Our species, Homo sapiens, didn't show up until about 200,000 years ago.) But the new find is approximately 3.39 million years old, older than the famous Australopithecus fossil "Lucy," who lived near the find site 3.2 million years ago...."
Those bones aren't all that impressive at first glance. Their age, and parallel cuts that don't look like tooth marks - and do look like what happens when someone cuts meat off bone with a sharp rock - make them evidence of tool use. Evidence of really, really early tool use.
And, as often happens when new data is discovered, existing theories have to be revised - and maybe filed as something that made sense at the time.
"...Pinning down the emergence of stone tools and meat-eating is key for understanding our evolutionary history, the researchers said. Until now, the use of tools seemed linked to an increase in brain size in hominins, prompting theories that the extra calories from butchered meat fed our ancestors' growing brains. The realization that both meat-eating and tool use significantly predate the Homo genus could force another look at those theories.
" 'There had long been an association between tool use and our genus,' said David Braun, an archaeologist at the University of Cape Town, who was not involved in the research but penned a commentary on the findings in Nature. 'That doesn't seem to be the case anymore.'..."
One thing that's missing are the tools themselves. We can make educated guesses about what they were like from the marks they left on bones: but without the sharp rocks themselves, there's no way to tell whether somebody modified a stoke to make a stone tool - or just found a conveniently sharp-edged stone.
Tool use isn't tool making - and the distinction is important. To paleontologists studying how we got to be what we are, anyway.
In this case, though, even tool use is impressive. Odds are the stone used had been carried to the site where the bones were found - from a source over a mile away. That implies a modest amount of planning.
I'm not terribly surprised by this discovery. I've been interested in paleontology for about a half-century, and noticed a pattern where humanity's background is concerned. In general, things happened earlier than we thought they did.
In the case of these 3,390,000-years-old bones, about 800,000 years earlier.
- "Homo Erectus, Kitchens, and Human (Pre)History"
(December 21, 2009)
- " 'Journey of Mankind:' 160,000 Years of Ups and Downs"
(November 1, 2007)
Related posts, at
1 "Hominin" seems to be a newish term, and not - as I thought at first, a typo. More:
What's a nice Catholic guy like me doing, writing about evolution? The short answer is: being interested in this creation. I've discussed this before:
- "Age of the Earth, Illustrated: Almost A Century Ago"
(August 10, 2010)
- "Copernicus, Galileo, Science and a Reality Check"
A Catholic Citizen in America (October 26, 2009)
- "Trilobites, Arthropods, Evolution, and Why Mothra Isn't Real"
(October 17, 2009)
- "Dinosaurs, Mutant Chickens, Evolution, and Faith in God"
A Catholic Citizen in America (June 29, 2009)
- "Vatican Says: 'Belief in Aliens Doesn't Contractict Faith' "
(May 14, 2008)