Posted: Thu 01 Oct 2009 16:30 Post subject: Fossils Shed New Light on Human Origins
Quote:
WALL STREET JOURNAL
AFRICA NEWS OCTOBER 1, 2009, 11:48 A.M. ET
Fossils Shed New Light on Human Origins
By ROBERT LEE HOTZ
After 15 years of rumors, researchers in the U.S. and Ethiopia on Thursday made public fossils from a 4.4-million-year-old human forebearer they say reveals that our earliest ancestors were more modern than scholars assumed and deepens the evolutionary gulf separating humankind from today's apes and chimpanzees.
The highlight of the extensive fossil trove is a female skeleton a million years older than the iconic bones of Lucy, the primitive female figure that has long symbolized humankind's beginnings.
An international research team led by paleoanthropologist Tim White at the University of California, Berkeley, unveiled remains from 36 males, females and young of an ancient prehuman species called Ardipithecus ramidus, unearthed in the Awash region of Ethiopia since 1994. The creatures take their scientific name from the word for root in the local Afar language.
"It is not a chimp and it is not human," said Dr. White. "It gives us a new perspective on our origins."
Already, the discoveries have experts reworking the human pedigree. "They are extraordinary fossils," said anthropologist Alan Walker at Pennsylvania State University, who wasn't part of the project. They undoubtedly will shape debates about human origins for years to come, as scholars argue whether these creatures should be counted among our most ancient direct ancestors or cataloged as an intriguing dead-end.
"There are going to be generations of dissertations based on this," said Carol Ward, an independent expert on ancient anatomy at the University of Missouri Columbia.
Documented in 11 research papers to be published Friday in the journal Science, the fossils offer a detailed look at a species of sturdy, small-brained creatures that dwelled in an ancient African glade of hackberry, fig and palm trees, by a river that long ago turned to stone. Despite their antiquity, their bodies were already starting to presage humanity, the scientists said.
Indeed, unlike apes and chimps, they had supple wrists, strong thumbs, flexible fingers and power-grip palms shaped to grasp objects like sticks and stones firmly. They were primed for tool use, even though it would be another two million years or so before our ancestors began to fashion the first stone blades, choppers and axes.
But they were still evolving the ability to walk upright, with a big toe better suited for grasping branches than stepping smartly along, an analysis of their anatomy shows. They made their home in the woods, not on the open savannah grasslands long considered the main arena of human development. Yet their upright posture, distinctive pelvis and other toes suggest they walked easily enough. Most importantly, they showed no sign they walked on their knuckles, as contemporary chimps and apes do.
"They are not what one would have predicted," said anthropologist Bernard Wood at George Washington University. Although the differences between humans, apes and chimps today are legion, we all shared a common ancestor six million years or so ago. These fossils suggest that creature–still undiscovered--resembled a chimp much less than researchers have always believed.
In fact, so many traits in chimps and apes today are missing in these early hominids that researchers now question the notion that modern chimps and apes embody vestiges of our primate past, retaining primitive traits once shared by our ancestors. "We all thought the ancestral animal would look more like a chimp," explained Yale University anthropologist Andrew Hill.
Instead, the new finds show that what seems most ancient about nonhuman primates today–such as canine fangs, long limbs with hooked fingers meant for swinging through trees and hands designed for knuckle-walking--may actually be the product of more recent development, the researchers said.
"It is the chimps and gorillas that have been evolving like crazy in terms of limbs and locomotion, not hominids," said Kent State University anthropologist Owen Lovejoy, a senior scientist on the research team. "We took a different tack. We went social."
The project began with the discovery of a single tooth. But it soon grew into arguably the most comprehensive effort in the field of hominid studies, involving 47 scientists world-wide, as scores of unusually fragile and shattered specimens emerged from the rock. The skull, for example, was in so many pieces it had to be reconstructed digitally, requiring hundreds of CAT scans and 1,000 hours of computer processing. The pelvis alone took six years to reconstruct.
"We took enormous flak" for spending so much time analyzing the fossils, said Dr. Lovejoy. "We wanted to get it right and people had to wait until it was right.'
Posted: Thu 01 Oct 2009 16:49 Post subject: Re: Fossils Shed New Light on Human Origins
Robert Lee Hotz wrote:
"We all thought the ancestral animal would look more like a chimp," explained Yale University anthropologist Andrew Hill.
Instead, the new finds show that what seems most ancient about nonhuman primates today–such as canine fangs, long limbs with hooked fingers meant for swinging through trees and hands designed for knuckle-walking--may actually be the product of more recent development, the researchers said.
"It is the chimps and gorillas that have been evolving like crazy in terms of limbs and locomotion, not hominids," said Kent State University anthropologist Owen Lovejoy, a senior scientist on the research team. "We took a different tack. We went social."
I love it! We do not descend from apes. Apes evolved from us! ROFLMAO!
Posted: Tue 06 Oct 2009 17:11 Post subject: Re: Fossils Shed New Light on Human Origins
fwsweet wrote:
Robert Lee Hotz wrote:
"We all thought the ancestral animal would look more like a chimp," explained Yale University anthropologist Andrew Hill.
Instead, the new finds show that what seems most ancient about nonhuman primates today–such as canine fangs, long limbs with hooked fingers meant for swinging through trees and hands designed for knuckle-walking--may actually be the product of more recent development, the researchers said.
"It is the chimps and gorillas that have been evolving like crazy in terms of limbs and locomotion, not hominids," said Kent State University anthropologist Owen Lovejoy, a senior scientist on the research team. "We took a different tack. We went social."
I love it! We do not descend from apes. Apes evolved from us! ROFLMAO!
I wonder if this discovery will be the key to making evolution more acceptable to those who do not accept it?
Posted: Thu 08 Oct 2009 14:33 Post subject: Re: Fossils Shed New Light on Human Origins
sagascend wrote:
I wonder if this discovery will be the key to making evolution more acceptable to those who do not accept it?
I doubt it. It is a religious thing.
Incidentally, I would not want anyone to misinterpret my little joke above. Our lineage split from that of chimps and gorillas about 5.5 MYA, but our species (H. sapiens) first appeared only about 0.1 MYA.
What I was laughing at was this: The assumption has been that the 5.5 MYA common ancestor of chimps, gorillas, and humans looked more like chimps and gorillas (long canines, long arms, poorly adapted for running, knuckle-walking, etc.) than like humans. It now seems that the assumption was wrong, and the 5.5 MYA common ancestor looked more like humans (from the neck down) than like modern-day chimps and gorillas, whose knuckle-walking adaptations seem to be more recent. I said "from the neck down" because our extraordinary brain is unique to our genus and began to expand within the past 1-2 MY.
This is truly fascinating and illuminating research! So, evolution does not always involve a progression towards the traits we modern people prize. "Knuckle walking", long cannines, and other ape and chimp features, are clever adaptations for animals which took a different path. These characteristics aren't "primitive" at all, they are actualy, relatively advanced!
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