Thursday, September 8, 2011

Nearest Ancestor Of Man Can Take Step In Our Development

Nearest Ancestor Of Man Can Take Step In Our Development
A surprising mix of primitive and found in the human brain, hips, feet and hands of an extinct species identified last year to make a strong case to be the immediate ancestor of mankind, the scientists announced.
These new results could be much time to write the exact steps in the theories of human evolution has also added the idea that the first human female pelvis can be printed on the changed nature of the larger brain of the offspring. In addition, new evidence shows that this species was in the hands of a toolmaker.Fossil hominid known as Australopithecus disappeared sediba was accidentally discovered by the 9 year old son, a scientist in the rest of a cave in South Africa in 2008, the detailed findings by researchers at the last year. Australopithecus means "southern ape" and is a group that includes the iconic fossil Lucy, then sediba means "source" of the Sotho South African language. [See images of the ancestor of man]
Two samples were found clues - a juvenile male that was developed as a 10 - to man 13 years old and an adult may be about 20 years late or 30 years. The species is both a hominid and hominid - Hominids are humans, chimpanzees, gorillas and their extinct ancestors, while hominids include cash, after Homo, the human lineage separated from that of chimpanzees.
To begin to see where the gold. sediba could fit into the family tree, researchers identified the age of fossils dating from the surrounding sediments calcified advanced uranium-lead dating techniques and a method called paleomagnetic dating, which measures the number of times the magnetic field Earth reversed. Who discovered the fossils were 1.977 million years old, which predates the first appearance of specific traits in the human lineage Homo in the fossil record. Here. sediba or less the same age that hominids such as Homo habilis and Homo rudolfensis, which were considered as potential ancestors of Homo erectus, the first undisputed predecessor of modern man. [10 things that make humans special]
"Since the first fossil human ancestors to grow, we need to give more accurate is becoming critical," said researcher Robyn Pickering at the University of Melbourne in Australia.
Small but how the human brain
Most aspects of the AU. sediba display has an intriguing mixture of suspicion, both human and more primitive than it could be an intermediate form between Australopithecus and Homo.
"The fossils show an incredibly long, but the small brain, a well-developed long-hand thumb, as a man, very modern, hip, leg and ankle, but never seen any form of hominid species, which combines features of both apes and humans together with anatomical package, "said the scientist Lee Berger, a paleoanthropologist at the University of the Witwatersrand in Johannesburg, South Africa. "Many of the more advanced features found in the brain and body, and the former makes it perhaps the best candidate for the ancestor of our family, genus Gay, the most previous findings, as Gay habilis."
The brain is often considered what distinguishes mankind from the rest of the animal kingdom, and the juvenile specimen of the AU. sediba was exceptionally well-preserved skull that may shed light on the pace of brain evolution in early hominids. For more information, the researchers scanned the space in the skull where his brain has been using the European Synchrotron Radiation Facility in Grenoble, France, the result is the most accurate scanner ever built by an early human ancestor, with a level detail up to 90 microns, or just below the size of a human hair.
The analysis revealed Au. sediba had a brain smaller than that seen in humans with an adult version can only be as large as the size of a grapefruit. However, it was similar to the human in many ways - for example, the orbitofrontal region directly behind the eyes, apparently, expanded to be more like the frontal lobe of a human form. This region is associated with humans in higher mental functions such as multitasking, a skill that can contribute to the human capacity for long-term planning and innovative behavior.
"We could see the beginning of capabilities," said researcher Kristian Carlson at the University of Witwatersrand LiveScience.
These new findings cast doubt on the old theory that the brain gradually increase in size and complexity of Australopithecus to Homo. Instead, their results support a different idea - that the brain does Australopithecus gradual increase in complexity, more and more like Homo and later increased in size rapidly.
Hips modern
This mosaic of primitive and modern was the case with your hips as well. A partial analysis of the pool of women to par. sediba revealed that he had modern features, similar to humans.
"It 'amazing to find such a basin made a creature so small brain," says research scientist at the University of the Witwatersrand Labor Kibii. "It 'a short and wide as the human pelvis ... parts of the basin can be separated from the people."
The researchers thought that wider hips developed human-like brains of offspring. New results of the human pelvis as Au. sediba despite the small brain of the offspring suggests pelvis may instead be that originally developed to help improve this hominid could wander through the landscape began to expand throughout the grassland habitats.
When he came to leave, to examine the feet and ankles fossils revealed surprises about the. sediba could have went around the world. No hominin ankle has never been described with such primitive and advanced characteristics.
"If the bones had been found stuck, the computer may be described as belonging to different species," said researcher Bernhard Zipfel, University of Witwatersrand.
The researchers found that the ankle joint is more often than humans, some evidence of human learning as well - efined Achilles tendon, but the bones of the heel and Shin seem to be the most ape-like. This suggested hominid probably also climbed trees still Halkida in a unique way, not exactly like humans.
In general, these anatomical features have enabled the couple. sediba to walk so you can be more energy efficient, with tendon energy storage and return of this energy for the next step, said researcher Steve Churchill of Duke University in Durham, North Carolina "are kinds of things to do with the genus Homo, "he said.
What is beautiful in the hands of ...
Finally, the analysis of Au. sediba hands could have been referring toolmaker. Fossils - the most complete manual is already known hominid, missing only a few bones, and belonged to an adult female individual - has shown the other hand, was capable of strong attachment to the need for tree-climbing, but it was also a inch long and short fingers. These would make it possible to extract useful precision instruments, one of which is just the thumb and fingers with the palm does not play an active role.
In total, the hand of the AU. sediba has more features related to the manufacture of tools of the human species first seen as a user of the tool, the "handyman" Homo habilis, researchers said Tracy Kivell at the Max Planck Institute of Anthropology developments in Germany. "This suggests that sediba may also have been a toolmaker."
Although scientists have excavated the site for stone tools, hand "and the morphology of the brain suggest that the Au. Sedibe may have had the ability to make and use complex tools," said Kivell.
Scientists warn that, although they suggest that the Au. sediba was an ancient human lineage, all these apparent similarities between this and we may just be coincidence, this extinct species evolving similar characteristics because of our race, perhaps, that in similar circumstances. [Top 10 Missing Links]
In fact, it can be just as interesting to imagine that the. sediba are not the direct ancestors of Homo, as it opens the possibility "of independent evolution of similar characteristics," Carlson said. "Whether on the same line leading to Homo, I think there are issues interesting and implications. "
The scientists detailed their findings in September 9th issue of the journal Science.

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