may the force be with you

NAIROBI (AFP) - Four-million-year-old remains in Ethiopia have provided the first hard proof of a link between two key stages of human evolution by bridging the gap between pre-human species, paleontologists said.

"For the first time, we found fossils that allow us to connect the first phase of human evolution and the second phase," Dr Berhane Asfaw, anthropologist and co-research director of the project that found the remains, told a news conference Wednesday in Addis Ababa.

"The fossils represent unambiguous evidence for human evolution," he said.

The remains of eight individuals found in the northeastern Afar region of Ethiopia belonged to the species Australopithecus anamensis -- part of the Australopithecus genus thought to be a direct ancestor to humans, according to a report due to be published Thursday in Nature magazine.

"The fossils are anatomically intermediate between the earlier species Ardipithecus ramidus and the later species Australopithecus afarensis," he said.

The fossils were found by a team directed by the paleoanthropologist Tim White from the University of California, Berkeley, working in the Asa Issie site in the Middle Awash area, 230 kilometres (143 miles) north of Addis Ababa.

The ecology of the surrounding area indicated that the specimens were forest-dwellers, the Nature report said.

In 1992 White found remains of a more primitive hominid, Ardipithecus ramidus, which inhabited the region around the same time as the anamensis species. But no evolutionary link between them has been established until now.

The origin of Australopithecus is a key problem in the study of human evolution and a contentious subject among anthropologists. Some see them as early ancestors to humans, while others believe they represent a dead branch of the hominid genealogical tree.

A notable specimen of the newly found fossil's descendant species Australopithecus afarensis, a three-million-year old fossil nicknamed Lucy, was discovered in 1974.

"We have proved that one (species) is transforming into the other, so this evidence is important to show that there is human evolution... that human evolution is a fact and not a hypothesis," Asfaw said.

The anamensis species had previously been found in the Lake Turkana region of Kenya, but a link between the earlier and later stages of evolution could not be proven until anamensis was found in the same area as the other species.

"The ecological setting where we found the fossils shows that the first phase of the human evolution took place in the forest," he said. "They started moving out of the forest only after anamensis."

Ethiopia is "the cradle of humanity", according to Nature. All three of the species linked together by the new finds were found in Ethiopia.

"It is the only place in the world where the three phases of evolution could be documented and proved," Asfaw said.

"All (three species) were able to be found in one place, proving that evolution is a fact," Asfaw said. "Successive records that we see here prove that the Afar region is the origin of human kind."

source:http://news.yahoo.com/s/afp/sciencepaleontology;_ylt=Apq73Z7wNWOFRgnKBqGgy9wDW7oF;_ylu=X3oDMTBhcmljNmVhBHNlYwNtcm5ld3M-