ARCHAEOLOGY-KENYA: Scientists Discover Oldest Ancestor

By IPS Correspondents Reprint | | Print |

Judith Achieng'

NAIROBI, Dec 4 2000 (IPS) - A team of scientists say they have discovered the oldest known ancestor of the human race.

The ancestor, they claim, existed some six million years ago and is much closer to humans than the earlier discovered pre- historic hominids.

The latest discovery named, “millennium ancestor”, challenges the 1994 discovery in Ethiopia, of a hominid thought to be 4.5 million years old.

The team, composed of Kenyan and French scientists, say the discovery puts to challenge previously held views of the earliest stages of the pre-human origins.

It also provides key information about the things like posture, locomotion and dietary habits not well explained in the case of other early fossils.

“They are older and more human than the first hominids. It will definitely need (a) rethinking of existing ideas of the origins of human beings,” French researcher Brigitte Senut, of the Paris based Museum National d’Histoire Naturelle, said here.

“This is a way of opening minds. It is a challenge and we hope it will be challenged by another discovery,” she told reporters here.

The fossils were discovered in the Tugen Hills in Kenya’s Rift Valley province, close to President Daniel arap Moi’s birthplace.

Specimen was collected from a number of locations – including Kapsomin, Kapcheberek, and Aragai – bringing to five the number of hominid individuals represented in the collection.

The first of the specimens was discovered on Oct 23 by a local resident of the area, Kiptalam Cheboi, in an erosion gully with sedimentary strata dating back to six million years.

Until now, the earliest hominid known was the Ardipithecus ramidus, or “ground man – root” discovered in Aramis, Ethiopia in 1994.

It was, however, difficult for scientists to determine whether the A. ramidus was bipedal since most of its hip bones and femurs were missing.

The remains of the “millennium ancestor”, according to the researchers Senut and Martin Pickford of College de France, consist of pieces of jaws with teeth as well as isolated upper and lower teeth.

Pieces from arms, legs and finger bones were also discovered in three localities near the village of Rondinin.

The scientists explained that the three femur bones in the collection had been chewed, indicating that the individuals to which they belonged had probably fallen prey to a carnivorous animal.

From the femur bones, or the thighbone, usually the longest and thickest bone in the human skeleton, the scientists deduced that the male of the species is much larger than the female who, they deduce, is nearly the size of a chimpanzee.

Preliminary studies conducted by the scientists, on the arms and finger-bones, reveal that the Kapsomin hominid was an agile climber of trees while its leg bones indicate that it walked on two feet.

“We can’t say that this is the ancestor, but we say there is a creature that climbed trees and had all the features of humans,” Senut told reporters here.

The scientists noted that some of the teeth are human like, even though the canines are much larger than humans but smaller than those of apes.

This description of the teeth reveals that the species was omnivorous, fruits being its most preferred diet. “Some of the teeth, are primitive, while others are remarkably modern,” noted Pickford.

Two separate tests, one in the 1970s by British experts and the other in the 1980s by American experts, have dated the layers of lava, from which the fossils were recovered, at six million years.

The paleontology expedition is part of a collaborative research project between the Community Museums of Kenya, and the Paris based College de France.

There are about 200 such fossil sites in Tugen alone, but Kenya has no practising paleontologist. “Unless other people come in, such heritage will be lost,” laments Eustace Gitonga, who heads the team.

Kenya, Tanzania and Ethiopian soils are considered among the richest in fossil deposits, due to their ability to preserve fossils, an attribute credited to its non acidic nature.

Tanzania is famous for the first hominid fossils discovered at Olduvai Gorge. “If the sediments were acidic, the fossils would definitely be destroyed,” said Pickford.