Rhino
Sat, Mar-29-08, 06:16
Volume 61 Number 1, January/February 2008 by Zach Zorich
KNM-ER 42700 and KNM-ER 42703 • Lake Ileret, Kenya
Whether they are mother-and-daughter species or two sisters,
the relationship between Homo habilis and Homo erectus is
becoming strained. A pair of discoveries near Lake Ileret in
Kenya call into question the idea that H. erectus, the species
from which modern humans evolved, is descended from H.
habilis, the earliest hominid known to use stone tools.
A team of paleoanthropologists led by Meave and Louise Leakey
of the Koobi Fora Research Project uncovered the upper jawbone
of a H. habilis dated to 1.44 million years ago, and the skull
of a H. erectus dated to
1.55 million years ago. H. habilis was thought to have
gradually evolved into H. erectus over hundreds of thousands
of years, fading out of existence around 1.65 million years
ago. A previously discovered H. erectus fossil dated to 1.9
million years combined with the new finds show the two
species lived together in the same lake basin for close to
500,000 years.
The discovery of a Homo habilis jawbone and a Homo erectus
skull that are close in age has paleontologists rethinking the
idea that H. habilis evolved into H. erectus. (National
Museums of Kenya/Fred Spoor)
"I think increasingly they will be recognized as sister
species that lived in the same area and did different things,"
says Fred Spoor of University College London and a member of
the team. H. erectus' smaller teeth and less powerful jaws
suggest it was probably eating more meat. If the two species
both evolved from a common ancestor, it changes the human
race's relationship to H. habilis. "Strictly speaking, if our
scenario is correct," says Spoor, "Homo habilis, as we know
the species, seems to be a dead branch."
KNM-ER 42700 and KNM-ER 42703 • Lake Ileret, Kenya
Whether they are mother-and-daughter species or two sisters,
the relationship between Homo habilis and Homo erectus is
becoming strained. A pair of discoveries near Lake Ileret in
Kenya call into question the idea that H. erectus, the species
from which modern humans evolved, is descended from H.
habilis, the earliest hominid known to use stone tools.
A team of paleoanthropologists led by Meave and Louise Leakey
of the Koobi Fora Research Project uncovered the upper jawbone
of a H. habilis dated to 1.44 million years ago, and the skull
of a H. erectus dated to
1.55 million years ago. H. habilis was thought to have
gradually evolved into H. erectus over hundreds of thousands
of years, fading out of existence around 1.65 million years
ago. A previously discovered H. erectus fossil dated to 1.9
million years combined with the new finds show the two
species lived together in the same lake basin for close to
500,000 years.
The discovery of a Homo habilis jawbone and a Homo erectus
skull that are close in age has paleontologists rethinking the
idea that H. habilis evolved into H. erectus. (National
Museums of Kenya/Fred Spoor)
"I think increasingly they will be recognized as sister
species that lived in the same area and did different things,"
says Fred Spoor of University College London and a member of
the team. H. erectus' smaller teeth and less powerful jaws
suggest it was probably eating more meat. If the two species
both evolved from a common ancestor, it changes the human
race's relationship to H. habilis. "Strictly speaking, if our
scenario is correct," says Spoor, "Homo habilis, as we know
the species, seems to be a dead branch."