SCIENTISTS FIND NEW HUMAN SPECIES IN NORTHERN KENYA

Fossils from Northern Kenya show
that a new species of human lived
two million years ago, researchers
say.
The discoveries suggest that at
least three distinct species of
humans co-existed in Africa.
The research adds to a growing
body of evidence that runs
counter to the popular perception
that there was a linear evolution
from early primates to modern
humans.
The research has been published
in the journal Nature.
Anthropologists have discovered
three human fossils that are
between 1.78 and 1.95 million
years old. The specimens are of a
face and two jawbones with teeth.
The finds back the view that a skull
found in 1972 is of a separate
species of human, known as
Homo rudolfensis. The skull was
markedly different to any others
from that time. It had a relatively
large brain and long flat face.
But for 40 years the skull was the
only example of the creature and
so it was impossible to say for
sure whether the individual was
an unusual specimen or a
member of a new species.
With the discovery of the three
new fossils researchers can say
with more certainty that
H.rudolfensis really was a
separate type of human that
existed around two million years
ago alongside other species of
humans.
For a long time the oldest known
human ancestor was thought to
be a primitive species, dating back
1.8 million years ago called Homo
erectus. They had small heads,
prominent brows and stood
upright.
But 50 years ago, researchers
discovered an even older and
more primitive species of human
called Homo habilis that may have
coexisted with H. erectus. Now it
seems H. rudolfensis was around
too and raises the distinct
possibility that many other species
of human also existed at the time
This find is the latest in a growing
body of evidence that challenges
the view that our species evolved
in a smooth linear progression
from our primate ancestors.
Instead, according to Dr Meave
Leakey of the Turkana Basin
Institute in Nairobi, who led the
research the find shows that there
was a diversity early on in the
evolution of our species.
"Our past was a diverse past," she
told BBC News, "our species was
evolving in the same way that
other species of animals evolved.
There was nothing unique about
us until we began to make
sophisticated stone tools."
In other groups of animals many
different species evolve, each with
new traits, such as plumage, or
webbed feet. If the new trait is
better suited to the environment
then the new species thrives, if
not it becomes extinct. According
to Professor Chris Stringer of the
Natural History Museum in
London, fossil evidence is
increasingly suggesting that
human evolution followed the
same pattern.
"Humans seem to have been
evolving in different ways in
different regions. It was almost as
if nature was developing different
human prototypes with different
attributes, only one of which, an
ancestor of our species, was
ultimately successful in
evolutionary terms," he said.
According to Dr Leakey, the
growing body of evidence to
suggest that humans evolved in
the same way as other animals
shows that "evolution really does
work".
"It leads to amazing adaptions
and amazing species and we are
one of them," she said.
-BBC