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Familiar Fossils
of all later hominids ... the ancestor of the human lineage.”
Harvard anthropologist Daniel Lieberman commented, “This
will have the impact of a small nuclear bomb” in the field of
human evolution.” The reason? Till date, eastern Africa had
been thought to be the cradle of human evolution. If Brunet’s
group is correct, hominids must have become distinct from
chimpanzees significantly earlier than that, spreading out
across central and east Africa in the age before Toumaï walked
the Earth. It hints at, “…an early
Sahelanthropus
pan African distribution of
tchadensis is
hominids (at least from 6 million
Toumaï to those
years ago) and an earlier
who know him
chimpanzee-human divergence
well. When an
(at least as early as 7 million
ancient fossil skull
years ago) than previously
with features more
indicated by most of the
akin
to
modern
molecular studies.”
humans
was
However, other scientists
excavated in Chad, the
are not convinced that Toumaï
name Toumaï seemed
is worthy of the crown being
Reconstructed Banjo skull
absolutely appropriate. Toumaï or “Hope
placed on his bony skull. They
of Life” is what children born before the
are of the opinion that Toumaï
dry season in the Djurab desert are called.
is very “apelike”. Milford Wolpoff, University of Michigan, USA
Toumaï’s skull was found by Ahounta Djimdoumalbaye, believes Toumaï is not human. He said, “We think Toumaï is
undergraduate Life Science student at the University of
an ape and we think it’s probably a female because of its
N’Djamena, on 19 July 2001. He was working with an canine teeth.” Surprisingly, Wolpoff and his colleagues studied
international team consisting of scientists from ten countries. the same parameters that Brunet and his colleagues had but
The Franco-Chadian Paleoanthropological Mission was concluded that Toumaï was not a hominid. The crux of the
led by the University of Poitiers’(France) Michel Brunet. argument being that the evidence from the marks left by the
Toumaï is considered a new hominid, a new genus and new neck muscles on the skull indicate that Toumai did not
species.
habitually hold its head in an upright position and was thus
Toumaï’s Latin name pays homage to Africa’s Sahel region not a biped. “I expect it could hold its head upright; any ape
–the discovery site and to Chad, the country where he was can,” said Wolpoff. “What the bone reflects, through the
found along with other fauna from about 7 million years ago. position and size of the scars left by the neck muscles, is that
The research journal Nature describes Toumaï’s skull in
it did not habitually keep its head in that position.”
almost poetic terms, “At between 6 and 7 million years old,
Brunet objected saying that that this analysis based on
this skull is the earliest known record of the human family.” measurements taken from published photographs of the skull
Interestingly, this area where the most ancient hominid skull
is distorted. “Undistorted, the evidence left by the neck
was excavated has been called “virtually virgin territory for muscles is within the range of fossil hominids and is nothing
anthropologists before Brunet’s group came on the scene.” like that of any quadrupedal ape.”
Toumaï is the only relatively complete fossil discovered in a
In 2005, when some more fossil bones were discovered,
fossil gap of five million years between the ancestral apes of scientists “unmangled” the skull and “performed a virtual
nine million years ago and the australopithecines from four reconstruction…” They had to do computer studies as opposed
million years onward.
to a “hands-on” study because the skull, … “is heavily
Toumaï’s remains are fragmentary. What has actually mineralized and distorted. It is impossible to do one by
been recovered are a nearly complete, although badly physical means…” Their reconstruction confirmed that
distorted, cranium, two lower jaw fragments and three isolated Toumaï shared key features with later hominids. The foramen
teeth. He would have had ape-like brain size and skull shape, magnum – where the spinal cord exits the skull – is similar to
a human-like face and teeth. He had a remarkably large brow- that in humans than to apes, suggesting Toumaï walked
ridge, rather like that of hominids. Limbs have not been found. upright.
So it is conjectural to say if he walked on all fours or was a
Perhaps Professor Chris Stringer, Head of Human Origins,
biped. Yet, Toumaï’s undisputed claim to fame is that he dates Natural History Museum, London, was right in saying that
to a “crucial yet little-known interval” when the human lineage there is growing evidence that human evolution was “bushy”
was separating from the lineage that leads to chimpanzees. rather than linear.
The skull is definitely an interesting combination of primitive
The controversy goes on… making the telling of the tale
and more modern characteristics.
all the more tantalizing.
Brunet and colleagues studied the tooth type, thickness
of the enamel, the shape and position of the head, and facial
Dr Sukanya Datta, Scientist NISCAIR posted to Director General's Technical
features before claiming that Toumaï may be “…the ancestor
Cell, CSIR HQ, Email: [email protected]
Toumaï’s
Tantalizing Tale
SCIENCE REPORTER, OCTOBER 2011
60