"...Recent sequencing of
ancient Neandertal DNA suggests that their
common ancestor with modern humans lived
a bit less than 500,000 years ago, quite likely
in Africa (Science, 13 February, p. 870).
Some researchers call this common ancestor
H. heidelbergensis, although they disagree
about which fossils to group in that species.
In his talk at Gibraltar, Tattersall argued that
the real evolutionary picture might be much
more complicated..."
"...Tattersall agreed that some fossils—
including the 225,000-year-old Steinheim
skull found near Stuttgart, Germany, and a
400,000-year-old skull from Swanscombe,
England—might fit Hublin’s “accretion
model.” But others, he said, emphatically do
not. The big stumbling block is one of the
most spectacular fossil finds in the history of
paleoanthropology: the discovery since the
mid-1990s of thousands of bones from some
28 hominin individuals at the cave site
of Sima de los Huesos in northern Spain
(Science, 2 March 2001, p. 1722). The published
finds include four hominin skulls with
both Neandertal-like and non-Neandertal features.
And the team working at the site, co-led
by anthropologist Juan Luis Arsuaga of the
Complutense University of Madrid, has
assigned its fossils to H. heidelbergensis.
The Sima fossils were f irst dated to
about 350,000 years ago. But more recent
uranium-series dating, led by geochronologist
James Bischoff of the U.S. Geological
Survey in Menlo Park, California, suggests
that they are at least 530,000 years old. That
would make them as old as or older than
“classic” H. heidelbergensis fossils from
southern France, Greece, and other places—
fossils that the Sima skulls don’t much resemble,
Tattersall insisted. Tattersall concludes
that two or more hominin lineages must have
existed side by side in Europe for several hundred
thousand years before H. sapiens arrived
from Africa. One line led to the Neandertals
and may have included the Sima fossils;
another, rightly called H. heidelbergensis,
went extinct while the Neandertals lived on
until at least 30,000 years ago..."
Jim Bischoff is having a heyday recently!
See:
http://www.archaeologyfieldwork.com/forums/viewtopic.php?t=6082"...Tattersall then looked at Arsuaga, who
was sitting in the audience waiting to speak
next: “My central plea is to the colleagues
who assigned the Sima de los Huesos fossils
to H. heidelbergensis. They are clearly not
Neandertals, but not being a Neandertal does
not make them H. heidelbergensis. They need
another name.” A hush fell over the room as Tattersall sat
down and Arsuaga got up to speak. To nearly
everyone’s surprise, Arsuaga agreed that the
Sima de los Huesos skulls looked nothing
like other H. heidelbergensis specimens. Nor,
he said, do 13 other skulls his team had
recently excavated there. “We have always
said that we put the Sima hominins under the
H. heidelbergensis umbrella for convenience,
for practical reasons,” Arsuaga said, adding
that his team agrees with Tattersall that the
accretion scenario is not likely. But he resisted
Tattersall’s call to rename the Sima fossils,
at least until the remaining 13 skulls are published
in coming months..."
"...Chris Stringer, a paleoanthropologist at the
Natural History Museum in London whose
early research led to the recognition of H. heidelbergensis
as a formal species, says a lot is
riding on the new 530,000-year minimum date
for the Sima fossils. If the dating is right,
Stringer says, “it would be evident that an early
form of Neandertal was [in Europe] alongside
of H. heidelbergensis.” But he argues that the
dating is at the limit of the uranium-series technique
and also contradicts other molecular and
fossil evidence suggesting that the Neandertal
line split off somewhat after 500,000 years ago.
Bischoff defends his methodology, however,
saying that the date is a “conservative” estimate
and that the Sima hominins could be even older
than 530,000 years but not younger..."
New Work May Complicate History
Of Neandertals and H. sapiens
SCIENCE VOL 326 9 OCTOBER 2009
MICHAEL BALTER
