“ Our metabolic pathways aren’t designed to handle Big Gulps. ” — KATHLEEN MELANSON, PAGE 16
In the News
Icy isolation may
have led to new
Cold-climate refuges possibly
influenced Homo evolution
After ancient people left heir African homeland, they migrated into Asia and Europe, taking refuge from
ice age conditions in areas isolated from
other populations, two new reports suggest. That isolation may have prompted
the evolution of new Homo species,
including a mysterious Asian population dubbed Denisovans and possibly an
unusual-looking humanlike group now
identified in China.
Ice age asylums “are critical to understanding the expansion of H. sapiens out
of Africa, the extinction of Neandertals
and Denisovans, and interbreeding
between these populations,” comments
anthropologist Robin Dennell of the
Fossils reveal some of the diversity of human and humanlike species, including
(from left) a skull from an unidentified possible new species found recently in
China, Homo sapiens, Homo heidelbergensis and Neandertal. These and related
species may have evolved in ice age refuges throughout Asia and Europe.
University of Sheffield in England.
Fossils unearthed in two caves in
southwestern China come from an
unusual-looking line of Homo sapiens,
or perhaps a previously unknown Homo
species, say anthropologist Darren
Curnoe of the University of New South
Wales in Sydney and his colleagues. This
group lived near modern-looking people
between 14,300 and 11,500 years ago.
Ancient bones unearthed previously
and in new digs at the Chinese caves
combine features of people today with
flaring cheekbones and other traits of
poorly understood African Homo fossils from more than 100,000 years ago.
Because this anatomically peculiar
population survived alongside modern-looking people until almost 11,000 years
ago, Curnoe suspects that the new fossils
represent a separate Homo species that
originated in Asia.
“We’re cautious about classifying
these fossils, because scientists lack
a satisfactory biological definition of
Homo sapiens,” Curnoe says. He and his
colleagues report the findings online
March 14 in PLoS ONE.