Note: Time has proven the research
detailed here to have been on the wrong side of the facts, but
at the time this was still very much an open question.
After miners unearthed a skull and bones in a
Neander Valley cave in Germany in 1856 - three years before the
publication of On the Origin of Species - the remains were
initially described either as those of a 'brutish' race or someone
disfigured by disease.
As Darwinian evolution caught on, so did the
realisation that these fossils were evidence of an earlier human
species. Scientists have been debating Neanderthal's place in human
evolution ever since.
An ongoing question concerns the possibility that
Neanderthals and early humans mated, since they likely crossed paths
during thousands of years of European cohabitation. In a 2004 study,
Mathias Currat and Laurent Excoffier presented a simulation model based
on what was then known about the population density and distribution
in Europe of Neanderthals and anatomically modern humans, Homo
Their results complement then-recent genetic and
morphological evidence indicating that early human and Neanderthal
interbreeding was unlikely.
The twentieth century notion that modern Europeans
directly descended from Neanderthals has mostly yielded to two
competing models: one postulated that modern humans arose in Africa
after 200,000 years ago and completely replaced coexisting archaic
forms with no interbreeding, while the other proposed a gradual
transition with interbreeding.
Though mounting genetic evidence (based on mitochondrial
DNA extracted from fossils) suggested by the start of the twenty-first
century that Neanderthals and early humans did not interbreed, the
evidence to that point was inconclusive.
It was thought possible, for example, that any
Neanderthal gene 'leakage' could have been lost through genetic drift
if the mating populations were small. And because so few fossils were
available to analyse, previous studies could rule out only Neanderthal
contributions over twenty-five percent.