It used to be that carbon 14 dating of Neanderthal sites and
modern human sites showed a 20,000 to 30,000 year overlap. The Neanderthals were believed to had co
existed with modern humans in Europe for 20 or 30
thousand years.
Then there was a
recalibration of the Carbon 14 data that showed the Neanderthal sites
disappeared about the same time that sites of modern men appeared. Which leads to the obvious conclusion that Neanderthals
lost the competition with modern man and were wiped out. Unpleasant idea, but likely.
Carbon 14 data is tricky.
Energetic particles from the Sun and cosmic rays strike ordinary Carbon
12, and turn it into radioactive Carbon 14.
This has a half life of 14 thousand years, a good long time. Living organisms take in both sorts of
carbon. When the organism dies it stops
taking in carbon. By measuring the
radioactivity from the carbon 14 in the organic material we can tell how many
years has passed since the organism died.
It’s a delicate measurement; the radioactivity of the Carbon 14 is not
very strong, compared to say Uranium.
It gets even weaker as time goes by, 14 thousand years, Carbon 14 half
life, reduces the radiation by half.
I am not hep to just
how the Carbon 14 dating was adjusted, but the result moved the oldest
Neanderthal sites back 20 to 30 thousand years, putting then up again modern
men moving into Europe.