03 Sep '11 19:20>
Originally posted by Proper KnobThat 230kya figure is based on finds from Pontnewydd Cave in North Wales. A lot of stone tools were found, and a few teeth. These teeth are have characteristics which are generally considered to be indicative of neanderthal lineage.
That neanderthal DNA is in the human genome is based on genetic evidence. The figure given for the extinction date of neanderthals is based on the fact that no neanderthal remains have been found dated younger than 27,000yrs (or so).
The earliest neanderthal remains in the UK have been dated to around 230,000yrs ago, so i'm not sure where the encycoopedia Britannica got that figure from.
http://www.museumwales.ac.uk/en/rhagor/article/1968/
It's not really possible to say when the first 'neanderthals' appeared, although the earliest neanderthal traits appear around 600kya. The earliest agreed neanderthal fossils are probably those from Ehringsdorf, which are pretty soundly dated to a little more than 200kya.