How many Neanderthal genes do you have?
Humans have evolved and like many evolving organisms, we have a had a few less successful branches along the way.
This BBC article shows how in the distant past Human evolution split into branches, one of which became us (Homo Sapiens) and another became Neanderthal man. But there is some evidence in our genes to say there was some interbreeding later on, after Homo Sapiens (us) started to migrate out of Africa.
[Neanderthals] are not totally extinct, in some of us they live on – a little bit
Professor Svante Paabo
Max Planck Institute for Evolutionary Anthropology
Apparently as much as 4% of your genes come from Neaderthal – remember that next time someone says you look like a caveman first thing in the morning!!
(4% Caveman + 96% Physicist)