Australian Aborginals have one of the oldest histories of any peoples, dating back 50,000 years.
Photo Credit: Rusty Stewart/Flickr (CC BY-NC-ND 2.0)
If you are a creationist who insists that Earth is somewhere between 6,000 and 10,000 years old and that everyone save for a single family living in the Middle East were drowned in a global flood about 4,000 years ago, it really doesn't help that you have no evidence for that claim.
Imagine then having to cope with scientists continually coming up with evidence that it couldn't possibly be true! Evidence that modern humans have lived continuously and with little or no contact with other human groups, for 50,000 years in a single continent, for example.