Most what scientists think they know is wrong. The fossil record is far from complete.

Modern Humans are likely much older than previously thought. Three years ago, a man's DNA in South Carolina indicates that Homo Sapiens may be 70% older than originally thought.

http://www.natureworldnews.com/articles/749/20130306/scientists-rethink-human-tree-root-unique-dna-found-sc-man.htm

Thanks for posting.