I was watching it more closely last night also. I seem to remember that H. erectus/ergaster was thought to have appeared 1.8 million years ago which also corresponds to the start of the Pleistocene. I was a little disappointed that they did not have anything on the transitional forms such as H. heidelburgensis and Tautaville Man that could have been ancestors of Neanderthals.

The interbreeding of Neanderthals with AMHs is extremley controversial. DNA says no, physical traits and common sense says yes.

There does not seem to be a clear break between H. erectus and H. sapiens in southeast Asia. The 1100cc brain sizes mentioned in the History Channel timeline come from that region. In fact some believe that H. erectus survived on Java up until 30,000 years ago. Some of the early crania from Australia display some very primative features.