Fossils found a few years ago in Lake Turkana, Kenya that date back to less than 2 million years ago show that at least one of our ancestors was flat- faced, meaning little prognathism and less of an ape- like face. The time that this species was alive proves that there were at least two forms of “non- erectus” species living at the same time in the same location.
This is an interesting article that refutes the idea that our Homo sapiens interbred with Neanderthals. A few years ago, evidence was found that showed there was shared DNA between us and Neanderthals. Scientist at the University of Cambridge are saying that the shared DNA is not a result of interbreeding but is the DNA of our shared ancestor, Homo heidelbergensis.