From Nat'l Geographic.
Skull found in Ethiopia apparently bridges some of the gap in the fossil record between modern h. sapiens and h. erectus. Interesting, to say the least. Apparently undiscovered until now, and the article states there are 3 ! different homind species that might have led to the evolution of modern humanity.
Also related: Early Humans Prey, not Predators.
Apparently great, great, etc grandpa was constantly on the run from those pesky saber tooths. The only thing that may have saved us is cooperative groupings. Current primate species behavior comes to mind -- a couple of young males serve as lookouts while the rest of the band feeds.
"Early humans survived while other primate species died out because our ancestors cooperated to alter their surroundings, the researchers say.
This cooperation deflected the risk of predation onto other nearby prey species, which became more vulnerable because early humans weren't as easy to catch. "
Being more difficult to catch, the big cats that preyed upon early humans shifted their diet to other species. Way to go, grandpa.