I think what happened with homo (Its what makes sense to me) is that we are all used to be a homo, the very first to evolve a intelligent brain, which used to only eat fruits and veg, but after a few million years of that, a rare, I mean very rare mutation happened which is the mutation of teeth and digestive system that can eat meat, and because of it, it made the brain grow better and soon we discovered fire and was able to cook the meat and made our brain grow even faster which now known as humans.
The tree was split separating us from primemates.