Once the basic structure is formed, the power joins in.

Human Cells are incredible strong, not only sturdy beyond belief, with the ability not only to crush steel with their bare hands if they grow a little bit, but also able to move around with incredible weight on their bodies and unleash power beyond any regular human. Not only that: They are incredibly nimble and perfectely engineered for long range combat as much as they are for a bloody melee, all thanks to the 'Predator's' meddling in their base nature.

Little by little any hope for there to be anything resembling what humanity once was is erased, but the mannerism and ways of thinking remain. Hopefully that will last.