We think of ourselves to be the alpha dogs of the Creation and...here comes the truth to burst your bubble!
Man nearly went down the chute because he was too busy trying to make better tools and don't making more bodyguards!

The world had seen the dinosaur getting the pink slip by a meteor falling on the top of its capitulum and taking away two things with one stone, meat for man’s supper and man being supper for the dinos.
As necessity is the mother of “do something or you gonna die of hunger” the schmuck with a spear did need to improvise and it took from 2.5 to 1.6 millions of years, before the man from Nazareth, to improve and be called Homo Habilis because he could whack anything with his man made stone club (the wood ones were only used for love foreplay).
So, Homo Habilis was for a long while very happy to be the top dog of the human kennel of the times, but it is sadly to say, they were so few…
With dinos gone, Darwin’s theory about the surviving of the fittest came flourishing with full force.
Sabeltooth tigers, velociraptors, crocs, bears not on a berries diet, anything capable of eating meat multiplied at a rate that man couldn’t compete as man was trying to become Habilis, and had became part of their menu as well.
And Darwin was right, endangered man species came with an evolution’s clever solution, which lasted up to this age.
Here comes Homo Erectus. (from 1.6 million years BC)

Homo Erectus was at first not too dangerous but in a bus full of naked apes or around people bend over plucking berries.
We need to make it clear that he was thrown from Paradise as well, for eating the fruits of the forbidden Viagra tree.
In no time, Homo Erectus was multiplying faster that the carnivorous could consume and man started to diminish the damn predators number until it was man putting in peril of extinction everybody else.
Homo Erectus was very popular with fifty per cent of the population, the other fifty per cent looked with suspicion at his approach as they pressed their backs against any wall, boulder, big tree…you get the idea.
Now, it is a mystery how the brain of Homo Erectus developed, because it needs plenty of oxygenated blood to do so, and, as we know, his blood was somewhere else…Yes, how! Darwin didn’t said it either!
Also, Homo Erectus could find water underground just walking over it.
Never mind that Darwin or anyone else didn’t explained it to us, but by the time they were trying to figure it out…

…here comes Homo Sapiens.
He was called so because he was the one that knew how to do it, but not selective, as the seven billions of quarreling us has proved it.
Now, wouldn’t you prefer to roam this world as a forever Homo Erectus instead of a premature fastest kid around Homo Sapiens?