On the other hand, the best of our inventions and discoveries seem to have been just barely within our grasp, and it took modern Homo sapiens 200 thousand years

On the other hand, the best of our inventions and discoveries seem to have been just barely within our grasp, and it took modern Homo sapiens 200 thousand years to reach this level of domination of the planet. A slightly less intelligent species (or perhaps one lacking just the right body type), such as our own ancestors or perhaps our extinct close relatives, might have taken 10 million years instead of 200 thousand, or just never have done it at all.