Jim, you wrote
Instinct was first – it developed through all our predecessor species. With the advent of our species, the one with a gigantic brain, came reason: the ability to speculate about cause and effect in most profound ways.
Did this profound ability to reason, or reason profoundly, arrive in full flower at the dawn of man? Where did it come from? A new born baby has legs but it can not walk. The mere potential represented by its' legs doesn't mean much without a year of stimulus and lesser physical excertions. That's also an ability well developed in earlier species. Might the potential of a large brain be nearly meaningless without 100,000 years of stimulus provoking variation and selection of various behaviors???