Might have been better to say humans evolved into logical reasoning beings to replace our instincts.
I think it might be more correct to say that our instincts are not at the surface. We still HAVE the instincts. Some suppress instincts and some are more in tune with instinct but we all have them. They are not gone.

I also think that if we were suddenly thrust into situations which were a bit more dire than the day to day starbucks world we live in, our instincts would fire up FAST. We (at least those of us who have access to computers and time to lounge about on forums) are not required to rely on our instinct to survive. If we WERE, we would be far more in tune with them. Our lifestyle suppresses the need.