[davidgould]

There is no such thing as "the top of the evolutionary ladder." There is well fit to an environment and not well fit. To say "top of the ladder" implies that evolution encodes the concept of "progress". It does not. This notion of "top of the ladder" has been used to promote all sorts of pseudo-scientific racism and used to justify all sorts of bad conduct up to and including genocide.

I'm not accusing you of any of this, just pointing out that a seemingly innocuous, almost cliched term like "evolutionary ladder" can carry a lot of unwelcome baggage.