This is something I've never really considered before, but seems to make sense.
When people stopped competing on who could keep eating enough for survival and as social interaction between people increased, the evolutionary battle moved from being physically based to one based on knowledge.
Though this is really a different way of thinking about evolution, there are a lot of parallels I can think of between classic evolution and a knowledge based evolution.
I'd say that as knowledge became more important this evolutionary race moved from just being about independent people a common pool of knowledge grew, almost as an ant hive has a swarm life of it's own, all building for a common purpose, the advancement of that race as a common goal.
Just my 2 cents, as I said I've never really considered this before so I'm only just getting my head round it