Liberals wear their belief of evolution as a cloak. They use it to distinguish themselves from the religious. Liberals love to feed their ego, their self-image of being more intelligent and more enlightened and more open to critical reasoning. They mouth the words but the lay liberal doesn't know jack about evolution.
The engine that drives evolution is difference. Without differences evolutionary principles cease functioning. You can't believe in evolution and simultaneous believe in uniformity. Liberals adhere to the religious view that there is a uniformity of intelligence across all of mankind.
The liberal position on evolution is a hot mess. There has been no mystical force which put a force field around the human brain and kept it uniform for all of mankind. That's an appeal to a religious position.