" tribalism (the parent of nationalism) has a bonafide evolutionary function also. The evolutionary dialectic is between the survival of the species and which members of the species will survive."

This is a misreading of Darwin. Tribalism is arbitrary and not essentially biological.
The more biological incentive is toward empathy and compassion. Read
Frans de Waal's recent book, "The Age of Empathy". Also, ascribing human behavior which is often manipulated by psychology to Darwin's evolutionary theory is a false interpretation.
Darwin never said anything like this in "Origin of Species".