Study of natural selection on groups is the most thorough rejoinder to to the libertarian dogma. Natural selection on groups is actually a mathematical truism. And it has a proportionate practical effect whenever transactions between individuals are not zero sum. The prominent effect is to promote specialization of individuals. Witness all of the specialties in the groups called ecosystems. The deprecation of groups by promotion of the concept of individuals is mathematically only a false dichotomy. Mathematical simulations have suppressed evidence of groups by excluding non zero sum transactions, individual specialization and extreme circumstances.
Denying natural selection on groups is logically equivalent to asserting that, on average, contracts and alliances are not worthwhile, and should often be opportunistically abandoned. This is a latent contradiction in the libertarian view.
Conservative and even liberal systems of morality are often eager to control or ignore individual diversity, under the sway of patriarchal, military, or priestly and academic hierarchies. But there are natural dynamics neglected by this attempt at control.
Michael J. Burns