This paper derives the conditions under which fitness-reducing alleles can survive in a long-run stationary equilibrium for a trading population, extending the results in Saint-Paul (2002) for arbitrary systems of sexual reproduction.

This Paper studies how an institution such as markets affects the evolution of mankind. My key point is that the forces of natural selection are made weaker because trade allows people to specialize in those activities where they are strong, and to offset their weaknesses by purchasing adequate...