King selection

Discovery News has a fascinating review of new research which suggests that royal fratricide tended to follow Hamiltonian principles, that is, cousins were killed so that nearer relations could prosper. Hamilton's Rule states that an "altruistic" behavior is genetically beneficial if Cost < Benefit to Other X Coefficient of Relationship to Other (C < B*r). Roughly speaking, if you have a coefficient of relation to a siblling of 0.5, then for every unit of fitness you sacrifice for a sibling they need to increase their own fitness by over two units. The logic is simple: imagine you carry a gene which states "be altruistic to your siblings!" To make this simple, assume that it was a de novo mutation in one of the parents. Well, there is a 50% chance that your sibling is carrying this gene (assume that the parent is heterozygous, so expectation is half of the offspring ...