Albert, Survival of the Fittest and the Selfish Gene are universal concepts. You point out a few isolated aspects to justify it. You specify that in times of scarcity the older birds will kill their younger siblings. I was not aware of this and do not know how well it has been documented, but if in extreme situations this way of adaption is practiced, I do not see it as a problem.
Lions are a center of interest because they seem to be an example of Survival of the Fittest. The Pride is not an institution based on the individual. The work of the pride is done by the females collectively. They do the hunting and child raising. The alpha Lion provides the unity of the pride. He expels all other mature males. The role of the Lion is the leader, who protects the rest of the pride and also scavenges to supplement their diet. The act of killing the offspring of his predecessor is seen more a a political move, rather an a sexual act.
When David took over the kingdom from Saul and his son Jonathan, the e3xpectation was that he wipe out the male offspring of the old regime. The opposition that resisted him formed around these people. He only preserved the life of the crippled son of Jonathan. The question was not one of genes, but of politics.
@Lynn_Munter,to make survival of the fittest into a strategy is to trivialize that concept. The same for the Selfish Gene. On the other hand if we say that the Selfish Gene is “natural” then humans and nature are innately evil. Then what is happening in Syria is “natural” as well as sinful. We must insist that Syria is not the natural or normal way for humans to exist.
Goodness is natural, not unnatural. That does not mean that goodness is easy, but it is normative.