Question: What are the evolutionary implications of the fact that larger coalitions of male lions consist almost entirely of close relatives?

In a lion pride there are usually only a few males (the coalition), between 1-4. They can be related or unrelated, but depending on how many there are will determine how beneficial living in the pride is for unrelated males. With a coalition of two males, it wouldn't matter whether you are related or not to the other male because studies have shown that both males tend to reproduce equally in these cases. Now, if there is a coalition of more than two males, only the two highest ranking males will do most of the mating, leaving the other males to contribute to the prides protection and hunting but without the benefits of spreading their genes. Thus unless you are kin to the other males in the coalition, you will not benefit your genes by wasting time helping this pride. Therefore we tend to see prides with more than two males being more related because although the other males might not mate as much, they are still helping their genes because they share half of there genes with the other males.

Family Planning

The Selfish Gene: Chapter 7 summary

    This chapter focuses on reproduction, population numbers in specific groups of a species, and how evolution has played a role in controlling birth-rates. Individuals must balance between bringing new individuals into the world and caring for the ones already in it. Or, "child bearing vs. child caring," as Dawkins puts it. Using one is not evolutionarily stable as we saw in the previous chapter. By using the idea that individuals unconsciously choose to regulate their birth-rates "for the good of the species," Wynne-Edwards makes the claim for group-selection. In this chapter, Dawkins uses the selfish gene theory to explain these same phenomena.
    Unlike humans, all other organisms lack the ability to foresee the devastating effects of overpopulation. Populations are controlled by their ecological limitations, large groups of individuals deplete resources which ultimately lead to starvation. But why don't we see this with all population? The Wynne-Edwards explanation would be that species work altruistically to artificially control birth-rates. As seen with species that control territories and fight for the right to mate, this explanation says that only certain individuals gain the right to mate, thus controlling birth-rates. It even goes on to explain that individuals conduct censuses of their population numbers to determine their birth-rate.
    What the selfish gene theory tells us is that individuals are actually acting out of selfishness to preserve their genes even though this can look altruistic. There is a surprising number of "costs" that are associated with bearing children. Costs that will determine the proportion of children that will survive to carry on their parent's genes. It turns out that individuals do control their own birth rates, but not in the same sense as Wynne-Edwards understands it. There is an ideal number of children that would provide the lowest burden of care, protection, and weaning by the parents whilst having the greatest chance that genes would be preserved in the surviving children. Each species has a more or less specific brood size each breading season and this has been determined by the evolution of the species in its specific environment.
    One experiment was seen to support the Wynne-Edwards idea of autistic group selection. It used mice living in a confined space with endless supplies of food and water in order to see how birth-rates were affected when the population filled the space. As the population grew, the birth-rate slowed down before filling the space, why was this? Wynne-Edwards would explain this as the mice controlling their numbers for the good of the group. The selfish gene theory concludes nearly the same, but that the mice  would have no idea that the resources were endless and that "animals tend to have the optimum number of children from their own point of view." This would mean having less children in order to optimize their chance that the maximum amount of children would go on to preserve the parents genes.

Geneamanship

The Selfish Gene: Chapter 6 summary

    A gene is not a single entity, it is comprised as all replicas that reside in certain organisms. This chapter discusses how genes may be able to assist other replicas of the same gene that are within other survival machines. Although the may seem altruistic and "good for the species," it is purely out of a genes selfishness as we shall see.
   It could be incredibly successful for a gene to be able to achieve its desired trait in addition to showing some physical aspect (such as a green beard) so that others having this gene could recognize each other and ensure the survival of the gene by helping one-another. But of coarse this is not particularly likely to occur. How else would a gene be able to recognize another bearer of the gene? One of the best ways to recognize the bearer of similar genes is ones relatedness to us, our kin. If one brother dies in order to save the life of 10 of his brothers, one copy of the "kin-altruism gene" would be lost but at the cost of saving possibly 10.
    Here we are talking mainly about rare genes within a genepool. We can assume that a particular rare gene you might have would be much more likely to be within close kin as opposed to the rest of the population. To be exact, there is a 50 percent chance that your sister or brother would have the gene, as well as your children. The probability of a certain kin having a specific gene is called its relatedness and is calculated by identifying a common ancestor, then count the generation distance between them, and then multiply 0.5 by itself for each generation. The general equation is (1/2)to the power of g.
    In order for an individual to expend the energy and time to help another, the benefit must out way the risk for that individual. "In order for altruistic behaviour to evolve, the net risk to the altruist must be less than the net benefit to the recipient multiplied by the relatedness." W. D. Hamilton devised this rule in 1964 that shows quantitatively how these are related.

"C" is equal to the reproductive cost of the individual that is behaving altruistically. 

    Now, Dawkins is not saying that individual genes actually calculate these odds before deciding to help a relative or send out a call to others that there he has found food, "what really happens is that the gene pool becomes filled with genes that influence bodies in such a way that they behave as if they had made such calculations." In addition, the calculation is but a simple estimate of the many factors that play into these decisions. 

    The chapter concludes with a discussion of some exceptions to this rule of probability and that an index of certainty many play a large role in these decisions. Evolution has provided many species increased ways to recognize specific relatives due to certain "cheaters" that take advantage of altruistic behavior and thus increase the need for individuals to become more keen on recognizing close kin. The example given is that of how birds "cheat" by placing their eggs in another nest for another bird to raise as their own, this is called brood parasitism. This would lead to a birds need to distinguish her eggs from everyone else's. For example, a mother might be much more certain who her son is because of the large amount of time they have spent with each other as opposed to a sister and brother, how are they for certain that they are related? This may help explain the increased parent/child relationship in comparison to brother/sister relationships. Dawkins also uses this to explain that parent/child altruism is not just a form of "group selection," but is actually kin selection.

    The photo shows four bird species eggs (left egg) in comparison to the mimicked egg of a cuckoo (right egg).