A. a Part of DNA and Its Replicas Throughout the World

Dawkins Chapter 6 Outline

I. Selfish gene a. A part of DNA and its replicas throughout the world b. Ultimate goal is more replication through survival and reproduction II. Altruism a. Selfish gene replicas helping other replicas survive b. Increased by index of relatedness c. Kin-selection altruism i. Helping close relatives survive at a cost to oneself III. Altruistic Suicide a. Dying to save a relative b. Only advantageous when one saves enough of one’s genes in multiple relatives to compensate for one’s own death i. Ex: more than 2 siblings, more than 4 nieces or nephews IV. Risk a. The index of relatedness is not consciously contemplated before helping a relative, but rather the amount of risk to oneself b. The lower the risk to oneself, the increased probability of helping a relative, even a distant relative V. Altruism considerations a. It will increase proportionally based on the i. index of relatedness ii. the certainty of relatedness iii. the younger the age iv. the higher the reproductive potential v. the lower the risk to one self.

Dawkins Chapter 6 Summary

The selfish gene is a part of DNA and its replicas distributed throughout the world. The goal of these replicas and ultimately of the selfish gene is more replication. And through replication, the selfish gene will become more numerous in the gene pool through survival and reproduction.

Altruism is explained by the selfish gene replicas helping other bodies, which contain the same replicas, to survive. Close relatives or kin have a very high chance of containing the same replica genes, thus altruism among kin is very common. Even a gene that is rare in a population may be common within a family. One has a 50% chance of having the same rare gene as a sibling since they share 50% of their genes. The same is true for a parent and a child. The term used to describe the chance that two relatives share the same gene is index of relatedness.

Altruistic suicide means dying to save close relatives. The gene for altruistic suicide will only survive if the individual saves enough relatives and therefore one genes’ to compensate for one’s own death. For example, an individual would have to save more than two siblings or parents, or more than four grandparents or nieces and nephews.

Parent-child altruism and sibling-sibling altruism should hold the same value. Kin selection is within family altruism; and the closer the relation, the stronger the altruism.

Dawkins makes it clear that kin selection is NOT a special case of group selection, but a special consequence of gene selection.

In reality people to do not consciously consider the amount of relatedness to another person when deciding whether to help or not; but rather, weigh the risk that may be incurred by helping. If the risk is low, then helping a distant relative is more likely. Genes for helping a younger, potentially reproductive family member has a higher selective advantage. According to Dawkins, in order for altruistic behavior to propagate, the net risk of altruism must be less than the net benefit to the genes calculated by the index of relatedness. Genes that survive participate in situations that usually have a high net benefit. Estimates of cost and benefit are based on past experience and conditions of past gene survival. So as long as the environment does not change drastically, past estimates will suffice and probably be correct. In summary, altruism will proportionally increase depending on the index of relatedness, the certainty of relatedness, the younger the age, the higher the reproductive potential, and the lower the risk to one self.

Dawkins Chapter 7 Outline

I. Child-bearing vs rearing a. Bearing: bringing a new child into the world b. Rearing: caring for an existing individual c. Constantly competing against each other for a stable strategy i. Solution is a mixed strategy of bearing and caring II. Population growth a. Depends on when and how many children an individual bears b. Natural population control: plague, famine, and war c. Only the human population is increasing proportionally and surviving to senility III. Ultimate goal a. Maximize the number of surviving offspring b. Limiting factor is the number of resources that can obtained by the mother and or her mate c. Not for the good of the species

Dawkins Chapter 7 Summary

Dawkins makes the distinction between child-bearing and child-rearing in this chapter.

His aim is to separate parental care from kin-selected altruism. Child-bearing is defined as bring a new individual into the world. Child-rearing is defined as caring for an existing individual. He states that individuals must make bearing and caring decisions regarding offspring. A caring decision is whether or not to feed an individual who will probably die without intervention. Bearing decision is whether to reproduce at any cost. Bearing and caring are at odds with one another for an individual’s time and resources. If one chooses to care for an existing child, one will be unable to bear another child at the same time and vise versa. According to Dawkins, caring can only be an ESS if it is part of a mixed strategy with bearing. In birds and mammals, a decision to bear a child is usually followed by a decision to care for the child. However, just as there is decision process for being altruistic toward others, there is one for bearing a child.

Population growth depends on when and how many children people bear. It is also controlled by famine, plague, war, and hopefully birth control. Dawkins argues that if the population continues to increase proportionally, starvation will eventually be the primary source of population control. However, survival machines are controlled by selfish genes that cannot see into the future and have an ultimate goal of replication. Interestingly enough, animal populations never proportionally increase, but rather fluctuate. And even better, animals rarely die of old age, disease, famine, or predators eliminate that possibility. Up until recently, the human population did not survive to senility. Dawkins argues that population growth is ultimately controlled by starvation and disease. But, if a species could regulate the birth-rate, starvation would not be an issue.

Ultimately, the goal is to maximize the number of surviving offspring by regulating the number of children one produces. Bearing and caring for a child is extremely costly. The number of children a female can successfully bear and raise is dictated by the amount of resources she and or her mate can attain. Human mothers devote the most amount of time to raising children. Unfortunately, the welfare state has interfered with natural selection and population control. Dawkins states that the welfare system is the greatest altruistic system in the animal kingdom, but it is unstable because it can be abused by selfish individuals. In the end, individuals practice family planning by optimizing the number of surviving children based on the amount of resources that can be obtained. This also means having neither too many nor too few children. The strategy evolved for selfish reasons rather than for the good of the species. When an individual has too many offspring, they end up with less surviving offspring than someone who had fewer children.