Bio 1B Lecture Outline please print and bring along Fall 2007 B D Mishler Dept of Integrative Biology 2 6810 bmishler berkeley edu Evolution lecture 14 Darwin and human culture sociobiology Dec 7th 2007 1128 1133 ch 51 in 7th ed 1144 1148 ch 51 in 6th ed Summary of lecture Economic theory Political theory Evolutionary ethics Sociobiology Creationism Science as a process Cultural evolution versus biological evolution Economic theory survival of the fittest There has always been a tight two way relationship between Darwinism and capitalistic economic theory Adam Smith and his invisible hand of the marketplace was influential on Darwin As we have already discussed the economist Thomas Malthus had a large impact on Darwin with his theories about population and resource growth Likewise Darwin s principle of natural selection excited economic theorists for example Herbert Spencer who actually coined the term survival of the fittest not Darwin The robber barons of early raw capitalism in the United States were fond of using Darwin or at least their interpretation of Darwin as justification for them having most of the money and the workers little Modern advocates of trickle down economics even today depend on Darwinian justifications Present day evolutionary biologists are fond of using economic analogies in evolutionary biology and ecology niche relationships food webs adaptation game theory Political theory Marx was likewise enamored of Darwin and imagined a connection between natural selection and the struggle between the classes throughout history Evolution 14 pg 1 Many other politicians including several American presidents have used Darwinian metaphors when justifying actions of the strong countries ruling the weak ones colonialism etc Relationships between the races and between the genders Darwinian arguments have been used to support racism sexism and probably any other ism Evolutionary ethics Is what is natural good Many philosophers have looked to nature for guidance on what is right and good One justification given is that human cultures have evolved their morals ethics gender roles etc through natural selection and it is dangerous to depart from what has worked through trial and error over the millennia The other side of the coin is doesn t imply ought Might doesn t imply right Civilization exists to moderate our animal past Sociobiology sociobiology systematic study of the biological basis of all social behavior Explanations have been attempted for heroism homosexuality gender differences in math and science abilities gender roles in general and many other aspects of human behavior altruism the aiding of another at one s own risk or expense Fig 51 28 6th kin selection a phenomenon of inclusive fitness used to explain altruistic behavior between related individuals Fig 51 35 7th Fig 51 31 6th inclusive fitness the fitness of a gene or genotype measured by its effect on survival and reproduction both of the organism bearing it and of the genes identical by descent borne by the individual s relatives Many social behaviors are selfish Natural selection favors behavior that maximizes an individual s survival and reproduction On occasion some animals behave in ways that reduce their individual fitness but increase the fitness of others This kind of behavior is called altruism or selflessness In naked mole rat populations nonreproductive individuals may sacrifice their lives protecting the reproductive individuals from predators Altruism can be explained by inclusive fitness Inclusive fitness is the total effect an individual has on proliferating its genes by producing offspring and helping close relatives produce offspring Evolution 14 pg 2 Hamilton s Rule and Kin Selection Hamilton proposed a quantitative measure for predicting when natural selection would favor altruistic acts among related individuals Three key variables in an altruistic act o Benefit to the recipient o Cost to the altruist o Coefficient of relatedness the probability that if two individuals share a parent or ancestor a gene in one individual will also be present in the second individual Natural selection favors altruism when the benefit to the recipient multiplied by the coefficient of relatedness exceeds the cost to the altruist This inequality is called Hamilton s rule Kin selection is the natural selection that favors this kind of altruistic behavior by enhancing reproductive success of relatives An example of kin selection and altruism is the warning behavior in Belding s ground squirrels Altruistic behavior toward unrelated individuals can be adaptive if the aided individual returns the favor in the future This type of altruism is called reciprocal altruism Social Learning Social learning forms the roots of culture Culture is a system of information transfer through observation or teaching that influences behavior of individuals in a population For example in mate choice copying individuals in a population copy the mate choice of others This type of behavior has been extensively studied in the guppy Poecilia reticulata Vervet monkeys produce a complex set of alarm calls Infant monkeys give undiscriminating calls but learn to fine tune them by the time they are adults No other species comes close to matching the social learning and cultural transmission that occurs among humans Evolution and Human Culture Human culture is related to evolutionary theory in the distinct discipline of sociobiology Human behavior like that of other species results from interactions between genes and environment However our social and cultural institutions may provide the only feature in which there is no continuum between humans and other animals Therefore sociobiology only provides partial maybe even limited insight into human behavior Nature vs Nurture Evolution 14 pg 3 Creationism then and now A reminder about the first go around in Darwin s time Current events creation science intelligent design battles in the schools and textbooks A reminder of the differences between scientific and other ways of looking at the world What is or should be the relationship between science and religion Good fences make good neighbors Diagram at left from Antievolutionism and Creationism in the United States by Eugenie Scott http www ncseweb org resources articles 4550 antievolutionism and creationi 2 13 2001 asp Science as a process How does science progress Ideas memes competing in the academic environment for new adherents Philosophers
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