Chapter 20 Cultural and Social Evolution

1. Chapter 20Cultural andSocial Evolution Figure CO: A lion and her cubs © George Lamson/ShutterStock, Inc.

2. Overview • Unlike most other animals, humans transfer information from generation to generation through genes and culture • Animal Behavior – Ethology – Sociobiology • All organisms exhibit behaviors, not just animals • Human language abilities • Social Darwinism – a discredited social philosophy • Biological and cultural evolution interact • Eugenics, genetic engineering and cloning

3. Animal Behavior • Animal behavior is the scientific study the behavioral relationships of animals to their physical environment as well as to other organisms, and includes such topics as how animals find and defend resources, avoid predators, choose mates and reproduce, and care for their young • The study of animal behavior is concerned with understanding the causes, functions, development, and evolution of behavior • The causes of behavior include both the external stimuli that affect behavior, and the internal hormonal and neural mechanisms that control behavior • The functions of behavior include its immediate effects on animals and its adaptive value in helping animals to survive or reproduce successfully in a particular environment

4. Animal Behavior • The development of behavior pertains to the ways in which behavior changes over the lifetime of an animal, and how these changes are affected by both genes and experience. • The evolution of behavior relates to the origins of behavior patterns and how these change over generations • This discipline was founded by American biologists and psychologists, primarily after WWII, and included considerable emphasis on laboratory experimentation • Many behavioral psychologists emphasized the study of learned behaviors • Pavlov and his dog studies is the classic example

5. Ethology • Ethology is the scientific study of animal behavior, and a sub-topic of zoology • The modern discipline of ethology begun during the 1930s in Europe and parallel to but rather independent of the Modern Synthesis • Ethology is a combination of laboratory and field science, with a strong relation to certain other disciplines — e.g., neuroanatomy, ecology, evolution • Ethologists are typically interested in a behavioral process rather than in a particular animal group and often study one type of behavior (e.g. aggression) in a number of unrelated animals — a comparative approach

6. The Nobel Prize in Physiology or Medicine 1973 • Karl von Frisch, Konrad Lorenz, and Nikolaas Tinbergen "for their discoveries concerning organization and elicitation of individual and social behavior patterns“ • A rare prize for evolutionary biologists for the founders of modern Ethology from the Nobel Committee

7. Karl von Frisch (1886 - 1982) • Austrian entomologist who studied insect communication • Made major contributions to the study of honey bees, their ability to communicate to hive mates about food sources with the waggle dance, use of pheromones, and their ability to see in color and in ultravioltet and polarized light. • Wrote Dancing Bees, A Biologists Remembers,Animal Architecture, and other works

8. Konrad Lorenz (1903 - 1989) • Austrian ornithologist and ethologist • Studied instincts and fixed action patterns in birds, and later became interested in human behaviors • Wrote many books including King Solomon’s Ring and On Agression

9. Nikolaas Tinbergen (1907 - 1988) • Dutch zoologists who studied fish, birds and insects in nature and the laboratory, and later autism • A better experimentalist than Lorenz, the theoretician • Wrote The Study of Instinct, The Herring Gull’s World, Social Behavior in Animals, Curious Naturalists, etc. hawk- goose effect ↑

10. Robert Hinde (1923 - ) • British zoologist who studied birds, then primates, and later humans • Wrote Animal Behaviour: A Synthesis of Ethology and Comparative Psychology (1966), a classic work that helped integrate research in psychology and ethology, Biological Bases of Human Social Behaviour (1974), Individuals, Relationships and Culture (1987), Towards Understanding Relationships (1979), and Why Gods Persist (1999), etc.

11. Desmond Morris (1928 - ) • British ethologist, popularizer of science, and surrealist painter. • Happy to take controversial positions when advocating for the biological basis of human behaviors • Wrote the bestsellers The Naked Ape and The Human Zoo, among nearly eighty volumes

12. David P. Barash (1946 - ) • American psychologist and sociobiologist • Barash has been named one of the country's "101 Most Dangerous Professors," by right-wing writer David Horowitz, because of his advocacy of peace and other progressive causes, as well as his avowed atheism and persistent exploration of evolutionary biology and its application to human behavior • Excellent writer and author of more than 25 books One of his most recent books is Natural Selections: selfish altruists, honest liars and other realities of evolution (2007)

13. George B. Schaller (1933 - ) • Perhaps the world’s greatest living field biologist and ethologist • Preceded Dian Fossey with his 1959 study of the mountain gorilla • Since has studied big cats, pandas, African, Tibetan, Brazilian, Chinese and Southeast Asian fauna • Helped establish many national parks in Asia • Has won many awards and written several dozen books, beginning with The Mountain Gorilla – Ecology and Behavior (1963), and, recently, A Naturalist and Other Beasts: Tales From a Life in the Field (2007)

14. Nature versus Nurture? • Animal behavior is best explained by investigating the contributions of both genes and environment • Behaviors form a spectrum from innate behaviors which exhibit little variation among members of a species and appear at predictable times in development to learned behaviors which require exposure to various environmental stimuli to develop, usually require trial-and-error repetition to improve their efficiency and exhibit considerable variation among members of a species • In all cases, organisms with genes must interact with their environment for behaviors to occur

15. Instincts • Relatively complex innate, predictable, stereotypical behaviors which are present in individuals, sometimes even from birth, and performed completely without requiring any experience • The simplest are muscular and autonomic reflexes such as pupil constriction in bright light or a flexor reflex when the hand touches a hot object • More interesting are fixed action patterns, e.g., courtship rituals in many animals, nest building, predator defense behaviors, etc.

16. Filial Imprinting • Konrad Lorenz himself raised these greylag goslings from first hatching, so it was to him that they imprinted, expressing their innate behavior of following their “parent” • Imprinting behaviors usually trigger at critical times in development • Now imprinting is used to reintroduce captive-reared birds to life in the wild

17. Biased Learning • Biased learning is a restricted form of learning ― the ability to learn and modify behavior from a restricted set of environmental stimuli • Lorenz, Tinbergen, and others demonstrated that imprinting and other “innate” behaviors develop from heritable “hard-wired” neurological programs which may still be influenced by biased learning • Following behavior in water birds, mate identification in various birds, mating rivals, etc.

18. Sexual Imprinting • Male zebra finches select a mate based on the color pattern of the female that rears them, regardless of species • On the other hand, their courtship song and dance require some learning

19. Reverse Sexual Imprinting • When two people live in close domestic proximity during the first few years in the life of either one, both are desensitized to later close sexual attraction • This phenomenon, known as the Westermarck effect, was first described by Finnish anthropologist Edvard Westermarck • Documented in biological families, Iraeli kibbutz, Chinese Shim-pua arranged child marriages, and many other cultural setting

20. Genetic Sexual Attraction • When a brother and sister are brought up separately, never meeting, they may find each other very sexually attractive as adults; first cousins are also often highly attracted • Charles Darwin and Emma Westwood were first cousins, but did know each other through their youth • This suggests that the Westermarck effect evolved to inhibit inbreeding with its negative genetic consequences

21. Inherited Behavior in Lovebirds • Experiment • Two species of lovebirds were interbred. Female Fischer's lovebirds cut long strips of nesting material, which are carried individually to the nest. Female Peach-faced lovebirds cut short strips and carry several at a time by tucking them into her back feathers. • Results • Hybrid females cut intermediate length strips and tried, but failed, to transport them by tucking into back feathers. They learned to carry strips in their beaks, but never gave up all tucking behavior. • Conclusions • Phenotypic differences in the behavior of the two species are based on different genotypes. Innate behavior can be modified by experience. Learned behaviors are typically based upon gene-determined neural systems that are receptive to learning.

22. Genes vs. Environment— Bird Song • Three calls of the male meadowlark are shown, one set produced by a free-living individual and one produced by a hand-reared male kept isolated from ever hearing the songs of another male. The meadowlark’s genetic program is sufficient to produce normal songs.

23. Genes vs. Environment — Bird Song • The free living male chaffinch produces a complex song, but if raised in song isolation, its song is much different. If the chaffinch is exposed to the song of a tree pipit, then the chaffinch song picks up some of this vocal culture. Not only is the chaffinch genetic program insufficient to produce the normal song, but song culture (exposure to the tree pipit) can modify it.

24. Learned Behaviors • Learning can be defined as a persistent change in behavior that occurs as a result of experience • In general, learned behaviors will always be: • Nonheritable -- acquired only through observation or experience • Extrinsic -- absent in animals raised in isolation from others • Permutable -- pattern or sequence may change over time • Adaptable -- capable of modification to suit changing conditions • Progressive -- subject to improvement or refinement through practice

25. Learned Behaviors • Learned behavior is more flexible and often more complex than innate behavior • The capacities for most behavioral traits, like so many other adaptations, result from evolutionary selective forces • Most behaviors have instinctive and learned components, a spectrum related to the size and complexity of the animal’s nervous system

26. Learned Behaviors • Imo, the Japanese Snow Monkey genius (Macaca fuscata) learned to wash yams in sea water and dip a handful of rice and sand in the water to remove the sand grains • Caledonian crows learn to modify twigs to probe for grubs • Both are traditions that vary among demes Figure 01: Caledonian crow tool making © Behavioural Ecology Research Group, University of Oxford

27. Gene/Environment Interactions • Behavioral geneticists interested in humans began with twin and adoption studies • Linking specific behaviors to specific genes is just beginning to be possible and will rarely be as simple as a one gene-one behavior model • Human environment includes: • Prenatal experiences • Family upbringing and parental and sibling interactions • Extended family and peer interactions • Societal experiences, interaction with the educational system, media, marketing, religious and political institutions • Demographics: gender, age, geography, culture, language, literacy, socio-economic status, etc.

28. Genes vs. Environment — Speech Louis Leakey English Jomo Kenyatta Kikuyu • Human language comes in a variety of dialects, here represented as A–G. • In humans, genes provide a person with the innate ability to speak language(s), but the culture into which the person is born provides the particular language(s) learned • The final behavior is an interaction between genes and culture • Second language acquisition is easiest when exposure occurs before 12 years of age

29. Key Hominid Behavioral Trends • Bipedal locomotion and an eventual habitat shift beyond the tropical forest • Altered reproductive strategy: continuous female receptivity and no cues for maximum fertility (ovulation); enlarged female breasts but no vulval swelling; enlarged penis and glans though the testes are medium-sized relative to body size for a primate • Prolonged pair bonding - (serial) monogamy • Enlarged brain, tool use and tool making • More complex social systems and culture • Language development

30. Learning, Society and Culture • Intelligence — and our consequent ability to learn from our own experience or from the experiences of others • Cultural transmission of learned behavior eliminates the hazards encountered when an individual must learn by trial and error to cope with environmental variables

31. What Makes Human Thinking Unique?

32. What is Language for? • Language helps us to pass on and develop technologies (how to make better spears) • It helps us to coordinate activities (e.g., hunting) • We can communicate knowledge about relevant aspects of the environment (e.g., there’s a big herd of buffalo behind the hill where we camped 5 days ago)

33. What is Language for? • Language helps us identify things with names and descriptions. • It helps us to express our emotions • It helps us remember and utilize the past as well as plan for the future Could we achieve any of this without language? Could we even think this without language?

34. Speech and Symbolic Language • Chimpanzee, adult. The language of a signing chimp is here translated into the English words • Human, 21 months of age. The spoken words are shown • Human, 6 months later than (b). The actions or prompts of the interrogators are not included

35. Can Animals Develop Languages? • Allen and Beatrice Gardner (1969) ( http://www.friendsofwashoe.org/ ) • Chimpanzee – Washoe learned ASL; 160 word vocabulary • Rules of language or Operant conditioning (Nim Chimpsky)? • Penny Patterson & Koko (1971) ( http://www.koko.org/index.php ) • Koko the gorilla; understands 1,000 ASL signs & approx 2,000 spoken English words • Irene Peperberg – Alex the African Grey parrot (1975-2007). • ( http://www.alexfoundation.org/ ) • Could identify fifty different objects and recognize quantities up to six; could distinguish seven colors and five shapes; had a vocabulary of about 150 words (operant conditioning?) • Sue Savage-Rumbaugh (http://www.npr.org/templates/story/story.php?storyId=5503685 ) • Bonobo chimpanzee – Kanzi (the Einstein of chimps?) • Used symbols that represented language • Receptive language – 72% of 660 requests

36. When Did Language Evolve? chimp-human common ancestor 5-8 million years ago ? Australopithecus africanus Australopithecus robustus Australopithecus afarensis Homo habilis Homo erectus Neanderthal gorillas common chimpanzees bonobos ArchaicHomo sapiens sapiens

37. Language Gradually Evolved We hunt Many buffalo there Food Don’t attack until I say Ugh Ugh-Ugh Let’s take the kill back to the others Let’s spend the winter here. It’s more sheltered and there are many animals to hunt Because out language skills got better we survived better. But it all happened slowly and gradually. I have seen herds of antelope over the hill. I think we should move there.

38. Why Is Language So Interesting? • Because everybody knows that only humans talk although other animals may understand a number of words • Language makes long-term cumulative cultural evolution possible • A novel type of inheritance system with unlimited hereditary potential

39. What Is So SpecialAbout Human Language? • Basically, it is the fact that we make sentences using grammar • Languages are translatable into one another with good efficiency • Some capacity for language acquisition seems to be innate • The “Holy Grail” is the emergence of Syntax • A system of rules for arranging words into sentences • Different rules for different languages • A sentence must have a noun phrase and a verb phrase

40. Language Defined Language: symbols that convey meaning, plus rules for combining those symbols so that they can be combined to generate infinite variety of messages • 3 - Properties of Language • Symbolic: represents objects, actions, events & ideas (ex: car = class of objects that have certain properties) • Generative: limited number of symbols can generate infinite array of novel messages (there is always something novel) • Structured: infinite variety is structured in a limited number of ways (Rules govern the arrangement of words into phrases and sentences)

41. Understanding Language Evolution Is Difficult

42. Gossiping Hypothesis • 2/3’s of all conversation is about social relationships • Both in developed countries and for hunter-gatherers • Does this kind of language use have any effect on our fitness? • Does it help our survival rate? • Does it increase our reproductive success?

43. Substitute for Grooming Hypothesis • Monkeys and Apes are very social • They maintain complex relationships • Grooming is their main form of social interaction

44. Increasing Group Size Hypothesis • Largest group size for non-human primates is 50-55 (Chimps and Baboons) • For modern hunter-gatherers is about 150 • Primates spend up to 20% of their days grooming • Human’s would need to spend 40% of their time to cover such a large group  Language is ‘vocal grooming’

45. Genetic Origin of Language http://www.youtube.com/watch?v=k27DfgKGVp8 • Early hominids probably began using gestures to communicate intentions within a social setting. • FOXP2 gene: Language or Speech gene responsible for major inherited speech disorder (KE family studied) • Over 3 generations, half the family afflicted • Inability to form intelligible speech • Defects in processing words according to rules • Caused by a single nucleotide mutation on exon 14 of chromosome 7 • Very conserved gene – 1 change in 75 million years before the divergence of chimps & humans and 2 in the 6 million years since that divergence • Mutation occurred 10,000 – 100,000 years ago and may be critical for the development of modern human speech

46. Evolution of FOXP2 • Grey boxes mark single amino acid mutations • 0 mutations in 75 million years for chimps • 1 for mice • 2 for humans in last 6 million years • This suggests Neandertals have the same human allele 75 Mya

47. Vocal Anatomy Gradually Evolved

48. Vocal Anatomy Figure B02: Views of how adult humans produce three vowel sounds by positioning the tongue Figure B01A: Upper respiratory system of humans adult Adapted from Aiello, L., and C. Dean. An Introduction to Human Evolutionary Anatomy. Academic Press, 1990. Figure B01B: Upper respiratory systems of chimpanzee • In the chimpanzee and Austrlopithecine, the pharynx is short and the soft palate and epiglottis meet to separate the oral cavity from the pharynx while breathing • In the human, the pharynx is longer, the oral cavity is taller, and the tongue is shorter and has more room to change size and shape to form the sounds of speech Figure B01D: Upper respiratory systems of australopithecine Figure B01C: Upper respiratory systems of human infant Adapted from Conroy, G. C., G. B. Weber, H. Seidler, P. V. Tobias, et al., Science 280 (1998): 1730-1731; and Lieberman, P. The Biology and Evolution of Language. Harvard University Press, 1984; and Lieberman, P. Uniquely Human: The Evolution of Speech, Thought, and Selfless Behavior. Harvard University Press, 1991.

49. Vocal Anatomy Various investigators have suggested that the Neandertal vocal anatomy is intermediate and, perhaps, less efficient for making the variety of sounds of modern human speech

50. Vocal Anatomy The modern human palate is arched which gives greater variety to tongue shapes to articulate speech