ANG 6930 Proseminar in Anthropology IIA: Bioanthropology

1. ANG 6930Proseminar in Anthropology IIA: Bioanthropology Day 4 ANG 6930 Prof. Connie J. Mulligan Department of Anthropology

2. Did everyone get their assignments back? • I’ve graded everything so if you didn’t get something back, that means I didn’t get it • You should have received: • Quiz 1 • Questions/comments from last week • Journal analysis abstract

3. Journal analysis • Great abstracts • Average – 19 • Most frequent mistakes • Forgetting to explain your choice of additional journals • Remember to turn your graded abstract in with your final paper

4. Quiz #2

5. This week • Primate evolution, ecology and behavior • Primatology as anthropology • Diversity of living primates • Primate models for human evolution and behavior • Comparison of humans and other primates • Reading • The Human Species, Chpts 5 (Primates), 6 (Primate behavior and ecology), 7 (The human species) • Course packet • Martin RD. 2002. Primatology as an essential basis for biological anthropology. Evolutionary Anthropology 11:3-6. • Strier KB. 2003. Primate behavioral ecology: From ethnography to ethology and back. American Anthropologist 105:16-27. • Rieseberg LH and Livingstone K. 2003. Chromosomal speciation in primates. Science 300:267-268. • Khaitovich P et al. 2005. Parallel patterns of evolution in the genomes and transcriptomes of humans and chimpanzees. Science 309:1850-1854. • Amici et al. 2010. Monkeys and apes: Are their cognitive skills really so different? American Journal of Physical Anthropology 143: 188-197. • Judson O. 2008. Wanted: Intelligent aliens, for a research project, New York Times blog

6. Next week • Hominoid to hominin • Dating the ape-human split • Australopiths • Early hominin subsistence and social organization • Origins of genus Homo • Homo erectus, Neanderthals and other archaic humans • Reading • The Human Species, Chpts 9 (Primate origins and evolution), 10 (Beginnings of human evolution), 11 (Origin/evolution of genus Homo), 12 (Evolution of archaic humans) • Course packet • “A new kind of ancestor: Ardipithecus unveiled”, Science, 326:36-40. • “Candidate human ancestor from South Africa sparks praise and debate”, Science, 328:154-155. • Klein RG. 2009. Darwin and the recent African origin of modern humans. Proceedings of the National Academy of Sciences 106:16007-16009. • “New statistical model moves human evolution back three million years” ScienceDaily, 11/9/2010. • Teaford MR and Ungar PS. 2000. Diet and the evolution of the earliest human ancestors. Proceedings of the National Academy of Sciences 97:13506-13511. • Conroy GC. 2002. Speciosity in the early Homo lineage: Too many, too few, or just about right? Journal of Human Evolution 43:759-766. • Premo LS and Hublin J-J. 2009. Culture, population structure, and low genetic diversity in Pleistocene hominins. Proceedings of the National Academy of Sciences 106:33-37. • Hublin JJ. 2009. The origin of Neanderthals. Proceedings of the National Academy of Sciences 106:16022-16027. • “Tales of a prehistoric human genome” Science 2009, 323:866-871. • Optional (on Sakai) – Noonan JP. Neanderthal genomics and the evolution of modern humans. Genome Research 20:547-553.

7. Terminology • Chromosome • Genome • DNA

8. Terminology • Chromosome • Molecules in the nucleus that carry genetic information in a linear sequence • Genome • All the genetic information in an organism, i.e. one representative of each chromosome • Nuclear, mitochondrial, chloroplast • DNA • Deoxyribonucleic acid • The molecular basis of heredity • Chromosomes are composed of DNA • The genome is composed of chromosomes

9. Terminology • Locus • Gene • Allele

10. Terminology • Locus - region of the genome • Gene - DNA sequence that encodes a protein • Allele - one of several alternative forms of a DNA sequence, can be coding or non-coding

11. Introduction to Living Primates

12. Why Study Primates? • Reasoning by homology • Closely related species tend to be similar in morphology and behavior • Studying nonhuman primates gives insight into human ancestors • Reasoning by analogy • Natural selection leads to similar organisms in similar environments • Studying biological diversity in ecological context sheds light on evolutionary processes

13. Why Study Primates? • Primates are our closest relatives • Morphological, biochemical, and behavioral similarity reflects evolutionary relatedness • Reasoning by homology • Primates are a diverse order • Variable ecology, diet, morphology, mating patterns, and social structure • Reasoning by analogy

14. Forms of Primate Social Organization   

15. Solitary • Smallest social group • Females maintain separate home ranges with juvenile offspring • Males may establish own ranges or may defend ranges of several adult females • Adult females and males have infrequent contact, mainly mating • Except orangutans, all solitary primates are prosimians

16. Monogamy • One male and one female form long-term pair bond • Show high levels of paternal care of offspring • Share territory with immature offspring • Not very common • Characteristic of gibbons, some small New World monkeys, a few prosimian species

17. Polyandry • One female paired with two or more males • May be more than 1 female, but only 1 is reproductively active • Share home range with offspring • Not very common • May occur among some marmosets and tamarins

18. Polygyny: One-male • Several adult females, a single resident male, and immature offspring • “Bachelor males” often form all-male groups • Variable dispersal patterns • Common among howlers, langurs, gelada baboons

19. Polygyny: Multimale-multifemale • Most common form of primate social organization • Several adult males, adult females, and immature offspring • Most are female-bonded • Males may move between coed groups, remain solitary, or join all-male groups • Lots of variation in terms of size, composition and distribution • Macaques, savanna baboons, some New World monkeys

20. Sexual selection infanticide hypothesis • Hrdy (1977) proposed infanticide enhances male reproductive success • Continuing controversy, but growing data • Infanticide reported in ~40 primate species • Researchers have observed >60 infanticidal attacks and many nonlethal attacks • Observed in one-male and multi-male groups • Increasing evidence confirms predictions of hypothesis

21. Infanticide linked to changes in male membership and status • C.P. van Schaik reviewed 55 infanticides observed in wild • 47 (85%) followed changes in male residence or dominance rank

22. Infanticide shortens interbirth intervals • Lactation generally prevents conception • Cycling resumes quickly if infant dies • Reduces birth intervals by 25-30% in some species • From an evolutionary perspective, new male can more quickly increase the proportion of his offspring in the group

23. Males do not kill their own infants • C.P. van Schaik • 40 of 55 infanticides committed by males not in group at conception • 11 of remaining cases by males not seen mating • V. Sommer – genetic relationship impossible or unlikely in 52 of 55 cases • C. Borries et al. • DNA analyses confirm killer  father in 22 of 23 cases • Paternity unclear in other case

24. Males gain reproductive benefits • C.P. van Schaik • Infanticidal males subsequently mated with mother in 25 of 55 cases • May have mated with mother in 13 other cases • C. Borries et al. • Documented five infanticidal attacks • Four mothers subsequently gave birth • In all cases, DNA identified presumed killer as father

25. Unanswered questions • Does infanticide occur more frequently under certain ecological conditions? • Is there a hereditary predisposition to commit infanticide?

26. The altruism conundrum • Primates perform altruistic behavior in nature • Grooming, alarm calls, food sharing • Altruistic behaviors decrease individual fitness  cannot evolve by natural selection • Altruistic behaviors cannot be favored just because the group benefits

27. W.D. Hamilton and Kin Selection • Ordinary selection can favor altruistic behavior if genetic relatives interact selectively • If you increase fitness of a kin, some proportion of your genes have increased chance of survival • Implications • Altruism is limited to kin • Closer kinship encourages more altruism • Closer kin = higher percentage of your genes • rb > c(Hamilton’s rule) r = average coefficient of relatedness between actor and recipients b = sum of fitness benefits to individuals affected by behavior c = fitness cost to individual performing behavior

28. Primate Diversity

29. Old and new versions of primate phylogeny Old • New • Breaks up prosimians • Lemurs more ancestral • - ‘Prosimians’ used casually, but not formally

30. The primate pattern • No single derived feature shared by all primates • Traits well-suited to arboreal environments • Grasping hands and feet • Binocular (overlapping fields of vision = detail) stereoscopic (image sent from both eyes to both hemispheres = depth) vision • Perceive distance and depth • Controversy over selection of adaptations • Arboreal hypothesis • All traits evolved as arboreal adaptations • Insect predation hypothesis

31. The primate pattern, cont • Grasping hands and feet • Opposable big toe, prehensile hands • Flat nails instead of claws, tactile pads • Hindlimb-dominated locomotion • Greater reliance on sight than on smell • Unspecialized olfactory apparatus, reduced in diurnal primates • Eyes moved forward, developed visual sense, color perception

32. The primate pattern, cont • Reproduction and life history • Females have small litters, increased birth spacing • Trend toward longer lives and longer periods of gestation, infancy, childhood, and adulthood • Requires more parental care • Brain and behavior • Large brain compared to mammals of similar size • More complex brain anatomy • Increased learning and behavioral flexibility • Cultural transmission of new behaviors • Food washing – began by young macaque (named Imo), taught to all newborn infants although adults did not acquire behavior • Not innate behavior, but learned behavior

33. Remember… • None of these traits make primates unique • Example: dolphins have large brains, extended juvenile dependence, and flexible social behavior • Not every primate possesses all these traits • Some prosimians have claws, more developed olfactory senses • Humans have lost opposable big toe

34. Mouse Lemur

35. Ring-Tailed Lemur

36. Ring-Tailed Lemur

37. Blue-Eyed Lemur

38. Aye-aye

39. Sifaka

40. Slow Loris

41. Tarsier

42. Squirrel Monkey

43. Spider Monkey

44. White-Faced Capuchin

45. Great-Nosed Proboscis (Nasalis)

46. Zanzibar Red Colobus

47. Black-and-White Colobus

48. Long-Tailed Macaques

49. Bonnet Macaques

50. Assam Macaques