ANG 6930 Proseminar in Anthropology IIA: Bioanthropology

1. ANG 6930Proseminar in Anthropology IIA: Bioanthropology Day 6 ANG 6930 Prof. Connie J. Mulligan Department of Anthropology

2. New research in last week’s Science • Out of Africa • Did Modern Humans Travel Out of Africa Via Arabia? A German-led team argues on page 453 of this week's issue of Science that tools found under a rock overhang in Jebel Faya, United Arab Emirates, were made by modern humans who may have crossed directly from Africa as part of a migration spreading across Europe, Asia, and Australia. http://www.sciencemag.org/cgi/content/summary/331/6016/387 • The Southern Route "Out of Africa": Evidence for an Early Expansion of Modern Humans into Arabia S. J. Armitage et al.Artifacts in eastern Arabia dating to 100,000 years ago imply that modern humans left Africa early, as climate fluctuated. http://www.sciencemag.org/cgi/content/abstract/331/6016/453 • Stone tools found in UAE date to ~125kya and are similar to E African tools • Pushes back exit of AMHS from Africa by tens of thousands of years • Weak link – are tools truly E African, or could they be Neanderthal and not evidence of an earlier exit by AMHS? • What do the molecular data say?

3. This week Origin of modern humans/Human biodiversity and race Homo floresiensis Anatomically modern Homo sapiens African replacement or multiregional evolution? Global patterns of human genetic variation Anthropological critique of race Reading The Human Species, Chpts 13 (Origins of modern humans), 14 (Human variation) Course packet Tattersall I. 2009. Human origins: Out of Africa. Proceedings of the National Academy of Sciences 106:16018-16021. Powledge TM. 2006. What is the Hobbit? PLoS Biology. 4:2186-2189. Scheinfeldt L et al. 2010. Working toward a synthesis of archaeological, linguistic, and genetic data for inferring African population history. Proceedings of the National Academy of Sciences 107:8931-8938. Serre D and Pääbo S. 2004. Evidence for gradients of human genetic diversity within and among continents. Genome Research 14:1679-1685. Haak W. 2008. Ancient DNA, strontium isotopes, and osteological analyses shed light on social and kinship organization of the Later Stone Age. PNAS. 105:18226-18231. “On the origin of art and symbolism” Science 2009, 323:709-711.

4. Next week (last week!) • Evolution of human life history and intelligence • Textbooks • Population history, Natural selection and adaptation, Agriculture and civilization • Coursepack • Reproduction and fertility, Human growth and development, Aging and senescence, Primate intelligence, Social behavior, Evolution of language • Reading • The Human Species, Chpts 15(Recent microevolution in human populations),16(Human adaptation),17(Biological impact of agriculture and civilization) • Course packet • “Are humans still evolving?” Science 2005, 309:234-237. • Gravlee CC et al. 2009. Genetic ancestry, social classification, and racial inequalities in blood pressure in southeastern Puerto Rico, Public Library of Science ONE 4:e6821. • “Dental evidence suggests Neanderthals matured faster than we do” Science 2007. • Hawkes K. 2004. Human longevity: The grandmother effect. Nature 428:128-129. • Lähderpera M, Lummaa V, Helle S, Tremblay M, Russell AF. 2004. Fitness benefits of prolonged post-reproductive lifespan in women. Nature 428:178-181. • Finch CE. 2010. Evolution of the human lifespan and diseases of aging: Roles of infection, inflammation, and nutrition. Proceedings of the National Academy of Sciences. • “Civilization’s cost: The decline and fall of human health” Science 2009. 324:588. • Herrman E et al. 2007. Humans have evolved specialized skills of social cognition: The cultural intelligence hypothesis. Science 317:1360-1366. • “Nonhuman primates demonstrate humanlike reasoning” Science 2007, 317:1308. • Journal analysis due, take-home exam handed out and due next week

5. Origin of Modern Humans

6. Overview • Morphology and fossil record of anatomically modern humans • Evolution of human behavior • Upper Paleolithic technology and culture • Revolution or evolution? • Modern human origins debate • Genetic data • Fossil record

7. The big picture Evidence of modern human behavior in Europe and Australia Archaic populations evolving to anatomically modern H. sapiens Only modern H. sapiens in fossil record Likely migrations from Africa Years BP 90,000 80,000 70,000 60,000 50,000 40,000 30,000 10,000 20,000 150,000 140,000 130,000 110,000 100,000 120,000

8. Evolutionary trends from hominid to human • What are some of the characteristics that evolved to make us uniquely human?

9. Evolutionary trends from hominid to human • What are some of the characteristics that evolved to make us uniquely human? • Bipedalism - ~4 mill yrs ago • Ardipithecus ramidus (oldest hominid) and Australopithecus anamensis • Smaller teeth (change in diet) - ~3 mill yrs ago • Australopithecus afarensis (Lucy) • Reduction in robustness - ~2.5 – 3 mill yrs ago • Australopithecus africanus or A. garhi •  in brain size - ~2 – 2.5 mill yrs ago • H. erectus • Art (symbolic expression) – 40,000 yrs ago • H. sapiens

10. Morphology of modern H. sapiens • Small face with protruding chin • Rounded skull • High vaulted cranium • Vertical forehead, no supraorbital torus • No occipital bun or torus • Less robust postcranial skeleton • Longer limbs with thinner-walled bones • More lightly built hands • More narrow pelvis, shoulders Cro-Magnon 1 ~30 ka Discovered 1868

11. Archaic humans on left • Low cranial vault, large brow ridge, robust (large) face • Modern humans on right • High cranial vault, vertical forehead, prominent chin, less robust (smaller) face • But, right (a) has a robust face and large brow ridges and right (c) has a sloping forehead, a larger face and large brow ridges. •  much morphological variation b/t archaic and modern

12. Fossil record of modern H. sapiens Jurmain et al.

13. Early modern Homo sapiens in Africa and Near East

14. Modern H. Sapiens in Europe, Asia, and Australia

15. Evolution of modern human behavior • Early modern humans able to create and transmit complex symbolic behavior • Moderns in W. Eurasia created tool industries collectively known as Upper Paleolithic • ~45-10 ka • Upper Paleolithic peoples • Technology of first moderns in Australia similar to European Upper Paleolithic • Sparse record in Asia, controversy in Africa

16. Complex behavior in Upper Paleolithic • Ecological range • Early moderns extended range farther east and north than previous hominids • Inhabited difficult, cold, dry environments • Technology • Assembled more sophisticated and standardized tools from wider variety of materials • Constructed elaborate shelters • Seafaring – 100 km of open ocean to Sahul (New Guinea, Australia, Tasmania)

17. Complex behavior in Upper Paleolithic • Social organization • Used raw materials from hundreds of kilometers away • Long-distance trade networks, migrations • Flint quarried in Poland identified in sites 400 km away • Symbolic expression • Created art, ornamentation • Performed ritual burials, practiced other symbolic behavior

18. Upper Paleolithic technology • Shift from round flakes to blade tools – Mode 4 • More time-intensive • More efficient use of raw materials • Greater variety • More specialized tools • Distinctive designs for tool types • Increased variation in time and space 1,3,4,5, 7,8,9 – points; 2 – borer; 6 – scraper

19. Upper Paleolithic technology • UP spanned depths of last ice age • Cold, dry grasslands, with temperatures to -50F • Required improved shelter • Evidence of multifamily huts • Clothing • Bone awls and needles common • Russian burial site includes caps, shirts, pants, shoes • Fox, wolf remains without feet Mezherich, Ukraine (15 ka)

20. Upper Paleolithic peoples in Europe better adapted to environment • Higher population densities than Neandertals • Increased lifespan • UP men sometimes reached 60, women rarely reached 40 • Neandertals rarely reached 40 • Decreased injury and disease • Relatively scare evidence of traumatic injury • Slightly more evidence of disease, but less than among Neandertals

21. Upper Paleolithic symbol and ritual Hohle Fels (30 ka) Le Chauvet (30 ka) Ivory horse fromVogelherd, Germany(30 ka) Venus of Willendorf(25 ka) Lascaux (17 ka)

22. Human revolution or evolution? • “Human revolution” • Sudden appearance of complex adaptive and symbolic behavior in Europe ~40 ka • Klein argues that African archaeological record parallels Europe • Brooks and Yellon argue African record predates Europe and shows more gradual change • A revolution is interpreted as evidence of sudden emergence of cognitively modern people • How plausible is this scenario? How well supported is it by the archaeological record?

23. Potential objections to revolution • Natural selection posits complex adaptations by accumulation of small changes • Fossil record and comparative primatology suggest continuity in evolution of intelligence • Punctuated event unlikely • Archaeological record fundamentally biased in favor of Europe • 10 times as many sites in France alone as in entire African continent

24. Origins of modern behavior in Africa • Sally McBrearty and Alison Brooks argue that MSA is not equivalent to Middle Paleolithic • Signatures of modern human behavior gradually appear in Africa between 250-50 kya • Transition from Middle (~200kya) to Upper (~40kya) Paleolithic in Europe should not be confused with origins of modern humans

25. Origins of modern behavior in Africa • Blades appear early in MSA (240-280 ka) • There is regional variation in MSA industries • Refined bone tools at MSA sites (72 ka) • MSA peoples transported raw materials over hundreds of kilometers • MSA peoples built stone shelters and hearths • There is evidence of decorative carving (77 ka), beads (50 ka), pigment use (240-280 ka) • New evidence of engraved ochre pieces 100 ka in S Africa (Science, 2009, 323:569) • Appear to be engraving, not just grinding off ochre, but who knows if it’s ‘symbolic’

26. What is ‘symbolic’?The ability to construct symbols that convey meaningSymbols must have a commonly understood meaning • “If it’s a one-off, I don’t think it counts. It’s not sending a message to anyone” • Thomas Wynn, Science, 2009, 323:709-711 Cave art, Le Chauvet (30 ka) Engraved ochre, S Africa (77 ka) A woman? Berekhat Ram, Israel (250 ka)

27. X Source: McBrearty and Brooks (2000) Journal of Human Evolution 39:453-563

28. Theories on the origin of modern humans

29. Multiregionalism vs replacement theories of human evolution • What is multiregionalism?

30. Multiregionalism vs replacement theories of human evolution • What is multiregionalism (also called regional coalescence)? • Evolution w/i a single lineage spread throughout the world/Multiple evolutions of anatomically modern humans throughout the world • Species changed as a whole while retaining regional characteristics • e.g.  in brain size seen ~700,000 years ago, worldwide • Based on continuity of million-year-old fossils and younger fossils in multiple regions outside of Africa • e.g. shovel-shaped incisors are more frequent in E Asia throughout many periods • Besides temporal continuity, what could account for the supposed similarity through time of certain morphological characteristics in the same geographic region? • Dependent on high levels of gene flow to keep us all the same species so we can interbreed • Postulates a global evolution of humans as opposed to a geographically restricted one in Africa • All humans over past 2 million yrs are part of the same evolutionary lineage

31. Multiregionalism vs replacement theories of human evolution • What is the replacement theory?

32. Multiregionalism vs replacement theories of human evolution • What is the replacement theory? • Homo erectus spread throughout world, 1-2 million years ago • Anatomically modern humans left Africa ~150,000-200,000 years ago and replaced all other hominid populations throughout the world • Depends on archaics and moderns being separate species • Little or no interbreeding b/t modern humans and older hominid populations • What kind of scenarios might explain a lack of interbreeding? • All of our ancestors lived in Africa 200,000 YBP

33. Assimilation Model • Relethford’s proposed model • Also called “weak” out-of Africa, primary African origin model • Out-of-Africa w/ admixture b/t archaic, indigenous pop’s and modern, invading pop’s • Basically an intermediate theory b/t out-of-Africa (OOA) and multiregionalism • Despite what Relethford says, I don’t consider his theory multiregional evolution b/c it’s simply interbreeding b/t 2 species (or subspecies) and not independent evolution of modern traits as multiregionalism was originally proposed • An intermediate model is supported by recent molecular genetic data indicating some interbreeding of AMHS with Neanderthal (possibly) and Denisova

34. Continuity with no gene flow Strict Out of Africa(complete replacement) Debate centers onthis range of admixture 0% 100% 25% Percentage of local, archaic admixture in first modern humans in Eurasia Adapted from Pearson, O.M. (2004) Evolutionary Anthropology 13:145-159

35. Gene trees • Compare DNA from pairs of living people, build tree to track history of particular gene • Many studies focus on mtDNA • Maternal inheritance – no recombination • High mutation rate – more accurate dating • High copy rate – easier to recover in fossils • Generally find two clusters – African and non-African • Does not falsify multiregional hypothesis

36. Genetic diversity • Greater heterogeneity in African populations taken as evidence of antiquity – more time to accumulate mutations • Pattern could also be shaped by population size • Relethford and Jorde: 50-70% of ancestors in Africa

37. Genetic diversity analysis • First split between African and non-African populations • Indicates African origin • Same pattern could be produced by slightly more gene flow out of African than into Africa • However, genetic data all show coalescence ~100-200kya – not consistent with multiregionalism

38. Population size and modern human origins • Genetic variation in living humans contains signature of past population size • Comparison of contemporary variation with simulated populations suggests rapid growth of population ~50 kya • Possibly no more than 10,000 adults ~200 kya • Assumptions uncertain: actual number may be lower if there was a lot of population structure

39. Bottom line - Mostly Out of Africa w/ possibility of non-African admixture Europe Africa Asia Present “Modernhumans” Time “Archaichumans” Past Europe Africa Asia Adapted from Relethford (2003)

40. Study of human variation

42. Anthropology and Race • History of anthropology tied to history of race concept • Early anthropologists played central role in creating racial worldview • Later, anthropologists played major role in dismantling American racial worldview • Today, anthropologists engage in public education about race and human diversity

43. Race in early Anthropology • Racial typology was guiding aim of 19th and early 20th century anthropology • Unilinear evolution • Rank human groups along single evolutionary path from “savagery” to “civilization” • Cultural and biological anthropologists • Biological determinism • Basic assumption that biology → culture

44. Boasian critique of race • Statistical averages do not reflect ideal types • No discrete boundaries • Significant within-group variation • Racial types are not fixed • Heredity and environment • Plasticity • Race  language  culture

45. Boas’s immigrant study • Commissioned by U.S. Immigration Commission • Boas and team of 13 assistants collected data on nearly 18,000 people • Largest data set of family measurements • Best remembered for critique of cephalic index

46. Cephalic Index • Anders Retzius devised cephalic index and built a theory of history on it • Ratio of head breadth to head length • Treated as fixed marker of racial phylogeny • Boas’s demonstration of change in generation undermined typology

47. Gravlee, Bernard, Leonard (2003) • Reanalyzed data Boas published in 1928 • Address three key findings • Differences between foreign- and U.S.-born • Increasing influence of environment over time • Differences between U.S.-born children and foreign-born parents

48. Rise of No-Race Anthropology • Cultural and biological anthropologists played a key role in challenging race • Livingstone: “There are no races, there are only clines” • After WWII, no-race position came to mean no discussion of race in anthropology

49. Race returns to Anthropology • AAPA (1996) and AAA (1998) released statements on race • Anthropologists advised Census on race • AAA launched $4 million public education project • Anthropologists engaged in interdisciplinary debate on human variation • Growing focus on social reality of race and racism

50. White female Black female White male Black male Health, race, and anthropology • Substantial disparities in life and death • Persistence of racial-genetic determinism in biomedicine • Opportunity to advance anthropological critique of race Source: National Center for Health Statistics