ANG 6930 Proseminar in Anthropology IIA: Bioanthropology

1. ANG 6930Proseminar in Anthropology IIA: Bioanthropology Day 2 ANG 6930 Prof. Connie J. Mulligan Department of Anthropology

2. This week • Science and Evolution • Reading • The Human Species, Chpt 1(pp 12-29) and Chpt 4 • Course packet • Park MA. 2005. Biological Anthropology, An Introductory Reader, Chpt 9 (pp 40-44), Natural Selection (1858), Charles R. Darwin and Alfred Russel Wallace • Mayr E. 1997. “What is science?” in This is biology: The science of the living world, pp 24-44. Cambridge: Harvard University Press • Scott EC. 1997. Antievolution and creationism in the United States. Annual Review of Anthropology 26:263-289 • Talbot M. 2005. Darwin in the Dock. The New Yorker, pp 66-77 • Berkman MB et al. 2008. Evolution and Creationism in America’s Classroom: A National Portrait. PLoS Biology, 6:0920-0924

3. Next week • Genetics and the development of evolutionary theory • Mendelian and molecular genetics • Population genetics • Evolutionary development biology (Evo Devo) • Reading • The Human Species, Chpts 2 (Human genetics), 3 (Evolutionary forces), 8 (Paleoanthropology) • Course packet • Tattersall I. 2000. Paleoanthropology: The last half-century. Evolutionary Anthropology 9:2-16 • Foley R. 2001. In the shadow of the modern synthesis? Alternative perspectives on the last fifty years of paleoanthropology. Evolutionary Anthropology 10:5-14 • Carroll SB. 2003. Genetics and the making of Homo sapiens. Nature. 422:849-857 • “Beyond Stones and Bones”, Newsweek, March 19, 2007. • Topic and abstract for journal analysis is due

4. Journal analysis • Your topic (the relevant question(s) and which other subfield you will be examining) and an abstract (<200 words) including your search strategy (which journals are you using and why) is due at the beginning of class on Jan 21. • In your abstract, describe the problem you are addressing and some of the history of this issue. Be sure to specify your two additional journals, and why you chose them, as well as the other subfield of anthropology that you will be studying. I encourage you to discuss your topic with me in advance, in person or by email. • The final paper is due at our last class, Feb 18. • Turn in your original (graded) abstract with the final paper

5. From last week

6. Current hot topics on humans • Top 10 mysteries about humans • http://www.livescience.com/history/091026-top10-origins-mysteries.html • Top 10 things that make humans special • http://www.livescience.com/culture/091030-origins-top10-special.html

7. Anthropology • Important to remember that a strength of anthropology is its holistic approach • What’s the difference between cultural anthropology and sociology? • What’s the difference between biological anthropology and biology? • Holistic view is not limited to the 4 anthropology subfields, but any relevant field • Many Anthro departments are splitting along subfield lines

8. Why do you think more anthropological research is not truly interdisciplinary? • How could you make your research relevant to someone outside your subfield?

9. Balaresque et al. 2007 • Demography • Migration/colonization • Out of Africa • Peopling of New World • Population origins • Semitic speakers • Admixture • Puerto Ricans • Adaptation • Natural selection • Skin color • Agriculture/domestication • Disease • Origin/intro to naïve pop’s • Genetic/cultural risk factors Peopling of the Americas Expansion out of Africa Domestication of the donkey Modified from Balaresque et al. 2007 Origin and expansion of Semitic speakers Genetic and cultural components to ethnicity and health

10. Chpt 1 - Science and Evolution • Development of evolutionary thought • Darwin and natural selection • Misconceptions about evolution • Science as a way of knowing • Science, evolution, and creationism

11. Landmarks in Euro-American Thought about Human Origins and Diversity Age of European Exploration Darwin publishes On the Origin of Species 1500 2000 1300 1400 1600 1700 1000 1100 1200 1800 1900 Years A.D.

12. Development of Evolutionary Thought • Ancient roots – differences and origins • Renaissance – empiricism and science • 17th-18th centuries – naturalism • 1800-1859 – Racial origins • 1859-1900 – Evolution and racial origins • 1900-1950 – Description and classification • 1950-present – New Physical Anthropology

13. Pre-Darwinian Theories and Seeds of (R)evolution

14. Pre-Darwinian thought • Ancient Greek philosophy • Static, unchanging view of the world • Aristotle (384-322 B.C.) • Greek philosopher and naturalist • Historia Animalium describes similarities between man, apes, and monkeys • Differences attributed to position in the scala naturae (Great Chain of Being) • Aristotle’s notion of scala naturae did not incorporate racial hierarchy • Argued for environmental causes of variation • Wooly hair of Africans due to harsh, arid climate • Straight hair of Thracians and Scythians due to moist air

15. Carolus Linneaus (1707-1778) • Swedish botanist and founder of taxonomy • Epitomized focus on description and classification • Systema Naturae (1735-1766) • Identified two-dimensional structure of nature, as opposed to one-dimensional “Great Chain”

16. Great Chain vs Linnaean Taxonomy Source: Marks (1995) Human Biodiversity

17. Linnaeus’s Classification of Humans • Homo sapiens in order Primates • Four geographic varieties mix culture and biology • H. sapiens europaeus • H. sapiens asiaticus • H. sapiens americanus • H. sapiens afer

18. George Louis Leclerc, Comte de Buffon (1707-1788) • French naturalist • Opposed Linnaeus • No unit higher than species • Species comprise Great Chain of Being • Dismissed evolutionary implications of Linnaean ideas • Posited microevolution in response to environment, but denied macroevolution

19. Buffon and Human Variation • Buffon rejected classification as goal of study, aimed to describe and explain diversity • Varieties of the Human Species (1749) • How is variation patterned? • What explains patterns of variation? • Buffon and Linneaus represent two strains of thought in 20th century anthropology

20. Georges Cuvier (1769-1832) • French zoologist and founder of paleontology • Embraced Linnaeus’s nested hierarchy, but not evolutionary implications • Best remembered for catastrophism • Mass extinctions, repopulation gives appearance of change • Consistent with Biblical view

21. Jean Baptiste, Chevalier of Lamarck (1744-1829) • French aristocrat • Regarded classification as sterile and theorized about process of evolutionary change • Inheritance of acquired characteristics • Organism altered during lifetime by environment and behavior • Change inherited by offspring

22. James Hutton (1726-1797) • Scottish geologist • Developed principle of uniformitarianism (1785) • Same geologic processes (erosion, continental drift) operate today as in the past • Earth has long history • Supernatural theories not required to explain history • Earth’s geology shaped by processes observable today • e.g. Deep soils formed by the weathering of bedrock over 1000s of years

23. Sir Charles Lyell (1797-1875) • Scottish geologist • Promoted and extended principle of uniformitarianism • Three-volume Principles of Geology (1830-1833) • Darwin – “I always feel as if my books came half out of Lyell’s brain.”

24. Charles Darwin (1809-1882) • Born into intellectual family in northern England • Enrolled in medicine, then graduated in theology • Joined HMS Beagle in 1831 as “unpaid gentleman scholar and naturalist”

25. Voyage of the HMS Beagle

26. Darwin and Wallace • Darwin outlined theory of natural selection in 1837 • 20 years later, young Wallace developed same theory • Darwin and Wallace co-presented at Linnaean Society of London (1858) • Darwin published On the Origin of Species a year later Alfred Wallace 1823-1913

27. Darwin’s observations • Much morphological variation • Variation made sense in terms of environment • Creatures in cold climates had fur • Birds in areas where insects live deep inside tree trunks have long beaks

28. Darwin’s Postulates • Infinite ability of populations to grow, but finite ability of environments to support growth • Malthus showed that the planet can not support uncontrolled growth, i.e. a large percentage of offspring will die and Darwin helps provide the answer as to who will die • Within populations, organisms vary in ways that affect ability to survive and reproduce • Variations are transmitted from parents to offspring • Natural selection – evolution by variation and selective retention

29. An Example – Darwin’s Finches • Darwin identified multiple species of finches on Galápagos Islands, attributed special role in his thinking

30. Drought and Darwin’s Finches • Natural experiment– severe drought—tests Darwin’s postulates • As food supply shrank, finch population declined • Beak depth affected survival • Parents and offspring had similar beak depths

31. Darwin’s Finches • Directional selection • Beak depth influences individual’s probability of survival • Distribution of beak depth shifts to right due to selection

32. Darwin’s Finches • Balancing selection • Selection maintains status quo when most common type is best adapted • Selection required to keep populations the same, not just to change

33. Individual Selection • Selection arises from competition among individuals, not among populations or species • Example – individual reproductive success vs species’ survival • Selection may favor high individual fertility, even if population growth threatens survival of species

34. Evolution of Complex Adaptations • Small variations are important • Continuous, not discontinuous traits important • Complexity arises from accumulation of small random variations • Typing monkeys - “Methinks it is like a weasel.” • Chance of randomly typing monkeys reproducing Shakespeare - ~ 1 in a trillion. Same as chance of randomly producing a human eye in a single trial • Convergence - complex adaptations have evolved independently multiple times • Selection favors intermediate phenotypes

35. Selection of Intermediate Steps Living gastropod mollusks illustrate intermediate steps between eye cup and camera-type eye

36. Rates of Evolutionary Change • 14 living species in Galápagos • All descended from single species within last half million years

37. Evolution of Evolutionary Theory • Darwin could not explain how variation was maintained • Assumed blending inheritance • Could not explain evolution beyond original range of variation • Acceptance of Darwinian mechanisms awaited rediscovery of Mendelian genetics • Modern Synthesis (1930-1950) • Evo-Devo (1980-present)

39. Science andCreationism

40. What is Science? [Empirical science] is systematic description and classification of objects, events, [and] processes, and the explanation of those events and processes by theories that employ lawful regularities, all of the descriptive and explanatory statements employed being testable against publicly observable data. O’Meara, 1989

41. Science Is… • Empirical • Systematic and explicit • Theoretical, explanatory, predictive • Self-critical, reflexive, based on testing • Public

42. Creationist Claims • “Evolution is only a theory” • Actually, evolution is both a fact and a theory • Fact is “an observation that has been repeatedly confirmed and for all practical purposes is accepted as ‘true.’” • Theory is “a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.” National Academy of Sciences

43. Creationist Claims • “Evolution is unscientific, because it is not testable or falsifiable.” • Microevolution and macroevolution • Fossil record and macroevolutionary hypotheses • “Living things must be products of intelligent design, because natural selection could not produce some complex beings.” • Evolution of camera-type eye • Convergence

44. Chpt 4 - Speciation and Phylogeny

45. Overview • Microevolution  macroevolution • Species concepts • Biological species • Ecological species • Evolutionary forces • Systematics, phylogeny, and taxonomy

46. Definitions • Microevolution • Changes in allele frequencies over relatively short time periods/small geographic ranges/small genomic ranges • Evolution over short time periods • Occurs in our lifetime, i.e. is observable to all of us • Macroevolution • Changes in allele frequencies over relatively long time periods/large geographic ranges/large genomic ranges • Evolution over long time periods • Creationists have problem with macroevolution b/c they say we can’t directly observe macroevolution • We can’t do million year experiments, but we can make testable predictions, like in geology or astronomy

47. What Are Species? • Species are real biological categories, not abstractions • Paleospecies are more abstract concepts • Controversy about how species are defined • Biological species concept • Group of organisms that naturally interbreed and produce fertile offspring • Ecological species concept • Natural selection plays important role in species differences • Reproductive isolation not necessary • Species occupy different ecological niches, but are not necessarily physically isolated from each other • Phylogenetic species concept • Some level of genetic variation is chosen to define different species

48. Modes of Speciation Cladogenesis Anagenesis

49. Phylogeny and Systematics • Phylogeny refers to evolutionary relationships among group of species, often depicted as a “family tree” • What is the “outgroup” in this tree? • Systematics is construction of phylogenies • Taxonomy is use of phylogenies in naming and classification

50. Approaches to systematics • Evolutionary systematics • Considers all homologous traits, primitive and derived • Based on descent and overall similarity • Complex algorithms to evaluate genetic distance or coalescence and translate that relationship into a tree • Cladistics • Argues that phylogenies should be constructed only on shared derived traits • Much simpler, less sophisticated and probably less realistic