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ORIGIN OF MODERN HUMANS

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ORIGIN OF MODERN HUMANS

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    1. ORIGIN OF MODERN HUMANS

    2. Genesis 2:7 And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.

    3. Apparent Age and History

    4. Some Short Readings linked on the Core 6 Webpage Fossil Hominids: The Evidence for Human Evolution African Legacy N'tal DNA H. floresiensis The Man from Neander Valley

    7. Some Extinct Hominines A. africanus A. afarensis

    10. Out of Africa I 1.8 million years ago (1.8 Ma) Homo ergaster/erectus populates the Old World Fairly well established: (Consensus Science)

    11. Out of Africa II 100,000 years ago (100 Ka) Homo sapiens populates the Old World Controversial: (Frontier Science)

    12. Out of Africa I 1/2 700,000 years ago (700 Ka) Homo antecessor (?) populates the Old World Even more Controversial

    13. TIME PERSPECTIVE of these lectures...

    14. IN THESE LECTURES... We’re concerned with the last 2,000,000 years (2 Ma) or so of Earth’s 4.5 billion year (Ga) history 2,000,000 ÷ 4,500,000,000 = .044 % If all Earth’s history were one day... .044% X 24 X 60 X 60 = 38 seconds

    15. THE ARCHEOLOGICAL AGES Classified by types of tools

    16. THE “STONE AGES”

    17. PALEOLITHIC “Old Stone Age” 2.5 Ma => about 10 Ka Started with Homo habilis (maybe Australopithecus garhi 2.5 Ma) Chopped stone tools

    18. NEOLITHIC ? 10 Ka => ? Agricultural Revolution A neolithic product: BEER!

    19. Beyond the NEOLITHIC Copper, Bronze Age, Iron Age,… Industrial Age 1700s in England Now: Information Age?

    20. Lumpers vs. Splitters Lumpers ==> Favor a “ladder” pattern to evolution (fewer species) Splitters ==> Favor a “bush” pattern (lots of different species)

    21. Anti-Evolutionary Creationists Can be both lumpers and splitters at the same time! Lumping: All Australopithecines are “apes”, and all Homo are “humans” Splitting: Yet, they complain about absence of “missing links”

    22. The Changing Position of Homo erectus

    23. First half of 1900s: Splitters Scholars commonly assigned a new species name to virtually each new fossil unearthed. E.g., Pithecanthropus erectus was the name given to “Java Man” Sinanthropus pekinensis was the name give to “Peking Man” Later both became Homo erectus

    24. Pre-1990s: Lumpers By 2 Ma in Africa, Homo habilis had evolved into Homo erectus. By 1 Ma, some H. erectus left Africa for Asia and, later Europe By 200 Ka, H. erectus had evolved to H. sapiens (either in Africa or separately in Africa and Eurasia).

    25. Present view: Moderate Splitting From discovery of early (1.6 - 1.8 Ma) H. ergaster/ erectus outside of Africa

    26. Moderate Splitting

    27. H. ergaster/erectus Scholars still disagree on the taxonomy (family tree) of these species, but all believe they are an evolutionary “step up” from H. habilis According to paleoanthropologists, “a new grade” of hominine evolution

    28. H. ergaster/erectus “firsts” First hominines outside of Africa Dmanisi (Georgian) skull D2700??? Systematic hunting Beginning of “home bases” Systematic tool making Fire! Extended childhood

    29. Something Between H. erectus and H. sapiens?

    30. H. heidelbergensis Lived 500 Ka - 100 Ka Little more “modern” than Homo erectus/ergaster ==> basically modern brain size Heavy brow ridges like Neanderthals, but less “robust”, more “human” face

    31. H. heidelbergensis “Heidelberg Man” in Europe (500Ka) “Rhodesian Man” in Africa (200Ka) Sometimes referred to as “Archaic” Homo sapiens Evolved into Neandertals in Eurasia, into H. sapiens in Africa

    32. GEOLOGICAL PERSPECTIVE Of the last 2 Ma

    34. Over 20 “ICE AGES” paired with “warm” interglacial periods In the past 2 Ma

    35. THE LAST “ICE AGE” Lasted from 70 Ka to 10 Ka

    36. American Midwest 16 Ka

    37. Human ancestors in the North had to cope with these ice ages...

    38. A BIT ABOUT DATING C-14 has a half life of 5,700 years, so only effective to about 70 Ka Works on organic material - wood, bones, shells, etc. Older stuff must be dated with K-Ar method on surrounding rocks But K-Ar only effective on rocks older than 100 Ka

    39. RECENTLY... Newer techniques (Thermoluminescence, electron spin resonance) Related to radioactive decay, but work in the “missing” time range (70 Ka - 100 Ka) Fact: All dating methods agree where they overlap

    40. How did early humans “make a living”? SCAVENGER OR HUNTER?

    41. SOME EVIDENCE Suggests that early man (Homo habilis => Homo erectus) was a scavenger (lack of hunting tools, carnivore teeth marks on bones) Later humans ... (Neandertal and moderns) were foragers = hunters & gathers Until the Agricultural Revolution

    42. FOR SURVIVAL Foraging societies are adapted to their natural environment E.g., they control population naturally by later breeding and prolonged lactation

    43. !KUNG BUSHMEN

    44. Modern Example of a foraging society: Live in Kalahari Desert Work 12-20 hours/week Eat healthier diet than many Americans Good article in Feb. 2001 National Geographic

    46. But, Foragers In colder climates didn’t have as much fun ... The “Ice Man”, whose preserved carcass was found in 1991, belonged to a foraging people in Europe about 5 Ka - Copper Age

    48. Out of Africa II 100,000 years ago (100 Ka) Homo sapiens populates the Old World, Replacing Neandertals and Archaic Hs. Controversy! (Frontier Science)

    49. Neanderthal “MEN”

    50. Neandertal remains were first discovered in 1856 in the valley (tal) of the Neander River near Düsseldorf Thought to be a diseased Mongolian Cossack Existed from probably at least 230 Ka to about 29 Ka At least 350 individuals found

    52. DISTINGUISHING FEATURES INCLUDE Short and stocky High brow ridges Weak chin Protruding face Muscular Slightly bigger brain!

    53. DISTINGUISHING FEATURES INCLUDE Short and stocky High brow ridges Weak chin Protruding face Muscular Slightly bigger brain!

    54. BRAIN SIZE Average Neandertal = 1450cc Average modern human = 1360cc Much variation in modern humans: Jacques Anatole France 1,000cc Ivan Turgenev 2,000cc 19th Century novelists - “geniuses”

    55. WERE NEANDERTALS “HUMAN”? I.e., are they Homo sapiens or Homo neanderthalensis or Homo sapiens neanderthalensis ?

    56. Or were they Homer sapiens ???

    57. Three lines of Evidence to establish Origin of Modern Humans Anatomy --> fossils Genetics --> mostly on present-day humans Archeology --> Tools and Art

    58. Genetic Diversity Modern humans are genetically less diverse than most other species .08 F vs. >.20 F

    59. Mitochondrial DNA Study

    60. MtDNA Study conclusions... Genetic variability shows the greatest amount of diversity in sub-Saharan African populations High variability suggests that the African populations have been accumulating genetic mutations for the longest time--i.e., they are the oldest living populations

    61. MtDNA Study conclusions... Genetic distance is greatest between African populations and other groups

    62. MtDNA Study conclusions... Tends to support the “Out of Africa II” (monogenesis) rather than the multiregional hypothesis

    63. MODERN RACES ? "From a scientific point of view, the concept of race has failed to obtain any consensus and none is likely, given the gradual variation in existence." (Cavalli-Sforza, History and Geography of Human Genes, p 19)

    64. N-tals HUMAN ? To answer this question, we must consider the meaning of culture, the uniquely human adaptation

    65. RECALL CORE 5 (ow…) This course is about ... Cosmic evolution (most of Core 5) Biological evolution (Core 6 so far) Cultural evolution This lecture crosses the boundary between biological evolution and cultural evolution

    66. CULTURE What it means to be “human”

    67. DEFINITION Culture = the patterned behavior and mental constructs that individuals learn, are taught, and share within the context of the groups to which they belong

    68. LANGUAGE Is essential for human culture But not equivalent to it

    69. Could N-Tals Talk? Had big brain with Broca’s Area, but... Did they have the right “plumbing”?

    70. Could N-Tals make all the same sounds as modern humans? Another example of “Frontier”science… Well, at least about the “plumbing” part

    71. Position of Larynx… Would indicate N-tal speech was probably very nasal, couldn’t make certain sounds: “ee”, “ah”, “oo”, as well as “g” and “k”

    72. But fossil Hyoid bone is like modern humans… Which supports the possibility of modern speech abilities…

    73. N’Tals had a shorter childhood than us… So perhaps N’tals didn’t have time to develop language skills as moderns These controversies show why this kind of thing is called “frontier” science…

    74. Neandertal Cultural Activities

    75. SPECIALIZED TOOLS Levallois technique (flaking) 20 different types discovered ==>

    76. HUNTING STYLE Did not know how to throw !

    77. HUNTING STYLE Did not know how to throw !

    78. Just Like the Rodeo

    79. BURIAL OF DEAD Ritual ? Evidence of plants in grave Shanidar Cave 60 Ka

    80. Shanidar Cave, Iraq

    81. ALTRUISM ? Some evidence of altruism This specimen was “old” and crippled Chimpanzees, e.g., abandon their sick

    82. ART ? No evidence of genuine “art” Were they too dumb or Just too busy?

    83. LANGUAGE ? Already discussed N-tal speech Did they use human language? How does human language differ from animal communication? “Evolution of Communication” lecture by Dr. Martin Nickels, March 24...

    84. LAST N-TAL FOSSILS Found are 29 - 32 Ka In Gibraltar (Portugal)

    85. Are N-tals “Human” DNA evidence… http://www.talkorigins.org/faqs/homs/mtDNA.html

    86. 1997 Mitochondrial DNA analysis from bones of the “type specimen” (the original one found in the Neander valley) Concluded common ancestor of Neandertal and H. sapiens to be 600 Ka Supports N-tals aren’t “human”!

    87. 1997 mtDNA Study Also gives powerful backing to the theory that all humanity descended from an "African Eve" about 100 Ka to 200 Ka =>”Out of Africa” hypothesis and that Neandertals were an evolutionary dead end

    88. CRO-MAGNONS and CAVE ART More in Jody Watkins’ lecture

    89. Point of Information “Cro-Magnon” is an historical but not scientific term… Very few if any paleoanthropologists use this terminology…

    90. CRO-MAGNONS First fossil found near Hotel Cro-Magnon in Les Eyzies in SW France - 30 Ka They are modern Homo sapiens AmHs = Anatomically modern H. sapiens Africa 130 Ka => present Europe 35 Ka => present

    91. CRO-MAGNONS Had better tools than Neanderthal Gave C-M a competitive edge over N-tal

    92. BETTER TOOLS ... E.g., spear thrower Note also the carving (art)

    93. An Unanswered Question Did C-M outcompete or outfight Neanderthals ? Only 1% “competitive edge” in niche could lead to extinction in 5,000 years! Or were N-tal genes absorbed into C-M population?

    94. N’tal replacement by modern H. sapiens … or absorption?

    95. CAVE ART Cro-magnons had a truly human culture Chauvet cave art 32 Ka Discovered in 1995 What’s the “meaning” of this art? ===>

    96. Chauvet Cave

    98. Paleogeography of Modern Humans Very simplified here… When were each of the continents settled by modern humans?

    99. Assuming “Out of Africa II”

    100. Continents were peopled in this order Africa (130 Ka) Asia Middle East (100 Ka) Remainder (60 Ka) Australia (60 Ka) Europe (35 Ka) Americas (20 - 30 Ka) Dec. 2000 Nat’l Geographic

    101. Native Americans - Florida 14 Ka

    102. Midterm Exam Wednesday March 1 Here in the Shen

    103. Recent Cro-Magnons in the field

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