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Origin of Modern Humans

The Genesis Account(s). Ge 1:27 So God created man in His own image; in the image of God He created him; male and female He created them.Ge 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 being. . I didn't co

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Origin of Modern Humans

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    1. Origin of Modern Humans Cavemen, Hobbits, & Us

    2. The Genesis Account(s) Ge 1:27 – So God created man in His own image; in the image of God He created him; male and female He created them. Ge 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 being.

    3. “I didn’t come from no monkey!” True! But, according to evolutionary theory, you and a monkey have common ancestors (way, way back) Just like you and your cousin have a pair of Most Recent Common Ancestors - MRCAs

    6. The previous two pictures are of Apes, not Monkeys! And you didn’t come from them either! But your Most Recent Common Ancestor (MRCA) with chimps is more recent… 6-7 million years?

    7. Main categories of Evidence Fossils Similarities and differences to modern apes and humans Anatomy Similarities among modern apes and humans Embryos

    8. Main categories of Evidence Vestigial structures and design “imperfections” Wrist bones Spine Tailbone Wisdom teeth

    9. Genetics Same “language” for humans as for all other life Francis Collins: The Language of God Closeness to Chimps

    10. Human and Chimp DNA Both have about 25,000 coding genes About 600 genes are different = 97.7% identical 3 billion base pairs (“rungs” on the DNA “ladder”) with 35 million differences = 98.8% identical

    11. Human and Chimp DNA You differ from your parents in about 100 base pairs Let’s say there’s 18 years in a generation 35 million/100 = 350,000 generations x 18 years = 6.3 million years since human/chimp MRCA You and a chimp are “350,000th cousins”!

    12. Human and Chimp DNA How many pairs of chromosomes do humans have? _____ Chimps have 24 pairs of chromosomes (so do all other Great Apes) So then, chimps and humans must be totally different “kinds” – end of story, right?

    13. Hmm…

    14. Human Chromosome 2 and Chimp 2p and 2q (ref) “The chimp chromosomes (2p and 2q) can be shown, when laid end to end, to create an identical banding structure to the human chromosome 2.” Murder suspects have been sentenced to death on the basis of less evidence than this!

    16. Hmm…

    17. Why Don’t Cats Eat Oranges? Answer: They have a gene that allows them to make their own Vitamin C

    18. So do all mammals except Primates: Monkeys, Apes… and Humans …and Guinea Pigs for some reason! “Convergent evolution”

    19. The “Vitamin C gene” Exists in us humans, but it’s “broken” FYI, this broken gene codes for the protein L-gulono-?-lactone oxidase Discussion question: Why would we be specially created with a gene the doesn’t work in us and our closest relatives but works in more distant relatives?

    20. Other broken genes There are other examples of these pseudogenes – for example, decreased sense of smell in humans FOXP2, which is related to the development of speech FOXP2 works in humans, but is broken in chimps “Molecular vestigial characters”

    21. Overall, evolution is more like a “fixer-upper” than a dream house very good or perfect

    22. Of course, it could all be an illusion! But, Scientific Method assumes that nature is real - that no tricky demons are making stuff up “Epistemology models Ontology”

    23. Ok, back to Hominine Evolution… Recall that Fr. Stang talked about some critters that have characteristics between modern chimps and modern humans – they’re a Genus called…

    24. Australopithecus

    26. Movie Theme for this Lecture Out of Africa and its sequel… Out of Africa II

    27. Out of Africa I 1.8 million years ago (1.8 Ma) Some groups of the Homo genus populate the Old World from Africa Fairly well established: Consensus Science

    28. Fossil Evidence Discovery of an early (1.6 - 1.8 Ma) Homo fossil outside of Africa

    29. Out of Africa II 100,000 years ago (100 Ka) Homo sapiens populates the Old World from Africa, replacing existing hominines This is controversial: Frontier Science

    30. TIME PERSPECTIVE of this lecture...

    31. In This Lecture... 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

    32. CULTURE! Is this what it means to be “human”? We’re now getting into Cultural Evolution, the third part of the course

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

    34. Early Culture Involved tools, and later, art – both of which need to be passed on from generation to generation by teaching, not genetics

    35. Culture Very likely requires language abilities – either spoken or symbolic Two complementary events in the Hominine lineage: Bipedalism ? frees up hands Broca’s Area in frontal lobe of brain to coordinate fine muscle movements, including what’s needed for speech

    36. THE ARCHEOLOGICAL AGES Classified by types of tools

    37. THE “STONE AGES”

    38. PALEOLITHIC “Old Stone Age” 2.5 Ma => about 10 Ka Started with Archaic Homo Recall last lecture: Brain size & Tools - keys to classification of the Homo genus Tool styles changed over time and can be used to classify cultures – kind of like index fossils

    39. CAVE ART Earliest is around 50Ka The Upper Paleolithic “Behaviorally” modern humans In addition to being Anatomically Modern Humans (AmHs) What’s the “meaning” of this art? Dawn of Human Creativity

    40. Chauvet Cave, France – 32 Ka

    41. NEOLITHIC ~ 10 Ka => ? Also know as the Agricultural Revolution A Neolithic product: BEER!

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

    43. How Scientists and other folks interpret evidence Lumpers vs. Splitters

    44. Lumpers vs. Splitters Lumpers ==> Fewer species from the same data. In the extreme, favor a “ladder” pattern to evolution Splitters ==> Many different species => favor a “bushier” tree pattern I’m more of a lumper in this lecture

    45. Two Examples of Lumping vs. Splitting The “Hobbits” – Flores Man Neandertals

    46. A Strange New Species(?) -- Homo Floresiensis Discovered Summer 2004 on the Indonesian island of Flores

    47. Flores Man – “The Hobbit” Parts of seven individuals found Lived as recently as 13 Ka Just over three feet tall Brain size in Australopithecus range Body and facial features more like Homo genus Evidence of advanced tool use and hunting

    48. Flores Man – “The Hobbit” One hypothesis is they are descendents of Homo groups from Out of Africa I – This would be an example of splitting Comparison of skulls of Flores Man with modern human ?

    49. Flores Man – “The Hobbit” Another hypothesis is they are mutant H. sapiens – This would be an example of lumping Comparison of mutant (above) with Flores Man (below) ?

    50. Latest research shows that that Flores Man is Not a tiny-brained mutant, But is a side branch – H. floresiensis Here the Splitters are more likely correct

    51. Neandertal “MEN”

    52. Neandertal remains were first discovered in 1856 in the valley (tal) of the Neander River near Düsseldorf Existed from probably at least 230 Ka to 29 Ka Fossils of at least 500 individuals have been found throughout Middle East and Europe (none in Africa or East Asia). Map ?

    55. Distinguishing anatomical features include Short and stocky High brow ridges Weak chin Protruding face Modern-size brain with Broca’s Area

    56. Distinguishing anatomical features include Short and stocky High brow ridges Weak chin Protruding face Modern-size brain with Broca’s Area

    57. How to Classify Neandertals? Are they “human”? That is, are they Homo sapiens? (Lumping) or Homo neanderthalensis? (Splitting) or Homo sapiens neanderthalensis? (in between)

    58. Or were they Homer sapiens ???

    59. We’ll get back to the Neandertal controversy in a moment…

    60. Sidebar: Anti-Evolutionary Creationists Can be both lumpers and splitters at the same time! Lumpers: All Australopithecines are “apes”, and all Homo are “humans” Splitters: They continually complain about absence of “missing links” (transitional fossils) Recall: Fr. Stang showed many examples of transitional fossils E.g., Brain size (1% ? 2%), thumbs and feet, angle of spine, pelvis, knees, activities – tools and fire, etc.

    61. Out of Africa II H. sapiens evolves in Africa and some populations of these migrate to the Old World replacing Neandertals and Later Homo Controversy! (Scientists aren’t afraid of controversy – the essence of Scientific Method is to address controversy)

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

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

    64. Mitochondrial DNA Study

    65. 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

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

    67. MtDNA Study conclusions... Supports the “Out of Africa II” (monogenesis) rather than the multiregional hypothesis

    68. How do Neandertals fit in? Anatomy Genetics Culture

    69. N’tal Genetics DNA recovered from several individuals October 2006 Nature article Within-group variation much less than between N’tals and moderns MRCA of them and moderns was 500 Ka Supports different species view Supports Out of Africa II as well

    70. Neandertal Culture Broca’s Area ? Possible language ability, but phonemes don’t fossilize! Specialized tools (Levallois technique) No cave art found Possible ritual burial – pollen in one grave Possible altruism – fossil of an old crippled individual found

    71. Specialized Tools Levallois technique (flaking) 20 different types discovered ==>

    72. Ritual Burial? Shanidar Cave, Iraq

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

    74. ART ? No evidence of genuine “art” Certainly no cave art Were they too dumb or Just too busy?

    75. Most Recent N-tal Fossils Found are 29 - 32 Ka In Gibraltar (Portugal)

    76. Out of Africa II Migrations

    77. An Open Question – What happened to the N’tals? Did H. sapiens from Africa outcompete or outfight Neandertals ? Only 1% “competitive edge” in niche could lead to extinction in 5,000 years! Or were some N’tal genes absorbed into the modern population?

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

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

    80. Continents were populated 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

    81. Native Americans - Florida 14 Ka

    82. Science doesn’t claim to know everything about everything But, it does claim to know something and to be fair about what it does know FYI – the alternative is epistemological nihilism If we don’t everything, then we know nothing.

    83. Midterm Exam Wednesday February 28 Here in the Shen

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