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It is therefore probable that Africa was formerly inhabited by extinct apes closely allied to the gorilla and chimpanzee: and as these two species are now man’s nearest allies, it is somewhat more probable that our early progenitors lived on the African continent than elsewhere. -Darwin (1871) The Descent of Man
Our Living Sisters Pan Gorilla http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html
Living Asian Apes Gibbon (Hyalobates) Orangutan (Pongo)
Features that distinguish the Hominins from other living apes • Bipedal Locomotion • Loss of fur • Reduced dentition • Enlargement of the brain • Vocal communication
Possible origins of bipedal locomotion • Figure 1 from Richmond, B. G., D. R. Begun, and D. S. Strait. 2001. Origin of human bipedalism: The knuckle-walking hypothesis revisited. Yearbook of Physical Anthropology. 44:70-105.
Bipedalism • Freed the hands and allowed more manipulative capabilities • Led to a higher thermoregulatory efficiency • Widened feeding potential • Reduced predation pressures • Was more energetically efficient mode of locomotion
Oldest evidence of bipedalism Australopithecus afarensis
Footprint experiment (Raichlen et al. 2010) A. Normal gait in sand (H.sapiens) B. Bent-knee, bent-hip gait in sand (similar to walk of apes) C. Footprint from Laetoli, Tanzania
Neoteny • An explanation for: • Nakedness • Large Brain Size • Reduced Dentition
Tales of the Lice • Human head louse vs chimp louse (how long ago we diverged) ~6-7MYA • Human head louse vs human body louse (how long ago we began to wear clothes) ~50-100KYA • Human pubic louse vs gorilla body louse (how long ago we began to lose fur to patches of hair) ~3-4MYA
Large Brain Potts 2011 Navarette et al. 2011
Vocal communication • Lower larynx • Fox P2 gene http://www.voice.northwestern.edu/VOICEBOX/Larynx.htm
Proconsul Likely a sister to the apes with a mix of ape-monkey characters 14-23 MYA Africa
Dryopithecus Early ape 15-9 MYA Africa, Eurasia
Ardipithecus • Africa • Brain ~300-350cc • 120 (f) cm tall • 50 (f) kg • ~6.0 – 4.2 MYA
Miocene Epoch • 23-5.3 MYA • Epoch of ape radiation (>100 species of apes in the latter part of the Miocene) • They ranged though Africa, Europe, and Asia • The end of the Miocene saw the separation between the African Apes (chimpanzees, bonobos, and gorillas) and the Hominin Apes • Africa moved northward and formed the Mediterranean Sea, which dried out multiple times. Data from NASA, USGS, NOAA
Pliocene Epoch • 5.3-2.5 MYA • Epoch of bipedal ape radiation. • They ranged though Africa • Gracile and robust lines • Pliocene relatively warm Data from NASA, USGS, NOAA
Human PhylogenyThe Smithsonian InstitutionMuseum of Natural History http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html
Hominin Series (A) Pan troglodytes, chimpanzee, modern (B) Australopithecus africanus, 2.6 My (C) Australopithecus africanus, 2.5 My (D) Homo habilis, 1.9 My (E) Homo habilis, 1.8 My (F) Homo rudolfensis, 1.8 My (G) Homo erectus, 1.75 My (H) Homo ergaster(early H. erectus), 1.75 My (I) Homo heidelbergensis, 300,000 - 125,000 y (J) Homo neanderthalensis, 70,000 y (K) Homo neanderthalensis, 60,000 y (L) Homo neanderthalensis, 45,000 y (M) Homo sapiens, 30,000 y (N) Homo sapiens, modern http://www.talkingorigins.com
Australopithecus afarensis Africa Brain 375-550 cc 107 (f)-152 (m) cm tall 29 (f) – 42 (m) kg ~3.0-3.9 MYA British Museum of Natural History and Smithsonian Museum
Australopithecus africanus Africa Brain 420-500 cc 110 (f)-140 (m) cm tall 30 (f) - 41 (m) kg ~2.4-2.8 MYA British Museum of Natural History and the Smithsonian Museum
Paranthropusrobustus Africa Brain ~530cc 110 (f)-130 (m) cm tall 32 (f) – 40 (m) kg ~1.0 – 2.0 MYA http://www.maropeng.co.za
Pleistocene Epoch • 2.5-0.012 MYA • Appearance and radiation of Homo. • They ranged though Africa and emerged into the rest of the earth. • Global climates extremely unsettled and variable Data from NASA, USGS, NOAA
Homo habilis • Africa • Brain ~500-800 cc • 100 (f) – 135 (m) cm tall • 32 (f) – 37 (m) kg • ~1.44-2.3 MYA http://macscience.files.wordpress.com
Olduwan stone tools in Ethiopia • 2.6 -1.8 MYA • Chipped pebbles and choppers, usually lava • Likely made by H. habilis
Homo erectus • Africa, Eurasia • ~Brain 750-1225 cc • 145 (f) – 185 (m) cm tall • 40 (f) – 68 (m) kg • ~0.3-1.8 MYA http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html
Range of H. erectus • Evidence for controlled use of fire • Acheulean tools (1.7-0.1 MYA) http://anthro.palomar.edu
Homo heidelbergensis • Africa, Eurasia • Brain ~1100-1400 cc • 157 (f) - 175 (m) cm tall • 51 (f) – 62 (m) kg • ~0.2-0.6 MYA Smithsonian Institution
Homo neanderthalensis • Eurasia • Brain ~1100-1400 cc • 155 (f) – 164 (m) cm tall • 54 (f) – 64 (m) kg • ~0.03-0.3 MYA Neanderthal Museum
Range of the Neanderthals http://www.rhesusnegative.net
Behaviors of H. neanderthalensis • Scavengers and up close spear hunting of large animals (see Figure) • Relatively complex stone tools (Mousterian, see Figure) • Tools from wood, bone, tusks, and antlers • Evidence of burials and ceremony • Possible verbal communication
Homo floresiensis • Asia (Indonesia) • Brain ~380-417 cc • ~106 (f?) cm tall • 30 (f?) kg • ~0.013-0.095 MYA
Homo sapiens • Africa to all land surfaces • ~1350 cc (975-1499) • US ave: 162 (f) – 175.8 (m) cm tall • US ave: 74 (f) – 86.4 (m) kg • ~present-0.2 MYA
Homo sapiens • Appeared ~200,000 years ago with a suite of behaviors similar to neanderthals • Likely in small populations (~140) with a total number of 100,000 • Bottleneck reduced to ~10,000 individuals
Theories regarding the origin of Homo sapiens Recent Out of Africa • More consistent with the genetic data • Mitochondrial • Y-chromosome • Genetic variability • Consistent with language families • Neanderthals a different species Multiregional Hypothesis • Explains racial differences by isolation and periodic mixing between populations • Connects H. erectus directly to H. sapiens • Neanderthal a step in the evolution of modern humans
Classic archaeologically-accessible evidence of behavioral modernity includes: • finely-made tools • fishing • evidence of long-distance exchange or barter among groups • systematic use of pigment (such as ochre) and jewelry for decoration or self-ornamentation • figurative art (cave paintings, petroglyphs, figurine) • game playing and music • foods being cooked and seasoned instead of being consumed in the raw • burial • Calvin. 2003. A Brief History of Mind; Stringer. 2011. Origin of our Species
Homo sapiens, the generalist Rick Potts of the Smithsonian Institution
Why are we the last ape standing? • We were lucky • We outcompeted the other bipedal apes • We killed the other bipedal apes