The Last Ape Standing

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

Mt-DNA Primate Tree

Our Living Sisters Pan Gorilla http://www.mnh.si.edu/anthro/humanorigins/ha/a_tree.html

Living Asian Apes Gibbon (Hyalobates) Orangutan (Pongo)

Apes in the Primates

Features that distinguish the Hominins from other living apes 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 70 footprints in volcanic ash dated to 3.6 MYA, Laetoli, Tanzania, discovered by a team led by Mary Leakey in 1978

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

Features that distinguish the Hominins from other living apes Neoteny Nakedness Large Brain Size Reduced Dentition

The Neotenic Apes

Hair loss and lice Summarized in Reed et al. 2007. Pair of lice lost or parasites regained: the evolutionary history of anthropoid primate lice. BMC Biology 5:7. doi: 10.1186/1741-7007-5-7

Phylogeny of some living primates and their lice Also from Reed et al. (2007)

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

Image from Anthropological Curiosities. Reduced dentition  Image from Anthropological Curiosities.

Features that distinguish the Hominins from other apes Vocal Communication Lower larynx Fox P2 gene

http://www.voice.northwestern.edu/VOICEBOX/Larynx.htm

PBS NOVA

Data from NASA, USGS, NOAA 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

Radiation of the Apes in the Miocene

Ardipithecus Africa Brain ~300-350cc 120 (f) cm tall 50 (f) kg ~6.0 – 4.2 MYA

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 Phylogeny From Wood (2010) Paranthropus Homo Australopithecus Ardipithecus Orrorin Sahelanthropus

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

Australopithicines Range restricted to Africa, 1-4 MYA Bipedal, but shoulders indicate well adapted to climbing Body size: 1.0 to 1.5 M Mass: 30-40 kg Brain about the size of a chimpanzee

Data from NASA, USGS, NOAA 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

Smithsonian Institution 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

The Denisovans Known from genomic evidence (taken from teeth and finger bones) Seem to be a subspecies or sister to Neanderthals Some interbreeding with Homo sapiens

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

Genetic variation in Homo sapiens

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