The Last Ape Standing It is therefore probable

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 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 • Widened feeding allowed more potential manipulative • Reduced predation capabilities pressures • Led to a higher • Was more thermoregulatory energetically efficiency efficient mode of locomotion

Oldest evidence of bipedalism Australopithecus afarensis footprints from Laetoli, Tanzania in volcanic ash following a rainfall around 3. 4 mya.

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 (similar to H. sapiens)

Neoteny • An explanation for: – Nakedness – Large Brain Size – Reduced Dentition

The Neotenic Apes Morphometry of the human skull changes little from fetus to mature adult

Hair loss and lice

Phylogeny of some living primates and their lice

Tales of the Lice • Human head louse vs chimp louse (how long ago we diverged) ~6 -7 MYA • Human head louse vs human body louse (how long ago we began to wear clothes) ~50 -100 KYA • Human pubic louse vs gorilla body louse (how long ago we began to lose fur to patches of hair) ~3 -4 MYA

Large Brain Potts 2011 Navarette et al. 2011

Reduced dentition The lower jaw of modern humans is quite weak compared to the other apes. Our chin is the result of a small shelf of bone that provides some added strength to a relatively weak jaw.

Vocal communication • Lower larynx • Fox P 2 gene http: //www. voice. northwestern. edu/VOICEBOX/Larynx. htm The genetic basis for vocal communication seems to lie, in part, with the Fox P 2 gene, which is shared with Neanderthals. The physical apparatus includes the larynx, and resonating chambers (mouth and nasal passages.

Vocal Communication The larynx of a chimpanzee is so high in the back of the throat that it can drink and breathe at the same time. Ours is so low that we run the risk of choking every time we swallow. Clearly, the more subtle vocal communication afforded by the added range of sounds generated by humans through a larger resonating chamber outweighs the risks.

PBS NOVA

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 -350 cc • 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 Phylogeny The Smithsonian Institution Museum of Natural History http: //www. mnh. si. edu/anthro/humanorigins/ha/a_tree. html

Human Phylogeny Dembo et al. (2016)

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 http: //www. talkingorigins. com (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

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

Paranthropus robustus • • • Africa Brain ~530 cc 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. 70. 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 Neanderthal vs rodeo trama 40 35 30 25 20 15 10 5 0 NEANDERTHAL T FO O LE G IS LV A N D PE LD U O SH H R M ER /A U N K TR EA D RODEO H • 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 patterns (redrawn Berger & Trinkhaus 1995)

Denisovans Enigmatic group of archaic humans, sister group to Neanderthals, known only from a few bones and teeth. The genome has been sequenced. Asia 50 -400 kya?

Range of Archaic Humans

Homo floresiensis • Asia (Indonesia) • Brain ~380 -417 cc • ~106 (f? ) cm tall • 30 (f? ) kg • ~0. 050 -0. 100 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. 3 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 selfornamentation • 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