The Evolution of Humans: A Journey Through Primate Ancestry and Development

1. Chapter 11 April 6, 2010

2. Humans • Kingdom: Animalia • Phylum: Chordata • Class: Mammalia • Order: Primates • Family: Homonidea • Genus: Homo • Species: Sapiens • Subspecies: Homo sapiens sapiens

3. Other Primates • Suborder: Haplorhini • Humans, tarsiers, monkeys, apes • Infraorder: Catarrhinni • Humans, old world monkeys, apes • Infraorder: Platyrrhinii • New world monkeys • Suborder: Strepsirhini • Lemurs, lorises, indiriids

4. Primates • Hominoidea – superfamily including humans, the small apes (gibbons), and the great apes (chimps, orangutans, gorillas) • Similarities in blood and protein chemistry • Humans share 98% of DNA with chimps • Pentadactyl – having 5 fingers and toes • Prehensile – ability of hands and feet to grasp objects

5. Primates • Clavicle and scapula (shoulder blade) allow for great range of movement and strength • Reduced sense of smell compared to other mammals • Stereoscopic, color vision • More mobility in head movement versus other mammals • Molars, canines, and incisors – adaptation to generalist diet • Large brains

6. Adaptations to Arboreal Existence? • Prehensile hands and feet, shoulder and arm design • color stereoscopic vision – for judging distance, identifying food and predators • Low numbers of offspring • Molecular clock – when did humans diverge from chimp ancestors? • mtDNA from mother • 5 to 10 mya

7. Early Primates • Arose 70 may during late Cretaceous • Related by common ancestor to insectivores and bats • Extinct suborder Plesiadapiformes – appeared in North America 65 mya • Arboreal • Size of squirrels or house cats – rodent-like with primate teeth • Ate seeds and insects • Died out 55 mya

8. 23 to 14 mya – great increase in ape diversity and range • Extensive forests covered Africa and Eurasia • 20 different genera of Caterrhinii apes from Africa, to western Europe, to southeast Asia • Pliopithecus – western Europe – similar to modern gibbons • Gigantopithecus – China and India – larger than modern gorillas • Ramapithecines – jaws and teeth like humans and apes; skull like orangutans • 14 mya – climate changes requiring adaptation to savanna climate • Lived at forest edge • Bipedal – uses less energy • Reduced canines

9. Pliopithecus sp.(1); Dryopithecus sp. (2); Australopithecus afarensis (3)Homo habilis (4) (Mammiferi, Primati). Gigantopithecus Pliopithecus sp.

10. Hominid • Hominid refers to humans and extinct bipedal primate that are ancestral or closely related to humans • Genus Australopithecus • Africa 5 mya • Forest-savanna ecotone • Reduced canines

11. Australopithecines • Appeared between 4 and 3.8 mya • Disappeared by 1 mya • Fossils found only in Africa • 3.3–5 feet; 66–132 pounds; small brains • Closer to modern chimps and gorillas than modern humans • No evidence of tool making or fire use • Ate nuts and grasses

12. Early Homo • Oldest Homo fossils 2.5 myo and from Olduvai Gorge, east Africa • Homo habilis (handy man) • Small hominid • Bipedal • Increased brain size • Manufacture and use of specialized tools • Oldowan Tradition

13. Homo habilis

14. Homo erectus Acheulean Tradition

15. Early Homo • Homo erectus – “Java Man” and “Peking Man” • Older than Homo sapiens, younger than Homo habilis • Found in western Europe, Republic of Georgia, Java, China, east and south Africa • 1.7 mya–300,000 years ago • Acheulean Tradition • Used fire

16. Homo sapiens • More prominent brow and thicker skull than modern-day humans • Appeared 400,000 years ago in Europe, Africa, and Asia • Eve Hypothesis – all modern humans descended from one African Homo sapiens female that lived 200,000 years ago • Multiregional Model – Homo sapiens evolved from Homo erectus separately at two or more geographic locations • Most Anthropologists support Out of Africa Model

17. Homo sapiens neanderthalensis • Fossils from 130,000 to 35,000 years ago • Europe and Near East • Only hominids that unquestionably did not evolve in sub-Saharan Africa • Not ancestral to modern humans • Evolved from archaic Homo sapiens • Mousterian Tradition • Fire, clothing, shelter, rituals, music

19. Homo sapiens sapiens • Adapted to warm conditons and open countryside • Human Revolution – 50,000 years ago rapid expansion inside of and out of Africa; creating art and ritual burials