11 Human Origins

•Purgatorius (Late Cretaceous •Plesiadapis:  (Paleocene) •Dermoptera (colugos = “flying lemurs”)

-Bats and bat-like creatures

* natural selection for life in the trees •Claws replaced by nails for tactile sensation.

*Adapiformes

–Eocene – Miocene

–Eocene – Recent –Long legs and tail –Procumbent lower incisors –North America and Old World; now just Madagascar and Comoro Islands Lemur, loris, bush baby, aye-aye.

–Omomyidae (extinct) and Tarsiidae (Recent) –Paleocene to Recent –Non-opposable thumb, adhesive pads on slim fingers and toes. –Nocturnal: large eyes and ears. –Tibia fused to fibula (single “tarsier” bone) –Omnivores.

•Large canines hone against premolar. •Molar-like premolars •Broad, square molars •Longer period of infant care. •Eosimiidae (Eocene) ancestral stock; China.  2-1-3-3 (loss of a premolar).  More vertical incisors than “prosimians”.  •Initially thumb-sized bodies.

•Platyrrhini (Oligocene – Recent): “flat nose”

–Flat nostrils open toward side of face. –Evolved from Egyptian Oligocene  Parapithecus (2-1-3-3), later becoming 2-1-3-2 in some species. –Retained arboreal habits with long, prehensile tail and little social development.

–Nostrils open ventrally; projecting nose in some. –Dental formula 2-1-2-3 or 2-1-2-2. More ground dwelling and socially develop

-Propliopithecus (aka Aegyptopithecus) is the ancestor to the Catarrhini.

–“Old World Monkeys”, e.g., Macaca. –Varied feeding preferences.

–Evolved from Propliopithecus. –Arboreal fruit eaters with generalized, quadrupedal locomotion (vertical clinging and leaping, or VCL)

Family Hylobatidae

–Kenyapithecinae (Miocene) –Ponginae (Miocene – Recent) –Homininae (Miocene – Recent) Medium to shorter armed; retained VCL initially

Superfamily Hominoidea

•Begin as arboreal (tree-dwelling) frugivores (eating mostly fruits and leaves) and omnivores, but some evolved wide, thick-enameled molars for tougher fruits, nuts, and roots, i.e., some food from the ground. •Ancestral stock group for australopithecines.

–Thick molar enamel; tougher foods. –Canines more nearly equal size in males, females.

–Miocene –Very thick molar enamel and wide molars like australopithecines –Reduced sexual dimorphism in canine teeth

•Miocene - Pleistocene •Eight feet tall, massive molars and premolars. •Ate coarse leaves Candidate for the “yeti” legend, as it overlapped modern humans during the Pleistocene epoch.

•Pongo (orangutan)

–SE Asia. –Mostly tree-dwellers. –Strong sexual dimorphism in canine teeth and cheek flanges; males larger

•Tribe Gorillini (Miocene – Recent) –Gorilla –Pan? (chimp) (traditional placement). •Tribe Hominini (Miocene – Recent) –Orrorin tugenensis (6.0 Ma) –Ardipithecus ramidus (4.4 Ma) –Australopithecus (4.2 – 1.0 Ma) –Kenyanthropus platyops (3.5 Ma) –Homo (2.5 Ma – Holocene)

-Lower evolution

•Reduced sexual dimorphism of canines, small in both males and females. •“Feminization” of males, more cooperative behavior, less male-dominance oriented, except for some politicians. •Initially protruding muzzle and small brain like chimps •Unique: dental arch diverges toward back and knees lock for fully upright stance.

Ancestor of Australopithecus

•Thicker tooth enamel, stronger jaws than both Ardipithecus and Homo. •Long arms and fingers yet fully bipedal. •Retention of some arboreal habits, thereby possibly limiting brain •Two subgenera: –A. (Australopithecus) (4.1-2.3 Ma) –A. (Paranthropus) (2.6-1.0 Ma)

•Locking knees, small canines, reduced sexual dimorphism, not larger brains. •Came from Australopithecus (Australopithecus) or Kenyapithecus.  •Ground dwelling makes possible larger brain: –Larger brain requires birth at developmental stage when brain is still small. –Birth at early developmental stage requires longer period of infant care. –Longer period of infant care requires life largely on the ground.

•Intuitive psychology: awareness of the mental lives of others, as well as self-awareness.  Abstract thought escalates.  Potential for religious thought. •Intuitive physics: objects exist when out of site, obey laws of motion.  Throwing expertise. •Intuitive engineering: tool function transcends the shape and composition of the raw material. Intuitive ethics: innate sense of “good” and “bad” behavior in human interaction

•East Africa, Pliocene – Pleistocene. •Retains long, strong arms, protruding mouth. •Thinner molar enamel, posteriorly expanded jaw, small canines and incisors, 630 cc brain.

•Cosmopolitan, late Pliocene – Pleistocene •Retains ancestral funnel shaped rib cage. •Larger brained, smaller teeth and jaws than H. habilis. •Enlarged hip and back joints for strong running. •Acheulian flaked stone tools; used fire.

•Loss of body hair occurred about 2.0 Ma according to DNA study of human scalp and pubic hair lice. Ancestors of H. erectus had only one louse species, as in hairy apes. •Hairless bodies permitted sweating over most of the body to aid cooling. •Cooled bodies allowed for endurance daytime hunting, running prey to exhaustion

•Pleistocene, Europe, Middle East. •Stocky, muscular bodies, short fingers and toes, large incisors, wide, long nose, no chin; posteriorly elongated foramen magnum. •Levalloisian, Mousterian tools •

Specialized tools from blades struck from prepared cores predominate.

Needles, skin clothing

Shafted stone, bone, and ivory tools; harpoons, spear throwers, fish hooks

•Archaic Homo sapiens left Africa between 100,000 and 200,000 years ago, gradually displacing populations of Homo erectus, Homo antecessor, and Homo sapiens neanderthalensis. •This happened before the final exodus of H. sapiens from Africa ca. 70,000 B.P. • Supported by some DNA studies.

•Multiple waves of invaders from the Old world, from both northeastern and southeastern Asia.