Primates

• Taxonomy
• Order Primates (Latin – first)
• Prosimians, monkeys, apes, humans
• Large cerebral hemispheres
• Mostly arboreal forms
• Brain development due to tree habitat
• Prehensile/grasping hands and feet – needed for tree life
• 5 digits on hand and feet
• flat nails on hands and feet
• opposable thumb in some forms
• generally no claws, no horns or hooves
• binocular vision – depth perception needed for tree-life
• Suborder Prosimii (before apes)
• Lemurs, bush babies, tarsiers, lorises
• From Africa, Philippines, Madagascar, Malay Peninsula
• Appearance – cross between a squirrel and monkey
• 2^nd toe with claw
• long prehensile tail
• Suborder Anthropoidea
• Monkeys, gibbons, apes
• Superfamily Platyrhinii (also Ceboidea from Gr. Kebos = long tail)
• Long tailed monkeys
• New World monkeys
• Capuchins (organ-grinder monkeys), spider and howler monkeys
• Broad nasal septum
• Non-opposable thumb
• Prehensile tail
• Superfamily Catarhinii (Cercopithecoidea from Gr. Kerkos – tail, pethekos – monkey)
• Generally tailless monkeys
• Old World monkeys
• Mandrills, Baboons, Rhesus monkeys
• Narrow nasal septum
• No tails
• Ischial tuberosities (butt cheeks)
• Internal cheek pouches, derived teeth
• Superfamily Hominoidea (from Latin homonis-man)
• No tails
• No cheek pouches
• Family Hylobatidae –
• gibbons
• Family Pongidae - higher apes
• Orangutan, Chimpanzee, Gorillas
• Familiy Hominidae – humans, old and new

Origins/Human Evolution

• Darwin and other anatomists note anatomical similarities between apes and humans
• Postulate common ancestor
• No fossil forms for awhile
• Neanderthals (Homo neanderthalensis ) uncovered – 1880 & 1892
• Java man (Homo erectus) discovered – 1891
• Recent discoveries – especially 1967-1977

40 million years ago [mya]- (Eocene Epoch 38-54 mya)

• primate ancestor
• like a tree-shrew
• nocturnal
• better grasping & manipulation
• better coordination
• improved brain functions (vision, etc.)
• ancestral line splits
• prosimians
• simians

25 mya (Oligocene 23-38 mya)

• ape-like forms appear
• found in Africa
• climate changes
• African forests change to woodlands
• Ape-like forms change from arboreal to terrestrial habitats

15 mya (Miocene 5-23 mya)

• Orangutan forms diverge from other primates

10 mya (Miocene)

• Gorilla-like forms diverge from other primates

8 mya (Miocene)

• ape-like forms in Africa adapt to savanna biome (grasslands w/ few trees)
• upright posture evolved
• hands free for manipulation and tool production
• poor fossils from this period

5 mya (late Miocene)

• Chimpanzee-like forms diverge from other primates

4 mya (early Pliocene 1.7 – 5 mya)

• hominid forms diverge from other primates
• Australopithecus afarensis appears
• Chimpanzee-sized
• Human ancestor
• “Lucy” 40% complete skeleton uncovered – Donald Johnson

3-4 mya (Pliocene)

• Australopithecus line splits
• Robust (heavier) and gracile (lighter) forms evolve
• Australopithecus line ends 1.75 mya

2 mya (Pliocene)

• Homo habilis appears in Africa
• Lighter bodied form than Australopithecenes
• But larger brain

1.5 mya (Pleistocene  11,000-1.7mya)

• Homo erectus appears
• Larger bodied
• Larger brain
• Cosmopolitan distribution

300,000 years ago (Pleistocene)

• Homo erectus lost
• Homo sapiens appear?

130,000 years ago (Pleistocene)

• Homo neanderthalensis appears
• Isolated populations
• Genetics vary

30,000 years ago (Pleistocene)

• Homo sapiens contemporary form appears.