Primate Evolution

Primate: evolved ~65-66 million years ago

       mammals, includes lemurs, monkeys, apes and human

       the earliest primates lived in the forest in Africa

Features shared by all primates

    1.  arboreal (live in trees)

    2.  opposable thumb

    3.  binocular vision (eyes face forward, see color,

stereoscopic view)

    4.  Flexible shoulder/hip joint (differing degrees

depending on species)

    6. large brain

Two Subgroups of primates

Prosimians: small bodied primates

    Purgatorius: earliest primate, lived ~66 million years ago

    Characteristics: large eyes, nocturnal, live in tropical

forest, eat insects, seeds, small fruits

    Examples: lemur, aye-aye, tarsier

Anthropoids: human-like primates

    Characteristics: more complex brains, larger & different

       skeletal features

    Examples: monkeys, apes, humans

3 Major Radiations of Anthropoids

Old World monkeys: (larger than new world monkeys)

    20-25 million years old

    Characteristics:  1. no prehensile tail

       2. include both arboreal and terrestrial monkeys

    Examples:  baboons, macaques

New World Monkeys: oldest monkey fossils 30-35 million years

ago

    Characteristics:

       1. prehensile tail- muscular/grasping, called an extra

hand

       2.  Live in rain forest

       3.  All arboreal

    Examples: marmoset, spider monkeys

Homonids: human-like

    Characteristics:

1. bipedal- upright

       2. long muscular forlimbs

       3. humans have larger brains

    Examples: apes (chimps, gorillas, orangutan, gibbons),

humans

Species of the evolution of primates

Australopithecus africanus- southern ape from Africa

discovered by Dart (1924)

1-2 million years old

    ape-like braincase and facial structure

    Foramen magnum- opening in skull through which spinal

       cord passes as it leaves brain (like humans)

       This meant that primates could walk upright before

           they had large brains

australopithecine- early homonids that lived in Africa that

possessed apelike and human-like characteristics

Australopithecus afarensis-

    discovered by Donald Johanson

 named the almost full skeleton Lucy

    3.5 million years old (the oldest we have)

    ape-like shoulders and forelimbs

    bipedal

    small brains (apelike)

    lived in small family groups

    slept and ate in trees

    rarely lived past 25 years

    lived in Africa

Homo

-erectus- upright human

       hunted

       discovered in East Africa (1985)- almost complete

skeleton of 12 year old male

       had tools- hand axes, fire pits

-habilus- discovered by Mary and Louis Leaky (1964)

       more human-like skull in Tanzania

       handy man used some stone tools

-sapiens- modern man (you!)

Neanderthals- best known of Homo sapiens

    lived from 35 000 to 100 000 years ago

    thick bones, large faces, prominent nosed

    lived in caves

    had religious views & communicated verbally

Cro-Magnon- identical to modern humans

       tool makers

       spoken language