Human Evolution

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Human Evolution
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I. How Do We Study Human Evolution?

1. Paleontologists study fossil primates and compare
   them with living forms
2. Archaeologists and anthropologists study ancient
   tools and cultures
3. Molecular Biologists examine DNA of different
   species looking for similarities and differences

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II. Where and When Did Humans Evolve?

• Homo sapiens evolved from ancestors we share with
  other living primates (chimpanzees, apes etc.)
• Homo sapiens evolved in Africa and spread around
  the world
• Homo sapiens first appeared 500,000 years ago
• The day before yesterday on an evolutionary
  time scale
• Over 60 million years after the dinosaurs went
  extinct

The spread of humans over time
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III. Characteristics of The Human Order -
Primates

• As a group, primates share several important
  adaptations
• Flat faces, reduced snout
• Eyes directed forward binocular vision for depth
  perception see in color
• Flexible fingers for grasping
• Full shoulder rotation
• Nails (vs. claws)
• Complex, large cerebrum
• Extended maternal care for young usually 1
  offspring at a time 2 mammary glands
• Complex social groups and behavior

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IV. Members of the Primate Order

• Prosimians
• 1. Lemurs, lorises and aye-ayes
• Nocturnal and have large eyes well
  adapted to seeing in the dark
• Anthropoids (human-like primates)
• New World Monkeys
• Monkeys in Central and South America
• All are arboreal with grasping tails
• Old World Monkeys
• Baboons and macaques
• Do not have grasping tails, some are arboreal
• Great Apes (Hominoids)
• Gorillas, gibbons, orangutans, chimps and humans

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V. Hominid Evolution

• Between 4 and 9 million years ago, the hominoid
  line in Africa gave rise to a small group of
  species called Hominids.
• Hominid Characteristics (that distinguish them
  from other hominoids)
• Omnivorous
• Bipedal locomotion
• Opposable thumb
• Remarkable increase
  in brain
  size (cerebrum)
• Compare chimp brain size (280-450 cm3) to human
  brain size (1200-1600 cm3)

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V. Hominid Evolution

• General Trends in Hominid Evolution Over Time
• Increase in brain size and body mass
• Reduction in area of lower face jaw angle size
  of brow ridge
• Increase in width of pelvic opening (why?)
• Presence of Brocas Area (indicates possibility
  of speech)

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VI. Hominid Ancestors

• Genus Australopithecus (Southern Ape)
• First known hominid
• Walked upright
• Four species existed
• A. boisei, A. robustus, A. afarensis and A.
  africanus
• Lived between 4.4 and 1.1 million years ago

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VI. Hominid Ancestors

• B. Genus Homo
• Homo habilis (Handy Man)
• Smaller face, larger brain than Australopithecus
• Used primitive tools made of stone and bone
• Lived between 1 and 2 million years ago

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VI. Hominid Ancestors

• B. Genus Homo
• 2. Homo erectus
• Larger brain than Homo habilis (cranial capacity
  gt 800 cm3)
• By 1 million years ago, they had spread from
  Africa to Europe and Asia
• Excellent tool maker (crafted and used hand axes)
• Used fire for cooking
• Lived in primitive huts
• Used speech to communicate

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VI. Hominid Ancestors

• B. Genus Homo
• Homo sapiens neanderthalensis
• First discovered in the Neander Valley in Germany
• Lived between 150,000 and 30,000 years ago
• Constructed burial sites for the dead
• Wore jewelry and clothing
• Very similar to modern humans

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VI. Modern Humans

• A. Genus Homo
• Homo sapien sapiens
• The first hominids truly identical to modern
  humans appeared in Africa, roughly 100,000 years
  ago and were called Cro-Magnon
• Complex culture talented artists
• Wide variety of stone and bone tools spear
  points, knives, chisels and needles
• Lived side by side the Neanderthals in several
  locations around the globe
• When Neanderthals disappeared, only Homo sapiens
  sapiens remained to populate the rest of the world