The Human Chimp

1
The Human Chimp

• Aug 18th

2
How Similar are Chimps and Humans?

• Implications
• What are the similarities?

3
Molecular Clocks

• Used to measure genetic distances and to date
  times of evolutionary divergence
• How it works
• Based on fossil evidence, lions and tigers
  diverged 5 mya and molecules differ by 1
• If we then took 2 other species and found they
  differed by 3, the molecular clock would say
  they diverged 15 mya

4
DNA

• The best molecule for use with molecular clocks
• To measure the change in DNA structure
• Mix DNA from 2 species
• Measure how many degrees of temperature the
  melting point of the mixed DNA is reduced below
  the melting point of pure DNA from a single
  species
• A melting point lowered by 1C means the DNAs of
  the 2 species differ by roughly 1

5
Family Tree of the Higher Primates
6
The Great Leap Forward

• When modern humans replaced Neanderthals
• 3 changes launched us in the direction of modern
  humans
• 4 mya upright posture
• 3 mya Australopithecus robustus and A.
  africanus
• 2.5 mya tool use

7
Man the Hunter

• Unclear whether early Homo sapiens were hunters
  or scavengers
• Big-game hunting led to
• The development of language and bigger brains?
• Concealed ovulation?

8
The Human Family Tree
9
The Great Leap Forward

• 40,000 years ago in Europe
• Arrival of anatomically modern people -
  Cro-Magnons
• Art, musical instruments, lamps, and trade
• Needles, rope, fish hooks, mortar and pestles,
  harpoons, darts, bows and arrows