101 1 10-12
TRANSCRIPT
Hominid
• Humans (and all human ancestors after human/chimpanzee split approx. 4-6 million years ago)– Range due to initial division followed by gradual divergence accompanied by continued
interbreeding
– Includes astralopithecines
• Chimpanzees + bonobos
• Gorillas
• orangutan
The “Missing Link”
• How does one species emerge from another? – If species X evolves into species Y, then there must be a point at which a child belongs to
the new species Y but his or her parents still at species X.
– Members of different species (generally) by definition cannot interbreed, yet obviously a child of species X should be able to breed with other members of species X
– So what’s going on?
• The “teapot theory” OR at what point does cold water become hot?
• Reality is a continuum– You can think of this like a bell curve OR a flip book
– There IS no disruption point Things smoothly and continuously link from one to the next. Change is gradual and cumulative
– Intermediate forms die out
– Can only be understood BACKWARDS, but is lived FORWARDS
So, what makes us unique?
• Reductio ad absurdum
• On one level, perhaps nothing. Remember the continuum!
• But keep these four things in mind:– Manipulator organ (for humans, hands + esp. opposable thumb)
– Disproportionate brain size (7.4X expected norm adjusted for body mass)• Bottlenose dolphins are next, at 5.4X
– Communication (language)
– History
Chronology
• Hunter-Gatherer: 100 KYA – 20 KYA
• Pastoral: 20 KYA- 11 KYA
• Neolithic Revolution: 11 KYA– “Hilly Flanks”