The Human Chimp Aug 22nd

How Similar are Chimps and Humans? Implications What are the similarities?

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

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 1°C means the DNAs of the 2 species differ by roughly 1%

Family Tree of the Higher Primates

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?

The Human Family Tree

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

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 The Great Leap Forward Examples of Aurignacian Culture art