Wednesday, February 9, 2011


Today, we took a quiz.

Human Ancestry

  • Early primates:

    evolved from insect-eating mammals during Cretaceous period (evidence from fossils)

  • were small

  • lived in trees (arboreal)

  • limber shoulder joints

  • could grab with their hands (dexterous)

  • nails started replacing claws

  • had depth perception (eyes close together in front of face)

  • eye-hand coordination

  • parents cared for their offspring

The 2 Major Primate Groups:


  • oldest

  • EX- lemurs, lorises, pottos, tarsiers

  • EX-monkeys, apes, humans

  • New World monkeys

  • in the Americas

  • arboreal

  • prehensile tails-could swing by tails and grab things with them unlike dogs or cats, it functioned as an extra appendage

  • Old World monkeys

  • mostly ground dwellers

  • EX- baboons-

  • -Prehensile tail, New World

Human Ancestors

  • closest anthropoid relatives=apes
  • gibbons, orangutans, gorillas, chimps
  • apes today live in tropical regions of Old World
  • Humans
  • young twig on vertebrate branch
  • chimps and humans diverged from common ancestor 5-7 million yrs. ago

  • Our ancestors are not modern apes and chimps; we diverged on a different branch than they did, but we both evolved from a common ancestor
  • they are more like our cousins than anything else

  • Human evolution is not a series of steps leading directly from an anthropoid ancestor to Homo sapiens; other groups have traveled to dead ends and died off
  • Many different human species coexisted
  • We are a subspecies of Homo sapiens

  • Human characteristics did not evolve at the same time
  • They evolved at different rates
  • Bipedalism-walking on two feet, led the way
  • We had some ancestors who walked on two feet and upright, but they still had ape-sized brains

Kinds of Hominids

Australopithecus-walked African savanna, came before Homo genus:

  • A. afarensis
  • early species
  • bipedal
  • a skull was found that was about 3.9 million yrs. old. It had a vertical backbone which provided evidence that upright posture is at least that old
  • Lucy-very complete skeleton of A. afarensis, female, 3ft tall, 3.2 million yrs. old
  • footprints also found, bipedal footprints in Africa, 3.7 million yrs. old
  • bipedalism is a very old trait
  • Australopithecus went extinct about 1.4 million yrs. ago


Lab 32-due Monday

Up pgs. 69-70, read and questions

Next scribe:

Aliza!! :)

No comments:

Post a Comment