BIO 104 5/3/96

The next exam will cover chapters 29, 18, 19, 40, & 39
A video was shown, which was about human fossils, and Lucy.
To view the video one can go to the BLC

Human evolution
     Primate Classification
     1. Prosimians
          -lemur & bush baby
     2. Anthropoids
          -began with monkey 25-38 MYA
               a. New World (S. America)
               b. Old World (Africa)
          Apes evolved from old world monkeys;  they are called
          Hominoids.
               a. gibbons
               b. orangutan
               c. gorillas
               d. chimp
               e. humans (Hominids)
     Trends in Ape Evolution
     1. bipedalism (upright posture)
          -natural selection advantage
     2. opposable thumb
          -make tools
          -first seen in monkeys
     3. stereoscopic vision (color vision)
     4. nurse their young
See Figure 19.4
     Who is our closest relative?
     -Based on DNA hybridization, the chimp is the closest
          relative to humans.
          -the DNA differs in less than 1%
     -Five MYA humans split from the apes:  1.5-1.6 MYA we 
          could be identified as truly human.
     -The modern human brain is three times as large as the 
          primitive human man.
     -Johanson discovered fossils of a pre-human "Lucy"
          -There was a fossil of a knee joint which could 
          indicate that this pre-human used a form of
          bipedalism.
     4.0 MYA-2.5 MYA Lucy was ancestor to Homo habilis and
          Homo erectus which is precursor to Homo sapiens
          -Neanderthals are not very different from us.
     Homo erectus: brain size is where we differ
     500,000 years ago: Homo sapiens appear
     
     -Mitochondrial DNA: All mitochondria are inherited from
      mother. Mitochondrial DNA indicates earliest hominids 
          originated in Africa - also consistent with fossil
          evidence.
DNA homologies show that we are all related to each other and
to other animals.