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Aim What factors can or did contribute to the extinction of a

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					                                      Figure 17-5 Geologic Time Scale
                Aim: How do we know that evolution
             Section 17-1
                          happened ?

                               (millions of                               (millions of                         (millions of
  Era      Period        Time years ago)      Era   Period          Time years ago)      Era   Period    Time years ago)
                                                    Permian           290 – 245
           Quarternary    1.8–present                                                          Vendian   650–544
                                                    Carboniferous     363–290
           Tertiary       65–1.8
                                                    Devonian          410–363
           Cretaceous     145–65
                                                    Silurian          440–410
           Jurassic       208–145
                                                    Ordovician        505–440
           Triassic       245–208
                                                    Cambrian          544–505




                                                    Geologic Time Scale


Go to
Section:
• What does Darwin mean when he states that
  Natural Selection works solely by and for the
  “good of each being” and that “all corporeal and
  mental endowments will tend to progress toward
  perfection” ?
                           Figure 17-2 Formation of a Fossil

            Section 17-1

           The fossil record provides evidence about
                  the history of life on Earth




                                                       The preserved
    Water carries small        Dead organisms are
                                                       remains may later
    rock particles to          buried by layers of
                                                       be discovered and
    lakes and seas.            sediment, which forms
                                                       studied.
                               new rock.

Go to
Section:
If we could follow the fossils
of a particular organism up
through the layers of the
Earth we would have a clear
picture of how organisms
changed over time
General trend in equid
body size over millions
       of years
While such trends as
  toe reduction and
  increase in size are
  real over time, the rate
  of change varied
  among different
  branches of the equid
  evolutionary bush
The cladogram graphically represents a
         evolutionary process
                         • Phylogenetic
                           tree of the
                           evolutionary
                           relatedness of
                           organisms
Anatomical comparisons indicate the similarities
in bone structure suggests a common ancestor
Comparative Embryology

           Similarity of embryos
             during development
             suggests a common
             ancestor.
Aligned DNA fragment and first chromosome banding
         patterns for man (Homo sapiens),
chimpanzee (Pan troglodytes), gorilla (Gorilla gorilla),
         and orangutan (Pongo pygmaeus).
This cladogram shows that..


              ………Humans share
               a common ancestor
               with other primates,
                we did not evolve
                    from them
    Prepare a refute to this situation

• Someone tells you that they are teaching
  that humans evolved from monkeys.
      Aim: What paths did evolution follow?

• DIVERGENT
  EVOLUTION
  "One ancestral
  stock evolves into
  two species,
  which continue to
  evolve and
  become less and
  less alike over
  time."
• PARALLEL
  EVOLUTION
  "In PARALLEL
  EVOLUTION two
  related species arise
  from a common
  ancestor. The two
  species then evolve in
  much the same way
  over time, probably in
  response to similar
  environmental
  selection pressures."
• "CONVERGENT
  EVOLUTION
  occurs when two
  or more groups
  that are not closely
  related come to
  resemble each
  other more and
  more as time
  passes. This is
  usually the result
  of occupation of
  similar habitats
  and the adoption of
  similar
  environmental
  roles.."
• Punctuated
  equilibrium
• This type of diagram
  reflects the theory that
  evolution has not occurred
  at a constant rate, rather it
  has occurred in short
  bursts with long periods of
  stability between. This
  theory explains the
  absence of the infinite
  range of intermediate
  fossils in branches of
  evolution such as the
  vertebrates.
Evolution of the Whale


Started on Land and
moved to the Sea
What happened to the Dinosaurs?

				
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