DARWIN _ EVOLUTION

Document Sample
DARWIN _ EVOLUTION Powered By Docstoc
					UNIT 4 EVOLUTION

Darwin & Natural Selection
        Who was Darwin?
Charles Darwin was an
English scientist
Darwin sailed to the
Galapagos Islands in
1831, on the HMS
Beagle
Took extended notes on
observations
Questioned idea that
species are constant
The H.M.S. Beagle
Galapagos
       Galapagos Islands
Multiple islands off the coast of Ecuador
(near equator)

Have examples of different species which
are thought to have descended from a
common ancestor

Example: Finches
Speciation
       Galapagos Finches
Originally a South American Finch arrived
on an island
Its descendants became diverse, with
different beak sizes for specific functions
14 different species identified
Example:
– Large thick beak for crushing seeds
– Sharp beak for getting insects from tree trunk
Galapagos Finches