Transcript Evolution and Natural Selection

Evolution and Natural Selection
April 17, 2009
Is Darwin on the test?
• Traveled around the world on the HMS
Beagle and studied species in the
Galapagos Islands off the coast of S.
America.
• Collected evidence that led to the
Theory of Evolution by Natural
Selection.
• Wrote On the Origin of Species
Darwin’s background information:
• Hutton and Lyle determine that the
Earth is REALLY old and ALWAYS
changing.
Darwin’s background information:
• Lamarck proposes that species change
by using traits more or less
– For example Popeye worked out and had
lots of muscles so his offspring would be
more muscled.
– Did not make sense when looking at actual
offspring i.e. Dad is fat and slow, kid is
skinny and fast…
Darwin’s background information:
• Malthus said that
even human
populations are
controlled by the
environment– War, famine, and
disease keep us
from running out of
land, resources, etc.
Darwin’s background information:
• Natural Variance- variation from one
individual to another within a single species.
Describe the following individuals
characteristics:
Darwin’s background information:
• Artificial Selectiondomestic
plants/animals are
bred based on
preferred natural
variation
characteristics.
– Ex: the fastest male and
female horse will be
bred to produce the
genetically fastest horse
offspring.
The evolution revolution.
• Creationism and Natural Selection
• Darwin wrote a TON of journals with
instructions that they be published only
if he had died.
• Darwin finally published
25 years after his travels.
•
http://www.catholic.com/library/Adam_Eve_and_Evolution.asp
Evolution by what?
• Natural Selection is the force behind
evolution.
• Natural selection means that any natural
variation in an individual that benefits the
individual will be passed on more then
natural variation in an individual that harms
the individual.
• So helpful variation gets multiplied, harmful
variation gets dead…until those helpful
things buildup and the creature is too
different then it’s ancestor to be the same
species.
I will survive…
• Another term for natural selection is
survival of the fittest.
– Those most “fit” for their home will fit in
and find a girl.
– Those less “fit” for their home will not get
the girl, the food, the glory…
– Sooner or later, the “most fit” are way
different then their ancestors-new
species.
A new species.
• A species has evolved when there is a
generation so different, that it can no
longer produce offspring with
individuals like and from the ancestors
species.
Descending:
• Slow change from
one species into
another is known as
the Descent with
Modification
Theory.
• The theory that all
life evolved from a
single ancestor
species is known as
Common Descent.
Homework:
• Outline chapter 14,
section 3.
• Answer the chapter
14.3 section
assessment.
• Due Monday.
• Don’t forget to bring
back your signed
permission slips and
parent chaperone
volunteer’s contact
information.