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1/3/12   Evolution – Change over time
  Theory – Well supported testable explanation of
events that occur in the natural world.
  I. Voyage of the Beagle
  Darwin born 1804
  Gets job as a naturalist in 1831
  Beagle sails around the world and ends up in Galapagos
Islands
  II. Darwin’s Observations
  A. Patterns of Diversity
  Notices that plants and animals are well suited for their
environments
  Why were some animals present in one environment and not
in another that was similar?
  B. Living organisms and Fossils
  Compared them for similarities
  C. Galapagos Islands
  Different climate – exp. Tortoises and Finches
  I. An Ancient Changing Earth
  A. Hutton’s Theory of Geological Change
  James Hutton 1795
  Earth is shaped by geological forces that took place
over log periods of time
  Earth is millions of years old
  B. Lyell’s “Principles of Geology”
  Erosion, volcanoes, earthquake, are the major source of
geologic change over millions of year.
•  SUMMARY
  II. Lamarck’s Theory of Evolution
  Influenced Darwin by :
  1. If Earth can change over time, couldn’t life change as
well?
  2. It would have taken many years for life to change and
that is only possible if Earth is extremely old.
  A. Tendency toward perfection
  Continually changing and acquiring features to help them live
more successfully
  B. Use and Disuse
  Alter size or change in organs by using their bodies in new
ways
  C. Inheritance of Acquired Traits
  Able to change your body in some way, you could pass this
change on to your offspring
Evaluating this theory:
  didn’t know how characteristics were inherited
  one of the first to develop a scientific theory of evolution
  paved the way for others
1 1/3/12   III. Population Growth
I. Natural vs. Artificial Selection
  Thomas Malthus
  Predicted human population will grow faster than space,
food, and supplies needed to sustain it.
  War, famine, and disease keep the population in check
A. Artificial – humans select which organisms breed based
on their characteristics
B. Natural – nature selects who survives and reproduces
•  SUMMARY
II. Evolution by Natural Selection
A. Struggle for existence
  Members of each species compete to obtain food, living
space, etc.
B. Survival of the fittest
  Individuals best suited to their environment will survive
and reproduce
  Fitness – ability of an individual to survive and
reproduce in a specific environment
  Adaptations – inherited characteristics that increase the
chance of survival
  Natural selection results in changes of inherited
characteristics in a population
•  aka: Natural Selection
III. Evidence of Evolution
  A. Fossil Record – view fossils from sequential layers of
rock and see how they changed over time
  IV. “On the Origin of Species”
  Book published by Darwin in 1859
  B. Geographic Distribution of Living Species
  C. Homologous Body Structures
  Same structure, similar function
  Common ancestor
  Vestigial organs – organs that have little or no function
(appendix, wisdom teeth)
  D. Embryology – look at similarities
  E. Bio Chemistry – DNA similarities
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