2. Darwin’s Theory
• Purpose:
– Explain how Darwin’s observations helped
him to develop his hypothesis
– Explain how natural selection leads to
evolution.
3. Darwin’s Background
• Born in England, 1809
• Studied Medicine at
Edinburgh University
• Transferred to Cambridge
University
• Studied to be a Minister
Library of Congress, Prints and
Photographs Division [reproduction
number, e.g., LC-USZ61-104].
4. Darwin’s Expedition - 1831
• Hired as Naturalist on H.M.S. Beagle
• Sailed on Five Year Scientific
Expedition
– Down East Coast of South America
– Up Pacific Coast to Galapagos Islands
– Made Stops on Mainland and Islands
– Observed Variety of Life and
Habitats
5. Darwin’s Work
• Outlined Theory in his Book in 1859:
– On the Origin of Species by Means of
Natural Selection
• Published Other Works on Biology
• Died in 1882
6. Darwin’s Theory
• What • Darwin noticed the
observations did diversity of living
Darwin make? things and the remains
of ancient organisms.
• What struck • Darwin was amazed by
Darwin about the diversity of living
these things that he saw and
observations? wondered what had
happened to the
fossilized animals.
7. Darwin’s Theory
• What kinds of • Darwin compared Galapagos
organisms to South
comparisons did
American organisms, and he
Darwin make on compared organisms among
his voyage? the Galapagos islands.
• What did Darwin • Darwin concluded the
conclude from animals on the islands
these came from the mainland
but had changed over
observations?
time.
8. Darwin’s Theory
• What did Darwin • Darwin noticed the
differences increased the
notice about
organisms’ ability to survive
differences ad reproduce in their
between species? particular environment.
9. Darwin’s Theory
• What did Darwin • Darwin hypothesized that
the organisms that arrived
believe led to the
on the islands faced
different conditions that were
adaptations in different from those on the
species on the mainland. Over many
Galapagos generations, the species
became better adapted to
islands? the new conditions.
10. Darwin’s Theory
• What did • Darwin’s ideas became
known as the theory of
Darwin’s ideas
evolution.
come to be known
as?
• What is • Evolution is the
evolution? gradual change in a
species over time
11. Darwin’s Theory
• What did • Darwin’s theory of natural
selection has four main
Darwin’s ideas
points:
come to be known – Overproduction
as? – Variation
– Competition
– Selection
• Overproduction means
• What does more individuals are
overproduction produced than can
mean? survive
12. Darwin’s Theory
• What is a variation? • Variation is any difference
between members of the
same species.
• How does
overproduction lead
to competition?
• How does
competition lead to
selection?
13. Darwin’s Theory
• What is a variation? • Variation is any difference
between members of the
same species.
• How does
overproduction lead
to competition?
• How does
competition lead to
selection?
