Transcript Darwin developed a theory of evolution

Darwin developed a theory
of evolution
Ch. 14.1
Ideas from Darwin’s Time
• Darwin published The Origin of Species
in 1859.
• This changed the understanding of
where organisms come from and how
they relate to one another.
• EVOLUTION  all changes that have
transformed life over an immense time
• Biological history of life on Earth
• Before Darwin’s ideas, it was believed:
– Species are fixed/permanent
– Earth is less than 10,000 years old and not
changing
• French naturalist observed fossils that
were SIMILAR to living animals at the
time
• Another naturalist (Jean Baptiste
Lamarck) proposed that life
evolves/changes
• Lamarck saw that species are NOT
permanent
– Evolution was a process of ADAPTATION
 inherited characteristics that improves
an organism’s ability to survive and
reproduce in a particular environment
The Voyage of the Beagle
• Darwin traveled from Britain to South
America
• Darwin collected specimens of plants
and animals
• He noticed that these organisms have
definite S.A. character (different from
similar species in Europe)
• Darwin went to the Galapagos islands
• Species were similar but different from
mainland species
• Slow processes of mountain building
and erosion shows that Earth must be
very old
Darwin Publishes his Theory
• After 5 years at sea, he was becoming
known as a knowledgeable naturalist
• Wrote his thoughts as a 200 page
essay, The Origin of Species
Darwin’s Two Main Points
• Life has a history of change
– Living organisms descended from ancestral
species (DESCENT WITH MODIFICATION)
• Individuals inherited characteristics wellsuited to the environment leave more
offspring than do other individuals (NATURAL
SELECTION)
Concept Check
• How did the work of Lyell and Malthus
influence Darwin as he developed his theory
of evolution?
• What characteristics of the Galápagos Islands
were particularly important for Darwin?
• What is natural selection?
• Which of the following is an adaptation: the
sharp teeth of a house cat, or a scar on the
cat's ear? Explain.