Darwin's observations of animals in South America and the Galapagos Islands led him to form ideas about evolution. He noticed that related species on the different islands had adaptations suited to their local environments. This helped Darwin develop his theory of natural selection, where organisms better adapted to their environment are more likely to survive and pass on their traits, leading to evolution over generations as populations adapt to their surrounding conditions.

2. armadillo
sloth
mockingbird
Giant tortoise
finch
cormorant hawk

3. Think about
Darwin´s
observations and
how he began to
form ideas of
evolution.

4. 1. What was Darwin´s job on the HMS Beagle? (p.140)
2. Define species (p.141)
3. What observation did Darwin make about animals from
South America and those on the Galapagos? (p.142)
4. What reason did Darwin use to explain the differences
he saw between the organisms from South America and
those on the Galapagos? (p.142)
5. Define adaptation (p.143)
6. Define evolution (p.143)
7. Define natural selection (p.144)
8. Explain the difference between
overproduction, competition, variation and selection
(pps. 144-145)

5. The process of Selective Breeding gave
Darwin ideas about Evolution

6. B
A

7.  = Process where individuals
with traits beneficial for their environment
are more likely to survive
 Natural selection causes evolution
= change in inherited
characteristics of a population (not
individuals) from one generation to the next

8. What happens to the number
of green beetles?
Why are there only orange
beetles?

9. = populations produce
more offspring than can possibly survive

10. = Every population has variation.
Much of this is due to inherited traits.

11. = In specific environments
certain traits are more advantageous and
they make the individual more likely to
survive (therefore passing on the trait more
frequently).

12. = Over time, traits that
improve survival and reproduction become
more common.