Ch. 15 Darwin

1
Ch. 15 Darwins Theory of Evolution
2
A. Voyage of the Beagle

• December of 1831-
• Beagle set out from England
• five-year cruise around the world with Darwin on
  board

3

4
B. Darwins Observations

• 1. Living diversity
• Brazilian rain forest
• Galapagos Islands
• Madagascar

5

• 2. Fossils
• Preserved remains of ancient organisms

6
After being on the boat for 5 yearshe went home
to England
7
C. Ideas That Shaped Darwins Thinking

• 1. An Ancient, Changing Earth
• Earth might be many millions of years old
• Hutton and Lyell
• If the earth is changing,
• the life on earth might be
• changing, too

8
C. Ideas That Shaped Darwins Thinking

• 2. Lamarks Hypotheses
• Aquired characteristics are inherited
• Wrong!
• Why do we care?
• Paved way for scientists to start thinking about
  what might cause living things to adapt to their
  environment

9
C. Ideas That Shaped Darwins Thinking

• 3. Population Growth
• Thomas malthus
• babies were being born faster that people were
  dying
• Same is true for other living things?
• What determines which living things live and
  which die?

10
D. Darwins Solution

• Read 378-379
• What happened next??
• What motivated Darwin to do this??
• He wrote a book and in 1859 published a book
  called On the Origin of Species
• An essay he received that contained the same
  ideas he had

11
D. Darwins Solution-Evolution by Natural
Selection
12
1. Theres a struggle for existence
13
2. Survival of the fittest

• Fitness is the ability to survive and reproduce
• Adaptation is a trait that increases chances of
  survival

14
3. Decent with modification

• -species today look a little different than their
  ancestors

15
Read 380-386

• Handout with questions
• Due today OR tomorrow at beginning of period

16
E. Evidence of Evolution

• 1. Fossil record

17

• 2. Geographic distribution of living species
• South America
• Australia
• Madagascar

18

• 200 mya?
• Broke up about 130 mya

19
(No Transcript)
20

• 3. Homologous Structures-develop from similar
  structures
• 4. Vestigial organs-functionless in some, useful
  in others

21

• 5. Embryological similarities
• Similar patterns of development