1. Star-nosed mole: Pre-questions for discussion
Introduction to Evolution
Star-nosed mole: Pre-questions for discussion
Pink snout has 22 finger-like projections that can touch 12 objects in less than 1 second.
Q: Why is this helpful?
Lives underground and has paddle shaped feet
Has great hearing but very poor vision?
Q: Why?

2. The Process of Evolution
DNA
Mutation
Changes in Genotype
Changes in Phenotype
Adaptations in Populations
Changes in the Gene Pool
New Species
Extinction
Evolution

3. Objectives Today I will know... Who is Charles Darwin
The meaning of survival of the fit
That Charles Darwin believed that individuals are more likely to survive if they have variations best suited to the environment.
Darwin’s theory of evolution is based on the ideas of natural variation and natural selection.
That species produce more offspring than can possibly survive.
Darwin’s theory of Evolution by natural selection is a process of change in species over time.

4. A 19th century (1800s) biologist
Who is Charles Darwin?
A 19th century (1800s) biologist
Observed adaptations of plants and animals
Adaptation- a feature that allows an organism to better survive in its environment
Old Darwin
Young Darwin
Adaptations vary with different environments

5. Most famous research took place at the Galápagos Islands
~near the equator west of South America
GREAT
BRITAIN
EUROPE
NORTH
AMERICA
ATLANTIC
OCEAN
The
Galápagos
Islands
AFRICA
Pinta
Genovesa
Marchena
Equator
SOUTH
AMERICA
Santiago
Daphne
Islands
Pinzón
AUSTRALIA
Fernandina
PACIFIC
OCEAN
Isabela
Figure 22.5 The voyage of HMS Beagle
For the Discovery Video Charles Darwin, go to Animation and Video Files.
Santa
Cruz
Andes
Cape of
Good Hope
Santa Fe
San
Cristobal
Tasmania
Florenza
Española
Cape Horn
New
Zealand
Tierra del Fuego

6. Darwin’s Focus on Adaptation
Darwin discovered:
Adaptations to the environment AND the origin of new species are closely related processes
Examples- Galápagos finches & Tortoises
Beak Shape
Shell Shape & Neck Length

7. (a) Cactus-eater (c) Seed-eater (b) Insect-eater Fig. 22-6
Figure 22.6 Beak variation in Galápagos finches
(b) Insect-eater

8. IN YOUR NOTES SKETCH BEAK SHAPE AND WRITE THE TYPE OF FOOD THEY EAT!
Fig. 22-6a
Figure 22.6 Beak variation in Galápagos finches
(a) Cactus-eater

9. IN YOUR NOTES SKETCH BEAK SHAPE AND WRITE THE TYPE OF FOOD THEY EAT!
Fig. 22-6b
Figure 22.6 Beak variation in Galápagos finches
(b) Insect-eater

10. IN YOUR NOTES SKETCH BEAK SHAPE AND WRITE THE TYPE OF FOOD THEY EAT!
Fig. 22-6c
Figure 22.6 Beak variation in Galápagos finches
(c) Seed-eater

11. Darwin’s two main ideas:
Descent with modification: All organisms are related through descent from an ancestor that lived in the past
Fossil evidence proves this!
Natural selection: individuals that are best suited to their environment survive and reproduce
Increases the adaptation of orgs to their envmnt
If envmnt changes, new adaptations will appear OVER TIME b/c of natural selection

12. Tortoises necks- Darwin’s evidence of adaptations

13. Darwin’s 4 Observations
Observation #1: Members of a population often vary greatly in their traits

14. Observation #2: Traits are inherited from parents to offspring (genetics)
Observation #3: All species are capable of producing more offspring than the environment can support
Observation #4: Because there is not enough food or other resources (limiting factors), many of these offspring do not survive

15. Have more offspring survive
Survival of the Fit
Individuals with traits that give a better chance of surviving and reproducing
Have more offspring survive
Unequal ability of individuals to survive and reproduce
Leads to the accumulation of favorable traits in the population over generations

16. Survival of the Fit
Survival of the Fit: individuals with favorable heritable traits survive and reproduce at a higher rate than other individuals

17. (a) A flower mantid in Malaysia (b) A stick mantid in Africa
Fig
(a) A flower mantid
in Malaysia
(b) A stick mantid
in Africa
Figure Camouflage as an example of evolutionary adaptation

18. (a) A flower mantid in Malaysia Fig. 22-12a
Figure Camouflage as an example of evolutionary adaptation
(a) A flower mantid
in Malaysia

19. (b) A stick mantid in Africa Fig. 22-12b
Figure Camouflage as an example of evolutionary adaptation
(b) A stick mantid
in Africa

20. Individuals do not evolve; populations evolve over time…
Important Notes about Evolution
Individuals do not evolve; populations evolve over time…
Natural selection can only increase or decrease heritable traits in a population
N.S. does not create new traits!
Local environment determines traits selected for or selected against