1. Evidence of Evolutionary Change

2. Comparing Fossils Evidence for Evolution
Shows that Living Systems change
Change is STILL happening

3. Galapagos Archipelago
Isolated Island used for scientific study
Biologists observed 2 species of birds:
Medium Ground Finch
Cactus Finch

4. Galapagos Islands Bird Experiment 12 year period Took measurements of:
Size of bodies
Thickness of beaks
2 severe dry spells
caused many bird fatalities

5. Galapagos Island Bird Experiment Results
Avg. characteristics of the surviving populations changed
Larger sized birds
Thicker beaks

6. Galapagos Island Bird Experiment Analysis Biological change
Influenced by natural circumstances
Passed on from generation to generation
Species change gradually
Small changes add up to significant differences

7. Comparative Anatomy
Branch of biology that concentrates on the similarities and differences in anatomical features of different species

8. Comparative Anatomy Look for structural similarities/differences
Similar characteristics may suggest evolutionary relatedness
Book pg 107 **Good Graphic**

9. Homologous Structure
Characteristic that is similar among different organisms because they evolved from a common ancestor
Ex. Forearm Structure
Consistent similarities
Develop same way in young
Different functions

10. Vestigial Structure
Structures that are functional in some species, but seemingly useless in others
“Vestige”—a remnant of
Ex. Tails
Most mammals have tails
Humans/Apes
Tail represented by last 3-5 bones of the backbone
Tail-moving muscles also present

11. Genetic Information DNA
Deoxyribonucleic Acid
Genetic “Blueprint”
Allows Scientists to determine how closely related 2 organisms are

12. % of DNA that is the Same as Human DNA
Genetic Information
Animal
% of DNA that is the Same as Human DNA
Monkey
(old world primate)
93%
Gibbon (lesser ape)
95%
Chimpanzee (great ape)
98+%

13. Genetic Information
Scientists can also show which organisms ARE NOT closely related
Bacterium
interpreted as an entirely different organism

14. Charles Darwin HMS Beagle 5 year journey
Mission: chart sections of the S. American Coast

15. Darwin
Deserted mission and spent time collecting specimen and recording observations
Questioned the geographical distribution of the organisms that he observed

16. Darwin Organisms similar to those in Europe, but very distinct
Organisms in mild S. America climates more similar to organisms in tropical S. America than to organisms in mild European climates
Organisms perfect for their environment

17. Darwin Returned to England and spent 20 years analyzing data
On the Origin of the Species (1859)
Word “evolution” not used
“descent with modification”
Evolution by Natural Selection

18. Darwin
Only published b/c realized that other scientists were thinking the same
Alfred Russel Wallace
Integrity