1. Evidence for Evolution
Direct Instruction
then synthesis on 24R

2. EVOLUTION = Change over Time =Descent With Modification =Adaptation of a species
Takes Place Over Long Periods of Time
-usually millions of years

3. Descent With Modification
Species Today Look Different From Their Ancestors
Each Living Species Has
-Descended
-With Changes
-From Other Species
-Over Time

4. Descent With Modification
Implies
All Living Organisms Are Related
Single Tree of Life
DNA, Body Structures, Energy Sources
Common Descent
All Species, Living (Extanct) & Extinct, Were Derived From Common Ancestors

5. Descent With Modification: An Example

6. Evidence of Evolution
Fossil Record
Comparative Anatomy
Comparative Embryology
Comparative Biochemistry
Comparative Biogeography

7. Evidence of Evolution— 1. The Fossil Record
Evidence of orderly change can be seen when fossils are arranged according to their age.
Derived Traits
vs.
Ancestral Traits

8. Evidence for Evolution – The Fossil Record

9. Evidence of Evolution— 2. Comparative Anatomy
Anatomy has different functions but constructed of similar bones in similar way.
Evo predicts that modifications of ancestral body parts are more likely than formation of entirely new parts
2 Kinds:
Homologous Structures: same structures/different functions
Analogous Structures: different structures/same functions
an analogy= a comparison using like or as (this snake tastes like chicken, but is it?)

10. Homologous Structures
Structures in different organism that indicate a shared ancestry
Check out these vertebrate forelimbs.

11. Homologous Structures

12. Check out these flying machines.
Analogous Structures
Different Structures in different organisms that have a common function.
Check out these flying machines.

13. Ape and Hominid Skeletons

14. Type of Homologous Structure
Vestigial Structures
Reduced or nonfunctional structures
provide evidence of an organism’s evolutionary history.

15. Ex of vestigial structures
Whale Evolution Video
Ex of vestigial structures
ibrary/03/4/l_034_05.html
5 min, 9 sec

16. Evidence of Evolution— 3. Comparative Embryology
Similarities In Embryonic Development

17. Human Fetus – 5 weeks

18. Comparative Embryology Shows common ancestry
Video:
ibrary/04/2/l_042_02.html

19. Evidence of Evolution— 4. Comparative Biochemistry
Proteins (Amino Acid)
MORE differences in AA sequences of distant related species
LESS differences = species that are more closely related.
Nucleic Acids
MORE differences in DNA sequences of distant related species

20. Similar DNA = Similar AA = Similar Organisms
Which is more related to the human,
the snake or the tuna?
Similar DNA = Similar AA = Similar Organisms

21. Evidence of Evolution— 5. Comparative Biogeography
Different Species On Different Continents Have Similar Adaptations due to similarities of the Environments

22. Organisms from different land masses look similar
The most recent common ancestor is those of the same geographical region.
But, the similar comparative anatomy demonstrates a distant common ancestor before the land masses separated.

23. Elephants Asian African
Ex of a species with a common ancestor that became geographically isolated over 5.5 MYA from others in their species and then continued to evolve.
And the evolution was convergent –Becoming the African and Asian Elephants we know today.

24. Evidence of Evolution
Fossil Record
Comparative Anatomy
Comparative Embryology
Comparative Biochemistry
Comparative Biogeography