1. Evidence to Support Evolutionary Theory
Fossils
Similarity of embryos
Homologous and analogous structures
Vestigial structures
Similarities in macromolecules

2. A) Fossils
Most of the evidence for evolution comes from the fossil record
Fossils show how much (or how little) organisms have changed over time
One of the problems with the fossil record is that it contains gaps. Not all organisms fossilize well, and there will be many fossils that have been destroyed by the movements of the Earth, or simply not yet been discovered.

3. B) Embryos of all vertebrates are similar – indicating a common ancestor

4. C) Homologous Structures
Develop from similar embryonic tissue
May or may not have a similar function
Suggest a common ancestor

5. C) Analogous Structures
Structures in unrelated organisms that carry out the same functions
Develop from different embryonic tissues
Do not share a recent common ancestor
Superficially similar because these adaptations evolved in response to similar
environmental needs
Wings of insects & wings of birds

6. Analogous Structures: These organisms do not share a recent common ancestor, but they have similar appendages that evolved to help them survive in an aquatic environment

8. D) Vestigial Structures
Reduced or nonfunctional structures
Examples: appendix, wisdom teeth, human tail bone
Interpretation: the vestigial structure was functional in some ancestor of the modern organism
Snakes have pelvic bones; they are known to be the descendants of four-legged reptiles

10. Vestigial Human Structures

11. E) Similarities in Macromolecules-
Proteins
MORE differences in amino acid sequences of distantly related species
FEWER differences between species that are more closely related
Nucleic Acids
MORE differences in DNA sequences between distant relatives

12. DNA sequences
Animal
Human
Gorilla
Chimpanzee
Orangutan

13. Three Different Patterns of Evolution
1) Coevolution 2) Convergent Evolution 3) Divergent Evolution

14. Coevolution
When two species are in close association and evolve together. Also when a species evolves as a result of evolution in another species.
These organisms may depend exclusively on each other & be highly specialized!

15. Convergent Evolution
When un-related species becomes more similar over time.
Example: streamlined bodies and swimming appendages on sharks (fish) & dolphins (mammals)

16. Divergent Evolution
When related species become more different over time.
An example is domestic dogs and wolves
Divergent evolution is the result of:
artificial selection
adaptive radiation – where many species evolve from one species

17. Label what type of evolution is occuring
Divergent
Convergent
Coevolution

18. Convergent or Divergent??
Homologous structures point to divergent evolution from a common ancestor
Convergent:
Analogous structures point to convergent evolution as a result of adapting to similar environments

19. Question: Convergent or Divergent Evolution? Why?
Dolphins & Penguins
Answer: Convergent Evolution
Dolphins are mammals
Penguins are birds
Both have developed flippers and streamlined bodies to swim & blubber to keep warm in water

20. Genetic Equilibrium
Genetic equilibrium is a theoretical condition where the frequency of alleles (traits) within a population stays the same from generation to generation
**** Genetic equilibrium does not exist *****

21. Five Reasons Why Genetic Equilibrium Does Not Exist
Migration
Mutations
Genetic Drift
Non- Random Mating
Natural Selection

22. 1) Migration – the movement into or out of a population
Immigration – the movement INTO a population
Emigration – the movement OUT a population
The genes will move also! 22

23. 2) Mutations – the alteration in alleles, or genetic information
New traits will form, while harmful traits will eventually be eliminated
Creates VARIATION
3) Genetic Drift – by chance, some individuals survive to pass on their genes to their offspring.
Has nothing to do with fitness
Pure luck
Greater effect on a small
population than on a
large population. 23

24. 4) Non-random mating – organisms tend to mate with others in close proximity; promotes inbreeding and leads to a change in frequencies of certain traits 5) Natural Selection – the fittest will survive; bad traits will be eliminated from the population due to natural selection 24

25. Tempo of Evolution
Gradualism is a process of evolution in which the formation of new species occurs gradually
Punctuated Equilibrium is a process in which the formation of new species occurs rapidly between periods of little or no change
Formation of new species is called speciation