1. Evolution

2. Evolution Change over time Occurs to a species, NOT INDIVIDUALS!!
Natural selection or Survival of the fittest

3. How Evolution Works Overpopulation
More individuals born than can survive

4. How Evolution Works Competition For limited resources
Some will survive, some will not

5. How Evolution Works Variation Differences among individuals
A result of genetic mutations
in DNA

6. How Evolution Works Adaptation
Some variation gives some individuals a slight survival advantage
These are favorable traits…

7. Types of Adaptations Structural
Physical structure that helps organisms survive

8. Types of Adaptations
Chemical
Chemicals that helps organism survive

9. Types of Adaptations
Behavioral = Behaviors that help organisms survive

10. Types of Adaptations
Camouflage

11. Types of Adaptations
Warning Coloration

12. Types of Adaptations
Mimicry

13. How Evolution Works Natural Selection
Those with best traits survive, reproduce and pass favorable traits on to their offspring
The mechanism of evolution

14. How Evolution Works Speciation
Isolation – causes changes; if one part of a population is separated or isolated from another, speciation is more likely

15. Evidence for Evolutionary Theory
Homologous Structures
Vestigial Structures
Embryology
Fossil Record

16. Homologous Structures
same kinds of cells that grow in similar patterns in different organisms
Ancient lobe-finned fish
Turtle
Alligator
Bird
Mammal
*Analogous Structures – Structures that are similar in function, but are not inherited from a common ancestor.
These limbs of these four modern vertebrates are homologous structures

17. Vestigial Structures Organs that no longer serve a purpose or function
This suggests that ancestors of modern whales probably had legs and lived on land.

18. Vestigial Organs

19. Embryology Common Ancestry
In their early stages of development, chickens, turtles, and rats look similar, providing evidence that they shared a common ancestry.

20. Embryology

21. Fossil Record Remains of ancient life Record of history of life
Shows change over time
Transitional fossils

22. Transitional Fossils

23. Transitional Fossils

24. Transitional Fossils

26. TIME Magazine; August 23, 1999, pp. 54-55.

27. Evidence Geographic Distribution of Living Species Beaver Beaver
Muskrat
Beaver and Muskrat
Coypu
Capybara
Coypu and Capybara
NORTH AMERICA
Muskrat
Capybara
SOUTH AMERICA
Coypu

28. All provide evidence of a
Common Ancestry
Similar structures
Similar structural location
Similar embryos
All provide evidence of a
common ancestor!!!!

29. The theories that led to evolution...
Bonnet – Periodic catastrophes affected the entire planet, and that after each catastrophe, life began anew.
Lamarck
Organisms constantly strive to improve themselves.
The most-used body structures develop, whereas unused structures waste away.
Once a structure is modified by use or disuse, the modification is inherited by the organism’s offspring (inheritance of acquired characteristics).
Darwin
There is variation within populations.
Some variations are favorable.
Not all young produced in each generation can survive.
Individuals that survive and reproduce are those with favorable variations.

30. Punctuated Equilibrium
Populations remain genetically stable for long periods of time, interrupted by brief periods of rapid genetic change.

31. Types of Evolution
Divergent Evolution – When isolated populations of a species evolve independently.
Convergent Evolution – Different species with different ancestors develop similar characteristics.
Coevolution – Over millions of years, species that interact closely often adapt to one another.

32. Types of Selection
Stabilizing Selection - A shift that favors the intermediate variants.
Directional Selection - A shift in frequency to an extreme phenotype.
Disruptive Selection - A selection that does not favor the most common variation within a population.

33. Frequencies Genetic Equilibrium – Constant state of allele frequency.
Genetic Drift – Random change in allele frequencies in a population due to chance events.

34. It’s not that far of a stretch…
Humans have forced evolution (or change in a species over time) …
Artificial Selection – nature provides variation and humans select variations that they think are useful