1. Evolution

2. With your partner….
Come up with 1 thing you are absolutely, 100% sure about the theory of evolution.
Come up with 1 thing you THINK is true about evolution.
Come up with 1 thing that evolution does NOT say.
Class Discussion.

3. What evolution does NOT say:
Does NOT say humans came from apes.
Does NOT say how life began on Earth.
Does NOT say one cannot have “faith”

4. What evolution IS:
Best theory we have right now to explain the variety of life one Earth.
Is supported by an enormous amount of evidence (that you must know for the test).
Is open to being changed or discredited if more scientific data is discovered.
Is a controversial topic, even today.

5. Evolution The process by which species change over time.
Overview of Evolution (*does not say we came from apes!)

6. Charles Darwin

7. “Descent with Modification”
Charles Darwin:
Wrote the book On the Origin of Species which gave us the theory of evolution through Natural Selection.
Overview of Darwin (Video)

8. End of Day 1 song:
Evolution Song

9. “THE SINGLE MOST IMPORTANT FACTOR IN THE THEORY OF EVOLUTION”
NATURAL SELECTION
“THE SINGLE MOST IMPORTANT FACTOR IN THE THEORY OF EVOLUTION”

10. How Evolution works through Natural Selection
Natural Selection is the “vehicle” that “drives” Evolution.
Natural Selection and Evolution
With your partner, come up with an analogy to show how evolution and natural selection are related:

11. The Four Parts of Natural Selection
Adaptation – The traits that improve survival and reproduction become more common.
Overproduction – Each population is capable of producing more offspring than can survive. This create competition.
Variation (due to genetics) – All offspring are different.
Selection – The offspring best suited to the environment survive and pass those traits on to their offspring.

12. A question to ponder….
With your partner, discuss how a giraffe’s neck got to be so long. Be able to explain the “how” part in some detail.

13. Natural Selection: 1)Adaptations
Definition: A trait that makes an organism better suited to its environment
Adaptations take time and occur over many generations

14. So how DID their necks get so long….
Class discussion….share your thoughts.
the answer....

15. Other Adaptations Discuss with your partner what adaptations
you see in this picture.

16. On your own, think about what adaptations are here?
Clown fish and sea anemone.

17. What about adaptations here?
Penguin

18. Natural Selection: 2)Overproduction
Organisms produce more offspring than can possibly survive.
This creates competition where the best fit for their environment will survive.
The competition is due to the fact that environmental resources are limited.
With your partner, come up w/3 examples of competition in nature..

19. Overproduction/Competition Video
Quick and simple example
Quick Lecture on Competition

20. Natural Selection: 3) Variation
The idea that all members of a species are slightly different from one another and this difference is in their genes.
This variation makes it more likely that at least some will survive a sudden catastrophic change or even a series of small changes. Over time this can lead to change in species…aka...evolution.
Think of one example of this in nature.

21. Genetic Variation
Mechanisms of Variety
Result of variety...

22. Natural Selection: Selection
“Survival of Fittest”
Those organisms best fit to their environment will survive (be “naturally selected”) and pass those traits to their offspring.
The traits are passed on via reproduction.
Those not fit don’t reproduce and their traits and genes for those traits aren’t passed.

23. Evidence for Evolution
1) The Fossil Record
2) Embryology
3) Comparative Anatomy
4) Molecular and Biochemistry
With your partner, discuss what you think each of these may be.

24. The Fossil Record
Fossils are the remains of organisms or the imprint of organisms in rock.
Fossils are usually found in sedimentary rocks.
Fossils can be dated by the rocks they are found in or by Carbon Dating parts of the organism.

25. The Fossil Record (continued)
Video clip

26. Carbon Dating of Fossils
Carbon 14 is a radioactive form of Carbon that occurs naturally.
When an organism dies the amount of Carbon 14 in the bones slowly decreases.
Approximately every 6000 years half of the Carbon 14 is converted to N-14.
If an organism is found to have half the original Carbon-14 the fossil is approximately 6000 years old.

27. Biogeography
Different continents with similar biomes have similar organisms.
Examples Rhea, Ostrich and Emu
This suggests that similar environments shape the evolution of organisms in similar ways.

28. Ostrich
Emu
Rhea

29. Embryology
Scientists compare how organisms develop from embryos (fertilized eggs) until they become adults
By comparing the changes the embryos go through you can determine if organisms are related.
Example: All vertebrates have a tail and gill pouches at some point in their development

31. Comparative Anatomy
The anatomy of different organisms are compared to see relationships
Homologous structures- structures that similar in two or more species
Example: Arm bones of many vertebrates have the same arrangement. (See book pg 384)
Vestigial Structures- structures that are “left over” from the past and have no clear function. Example appendix

33. Molecular and Biochemistry
Comparing the DNA and proteins of organisms for the number of differences
The differences are usually caused by some type of mutation
The fewer the number of differences the closer the relation between the organisms

34. Beyond Darwinian Theory
Forces that change allele frequencies
Microevolution

35. Allele Frequency
Allele Frequency-The percentage of dominant alleles and recessive alleles that appear in a population
Hardy-Weinberg principle tells us the number of each allele in a population based on mathematics
The number of each allele does not change unless an evolutionary force is acting on it.

36. Evolutionary Forces That Change Allele Frequency
Each of the following cause the allele frequency to change
Mutation
Gene flow (migration)
Nonrandom mating (mate choice)
Genetic drift
Natural selection

37. Mutation
One allele turns into another by a mutation in the genetic code
Does not occur very often and are usually lethal
Occurs 1-10 times per 100,000 cell divisions

38. Mutations Changes that happen in one generation
May occur by a change in either the egg or sperm of a parent
May be caused by a virus, drug, bacteria or radiation
May be caused by an error in cell division

40. Gene Flow (Migration)
The movement of genes (alleles) from one population to the next
Migration
Immigrants - bring in new alleles to a population
Emigrants – take alleles out of a population

41. Nonrandom Mating (Mate Choice)
When we mate with individuals like ourselves we change the allele frequency to become more ……
Homozygous
A mate is usually chosen based on certain traits

42. Genetic Drift Small populations and/or isolation
In small populations if a catastrophic event occurs one of the allele frequencies could be reduced
If individuals are “trapped” on an island, one of the allele frequencies could be reduced

43. Natural Selection “Survival of the fittest.”
If some alleles are “lethal” then they are selected against (reduced in number).
For example: if aa is lethal then the number of a’s in the population will go…
Down.

44. Patterns of Macroevolution
Adaptive Radiation
Divergent and Convergent Evolution
Coevolution
Extinction
Gradualism
Punctuated Equilibrium

45. Adaptive Radiation
Adaptive radiation - When many different species are developed from a single ancestor. Like a branching tree.

47. Divergent Evolution
Divergent Evolution - is the process of two or more related species become more and more dissimilar.

48. More Divergent Evolution

49. Convergent Evolution
Convergent Evolution - unrelated species become more and more similar as they adapt to the same environment

50. Convergent Evolution

51. Coevolution
Coevolution - the joint change of two or more species in close interaction.
Often predator and prey

53. Extinction
If all the members of a lineage die off or simply fail to reproduce, the lineage is said to be extinct.

54. Dodo Bird

55. Gradualism
Small changes in a species over long periods of time

56. Punctuated Equilibrium
Species remain stable for long periods of time and then quickly change