1. The process of evolution drives the diversity and unity of life.
Big Idea 1:
The process of evolution drives the diversity and unity of life.

2. So, what is evolution?
Evolution means “______________________________________”.
Organisms must adapt and change over time to become better suited (live longer) to ____________________________
The key is to live long enough to ______________the “______________” to their offspring!
All living organisms evolve – from bacteria to humans!

3. How Do Organisms Evolve?

4. How do organisms evolve?
_________________________(this was Darwin’s big break)
Often referred to as “survival of the fittest”
Has four parts
______________-no two organisms are completely alike
______________- some differences are passed from parent to offspring
______________- More offspring are born than can survive to reproductive age (why?)
After ____________________________, inheritance of adaptations will lead to evolution of the population.

6. ??
Natural Selection is also known as “survival of the fittest.” What component is NOT part of Darwin's natural selection?
Overproduction of offspring
Competition for resources
Genetic variation
Learned behaviors help organisms survive

7. Darwin’s Conclusions
Based on the amount of biodiversity we see today, __________________________________________and evolution has been going on for a long time.
If organisms evolve from other organisms, must all __________________________________________.

9. How do organisms evolve?
The Modern Synthesis- connects Darwin’s theory to the modern understanding of ____________________________

10. How do organisms evolve?
______________: A change in a DNA sequence.
Happens spontaneously and unavoidably.
________________________________________________

11. How do organisms evolve?
Mutations: A change in a DNA sequence.
Happens spontaneously and unavoidably.
The source of all new traits/genetic variation
Since any particular mutation is rare, this process __________________________________________in allele frequency over one generation
Some “green genes” randomly mutated to “brown genes”

12. Mutations create “alleles”

13. Evolution Defined:
Evolution: Changes in __________________ __________________ over time.

14. Evolution Misconception Alert!
Misconception: Individuals evolve.
_______________________________________________ _______________________________________________ ______________________________________________
The evolution of a population emerges from the individual fitness of members of that population.
As they survive and reproduce or not, the frequencies of alleles in the next generation will change accordingly.

15. How do organisms evolve?

16. Genetic drift:
Has a _________________________________ ____________________________, since each individual is more of the total alleles.
Idea: survival and reproduction doesn’t depend on fitness. No matter how fit, if you get struck by lightening and die, you still don’t pass genes on to offspring.

17. Genetic Drift affects small or large populations more? Why?
Small Pop Large Pop

18. ____________________________
The descendants of a small, founding population have different allele percentages than the population the founders came from.

19. Ex. Amish Populations and polydactyly

20. ____________________________
The survivors of a ________________________ decrease in a population may have a different allele frequency than the pre-bottleneck population

21. Ex. Modern Cheetahs are all genetically similar due to 2 bottlenecks

22. Gene Flow (aka. ______________)- Occurs when individuals move between populations and breed
Movement of alleles due to immigration and emigration

23. Example: Modern Human Migration

25. Sexual Selection
Persistence of traits that signify fitness and _______________________________________

26. Ex. Peacocks are male.

27. Can be intersexual or intrasexual

28. Evolution Misconception Alert!
Misconception: Evolution is “random”.
Evolution is a change in allele frequency in a population. That change involves ______________ ______________ (ex. Genetic drift) and ______________ ______________ (ex. Natural selection).

29. Summary: Four mechanisms can shift allele frequencies in population
Natural selection
Increases the frequency of alleles that contribute to reproductive success in a particular environment
Includes sexual selection and artificial selection
Genetic Drift
Causes allele frequencies to change randomly
Gene flow
Occurs when individuals move between populations and breed
Mutation
Produces new alleles
Modifies allele frequencies by introducing new alleles
Most effective when coupled with another mechanism

30. Several types of natural selection are known
__________________________________________________________________

31. Several types of natural selection are known
Individuals with _____________traits have ______________________
Intermediate phenotypes are retained

32. Several types of natural selection are known
Individuals with intermediate traits have _____________fitness
Over time we find increase in individuals with _______________ ________________ phenotypes

33. Several types of natural selection are known
No allele has selective advantage: _____________ _______________________
Caused _____________ _____________ (heterozygotes have higher fitness than homozygotes)
Ex. heterozygotes with sickle –cell allele are resistant to malaria (more later)

35. Q2: This picture illustrates what type of selection?
                                                    A sexual B disruptive C directional D stabilizing

37. Evidence for Evolution

38. Evidence for evolution
Comparative anatomy
Embryology
Biogeography
Fossil record
Molecular biology

39. Homologous Structures
Anatomically _____________ _____________ structures inherited from a common ancestor
“Same setup” – the limbs of many organisms have the same basic anatomy

40. Homologous Structures

41. Distantly Related but Similar (______________________structures)
Similar environments have selected for similar traits
Similar environments have similar ______________________________
__________________________________________________________

43. Homologous vs. Analogous?

44. _____________ structures- _________________________________________________________________
Snakes have tiny pelvic bones!
Whales have tiny pelvic bones, even today!
Why?
Kiwi wings – much to small, can’t fly.
Why would a bird have wings if it can’t fly?
_____________– important in digestion for many mammals, but not humans!

45. Biogeography- Study of where organisms live now and where ancestors lived in the past
Uses fossils
Patterns provide insight about how organisms evolved from ancestors

46. Closely Related but different

47. Fossil Record Species on Earth have changed over time
___________________- The earth is really old (4.6 billion years old)
____________________________________:   Show evolutionary progression_____________________________

48. Fossil Record
Transitional Fossils:   Show evolutionary progression between groups

49. Archaeopteryx is a transitional fossil between dinosaurs and birds.

50. Can you tell what is what?
Embryology & Developmental Evidence
Can you tell what is what?
Can you identify the:
Chicken
Rabbit
Fish
Human
Tortoise
Cow
Salamander
Pig

51. Ok, here’s the last one! Can you identify the: Chicken Rabbit Fish
Human
Tortoise
Cow
Salamander
Pig

52. Comparative Biochemistry (________________)
Scientists now know the DNA sequence of humans (and many other living organisms)
We can compare our DNA or other biological molecules to see how closely they match up with other organisms. The __________________________________________________________________________

53. Comparative Biochemistry
Chemical evidence has been used to establish the evolutionary relatedness (“____________”) of all life on Earth

54. __________________________________
_________________in one lineage, followed by divergence into many different adaptive forms
New species and new niches formed and filled
Can be triggered by access to _________________
…Or evolution of _________________ _________________resources (key innovations)

55. Adaptive radiation

56. Misconceptions about Evolution
Individuals DO NOT evolve. Populations evolve.
______________(changes in an individual in ______________ to an environmental change) is not evolution
______________(____________ features of organisms that fit life habits, allowing them to survive and reproduce) is evolution

57. Misconceptions about Evolution
Adaptation does not produce perfection.
Evolution is not progressive
________________________”__________________” or more complex organism. Evolution does not have a goal. It does not lead to “people”,
There are no “higher” and “lower” organisms
Individuals do not act for the good of the species

58. Evolutionary Biology: Is It Really Science?
Science is based on
Observation of phenomena
Proposed explanations of phenomena
Test those explanations
Can be reject the hypothesis
Evolutionary theory is an explanation (2) of the original maintenance of adaptations and biodiversity (1)
Is it testable?
How can we test descent with modification and natural selection

59. Evolution is a ______________________ ______________________ theory supported by thousands of scientific studies and many different types of evidence.

60. The word _____________________________ ________________________________. It means the idea must be supported by hundreds of thousands of pieces of evidence, gathered by many different scientists, whom over many years, reach the same conclusion.
When scientists label an idea a theory, they are saying they are 99.9% sure this is the way it is!