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2012-01-30 01:04:04
Evolutionary Discussion Heredity etc

Evolutionary Discussion, Heredity, etc.
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  1. On the Origin of Species developed two main ideas. What are they?
    - Evolution Explains life unity and diversity - Natural selection is a cause of adaptive evolution
  2. What were the names of the 7 scientists who set the stage for evolutionary theory to develop? (pre-Darwin)
    -Linnaeus -Hutton & Lyell-Malthus-Cuvier-Lamarck-Mendel-Wallace
  3. What did Linnaeus establish theories on?
  4. What did Hutton and Lyell establish theories on?
    Geological Change
  5. What did Malthus establish a theory on?
    Population growth resources
  6. What did Cuvier establish a theory on?
    Fossils and extinction
  7. What did Lamarck establish a theory on?
    Species Change
  8. What did Mendel establish a theory on?
    Inheritance patterns
  9. What did Wallace establish a theory on?
    Evolution & Natural selection
  10. What summarizes Darwin's perception of the Unity of Life?
    "Descent with Modification"
  11. Inductive reasoning
    A type of logic in which generalizations are based on a large number of specific observations
  12. Deductive reasoning
    A type of logic in which specific results are predicted from a general premise.
  13. What did Ernst Mayr do with Darwin's theory?
    He made three basic inferences based on five observations.
  14. What were Ernst Mayr's observations?
    -Population sizes would increase if everything survived. -Populations tend to be stable in size except in seasonal fluctuation -Resources are limited-Much variation is heritable
  15. Ernst Mayr's Inferences?
    -When more individuals than environment can support leads to a struggle for existence-Survival depends in part on inherited traits-Over many generations this unequal survival will yield changes in the population
  16. Biological Evolution is:
    The change in genetic properties of populations over generations.
  17. Evidence of biological evolution?
    -Artificial selection-Direct Observations in the wild -Homology-Fossil Record-Biogeography
  18. Biogeography
    Study of patterns of distrubution of animals
  19. What occurs in populations, evolution or natural selection?
  20. What occurs in individuals, evolution or natural selection?
    natural selection
  21. Gregor Mendel: Years? What experiments?What knowledge was he lacking?
    -1822-1884-Did experiments on pea plants to determine patterns of inheritance-He did NOT know about DNA
  22. What is a chromosome?
    A strand of DNA
  23. What types of organism's chromosomes are in homologous pairs?
    Diploid organisms
  24. What is a Gene Locus?
    A specific place on a chromosome that codes for a specific trait
  25. What is an allele?
    -An alternate form of a gene-Dominant masks recessive in phenotype
  26. What is a gene?
    A discreet hereditary unit found in DNA
  27. What is a genotype?
    An individuals genetic composition
  28. What is a phenotype?
    A visible characteristic of an individual it is also an interaction of genotype and environment.
  29. What does population genetics study?
    -Why there is so much variation in populations-Future characteristics of population
  30. Gene Pool
    All alleles together in a population (May be 1, 2, 3, or many many more.) NOTE: Individuals only have TWO alleles.
  31. Population
    Group of individuals of the same species that live in the same area and interbreed, producing fertile offspring.
  32. Frequency =
    p+q = 1- where p = Frequency of Dominate allele and q = frequency of recessive allele
  33. Can populations with identical allele frequencies have different genotype frequencies?
  34. How can you figure out allele frequencies if you only hvae phenotype frequencies?
    Using the Hardy-Weinberg Equation
  35. What is the Hardy-Weinberg priciple?
    A principle that states that the frequencies of alleles and genotypes in a population will remain constant from generation to generation, provided that only Mendelian segregation and recombination of alleles are at work.
  36. What is Hardy-Weinberg equillibrium?
    A gene pool where the only forces at work are mendelian segregation and recombination of alleles.
  37. What is the hardy-weinberg equation?
    p^2 + 2pq + q^2 = 1

    • p=expected frequency of genotype C^RC^R
    • pq= expected frequency of genotype C^RC^W
    • q=expected frequency of genotype C^WC^W
  38. What is the hardy-weinberg equation used for?
    Examining allele and genotype frequencies in populations
  39. In the hardy-weinberg equation, to find the probability of have a homozygous recesive allele you would take...
  40. In the hardy-weinberg equation, to find the probability of having a homozygous dominant allele you would take...
  41. In the hardy-weinberg equation, to find the probability of having heterozygous alleles you would take
  42. Hardy-Weinberg Assumptions:
    • 1.) No mutations
    • 2.) Random Mating (NO preferentioal mating)
    • 3.) No natural selection
    • 4.) Extremely large population size
    • 5.) NO gene flow
  43. Problems with H-W assumption of No mutations:
    • *Due to accidents in DNA.
    • * Happen ALL the time, but slowly
    • * Sorce of all genetic variation
    • * Required for evolution
  44. Problems with H-W assumption of Random Mating
    • * Males often compete for territories or mates
    • * Competition occurs through ornamentation, vocalization, fighting, etc.
    • *Female choice plays a roll
    • * Female choice ex: = lekking behavior
  45. Lekking Behavior
    When males congregate and do their display and then the females choose the mate. Generally one or few males do ALL of the mating.
  46. Problems with H-W assumption of no migration in or out
    Migration changes allele frequencies! Migration is generally always occuring.
  47. Problems with H-W assumptoin of an infinitely large population?
    ALL populations are finite. Moreover, populations risk genetic drift and sample error. Both of those are more likely to happen in smaller populations.
  48. What are two examples of genetic drift?
    • * Population bottle neck
    • * Founder Effect
  49. Population bottleneck
    • An example of genetic drift. This takes place when a population crashes, and a once rare allele becomes a prominant / common allele. These can be as small as one generation.
    • EX: Elephants and cheetahs both had this occur to them and now they have low genetic variation and great problems with converation because of this.
  50. Founder Effect
    • An example of genetic drift.
    • When a few individuals leave a group and start a new population. Once rare alleles can become very common alleles in the new population.
    • EX: Omish community that inbread and often have 6 fingers.
  51. Problems with H-W assumption of no natural selection?
    Adaptation always occurs. Traits favoring survival and reproduction will outlive those that don't.
  52. Natural selection basics
    • *More individuals are produced than survive due to competition for limited resources
    • * Individuals vary within populatinos
    • *Some variants have more offspring
    • *Individuals with favorable traits reproduce / survival of the fittest
  53. What is biological fitness?
    The ability to pass along many copies of your genes onto the next generation.
  54. Does natural selection act on phenotypes or genotypes?
  55. Directional Selection
    Natural selection in which individuals at one end of the phenotypic range survive or reproduce more successfully than do other individuals.

    EX: White polar bears VS black polar bears
  56. Stabilizing Selection
    Natural selection in which intermediate phenotypes survive or reproduce more successfully than do extreme phenotypes. Likely in a stable envioronment. Variance in phenotypes reduced.
  57. Diversifying selection
    Natural selection which favors extreme phenotypes. Variance increases. Possible in variable or patchy environments.
  58. Adaptation
    A trait that enhances fitness. Depends on many environmental factors and depends on other genes.
  59. Sexual Selection
    Natural selection in which both inter and intrasexual selection. Differential reproduction due to variation in ability to obtain mates. May lead to trade off.
  60. What are the results of sexual selection?
    • Increase fitness via sexual selection
    • decrease selection via other natural selection
  61. Is all evolution adaptive?
    NO. Drift and mutation are random. They MAY encounter NS but not necessarily.
  62. Is natural selection goal oriented or mindless?
  63. What are all of the reasons that natural selection does not creat perfect organisms?
    • *Adaptation is a comprimise, different selective forces at one time. Selective forces change over time
    • * Not all evolution is adaptive. (drift and mutation)
    • * Historical Constraints (Starting materials for a pop)
    • * Not enough variation (This doesn't allow for change!)
  64. What type of alleles help to maintain evolution the most? Homozygous recessive? Homozgous dominant? Heterozygotes?
  65. What is the heterozygote advantage?
    • They are the most fit because they have the most variance.
    • Ex: sickle cell animia : aa = anemic but Aa = malaria resistant . . . Aa is not infected but IS a carrier, keeping the sickle cell population allive and viable to be passed down
  66. How does a rare allele help you in frequency dependent slection?
    • * Rare individuals may survive parasites
    • * Predators search out similar traits each time (if you're different - wa la)
  67. How does timing of selection maintain evolution?
    Selective forces change over time.
  68. Neutral Variation
    Sometimes a variation doesn't do anything, but over time it very well may as the environment changes or a new predator shows up, etc.
  69. Continuous Variation
    Usually within a single species within a population where you see a casual change as you move across the population.
  70. Discontinuous variation
    One population varying greatly among another population of the same species. (What we normally talk about in bio)
  71. Sympatric Speciation
    Speciation occuring in populations that live in the same geographic area.
  72. Allopatric Speciation
    Gene flow is interrupted when a population is divided into geopgraphically isolated subpopulations.
  73. What helps to maintain continuous variation?
    • *Sympatry
    • *Successful interbreeding