Biology Exam 3 Vocab

Card Set Information

Biology Exam 3 Vocab
2011-11-30 00:11:47
bio vocab tubblish

Show Answers:

  1. Geographic isolation of populations precedes evolution of species-level differences
    Allopatric speciation
  2. A reproductive community of populations (reproductively isolated from others) that occupies a specific niche in nature
    • Mayr's Biological Species Concept
    • Note: Also called the isolation species concept
  3. Two types of reproductive barriers according to the Biological Species Concept
    • Prezygotic
    • Postzygotic
  4. Reproductive barriers in which zygotes are not formed from matings between two species
    Prezygotic barriers
  5. Reproductive barriers in which two species are able to form a hybrid zygote, but the resulting hybrid is inviable or breaks down.
    Postzygotic barriers
  6. The concept that selection on hybrids with postzygotic barriers can lead to prezygotic isolation
  7. Problems with the Biological Species Concept
    • It applies to sexual forms only
    • No temporal dimension
    • Not a single unit of evolution
    • Often not practically testable
  8. Defines a species as a lineage of ancestral-descendant populations diagnosably distinct from other such lineages
    Phylogenetic Species Concept
  9. Subdividing a formally continuous habitat
  10. Rare disposal across a pre-existing barrier
    Founder event
  11. Two sources of allopatry
    • Vicariance
    • Founder event
  12. Speciation in which multiple species lineages are generated from an ancestor in an undivided geographic area
    Sympatric speciation
  13. The idea that evolutionary change occurs in small increments
  14. The Ancon sheep example shows that which principle of Darwinian evolution is not always true?
    • Gradualism
    • Note: Ancon sheep example is an example of a large phenotypic change in a single generation
  15. A population-based mechanism of evolutionary change invoked to explain "adaptation"
    Natural selection
  16. Random component of natural selection
    • Variation is produced at random with respect to an organisms needs
    • i.e. new mutations are equally likely to be useful as they are to be deleterious
  17. Nonrandom component of natural selection
    Organisms with favorable traits have higher rates of survival and reproduction, causing populations to accumulate the most favorable variants and discard less favorable ones
  18. States that evolution by natural selection has a preset goal or direction; arguments of this sort must be avoided in evolutionary biology
  19. Characteristics of offspring are correlated with their parents in a population
  20. Later forms are superior to earlier forms in a general sense
    Progressive adaptation
  21. A trait that evolved by natural selection for a particular biological role
  22. A trait co-opted by natural selection for a role incidental to that trait's origins
    • Exaptation
    • Ex: bird feathers
  23. In creating a mathematical model, you must identify essential aspects of reality and remove distracting elements.
    Abstraction and simplification
  24. In creating mathematical models, unreal conditions used to facilitate study
  25. Three things that mathematical models try to achieve, though often at least one is sacrificed.
    • Reality
    • Generality
    • Precision
  26. Replication without mutation
    Identity by descent
  27. A type of DNA that is useful for study because it does not recombine and is transmitted only by mothers.
    Mitochondrial DNA
  28. The idea that all copies of homologous DNA trace back to a common ancestral molecule.
  29. Newly arising alleles are not predominantly ones advantageous to their possessors
    Randomness of mutation
  30. Destroys identity by descent
  31. A set of identical haploid genomes for a specified unit of measurement
  32. Definition of haplotype
    A set of identical haploid genomes for a specified unit of measurement
  33. Organism in which branches of a haplotype tree of chromosome-3 gene orders denote paracentric inversions
    Drosophila pseudoobscura
  34. A local population of reproducing individuals that has physical continuity over space and time
  35. Characterized by genotype frequencies
  36. The population of gene copies collectively shared by individuals of a deme
    Gene pool
  37. Population of potential gametes in a deme
    Gene pool
  38. Characterized by allele frequencies
  39. Hardy-Weinberg Equation
    (p^2)+(2pq)+(q^2) = 1
  40. Implies that Mendelian traits are NOT expected to show Mendelian ratios in demes
    Hardy-Weinberg Equilibrium
  41. Mutation rate
    (# newly mutate copies) / (total # copies of homologous DNA)
  42. When the rate of elimination of a lethal allele (q^2) equals the rate of creation of a lethal allele (mutation rate)
    Mutation-selection equilibrium
  43. Shows that Mendelian inheritance does not cause evolutionary change
    Hardy-Weinberg Equilibrium
  44. Hardy-Weinberg equilibrium shows that this does not cause evolutionary change
    Mendelian inheritance
  45. Assumptions of Hardy-Weinberg Equilibrium
    • Population infinitely large
    • Random mating
    • No mutation
    • No migartion
    • No natural selection
  46. Disease caused by variation at the beta-hemoglobin locus
    Sickle cell anemia
  47. Two alleles in sickle-cell anemia
    • HbA
    • HbS
  48. Disease that can be alleviated by eliminating phenylalanine from the diet
  49. Two diseases which provide good examples of gene/environment relationship in determining phenotype
    PKU and Scurvy
  50. Analysis of genetic variance for continuously varying phenotypes
    Quantitative genetics
  51. Set of phenotypes associated with a particular genotype in interaction with a variety of environmental conditions and genetic backgrounds
    Norm of reaction
  52. Type of inheritance in which a large number of loci contribute to many discrete categories
    Polygenic inheritance
  53. Numbers of facets in eyes of wild-type and Bar-eyed Drosophila vary widely and largely overlap
    Example of environmental variation (the variation is caused by changes in temperature)
  54. Average amount by which individuals of a specified genotype differ from the mean value of their population for a quantitative phenotype
    Genotypic deviation
  55. Calculating genotypic deviation
    Mean phenotype of the genotype minus mean phenotype of the population
  56. A measure of how much phenotypic variance is associated with genotypic variation in a population in a given generation
    Broad-sense heritability
  57. A measure of how much phenotypic variance is associated with additive genotypic variation in a population
    Narrow-sense heritability
  58. The average genotypic deviation caused by a gamete bearing a certain allele after fertilization with a second gamete drawn at random from a gene pool
    Average excess of a gamete type
  59. Synonym for "breeding value"
    Additive genotypic deviation
  60. Assigns a "phenotype" to a gamete, the physical basis of the transmission of phenotypes from one generation to the next
    Average excess
  61. Must be specified to calculate genotypic frequencies from frequencies of alleles in a population
    System of mating
  62. Sum of the average excesses of the alleles in a genotype
    Additive genotypic deviation
  63. Variance that can be transmitted through gametes to influence phenotypic variation in the next generation
    Additive genetic variance
  64. Genetic variance that cannot be transmitted through gametes to influence phenotypic variation in the next generation
    Non-additive genetic variance
  65. Non-additive genetic variance in a single-locus model
    Dominance variance
  66. Non-additive genetic variance in a two-or-more-locus model
    Epistatic variance and dominance variance
  67. Is necessary but not sufficient for dominance variance at the population level
    Mendelian dominance
  68. Mendelian dominance is necessary but not sufficient for this at the population level
    Dominance variance
  69. If dominant allele is rare and mating is random:
    • All copies are in heterozygous genotypes
    • All copies contribute equally to population-level variation
    • Genetic variance is additive
  70. If dominant allele is common and mating is random:
    • Copies occur in both homozygous and heterozygous genotypes
    • Copies in heterozygous genotpes contribute twice as much to populational variation as do copies in homozygotes
    • Produces some non-additive genetic variance
  71. Used to measure heritability without measured genotype approaches
    Covariance between parents and offspring
  72. Half of the additive genetic variance
    Covariance between parents and offspring
  73. Standardized covariance that varies from -1 to +1
    Correlation coefficient
  74. Disease that is genetically transmitted but not heritable
    Tay-Sachs Disease
  75. HbS allele is necessary but not sufficient for this disease
    Sickle cell anemia
  76. Often has no discrete alterative categories and no single gene necessary or sufficient to produce it
    Heritable phenotype
  77. Correlation coefficient between parent and offspring is greater than or less than correlation between siblings?
    Less than
  78. Relation between correlation between parent and offspring and heritability
    Correlation between parent and offspring is equal to half of heritability
  79. Locus whose variation contributes to population variation of a continuously varying phenotype
    Quantitative Trait Locus (QTL)
  80. Saturated, genome-wide linkage maping with SNP markers every 10 cM throughout genome
    Genome scan
  81. Used in a genome scan to mark an entire genome in 10 cM intervals
  82. Allows genome scans to identify where QTLs occur in a genome but can be misleading in identifying which variable site within a locus actually causes phenotypic variation
    Linkage disequilibrium
  83. Use haplotype tree to test SNP sites for influence on a disease phenotype
    Tree scan
  84. Non-additive genetic variance at the population level arising from interactions among genotypes at different loci
    Epistatic variance
  85. Mendelian epistasis is necessary but not sufficient for this
    Epistatic variance
  86. This is necessary but not sufficient for epistatic variance
    Mendelian epistasis
  87. An evolutionary force that causes many small changes
  88. An evolutionary force due to random changes in allele frequency
    Genetic drift
  89. An evolutionary force that is associated with finite population size (sampling error)
    Genetic drift
  90. 5 Properties of Genetic Drift
    • No Direction
    • Cumulative
    • Strength is inversely proportional to twice the population size
    • Can lead to loss of alleles
    • Isolated demes become genetically differentiated
  91. Populational parameter that permits SNP markers in a genome scan to identify chromosomal regions that contribute to variation in a quantitative phenotype
    Linkage disequilibrium
  92. Features substrate neutrality, underlying mindlessness and guaranteed results
    Algorithm (Dennett)
  93. Helps to reconcile Mendelian heredity and continuously varying phenotypes
    Polygenic inheritance
  94. Fate of alternative forms of genes or gene combinations over space and time in a reproducing population
    Genetic evolution