3. Adaptions and Natural Selection

The flashcards below were created by user myk5437 on FreezingBlue Flashcards.

  1. Natural selection
    • nature chooses the designs that work best in any given circumstance and therefore shapes organisms to meet the challenges they face
    • **reproduction!
  2. adaptions
    favorable traits that accumulate over time
  3. gametes
    sex cells
  4. diploidy
    carrying two copies of each gene
  5. haploid cells
    half of the chromosomes
  6. alleles
    alternative versions of a gene that can occur at the same locus
  7. homozygous
    two alleles match at a locus
  8. heterozygous
    two alleles differ at a locus
  9. how do genes affect phenotypes
    by coding for proteins
  10. heritability depends on... 3
    • 1. phenotypic variation
    • 2. genetic variation
    • 3. environmental variation
  11. 0 heritiability means
    all variation is due to environment. none of the differences are caused by genetic differences.
  12. constraints on NS perfection
    • cost - it must pay for itself in reproductive success
    • variation - selection only chooses what already exists
    • time - if environment changes too quickly, NS cant keep up.
  13. facultative adaptions
    • track environmental changes and adjust phenotype accordingly
    • ex. pupil size
  14. reaction norm
    a particular pattern of response to environment
  15. obligate adaptions
    adaptions that resist environmental influence
  16. susceptibilites
    occur when the facultative responses of an organism are overwhelmed
  17. heritability of facultative adaptions
    low, they are environmental responses.
  18. how does selection shape facultative responses?
    • through the expression, through reaction norms.
    • reaction norms can be highly variable
  19. levels of selection
    • gene¬†
    • individual¬†
    • group
  20. the front door to the next generation
    a gene that increases the fitness of its average carrier will eventually spread.
  21. the back door to the next generation
    a gene could spread if it caused its bearer to decrease their own fitness in order to increase the reproduction of other bearers of the same gene
  22. Hamilton's Kin selection theory
    back door to the next generation
  23. Hamiltons rule
    • rb>c
    • benefit to recipient X probability that recipient and altruist have the same gene > cost to altruist
  24. inclusive fitness
    = organisms reproductive success + organisms effect on reproduction of its relatives.
  25. altruist behavior is likely to occur when 1 2 3
    • 1. cost is low
    • 2. benefit is large
    • 3. high coefficient of relatedness (r)
Card Set
3. Adaptions and Natural Selection
dr. putts
Show Answers