Adaptive Landscape


  • range of environmental conditions tolerated
    . . . can be broken into 2n+1 sub-ranges,
    . . . where n = number of genes or chromosomes.

  • with p = q:

    n = 1
    .25 .50 .25
    AA Aa aa
    n = 2
    .0625 .2500 .3750 .2500 .0625
    AAAA AAAa AAaa Aaaa aaaa
    n = 3
    .015625 .093750 .234375 .312500 .234375 .093750 .015625
    AAAAAA AAAAAa AAAAaa AAAaaa AAaaaa Aaaaaa aaaaaa

  • However, if p is not equal to q:

    n = 1
    p AA Aa aa q
    0.1 0.01 0.18 0.81 0.9
    0.2 0.04 0.32 0.64 0.8
    0.3 0.09 0.42 0.49 0.7
    0.4 0.16 0.48 0.36 0.6
    0.5 0.25 0.50 0.25 0.5
    0.6 0.36 0.48 0.16 0.4
    0.7 0.49 0.42 0.09 0.3
    0.8 0.64 0.32 0.04 0.2
    0.9 0.81 0.18 0.01 0.1


  • assumptions of the Hardy-Weinburg...
    . . 1) mating is random,
    . . 2) there is no selection,
    . . 3) there is no mutation,
    . . 4) there is no immigration nor emmigration, and
    . . 5) the population is arbitrarily large (infinite)
  • However, in the Real World, these five assumptions are not met;
    . .. so the task becomes estimating which of the five
    . . . has the most influence on the observed results.
    . . 1) if mating is non-random,
    . . . -is mathematically complex, or
    . . . . requires simulation studies
    . . 2) if there is selection,
    . . . -multiply the Hardy-Weinburg values by fitness
    . . . . {AA, Aa, aa} = {wAA*p2, wAa*2pq, waa*q2}
    . . 3) if there is mutation,
    . . . -is mathematically complex, or
    . . . . requires simulation studies
    . . 4) if there is immigration or emmigration, and
    . . . -is mathematically complex, or
    . . . . requires simulation studies
    . . 5) if the population is small (finite)
    . . . -requires simulation studies

  • We do not currently have the mathematics necessary to solve these problems.



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    © 2004 Prof. LaFrance, Ancilla College