Evolution 2Evolution 2Dr. James . Whitfield, Ph.D

Hardy-Weinberg Hardy-Weinberg EquilibriumEquilibriumFive Factors are known to effect

HWE, these include

Hardy-Weinberg Hardy-Weinberg EquilibriumEquilibriumFive Factors are known to effect

HWE, these includeGene migration or gene flow

Hardy-Weinberg Hardy-Weinberg EquilibriumEquilibriumFive Factors are known to effect

HWE, these includeGene migration or gene flowGenetic drift

Hardy-Weinberg Hardy-Weinberg EquilibriumEquilibriumFive Factors are known to effect

HWE, these includeGene migration or gene flowGenetic driftMutation

Hardy-Weinberg Hardy-Weinberg EquilibriumEquilibriumFive Factors are known to effect

HWE, these includeGene migration or gene flowGenetic driftMutationGenetic recombination

Hardy-Weinberg Hardy-Weinberg EquilibriumEquilibriumFive Factors are known to effect

HWE, these includeGene migration or gene flowGenetic driftMutationGenetic recombinationNatural selection

Founder EffectFounder EffectThe founder effect can result if

genes/alleles migrate from one population to another. Genes are lost in the original and added to the new population. If this migration happens multiple times it is called gene flow. If the same changes occur by chance it is called genetic drift. In any of these cases if the change is substantial enough speciation may occur and these individuals will become the founders of future generations

Founder EffectFounder EffectThe founder effect can also occur

as a result of a genetic bottleneck. A bottleneck can occur after a natural disaster or a severe disease that wipes out a significant percentage of the population. The surviving population may not represent the same genetic make-up as the original population hence the survivors become the founders of the new population

Founder EffectFounder EffectThe founder effect can also result

as a consequence of natural selection. Given enough time natural selection coupled with gene flow, variation due to recombination of genes, gene flow and genetic drift can all lead to speciation. Three different types of populations may occur, they are referred to as

StabilizingStabilizingStabilizing – in stabilizing

selection the average is favored and the extremes are tightened (less favorable) genetic diversity is decreased

Robin eggs and human baby weight, spider size

DirectionalDirectionalDirectional – in directional

selection both extremes are favored but at different times

Bird beaks, peppered moth

DisruptiveDisruptiveDisruptive – In disruptive

selection both extremes are favored at the same time. It is not good to be average. Two distinct populations form

Sea spongesRabbits