{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Selection-Competition and Predation

Selection-Competition and Predation - SELECTION How do...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
SELECTION ??? How do measure such a concept Based on non-random breeding and on “fitness” Fitness = W = ability of some genotypes to leave more offspring to the next generation When W = 1 indicates best fit genotype (all offspring ) When W = 0 lethal genotype ( 0 offspring) When W = 0.5 genotype leaves ½ offspring for next generation
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
SELECTION COEFFICIENT(S) Measure of the intensity of selection S = 1-W Calculation of fitness W = Reproductive rate of unfavored alleles reproductive rate of favored alleles Consider the condition that for “normals” W = 1
Background image of page 2
A. Selection against dominant allele Genotypes AA Aa aa Dominant genes can be good, bad or neutral Most disadvantageous dominant lethal time of lethal events effects W Environmental event may change fitness of dominant—could disappear in single generation Partial selection against dominants
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
A case of Dwarfism Achondroplastic dwarfs produce 19.6% offspring as normal population (no differences in survival) Dwarfism is a dominant allele W = 19.6/100 = 0.196 fitness value Since S = 1-W S = 0.804 selection coefficient against dwarfs i.e. 80.4% of the expected offspring are removed solely by selection
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}