BIO2008: Lecture 4 0.0 / 5 ? BiologyLecture 4UniversityOther Created by: LMoneyCreated on: 10-05-14 20:14 what is the number for fitness usually between? 0-1 1 of 17 why is it RELATIVE fitness? it is relative to the fittest phenotype 2 of 17 at what level is fitness never measured? never at the level of the allele 3 of 17 what is the degree of dominance of an allele signified by? h 4 of 17 what is h when there is codominance? h=1/2 5 of 17 in what species do homozygotes have twice the fitness of heterozygotes? Drosophila melanogaster 6 of 17 in sickle cell anemia is the heterozygote fitter or less fit than the homozygote in areas with malaria? heterozygote is more fit 7 of 17 combining population genetic processes and looking at changes in allele frequencies: what is the weakest force? mutation, strongest force would be hard to predict 8 of 17 are most mutations disadvantageous or not? Most mutations are disadvantageous (90%), many are neutral (10%) and few are advantageous (1%) 9 of 17 what is outcrossing? opposite of inbreeding- introducing new genetic material into the breeding line 10 of 17 in outcrossing species, is there a large or small mutation load? considerable mutation load (around 1 per haploid human genome)- explains effects of inbreeding, most recessive alleles are at low frequencies 11 of 17 which processes are deterministic (theoretical- follow a law) and which are stochastic (actual- more realistic, with scatter) in population genetics? Deterministic: selection, mutation, migration Stochastic: random genetic drift 12 of 17 is selection more or less effective in small populations? less effective 13 of 17 are deleterious alleles more likely to be fixed in small or large populations? small populations 14 of 17 selection is weak relative to sampling, when what? 4 Ns 15 of 17 selection is strong, and will dictate allele frequencies, when? If 4 Ns >>1 16 of 17 what is an example of the interconnection between migration and selection? Blue ****. Evergreen Holm oak: lesser insect abundance Downy oaks: better reproduction because better synchronisation nest/food 17 of 17
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