UIowa Evolution Exam 1 – Study Guide & Revision Notes
3 Uses of phylogenetic trees - correct answer ✔✔1) Shows evolutionary patterns (how species,
individuals, lineages, viruses, etc. are related)
2) Supports (or refutes) a hypothesis (Speciation, coevolution, selection, etc.)
3) Helps to make predictions (Where we will find fossils, etc.)
Character - correct answer ✔✔A distinct, heritable trait
Character state - correct answer ✔✔Current status (present, absent, A or C, etc) of character
Homology - correct answer ✔✔Similarity of specific characters because of shared ancestry
Synapomorphy - correct answer ✔✔Shared derived character state
Shows shared ancestor
Unit of mutation rate - correct answer ✔✔mutations/bp/generation
(mult by genome size of a species to get mutations/genome/generation)
Expected heterozygosity (Hexp) - correct answer ✔✔Proportion of heterozygotes that would be
seen in an ideal population of randomly mating diploids
2 x frep (A1) x freq (A2) = 2pq
, nucleotide diversity (pi) - correct answer ✔✔the Hexp (2pq) site by site and averaged across the
whole sequence (L) multiplied by (n/n-1)
Nucleotide heterozygosity (theta) - correct answer ✔✔# of polymorphisms in a sample divided
by L x summation of (1/i) for 1 - (n-1)
Does not account for frequency of SNPs (2pq)
Average fitness - correct answer ✔✔(D x w11) + (H x w12) + (R x w22)
Expected genotype frequencies after selection - correct answer ✔✔ex. D' = (D x w11) / average
w
Directional selection fitness equations - correct answer ✔✔w11 = 1, w12 = 1-hs, w22 = 1-s
Selection coefficient (s) - correct answer ✔✔Difference between the fitness of a reference
genotype (highest) and a given genotype (lowest)
How strong selection is with 1 being lethal
Degree of dominance (h) - correct answer ✔✔The factor by which s is reduced in heterozygotes
relative to the worst homozygote
How much the heterozygote is affected by the deleterious allele. If H=1, bad allele is dominant
for fitness (fast evolution). If H=0, bad allele is recessive for fitness (slow evolution). If H>0 and
<1, the bad allele is semidominant.
Null Hypothesis (H0) - correct answer ✔✔This locus is at HWE in this population
3 Uses of phylogenetic trees - correct answer ✔✔1) Shows evolutionary patterns (how species,
individuals, lineages, viruses, etc. are related)
2) Supports (or refutes) a hypothesis (Speciation, coevolution, selection, etc.)
3) Helps to make predictions (Where we will find fossils, etc.)
Character - correct answer ✔✔A distinct, heritable trait
Character state - correct answer ✔✔Current status (present, absent, A or C, etc) of character
Homology - correct answer ✔✔Similarity of specific characters because of shared ancestry
Synapomorphy - correct answer ✔✔Shared derived character state
Shows shared ancestor
Unit of mutation rate - correct answer ✔✔mutations/bp/generation
(mult by genome size of a species to get mutations/genome/generation)
Expected heterozygosity (Hexp) - correct answer ✔✔Proportion of heterozygotes that would be
seen in an ideal population of randomly mating diploids
2 x frep (A1) x freq (A2) = 2pq
, nucleotide diversity (pi) - correct answer ✔✔the Hexp (2pq) site by site and averaged across the
whole sequence (L) multiplied by (n/n-1)
Nucleotide heterozygosity (theta) - correct answer ✔✔# of polymorphisms in a sample divided
by L x summation of (1/i) for 1 - (n-1)
Does not account for frequency of SNPs (2pq)
Average fitness - correct answer ✔✔(D x w11) + (H x w12) + (R x w22)
Expected genotype frequencies after selection - correct answer ✔✔ex. D' = (D x w11) / average
w
Directional selection fitness equations - correct answer ✔✔w11 = 1, w12 = 1-hs, w22 = 1-s
Selection coefficient (s) - correct answer ✔✔Difference between the fitness of a reference
genotype (highest) and a given genotype (lowest)
How strong selection is with 1 being lethal
Degree of dominance (h) - correct answer ✔✔The factor by which s is reduced in heterozygotes
relative to the worst homozygote
How much the heterozygote is affected by the deleterious allele. If H=1, bad allele is dominant
for fitness (fast evolution). If H=0, bad allele is recessive for fitness (slow evolution). If H>0 and
<1, the bad allele is semidominant.
Null Hypothesis (H0) - correct answer ✔✔This locus is at HWE in this population
