BIO 182 EXAM 2 WITH QUESTIONS AND
100% CORRECT ANSWERS|WELL
ILLUSTRATED AND WITH
VERIFICATIONS FROM EXPERT| 2025
NEW UPDATE.
Directional selection - answer ✔✔ a population's genetic variance shifts towards a new
phenotype when exposed to environmental changes (when a single phenotype is favored)
Line and equation of directional selection - answer ✔✔ linear line y=mx+c
Stabilizing selection - answer ✔✔ a decrease of a population's genetic variance when natural
selection favors an average phenotype and selects against extreme variation (intermediate
phenotypes are more fit than extreme ones)
Line and equation of stabilizing selection - answer ✔✔ quadratic (n-shaped) y=ax^2+bx+c
How do we know which selection (directional or stabilizing) is occuring? - answer ✔✔ the r^2
of a trendline (the highest number is the one with the best fit)
Heritability definition - answer ✔✔ a measure of how well differences in people's genes account
for differences in their traits
How might heritability change over time? - answer ✔✔ due to the possibility of the variance in
genetic values can change
Allopatric speciation - answer ✔✔ the physical isolation of a biological population by an
extrinsic barrier (geographic isolation)
Major differentiation mechanism by allopatric speciation - answer ✔✔ natural selection
Example of allopatric speciation - answer ✔✔ squirrels in the grand canyon
Sympatric speciation - answer ✔✔ evolution of new species from a single ancestral species
while living in the same habitat
Major differentiation mechanism of sympatric speciation - answer ✔✔ polyploidy
Examples of sympatric speciation - answer ✔✔ cultivated corn
100% CORRECT ANSWERS|WELL
ILLUSTRATED AND WITH
VERIFICATIONS FROM EXPERT| 2025
NEW UPDATE.
Directional selection - answer ✔✔ a population's genetic variance shifts towards a new
phenotype when exposed to environmental changes (when a single phenotype is favored)
Line and equation of directional selection - answer ✔✔ linear line y=mx+c
Stabilizing selection - answer ✔✔ a decrease of a population's genetic variance when natural
selection favors an average phenotype and selects against extreme variation (intermediate
phenotypes are more fit than extreme ones)
Line and equation of stabilizing selection - answer ✔✔ quadratic (n-shaped) y=ax^2+bx+c
How do we know which selection (directional or stabilizing) is occuring? - answer ✔✔ the r^2
of a trendline (the highest number is the one with the best fit)
Heritability definition - answer ✔✔ a measure of how well differences in people's genes account
for differences in their traits
How might heritability change over time? - answer ✔✔ due to the possibility of the variance in
genetic values can change
Allopatric speciation - answer ✔✔ the physical isolation of a biological population by an
extrinsic barrier (geographic isolation)
Major differentiation mechanism by allopatric speciation - answer ✔✔ natural selection
Example of allopatric speciation - answer ✔✔ squirrels in the grand canyon
Sympatric speciation - answer ✔✔ evolution of new species from a single ancestral species
while living in the same habitat
Major differentiation mechanism of sympatric speciation - answer ✔✔ polyploidy
Examples of sympatric speciation - answer ✔✔ cultivated corn
