BIOL 2200 Final Exam UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS
Evolution - CORRECT ANSWER descent with modification: gradual accumulation of
diverse modifications/adaptations that fit animals to a specific way of life - descent of all
organisms from ancestor of remote past
Change in species/population over time; at microevolutionary level, change in gene
frequencies of a population from generation to generation
Common ancestors across groups but change in genetic composition of a population over
time (from generation to generation)
Evolution = both a pattern and a process
Darwin - slow and subtle processes may produce substantial biological change
NOTE: INDIVIDUALS DO NOT EVOLVE - POPULATION evolves over time
VARIATION = key to evolution!!
Heritability - CORRECT ANSWER traits passed on over time
Natural selection - CORRECT ANSWER MAIN MECHANISM FOR EVOLUTION.
Individuals with certain inherited traits tend to survive and reproduce at higher rates than
other individuals because of those traits
Darwin's observations
> many offspring are produced, not all the same
> traits vary among individuals in population, may be heritable
,> some heritable traits give individuals an advantage in environment
> advantageous traits->more offspring->more common appearance of traits due to fitness
Development of Theory of Evolution - CORRECT ANSWER aristotle (BCE) - idea of
fixed, hierarchal structure of nature (higher order vs lower order), chain of being, indiv. Fixed
in time & unchanging
Lamarck - first introduced idea of changing organisms over time - first idea of
adaptation...based on traits that are useful/kept vs un-useful and thus not being passed on
Weismann - acquired traits not passed down to offspring
Darwin - descent w/modification, on the origin of species (1859); studied artificial selection
in pigeons; refuted Lamarck's ideas (both useful and useless traits can still be inherited -
useless ones not necessarily lost). VARIATION = KEY TO EVOLUTION
OVERALL, up until Lamarck, people thought species were static (unchanging)
Key examples of natural selection - CORRECT ANSWER - Galapagos finches - beak
size - feeding differences
- beach mice - coat color - survival advantage based on where live
- soapberry bugs beak length changes based on where seed in fruit is
- threespine sticklebacks: differences in armor based on habitat
- trout in lake Washington - environmental change leads to natural selection - lake cleanup
- antibiotic resistance (MRSA, TB)
- pesticide & herbicide resistance in plants
Sticklebacks - CORRECT ANSWER marine fish more armed than freshwater fish b/c
more predators (key example of natural selection/adaptation/evolution over time)
2 ecomorphs (limnetic and benthic) live in SAME LAKE but rarely interbreed
,> diff species - live in same lake but rarely interbreed b/c of spatial difference in habitats but
still sympatric speciation b/c no physical barrier exists
Homology - CORRECT ANSWER similarity in traits due to common ancestry
(anatomical, molecular)
May be different forms and functions, but common trait/structure overall.
(ex): similar bones in forearm of human cat, whale and bat - but different functions. Indicates
common ancestor
Convergence - CORRECT ANSWER similar form and function (common phenotype)
due to similar environment. May NOT necessarily have similar lines in . TREE
(ex): echidna vs hedgehog, shark vs dolphin
** similar to/essentially same ass homoplasy
3 mechanisms > evolution - CORRECT ANSWER 3 that lead to MOST altering of
allele frequencies & cause most evolutionary change
(1) natural selection - favors some individuals based on certain traits
(2) genetic drift - allele frequency may fluctuate unpredictable from one generation to next
(smaller populations)
> founder effect, bottleneck effect
(3) gene flow: transfer of alleles into or out of a population due to movement of fertile
individuals or their gametes
Genetic drift - CORRECT ANSWER chance events that alter allele frequencies
, (1) founder effect: small group of individuals becomes isolated from larger population,
establishes new population whose gene pool differs from source population (ex: storm blows
members of population to new island)
(2) bottleneck effect: severe drop in population size - may lead to lower genetic variation
*LARGEST EFFECT ON SMALL POPULATIONS - allele may be over- or
underrepresented in next generation
Gene flow - CORRECT ANSWER transfer of alleles between populations due to
movement of fertile individuals or their gametes. Reduction of genetic differences between
populations
Gene pool - CORRECT ANSWER all copies of all alleles at every locus in all
members of a population
Hardy-weinberg principle/equilibrium - CORRECT ANSWER indicates that
population is unchanging/not evolving
Frequencies of A1 and A2 given by p and q
Key idea - to find "likelihood of" having two alleles, multiply their two frequencies p and q
together. The total of all of these possibly frequencies will add up to 1
Ex, A1 (p=0.7) and A2 (p=0.3) you can calculate all possibilities and they will add up to 1
ASSUMPTIONS:
- no mutations present
- mating is random (no preference)
- no natural selection
QUESTIONS AND CORRECT ANSWERS
Evolution - CORRECT ANSWER descent with modification: gradual accumulation of
diverse modifications/adaptations that fit animals to a specific way of life - descent of all
organisms from ancestor of remote past
Change in species/population over time; at microevolutionary level, change in gene
frequencies of a population from generation to generation
Common ancestors across groups but change in genetic composition of a population over
time (from generation to generation)
Evolution = both a pattern and a process
Darwin - slow and subtle processes may produce substantial biological change
NOTE: INDIVIDUALS DO NOT EVOLVE - POPULATION evolves over time
VARIATION = key to evolution!!
Heritability - CORRECT ANSWER traits passed on over time
Natural selection - CORRECT ANSWER MAIN MECHANISM FOR EVOLUTION.
Individuals with certain inherited traits tend to survive and reproduce at higher rates than
other individuals because of those traits
Darwin's observations
> many offspring are produced, not all the same
> traits vary among individuals in population, may be heritable
,> some heritable traits give individuals an advantage in environment
> advantageous traits->more offspring->more common appearance of traits due to fitness
Development of Theory of Evolution - CORRECT ANSWER aristotle (BCE) - idea of
fixed, hierarchal structure of nature (higher order vs lower order), chain of being, indiv. Fixed
in time & unchanging
Lamarck - first introduced idea of changing organisms over time - first idea of
adaptation...based on traits that are useful/kept vs un-useful and thus not being passed on
Weismann - acquired traits not passed down to offspring
Darwin - descent w/modification, on the origin of species (1859); studied artificial selection
in pigeons; refuted Lamarck's ideas (both useful and useless traits can still be inherited -
useless ones not necessarily lost). VARIATION = KEY TO EVOLUTION
OVERALL, up until Lamarck, people thought species were static (unchanging)
Key examples of natural selection - CORRECT ANSWER - Galapagos finches - beak
size - feeding differences
- beach mice - coat color - survival advantage based on where live
- soapberry bugs beak length changes based on where seed in fruit is
- threespine sticklebacks: differences in armor based on habitat
- trout in lake Washington - environmental change leads to natural selection - lake cleanup
- antibiotic resistance (MRSA, TB)
- pesticide & herbicide resistance in plants
Sticklebacks - CORRECT ANSWER marine fish more armed than freshwater fish b/c
more predators (key example of natural selection/adaptation/evolution over time)
2 ecomorphs (limnetic and benthic) live in SAME LAKE but rarely interbreed
,> diff species - live in same lake but rarely interbreed b/c of spatial difference in habitats but
still sympatric speciation b/c no physical barrier exists
Homology - CORRECT ANSWER similarity in traits due to common ancestry
(anatomical, molecular)
May be different forms and functions, but common trait/structure overall.
(ex): similar bones in forearm of human cat, whale and bat - but different functions. Indicates
common ancestor
Convergence - CORRECT ANSWER similar form and function (common phenotype)
due to similar environment. May NOT necessarily have similar lines in . TREE
(ex): echidna vs hedgehog, shark vs dolphin
** similar to/essentially same ass homoplasy
3 mechanisms > evolution - CORRECT ANSWER 3 that lead to MOST altering of
allele frequencies & cause most evolutionary change
(1) natural selection - favors some individuals based on certain traits
(2) genetic drift - allele frequency may fluctuate unpredictable from one generation to next
(smaller populations)
> founder effect, bottleneck effect
(3) gene flow: transfer of alleles into or out of a population due to movement of fertile
individuals or their gametes
Genetic drift - CORRECT ANSWER chance events that alter allele frequencies
, (1) founder effect: small group of individuals becomes isolated from larger population,
establishes new population whose gene pool differs from source population (ex: storm blows
members of population to new island)
(2) bottleneck effect: severe drop in population size - may lead to lower genetic variation
*LARGEST EFFECT ON SMALL POPULATIONS - allele may be over- or
underrepresented in next generation
Gene flow - CORRECT ANSWER transfer of alleles between populations due to
movement of fertile individuals or their gametes. Reduction of genetic differences between
populations
Gene pool - CORRECT ANSWER all copies of all alleles at every locus in all
members of a population
Hardy-weinberg principle/equilibrium - CORRECT ANSWER indicates that
population is unchanging/not evolving
Frequencies of A1 and A2 given by p and q
Key idea - to find "likelihood of" having two alleles, multiply their two frequencies p and q
together. The total of all of these possibly frequencies will add up to 1
Ex, A1 (p=0.7) and A2 (p=0.3) you can calculate all possibilities and they will add up to 1
ASSUMPTIONS:
- no mutations present
- mating is random (no preference)
- no natural selection
