K
BIO 351 FINAL EXAM STUDY
C
GUIDE QUESTIONS AND
LO
CORRECT DETAILED /
YC
VERIFIED ANSWERS LATEST
UPDATE
D
U
ST
,Dobzhansky-Muller Model - ANS - gradual breakdown of reproductive compatibility
- build-up of epistatic incompatibilities in allopatry
- mechanisms evolve easily with no gene flow
- become increasingly difficult to evolve in situations with more migration
- build up is almost inevitable in pure allopatry given enough time, but the conditions for
reproductive isolation to evolve in sympatry are much narrower
Rhagoletis pomonella - ANS - apple maggot fly
- native to most of Eastern North America
- specialized in infesting hawthorn fruit
K
- 4 different paired sympatric populations
- life history timing: height of mating (highest fitness) for summer months corresponds with
domestic apple season and mating in fall months corresponds with hawthorn season
C
- codominance leads to both apples and hawthorns to be generated from a crossbreed
response of F1 hybrids from 3 sympatric sites - ANS - F1 hybrids completely fail to respond to
LO
either apple or hawthorn blends
- hybrids unfit
why are hybrids unfit? - ANS - insects have to navigate a chemically noisy world, making
decisions based on complex blends of volatiles
YC
- find the right host plant while avoiding bad host plants that might smell similar
- multiple genes involved in apple and hawthorn genotypes so hybrid has combination of these
genes
post zygotic isolation in Rhagoletis - ANS - the behavioral isolating mechanism is driven by a
combination of volatile preferences and avoidance loci (avoidance loci tend to mask preference
D
alleles)
- this interaction = epistatic
- even apart from epistatic incompatibilities, the most effective isolating mechanisms will often
U
be epistatic because intermediate genotypes find themselves in fitness valleys
adaptive radiation - ANS - an evolutionary pattern in which many species evolve from a single
ST
ancestral species
- the divergence of a clade into populations adaptive to many ecological niches
- caught in the early stages for apple maggot story
speciation - ANS - interface between micro and macroevolution
- variation gives rise to differences in appearances within species
- as a result of different environmental conditions, certain phenotypes may have higher fitness
- over time, shifts towards opposite ends of phenotypic variation leads to distinction of new
species
microevolution - ANS - change in allele frequencies in a population over generations
, - concerns evolutionary processes within populations
macroevolution - ANS - large-scale evolutionary changes that take place over long periods of
time
- evolution is an on-going process
- it's been taking place well over 3 billion years
- how have "mechanisms of evolution" played out in the long run
- concerns evolutionary change above the species level
senescence - ANS - deteriorative changes that occur in an individual with increasing age
K
- decline in age-specific survival probability
- decline in age-specific reproductive rates
C
life history evolution - ANS - age-specific probabilities of survival and reproduction that are
characteristic of a species
- relate to the pattern of investment an organisms makes in growth and reproduction
LO
- including age at first reproduction, the duration of reproductive periods, number and size and
offspring, lifespan
aging as an evolutionary problem - ANS - senescence inherently involves decreased survival
and/or reproduction
YC
- ubiquitous in nature (aging occurs across species)
- however there is both variation among species (different lifespans) and within species in the
aging process
variation in aging within species - ANS - life expectancy in humans has increased significantly
from the 1800s to present
D
- life expectancy also varies as a result of country GDP
+ some countries experience higher life expectancy than other in countries with the same GDP
U
lifespan v. life expectancy - ANS - lifespan = how long an organism survives
- life expectancy = statically derived demographic measure of the amount of time you likely have
left at a given age
ST
low life expectancies in human history aren't necessarily driven by low lifespans - ANS - ex.
life expectancy was ~30 for a lot of human history, does that mean this age was considered
elderly?
- No. it just means that early mortality was much higher. In most of these cases, if you made it to
adulthood, you were still expected to live into your 60s
why does our fitness decrease as we get older? - ANS - purely physiological "rate-of-living
theory"
- evolutionary perspective
BIO 351 FINAL EXAM STUDY
C
GUIDE QUESTIONS AND
LO
CORRECT DETAILED /
YC
VERIFIED ANSWERS LATEST
UPDATE
D
U
ST
,Dobzhansky-Muller Model - ANS - gradual breakdown of reproductive compatibility
- build-up of epistatic incompatibilities in allopatry
- mechanisms evolve easily with no gene flow
- become increasingly difficult to evolve in situations with more migration
- build up is almost inevitable in pure allopatry given enough time, but the conditions for
reproductive isolation to evolve in sympatry are much narrower
Rhagoletis pomonella - ANS - apple maggot fly
- native to most of Eastern North America
- specialized in infesting hawthorn fruit
K
- 4 different paired sympatric populations
- life history timing: height of mating (highest fitness) for summer months corresponds with
domestic apple season and mating in fall months corresponds with hawthorn season
C
- codominance leads to both apples and hawthorns to be generated from a crossbreed
response of F1 hybrids from 3 sympatric sites - ANS - F1 hybrids completely fail to respond to
LO
either apple or hawthorn blends
- hybrids unfit
why are hybrids unfit? - ANS - insects have to navigate a chemically noisy world, making
decisions based on complex blends of volatiles
YC
- find the right host plant while avoiding bad host plants that might smell similar
- multiple genes involved in apple and hawthorn genotypes so hybrid has combination of these
genes
post zygotic isolation in Rhagoletis - ANS - the behavioral isolating mechanism is driven by a
combination of volatile preferences and avoidance loci (avoidance loci tend to mask preference
D
alleles)
- this interaction = epistatic
- even apart from epistatic incompatibilities, the most effective isolating mechanisms will often
U
be epistatic because intermediate genotypes find themselves in fitness valleys
adaptive radiation - ANS - an evolutionary pattern in which many species evolve from a single
ST
ancestral species
- the divergence of a clade into populations adaptive to many ecological niches
- caught in the early stages for apple maggot story
speciation - ANS - interface between micro and macroevolution
- variation gives rise to differences in appearances within species
- as a result of different environmental conditions, certain phenotypes may have higher fitness
- over time, shifts towards opposite ends of phenotypic variation leads to distinction of new
species
microevolution - ANS - change in allele frequencies in a population over generations
, - concerns evolutionary processes within populations
macroevolution - ANS - large-scale evolutionary changes that take place over long periods of
time
- evolution is an on-going process
- it's been taking place well over 3 billion years
- how have "mechanisms of evolution" played out in the long run
- concerns evolutionary change above the species level
senescence - ANS - deteriorative changes that occur in an individual with increasing age
K
- decline in age-specific survival probability
- decline in age-specific reproductive rates
C
life history evolution - ANS - age-specific probabilities of survival and reproduction that are
characteristic of a species
- relate to the pattern of investment an organisms makes in growth and reproduction
LO
- including age at first reproduction, the duration of reproductive periods, number and size and
offspring, lifespan
aging as an evolutionary problem - ANS - senescence inherently involves decreased survival
and/or reproduction
YC
- ubiquitous in nature (aging occurs across species)
- however there is both variation among species (different lifespans) and within species in the
aging process
variation in aging within species - ANS - life expectancy in humans has increased significantly
from the 1800s to present
D
- life expectancy also varies as a result of country GDP
+ some countries experience higher life expectancy than other in countries with the same GDP
U
lifespan v. life expectancy - ANS - lifespan = how long an organism survives
- life expectancy = statically derived demographic measure of the amount of time you likely have
left at a given age
ST
low life expectancies in human history aren't necessarily driven by low lifespans - ANS - ex.
life expectancy was ~30 for a lot of human history, does that mean this age was considered
elderly?
- No. it just means that early mortality was much higher. In most of these cases, if you made it to
adulthood, you were still expected to live into your 60s
why does our fitness decrease as we get older? - ANS - purely physiological "rate-of-living
theory"
- evolutionary perspective
