Evol Bio Exam 2
In the coevolution of orchids and dupe wasps, natural selection favors which trait(s) in male dupe wasps?
Male dupe wasps become more discriminating once they learn the flower is a female wasp mimic.
Based on results in the Sandeep et al. 2013 paper, which illustrates there are still important levels of contemporary gene flow between some tiger reserves, what is the best approach conservation managers can take to sustaining the tiger populations of today (at least for those in this study)?
Manage the connected populations as a metapopulation with maintenance of intact-forested corridors to promote gene flow
describe the likely evolutionary steps that led to a complex eye like we see in humans?
a flat sheet of light-sensitive cells; light-sensitive cells in a cup; a pinhole camera without a lens; a pinhole camera with a lens
How does the term "lactase persistent" relate to the term "lactose tolerant"?
a lactase persistent person is lactose tolerant
In which population would a mutation for lactase-persistence be more likely to increase in frequency over time because of natural selection?
a population that raises wheat and sheep
In the study looking at shooting performance in NBA and WNBA players over the careers of these athletes, why is total scoring a particularly relevant metric in basketball for studying how aging may influence performance?
-All players and positions on the team are required to score in order for a team to be successful. -Age-related changes in whole-organism performance of players will be reflected by changes in scoring. -Scoring captures a range of performance traits and is therefore a useful proxy for whole-organism performance
Sexual selection differs from natural selection because
-Gender differences exist in the costs of reproductive effort. -Success is measure by number of matings obtained. -favors traits that increase mating success, not alway reproductive success.
In the basketball study, how did males and females differ in total scoring and which sex showed the largest effect of age on performance as measured by total points scored?
-Male scoring performance shows a marked effect of aging (scoring peaks around age 25), while women show little to no effect of aging on total scoring performance. -The biggest effect on differences in scoring performance among professional basketball players is attributable to sex; men score more points/min than women. -Women show more variance in total scoring performance than do men.
describe what we can determine about the evolution of the eye?
A variety of species exist that are likely to be similar to common ancestors whose eyes evolved to different degrees over time
Which discovery supports the hypothesis that evolution of the lactase-persistence trait was driven by the use of milk in pastoralist cultures?
Ancient pots used to hold milk are about the same age as the lactase-persistence mutations.
describe the origin of adaptations with new functions
Existing structures or molecules become molded by selection for new functions.
What did researchers discover about the genetic mutation causing lactase persistence?
It is found in a regulatory region (a "switch") upstream of the lactase gene.
In the basketball study, which sex showed a potential trade-off in performance allocation between the three scoring types? Compensation between scoring types involves which types of shooting?
Men; a switch from two-point to three-point shooting performance with age.
How could milk-drinking have provided strong favorable selection for lactase persistence?
Milk was safer to drink than water and reduced exposure to pathogens. Milk may have been a critical food source during times of famine. Milk is protein and fat-rich and therefore could have been an important, high-quality food source.
In the coevolution of orchids and dupe wasps, sexual selection favors which trait(s) in orchids and why?
Orchid flowers that best mimic female dupe wasps; increased pollination success.
Which of the following statements is FALSE? -Organisms can change their DNA in order to become better adapted to their environment. -Mutation must occur first, creating variation in the population, before natural selection can determine whether a trait is beneficial or not. -Mutations can be caused by physical or chemical factors, or even just mistakes made during DNA replication. -A new mutation may lead to a trait that could potentially be either harmful or beneficial, or make no difference at all.
Organisms can change their DNA in order to become better adapted to their environment.
Why are performance traits (e.g., sprint speed, swimming speed, endurance speed) likely targets of multi-locus natural selection?
Performance traits are generally encoded by many genes and closely tied to fitness of an organism
A giraffe and a mouse (both mammals) have the same number of vertebrae in their neck and spine. Which of the following accounts for this?
The vertebrae in their neck and spine are homologous because they share a common ancestor
Sharks (which are fish) and dolphins (which are mammals) are both shaped like a torpedo. Which of the following accounts for this?
Their shape arose through convergent evolution, since that shape is beneficial for animals living in the ocean
The enzyme lactase breaks the sugar lactose into which compound(s)?
galactose & glucose
In the Sandeep et al. 2013 paper, the authors found low but significant genetic differences (measured by FST) between the four tiger subpopulations. Which evolutionary force contributed most to these significant differences?
genetic drift
Selection favors which trait in professional basketball players and how is fitness measured for each player?
high scoring output; amount of salary earned
Natural selection does not always produce the perfect adaptation. For example, male barnacles (a sessile marine organism) have a penis and use internal fertilization during sexual reproduction. The enormously elongated penis found in male barnacles illustrates which type of constraint on adaptation?
historical constraint
In the Sandeep et al. 2013 paper, what did the authors hypothesize would be the difference between historical and contemporary levels of gene flow? Did their data support this hypothesis?
historical gene flow would be high and contemporary gene flow would be low; yes
Effective population size is almost always smaller than the census population size of a species, since it represents the individuals that contribute genes to the next generation. It can be calculated by the formula: Ne = (4NmNf)/(Nm+Nf). What do 'm' and 'f' represent and how do these values reflect the difference between effective population size and census population size?
m = males and f = females; demonstrate that effective population size is sensitive to differences in the number of reproductively active females and males
According to the video, how quickly could evolution take place, going from the simplest light-sensitive cells to a fully-functioning eye?
over the course of 400,000 generations
What does the wide variety of different types of animal eyes represent?
the intermediate forms that probably occurred in the common ancestors of today's animals