Bio 101- Exam 1 Review

to establish that evolution by natural selection is operating in a population, one must demonstrate---

-variability for a trait -heritability of that trait -differential reproductive success based on that trait

because it is possible for a female to mate with multiple males, any of whom could be the father, male mammals and birds will always

have some degree of paternity uncertainty

why do human taste preferences exist?

human feeding choices influence energy intake and, consequently, fitness

assume that you carry an allele, R, that causes you to help individuals to whom you are not related. This help increases their fitness and decreases yours. The frequency of allele R may still increase in the population

if individuals you help are likely to return the favor and help you at some point in the future

natural selection results from interactions between

individual organisms and their environment

behaviors that do not require environmental input for their development are called

instincts

evolution

is responsible for the increase in occurrence of antibiotic-resistant bacteria

which of the following is the best way to distinguish male from female

male produce motile gametes

adaptation shaped by natural selection

may be out of date, having been shaped in the past under conditions that differ from those in the present

effect of migration of individuals into a population

migration of individuals into a population generally increases the genetic variability within a population

in a species such as pigeons, in which males are almost indistinguishable in appearances from females, the most likely mating system is

monogamy

in a polyandrous mating system

multiple males tend to mate with the same female

the origin of all genetic variation is

mutation

evolution occurs

only via natural selection, genetic drift, migration, or mutation

from an evolutionary perspective, behavior can best be viewed as

part of the phenotype

most mutations are

random with respect to the environmental needs of the organism in which the mutation takes place

mate guarding is a reproductive tactic that functions to

reduce paternity uncertainty

kin selection

selection for a behavior that raises an individual's own chances of survival or reproduction, as well as those of a related individual

when a group of individuals colonizes a new habitat, the event is likely to be an evolutionary event because:

small founding populations are rarely genetically representative of the initial population

Many mosquito populations today are resistant to pesticides that were historically effective. This pesticide resistance arose in these populations because

some individuals were resistant to the pesticides before they were used, and those mosquitoes were more likely to survive and reproduce

from an evolutionary perspective, behavior can be viewed best as

some that is too complex to arise through natural selection

natural selection decreases genetic variability in a population. this statement is-

sometimes correct, especially in cases of stabilizing selection

natural selection can only act on traits

that are heritable

in a population in which a trait is exposed to stabilizing selection over time

the average value for the trait stays approximately the same and the variation for the trait decreases

When a sudden change in the environment, such as a flood or fire, reduces the size of a population the survivors' collective gene pool will be only a limited representation of what was present before the disaster. This phenomenon is call-

the bottleneck effect

during gene flow, where do the genes flow to?

the genes flow into and out of the population due to migration of individuals from one population to another

which of the following is the best measure of an organism's fitness

the number of fertile offspring it produces

an animal will preferentially feed on

the prey that provide the most energy relative to effort

a gene pool consists of

the total of all alleles present in a population

if you find a species of fish in which males are much more brightly colored and larger than females, what might you infer about their mating system

they are polygynous

You are studying a population of American robins, Turdus migratorius, in which approximately 2% of all individuals carry a recessive allele for leucistic (unusually white) coloration. The population suddenly expands when an influx of robins arrives during spring migration, and the frequency of the leucistic allele drops to only 1.5%. Has evolution occurred in the robin population in your study area?

yes, because allele frequencies in the population have changed over time

which of the following is an example of a female mating with a male only after submitting him to a courtship ritual

a female bower bird will mate with a male only after inspecting the small thatched structure he has built for her

population

a group of individuals of the same species that live in the same general location and have the potential to interbreed

a fossil is defined most broadly as

any preserved remnant or trace of an organism from the past

polygynous species

are usually sexually dimorphic, with males larger and more highly ornamented

what is the difference between artificial selection and natural selection

artificial selection requires human intervention, whereas natural selection does not

which of the following best explains why genetic bottlenecks and founder effects are evolutionarily important

both result in small populations that are influenced more by genetic drift

___________ selection favors organisms with phenotypes that are at one extreme relative to the average phenotype

directional

under the right conditions, which type of selection is most likely to lead to the formation of new species

disruptive selection