biology test

what was so revolutionary about darwin and wallace's theory of evolution by natural selection?

variation and changes in population

what is probably the best explanation for the fact that antarctic penguins cannot fly although there is evidence that millions of years ago there ancestors could do so?

with smaller wings they could swim better and get more food

Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate?

reduced hybrid viability

explain the role that humans play in artificial selection

they get to pick which ones get to breed

According to the concept of punctuated equilibrium,

C) a new species accumulates most of its unique features as it comes into existence.

During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception?

Characteristics acquired during an organism's life are generally not passed on through genes.

directional selection

Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve

For a biologist studying a small fish population in the lab, which Hardy-Weinberg condition is easiest to meet?

gene flow

Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact?

a behavioral reproductive isolating mechanism

A population of organisms will not evolve if _____.

all individual variation is due only to environmental factors

a species may be reproductively isolated through which if the following causes?

anatomy, behavior, ecology,

Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution? A) The two species live at great distance from each other. B) The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical. C) The sizes of the structures in adult members of both species are similar in size. D) Both species are well adapted to their particular environments. E) Both species reproduce sexually.

b

the appearance of a fertile, polyploidy individual within a population of diploid organisms is a possible source of a new species. if this individual is capable of reproducing to form a new population. scientists would consider this to be an example of: A. allopatric speciation B. sympatric speciation C. polygenic speciation D. genetic drift E. hardy weinberg equilibrium

b- sympatric speciation

the difference in cricket calls among sympatric species of crickets are examples of A.habitat isolation B. temporal isolation C. physiological isolation D. behavioral isolation E. geographical isolation

behavioral isolation

which of these conditions are always true of populations evolving due to natural selection?

condition 1: the population must vary in traits that are heritable condition 2: some heritable traits must increase reproductive success

although the seal and the penguin both have streamlines, fish-like bodies with a layer of insulating fat, they arent closely related. this similarity results from A. convergent evolution B. adaptive radiation C. homologous evolution D. coevolution E. analogous evolution

convergent evolution

Currently the only predators of Galápagos marine iguanas are Galápagos hawks. Iguana body size is not correlated with risk of hawk predation, although small iguanas can sprint faster than large iguanas. If predators (for example, cats) that preferably catch and eat slower iguanas are introduced to the island, iguana body size is likely to _____ in the absence of other factors; the iguanas would then be under _____ selection.

decrease; directional

if a population is in hardy weinberg equilibrium then

it is not evolving and allele frequencies remain the same with each generation

in a very large population a quantitative trait has the following distribution pattern. if there is no gene flow the curve shifts to the left or right and the population size consequently increases over successive generations what is most likely occurring?

directional selection

the occurrence of large or small beak sizes among seed crackers in the absence of medium sized beaks is an example of

disruptive selection

in science, what is it meant by the word theory

explanation based on many observations

Fitness

fitness is the measure of contribution of a genotype to the gene pool of the next generation

Soon after the island of Hawaii rose above the sea surface (somewhat less than one million years ago), the evolution of life on this new island should have been most strongly influenced by _____.

founder effect

in a small group of people living in a remote area of kentucky there is a high incidence of blue skin. a condition that results from a variation in the structure of hemoglobin. all of the blue skinned residents can trace their ancestors to one couple who were among the original settlers of this region. this is an example of

founder effect

An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. The surviving population happens to have broader stripes, on average, than the initial population. If broadness of stripes is genetically determined, what effect has the ground-squirrel population experienced during the earthquake?

genetic bottleneck

changes in the frequency of alleles in a population caused by random chance events are

genetic drift

disruptive selection

goes up and down

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms?

habitat isolationism

in the hardy weinberg equation the term 2pq represents the frequency of what?

heterozygotes

the wing of a bat, the flipper of a whale, and the forelimb of a horse appear very different, yet detailed studies reveal the presence of the same basic bone pattern. these structures are examples of A. analogous structures B. homologous structures C. vestigial structures D. balanced polymorphism E. convergent evolution

homologous structures

in what ways is natural selection not similar to artificial selection?

humans choose whst survive

A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do not seem to be optimally arranged because

natural selection is generally limited to modifying structures that were present in previous generations and in previous species

For biologists studying a large flatworm population in the lab, which Hardy-Weinberg condition is most difficult to meet?

no mutations

What five conditions are needed to maintain genetic equilibrium?

no natural selection, no immigration, random mating, no mutations , large population

why is reproductive isolation important from an evolutionary standpoint?

not allowing interbreeding

what expression represents the frequency of the homozygous recessive genotype?

q2

the production of sterile mules by interbreeding between female horses and male donkeys is an example of

reduced hybrid fertility

Adult male humans generally have deeper voices than do adult female humans, which is the direct result of higher levels of testosterone causing growth of the larynx. If the fossil records of apes and humans alike show a trend toward decreasing larynx size in adult females and increasing larynx size in adult males, then

sexual dimorphism was developing over time in these species.

analogous

show convergent evolution

According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that

speciation occurred rapidly in geologic time

Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer, or more, than this have reduced fitness. Which of the following terms best describes this situation?

stabilizing selection

for some traits such as birth weight, natural selection favors individuals that are average and the extremes are selected against this is known as: A. diversifying selection B. directional selection C. adaptive radiation D. disruptive selection E. stabilizing selection

stabilizing selection

stabilizing selection

stays the same

Homologous

term used to refer to chromosomes in which one set comes from the male parent and one set comes from the female parent

what is the relationship between the wing of a bat and the wing of a bird?

they are homologous and analogous

Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?

they didn't need it and so it gave them more of an advantage not to have it