Halfway- Quiz 7

Which of these humans is the "fittest" as far as natural selection is concerned?

A person with seven children who is killed in an automobile accident at age 40

______ is necessary for a population to survive over successive generations in response to environmental changes

Adaptation

the gene pool for a particular gene would include

All the alleles for a particular gene in all the individuals in the population

A population is

All the members of a species that live in a defined geographic region at the same time

for the Galapagos islands finch species Geospiza fortis, drought conditions produced a change in the population in which the next generation had larger beaks than the previous one. what produced this change in the population?

Birds with larger beaks had higher fitness, so they could produce more offspring that inherited the same trait

you are studying leaf size in a natural population of plants. the second season is particularly dry, and the following year the average leaf size in the population is smaller than the year before. but the amount of overall variation is the same, and the population size hasn't changed. Also, you've done experiments that show that small leaves are better adapted to dry conditions than are large leaves. which of the following has occurred?

Directional selection

The only known population of a reptile species lives on an African mountain. the population is relatively large, but no close relatives of this species are known. suppose you could stop all mutations within the population and all emigration out of this population. which statement best describes the probable future of this population?

Evolution will continue as natural selection acts on the genetic variability that exists in the population

How successful an individual is at passing on its genes to the next generation is known as:

Fitness

Shrews have been documented to travel across frozen lakes and establish populations on previously uninhabited islands, thus, the shrews have a limited gene pool. if this limited gene pool has allele frequencies that are very different from the allele frequencies found in the original population, then this would be an example of:

Founder effect

As world travel becomes easier and human populations intermix, the occurrence of what phenomenon will probably decrease?

Founder effect and genetic drift

Habitats set aside for endangered species are often sectioned into areas by roads, producing separate small populations. this causes problems in conservation because it reduces:

Gene flow between populations

The genetic makeup of any organism is its _______, which determines the physical characteristics called its ______

Genotype; phenotype

what is the difference between microevolution and macroevolution?

Microevolution describes changes within a population over a short period of time, whereas macroevolution describes larger changes such as the formation of new species over longer periods of time

Extreme hunting pressure has caused northern elephant seals to become less genetically diverse because of:

Population bottleneck

Imagine a population of monkeys in south America whose habitat has been reduced to the point where only 25 monkeys survive. this is an example of:

Population bottleneck

Which of the following statements about evolution is true

Populations evolve

The mate-attracting elaborate plumage of the male peacock is a result of

Sexual selection

Organisms that can interbreed with each other in nature but are genetically isolated from all other organisms are a

Species

How have caesarean sections and intensive neonatal (near-birth) medical care likely affected the average birth weight of amercian babies?

Stabilizing selection for birth weight no longer has as much of an influence

Disruptive selection operates whenever:

The extremes in a distribution of phenotypes are more fit than the average

If every sexually reproducing organism has only two alleles for each gene, how can there be a range of traits seen for a physical characteristic?

There can be more than two variations of a gene in a population

the term "natural selection" is not interchangeable with the term "evolution" because:

a population may evolve in ways other than through natural selection

At its most basic level, evolution is a

change in the frequency of alleles in a population

African black-bellied seedcracker finches have beaks that are either large or small. only large-beaked birds can crack open hard seeds, and small-beaked birds are more adept at handling small seeds. both have an advantage over intermediate-sized beaks. this is an example of a response to:

disruptive selection

A bottleneck may be dangerous to a population because

genetic variability is diminished

Mutations:

may do nothing, may be harmful, or may be beneficial

Which of the following is ultimately responsible for introducing new alleles into a population?

mutation

which of the following processes is not an agent of microevolution?

polygenic inheritance

Evolution by genetic drift is most obvious in

small populations

in order for migration to alter allele frequencies in another population:

the gene pool for the migrating population must be different from the population it is joining