CH. 14: Nonadaptive Evolution and Speciation: Urban Evolution

c

100 alleles out of a total of 1000 alleles would be an allele frequency of ______ a) .025 b) .05 c) 0.10 d) 1.00 e) 5

a

A male from species A mates with a female from species B. Male A's sperm swims and finds the egg, but the sperm is unable to penetrate the egg. This is an example of _____. a) gametic isolation b) hybrid infertility c) temporal isolation d) behavioral isolation e) ecological isolation

d

A population of aliens with similar genetics as humans is affected by a homozygous recessive condition known as "xbziq." This condition causes aliens to die at young ages because their digestive tracts are not able to effectively process food and obtain the necessary nutrients and energy from their diets. Approximately 2% of the newborn aliens have the xbziq condition. What is the carrier (heterozygote) frequency in the population? a) 2% b) 12% c) 14% d) 24% e) 86%

e

A population of ants on a median strip has 12 different alleles, A through L, of a particular gene. A drunk driver plows across the median strip, destroying most of the median strip and 90% of the ants. The surviving ants are homozygous for allele H. What is the impact of this event on the frequency of alleles A through L? a) The frequency of alleles A through L has changed drastically. b) All frequencies except H are reduced to zero. c) H frequency is now 1.0. d) This event is an example of a bottleneck effect. e) all of these

c

A scientist is studying a population of frogs in a pond. One day, copious amounts of pesticides are mistakenly released into the pond, killing off the majority of frogs (leaving only a few survivors). When the researcher revisits this pond five years later, he notices that the genetic diversity of this frog population has been dramatically reduced (compared to pre-pesticide levels). This is an example of _____. a) genetic drift b) nonadaptive evolution c) the bottleneck effect d) the founder effect e) none of these

e

A scientist studying a species of duck (species A) finds that this species only occurs in one small lake. Despite similar lakes that occur several hundred miles to the north, the other lakes are inhabited by a similar, but different duck species (species B). Which statement could be true? a)These two species mate at different times in the spring b)Species A may not have the ability to move to other lakes due to distance. c)The habitat of the northern lakes is not suitable for species A. d)In the other lake, species A may be outcompeted for food and shelter by the other species B. e) all of these

founder effect

A type of genetic drift in which a small number of individuals leaves one population and establishes a new population, resulting in lower genetic diversity than in the original population.

bottleneck

A type of genetic drift that occurs when a population is suddenly reduced to a small number of individuals, and as a result alleles are lost from the population.

c

An island has a population of 10,000 birds and has 80% gray individuals and 20% black individuals. Generation after generation, this ratio and population size remains basically the same. Which statement must be true about this population? a) it is undergoing natural selection b) Mutation created the black allele c) It is in Hardy-Weinberg equilibrium d) It does not have random mating of individuals e) all of these

nonadaptive evolution

Any change in allele frequency that does not by itself lead a population to become more adapted to its environment; the mechanisms of nonadaptive evolution are mutation, genetic drift, and gene flow.

c

Genetic diversity is measured in terms of allele frequencies (the relative proportions of a specific allele in a gene pool). A population of 3,200 mice has 4,200 dominant G alleles and 2,200 recessive g alleles. What is the frequency of recessive g alleles in the population? a) 0.01 b) 0.24 c) 0.34 d) 0.44 e) .53

e

Illegal hunting for ivory in Africa causes the deaths of 85% of an endangered elephant population. When considering the future survival of this population, which of these is a concern for scientists? a)an increase in the gene pool of recessive genes that may carry mutations b)decreased allelic diversity c)the ability of this population to exchange genes with neighboring populations d)inbreeding depression among survivors e)all of the above

c

Inbreeding ______ a)changes the allele frequency within a population b)increases the fertility rate in a population c)increases the proportion of homozygous individuals to heterozygous individuals d)is a direct result of the founder effect e)none of these

inbreeding

Mating between closely related individuals. does not change the allele frequency within a population, but it does increase the proportion of homozygous individuals to heterozygotes.

reproduction isolation

Mechanisms that prevent mating (and therefore gene flow) between members of different species.

b

Of the three populations described below, each of which has 1,000 members, which population has the highest genetic diversity? Note that only one gene is present and that this gene has three possible alleles: A1, A2, and a. Population A: 70% have an A1/A1 genotype, 25% have an A1/A2 genotype, and 5% have an A1/a genotype. Population B: 50% have an A1/A1 genotype, 30% have an A2/A2 genotype, 20% have an a/a genotype. Population C: 80% have an A1/A1 genotype, and 20% have an A1/a genotype. a) population A b) population B c) population C

a

Population genetics is the ______ a)study of the genetic makeup of populations and how it changes over time b)study of the allele frequency in a population c)study of the total collection of alleles in a population d)all of these e)none of these

a

Random changes in the allele frequency of a population between generations is the definition of a) genetic drift b) allele frequency c) evolutionary frequency d)bottleneck effect

e

The biological species concept defines a species as _____. a)a population that cannot interbreed with one another b)an interbreeding population in Hardy−Weinberg equilibrium c)individuals of a population that are fertile d)individuals that can breed in isolation e)members of a population that interbreed and produce fertile offspring

biological species concept

The definition of a species as a population whose members can interbreed to produce fertile offspring.

e

The feeding mouthparts of certain ants have undergone _____, such that different species' mouthparts are adapted for different food sources in their environment. a)mechanical isolation b) reproductive isolation c)ecological isolation d)a frameshift mutation e) natural selection

speciation

The genetic divergence of populations, leading over time to reproductive isolation and the formation of new species.

gene flow

The movement of alleles from one population to another, which may increase the genetic diversity of a population.

inbreeding depression

The negative reproductive consequences for a population associated with having a high frequency of homozygous individuals possessing harmful recessive alleles.

nonadaptive evolution

The other types of ______ are genetic drift and gene flow

Hardy-Weinberg Principle

The principle that, in a nonevolving population, both allele and genotype frequencies remain constant from one generation to the next.

allele frequency

The relative proportion of an allele in a population.

a

The study of mice in Manhattan, New York, offers a preview of what human activity will do to many other species. a)true b)false

population genetics

The study of the genetic makeup of populations and how the genetic composition of a population changes.

gene pool

The total collection of alleles in a population.

c

There are five characteristics that a population must have to NEVER experience a change in allele frequencies. Which of these is NOT one of them? a) no mutations b) a large population size c) natural selection d) no gene flow e) a lack of random mating

a

There are two populations of trout in an area, both of which inhabit a different lake. These lakes are connected by a stream, and trout from these two populations are able to breed with one another. This is an example of _____. a) gene flow b) genetic drift c) the bottleneck effect d) the founder effect e) none of these

b

Timber wolves in Wisconsin have gene pools with very few different alleles. Therefore, more defective, recessive traits are increasing in this wolf population. What are some steps that conservationists might consider to introduce new alleles into this population? a) Remove all the wolves in Wisconsin and replace them with wolves from other areas. b)Bring in an unrelated population of female wolves and release them to breed with the Wisconsin wolves. c) Let the wolf population die off from mutations before introducing new breeders. d) all of these e) none of these

e

Two populations of rodents have been physically separated by a large lake for many generations. The shore on one side of the lake is dry and has different vegetation from that on the other side. The lake is drained by humans to irrigate their crops, and now the mice populations are reunited. How could you assess if they are still members of the same species? a) You need to observe mating of the two mice populations. b) You need to see if their offspring are viable. c) You need to see if their offspring are fertile. d) You need to see if the offspring can mate and produce more viable offspring. e) all of these

c

What would you need to measure to be able to tell if a population was evolving? a)the number of homozygous individuals in the population b)the number of heterozygous individuals in the population c)the allele frequencies in the population over many generations d)the founder effect in the population e)no way to measure or qualify if evolution is occurring

c

Which of these defines the founder effect? a) It occurs when several small populations unite and "found" a larger population. b) It results in greater genetic diversity because of the larger population. c) It is one type of genetic drift. d) Rare alleles in the gene pool become more uncommon or disappear. e) This population is in Hardy−Weinberg equilibrium.

c

Which of these defines the founder effect? a)It occurs when several small populations unite and "found" a larger population. b)It results in greater genetic diversity because of the larger population. c)It is one type of genetic drift. d)Rare alleles in the gene pool become more uncommon or disappear. e)This population is in Hardy−Weinberg equilibrium.

d

Which of these is an adaptive trait with respect to evolution? a) mutation b) genetic drift c) gene flow d) natural selection e) none of these

e

Which population of organisms would you expect NOT to be in Hardy−Weinberg equilibrium, and thus to be evolving? a)a population of crocodiles living in the Nile River b)a population of killer whales living in the Atlantic Ocean c)a population of bacteria that is naturally occurring in a human's digestive tract d)a population of bacteria that is naturally occurring in a human's digestive tract e)all of these

c

Why is the Hardy−Weinberg equation important when it comes to public health issues? a)It can predict exactly how many people will be born with sickle-cell anemia every year. b)It is not useful in studying genetic drift or natural selection. c)It can be used to predict the frequency of recessive genetic conditions in a human population. d) It will not help scientists to understand if a population of organisms is changing. e) It is not used to study human populations.

a

Why is the Hardy−Weinberg principle useful when studying population genetics? a) It explains how alleles and genotypes behave in a nonevolving population, because the Hardy-Weinberg principle gives biologists a baseline to evaluate whether or not evolution is occurring in a population. b) It explains the rate of mutation occurring in a gene pool. c) It evaluates how random mating in a population will affect the number of recessive alleles in a population. d) It is able to identify how gene flow is occurring into a population using a mathematical equation. e) all of these

d

You have a population of dogs with three alleles for teeth size: L (large), M (medium), and S (small). Individuals with SS, SM, SL have small teeth. Individuals with MM have medium teeth. Individuals with LL or LM have large teeth. After a strange viral disease infected the population of dogs, all of the small-teethed individuals did not survive. What will happen to the population after 10 generations? a) Medium teeth will be missing. b) Only large teeth will be present. c) All three teeth types will be present. d) Small teeth will be missing. e) Only small teeth will be present.

2pq

frequency of heterozygous genotype

q^2

frequency of homozygous recessive genotype

p^2

homozygous dominant

allele frequency equation

p+q=1

genotype frequency equation

p^2 + 2pq + q^2 = 1

genetic drift

random changes in the allele frequencies of a population between generations; genetic drift tends to have more dramatic effects in smaller populations than in larger ones.

p

the frequency of the dominant allele

q

the frequency of the recessive allele