Question 1

With the extinction of the dinosaurs 65 million years ago,multiple niches that the dinosaurs once filled opened up and allowed mammals the opportunity to evolve and exploit those niches.In other words,mammals underwent a(an)

Accepted Answer

Adaptive radiation is the evolution of multiple species from a common ancestor, each adapted to exploit different niches. With the extinction of the dinosaurs, numerous niches opened up, providing opportunities for mammals to diversify and radiate into new forms. Therefore, the most appropriate choice is B, adaptive radiation. Sympatric speciation (A) is the evolution of new species from a single ancestral species while living in the same geographic area, which is not relevant to the scenario given. Exaptation (C) is a process in which a trait that evolved to serve one function is later adapted for a different function, which is also not relevant to the extinction of dinosaurs. Behavioral isolation (D) and phylogenetic isolation (E) are types of reproductive isolation that prevent two groups of organisms from interbreeding, which is not relevant to the scenario given.

Question 2

Genetic divergences may ultimately lead to

Accepted Answer

Genetic divergences can accumulate over time leading to differences in traits, behavior and morphology which can ultimately lead to the formation of new species. This process is known as speciation.

Question 3

Macroevolution may have been caused by

Accepted Answer

Macroevolution is the evolution of species at a larger scale, involving the origin of new taxa, such as families, orders, and phyla. It typically requires significant changes in morphology, physiology, or behavior, and may involve speciation, adaptation, extinction, or other processes. While the causes of macroevolution are complex and multifaceted, some of the major factors that have been identified include changes in homeotic genes (A), which control the development of body structures during embryogenesis; small, cumulative genetic changes (B), which accumulate over long periods of time and may generate novel phenotypes or functions; exaptation (C), which is the co-option of existing traits for new purposes or environments; and allopatric speciation (D), which occurs when a population becomes geographically isolated and diverges genetically and morphologically from its parent species. None of these factors are mutually exclusive, and multiple mechanisms may interact to produce macroevolutionary patterns and trends.

Question 4

In the 16th century,a Spanish ship explored a Pacific Island that had a small mountain range separating it.Mice that were on the ship escaped onto the island on both sides of the mountain range.After decades of separation the two populations developed different numbers of chromosomes and in spite of the populations coming together again,the chromosomal differences prevented successful interbreeding.What is true about this speciation event?

Accepted Answer

The initial separation of the mice populations by the mountain range is an example of ecological isolation, and the chromosomal differences that later prevented interbreeding represent mechanical isolation.

Question 5

Two species of toads have been successfully interbred in a laboratory but do not hybridize in nature because one species mates in summer and the other mates in the fall.This is an example of ____ isolation.

Accepted Answer

This scenario describes temporal isolation because the two species do not mate with each other in nature due to differences in their mating seasons.

Question 6

Which of the following is always a part of speciation?

Accepted Answer

Reproductive isolation (the inability of individuals from different populations to produce viable offspring) is always a part of speciation. This is because for two populations to be considered separate species, they must be reproductively isolated and unable to interbreed. Behavioral, temporal, ecological, and mechanical isolation are all types of reproductive isolation, but not all of them are always present in every case of speciation.

Question 7

Herbicide resistance and Bt genes from GMO crops are now commonly found in weeds.This is an example of

Accepted Answer

The occurrence of herbicide resistance and Bt genes in weeds is a result of gene flow, which occurs when genes are transferred from one population to another through interbreeding or pollen exchange. The use of GMO crops that contain these genes has increased the frequency of their occurrence in weed populations through natural selection, which favors individuals that are resistant to herbicides or can withstand the toxic effects of Bt proteins. This has resulted in an increase in the prevalence of these traits in weed populations, which can further reduce the effectiveness of herbicides and increase crop damage.

Question 8

In early evolutionary history,primitive fishes had lungs that eventually evolved into the lungs of terrestrial organisms and the gas bladders of modern fishes who use gills,not lungs,for oxygen/ carbon dioxide gas exchange.This is an example of

Accepted Answer

This is an example of exaptation because the primitive lungs were originally used for buoyancy control in water, but over time they were modified and used for gas exchange on land.

Question 9

Gene flow counters the effects of

Accepted Answer

Gene flow introduces new alleles into a population, which can counteract the effects of natural selection, mutation, and genetic drift by increasing genetic diversity and reducing differences between populations.

Question 10

In some species of flowering plants,pollen from unrelated species may germinate on the female stigma,but the pollen tube grows only a short distance and fertilization does not occur.This is an example of ___ isolation.

Accepted Answer

This is an example of mechanical isolation, where the structures of the reproductive organs prevent successful fertilization between unrelated species. In this case, the pollen tube is unable to penetrate the female's reproductive structures and reach the egg, preventing fertilization.

Question 11

Over evolutionary time,flowering plants have evolved colors,odors,and nectar that attract pollinating insects and the insects have evolved mechanisms that detect the changes in plants and to better collect pollen.This is an example of

Accepted Answer

This scenario describes the process of coevolution, where two species, plants and pollinators in this case, have evolved in response to each other's selective pressures.

Question 12

Ginko,a species of gymnosperm tree,has undergone very little change in its 270 million year evolutionary history.This is an example of evolutionary

Accepted Answer

Stasis refers to a lack of change or evolution over a long period of time. In this scenario, the ginkgo tree has maintained similar characteristics for 270 million years, indicating stasis. Exaptation refers to the evolution of a trait for one purpose and later adaptation for another purpose. Radiation refers to the rapid diversification of a group of organisms. Sympatric speciation refers to the emergence of a new species without geographic isolation. Behavioral isolation refers to the lack of mating between two populations due to differences in behavior or courtship rituals. None of these options accurately describe the lack of change seen in the ginkgo tree.

Question 13

Male songbirds sing to attract females to mate with.Different species of male songbirds sing different songs that will attract only the females of their species.This is an example of ___ isolation.

Accepted Answer

Behavioral isolation refers to differences in behavior or mating rituals that prevent interbreeding between species. In this case, the different songs sung by male songbirds of different species act as a behavioral barrier that ensures that each species mates only with its own kind.

Question 14

The migratory patterns of many animals encourage

Accepted Answer

Gene flow occurs when individuals or populations move from one geographic location to another, often resulting in the transfer of new or different genes. This type of migration can increase genetic variation within a population and prevent genetic drift, a process that can lead to the loss of genetic diversity.

Question 15

Northern elephant seals are ___ for every allele that has been tested.

Accepted Answer

Homozygous means having two copies of the same allele. Therefore, Northern elephant seals are homozygous for every allele that has been tested.

Question 16

One result of the bottleneck affect can be

Accepted Answer

The bottleneck effect often results in a reduction of genetic diversity, leading to increased homozygosity as the population size decreases and genetic variation is lost.

Question 17

Which of the following is NOT an example of gene flow?

Accepted Answer

The answer of Which of the following is NOT an...

Question 18

What percent of all species that have existed have gone extinct?

Accepted Answer

It is estimated that over 99% of all species that have ever lived on Earth are now extinct. This is due to a variety of factors such as natural disasters, climate change, and human impact on the environment. The process of extinction is a natural part of evolution, but the current rate of extinction is much higher than the natural rate, primarily due to human activities.

Question 19

Female preference for brightly colored blue or red males in Lake Victoria provides an example of

Accepted Answer

The answer of Female preference for brightly colored blue or...

Question 20

Which type of reproductive isolation mechanism is most closely related to allopatric speciation?

Accepted Answer

Ecological isolation, where geographic barriers create different environments that lead to divergent natural selection, is the most closely related to allopatric speciation. Allopatric speciation occurs when biological populations of the same species become isolated from each other due to geographic barriers, leading to genetic divergence and ultimately new species. This can be facilitated by ecological differences and natural selection acting on divergent environments. Temporal isolation, mechanical isolation, behavioral isolation, and genetic isolation may also contribute to the evolution of new species in allopatric populations, but they are not as closely related to allopatric speciation as ecological isolation.

Quiz 12: Processes of Evolution