/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 14 Which statement best describes t... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 18: Problem 14

Which statement best describes the relationship between genetic variation and speciation? a. Without genetic variation, speciation would occur more slowly. b. Without genetic variation, speciation would not be possible. c. Genetic variation influences sympatric speciation, but not allopatric speciation. d. There is no relationship between genetic variation and any form of speciation.

Short Answer

Expert verified
b. Without genetic variation, speciation would not be possible.

Step by step solution

01

Understand Genetic Variation

Genetic variation refers to the differences in DNA sequences between individuals within a population. This variation is crucial for the process of evolution.
02

Define Speciation

Speciation is the process through which new and distinct species arise in the course of evolution. It often occurs when populations are divided and subjected to different selective pressures.
03

Link Between Genetic Variation and Speciation

Genetic variation provides the raw material for natural selection to act upon. Without genetic variation, populations would lack the diversity necessary for new species to evolve.
04

Analyze Answer Choices

Review each option: a) Suggests slower speciation without variation - speciation might not occur at all. b) Indicates no speciation without variation - aligns with the need for genetic diversity. c) Differentiates between sympatric and allopatric speciation - less relevant for basic understanding. d) Claims no relationship - contrary to evolutionary principles.
05

Select the Best Answer

Option b (Without genetic variation, speciation would not be possible) is the most accurate because genetic variation is essential for the formation of new species.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Genetic Variation
Genetic variation refers to the differences in DNA sequences among individuals within a population. These differences are significant because they contribute to the unique traits within a species. Several factors create genetic variation, including mutations, sexual reproduction, and gene flow. Mutations are random changes in DNA that can introduce new traits. Sexual reproduction mixes genetic material from two parents, leading to offspring with unique genetic combinations. Gene flow occurs when individuals migrate between populations, bringing new genetic material with them. Genetic variation is the foundation for evolutionary processes, as it provides the raw material for natural selection and adaptation.
Speciation
Speciation is the evolutionary process by which populations evolve to become distinct species. This can happen in several ways, such as through allopatric speciation, where geographical barriers separate populations, or sympatric speciation, where new species arise within the same geographical area. Speciation often requires genetic variation, as different environmental pressures select for different traits. Over time, these changes accumulate, leading to populations that are genetically distinct and unable to interbreed. This divergence is critical in the formation of new species and contributes to biodiversity. Without genetic variation, speciation would not occur because there would be no differences for natural selection to act upon.
Evolutionary Processes
Evolutionary processes encompass all the mechanisms that drive the evolution of species. These include natural selection, genetic drift, mutation, and gene flow. Natural selection is the process where organisms better adapted to their environment tend to survive and produce more offspring. Genetic drift involves random changes in allele frequencies within a population, often having more pronounced effects in small populations. Mutations introduce new genes and alleles into a population, while gene flow incorporates genetic material from one population into another. These processes interact and contribute to the genetic variation necessary for evolution and speciation. Each mechanism plays a role in shaping the genetic landscape of populations over time.
Natural Selection
Natural selection is a key mechanism in evolution. It occurs when individuals with advantageous traits are more likely to survive and reproduce. These traits become more common in the population over generations. Natural selection acts on genetic variation within a population, favoring beneficial traits while disadvantaging harmful ones. For example, in a population of beetles, green beetles might be better camouflaged in a leafy environment compared to brown beetles. Predators are less likely to spot green beetles, so they survive longer and reproduce more, passing on their genes to future generations. Over time, the population will have more green beetles. This process drives the adaptation of species to their environments, contributing to speciation as different selective pressures lead to new traits and ultimately new species.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Prior to 1800 in England, the typical moth of the species Biston betularia (peppered moth) had a light pattern. Dark colored moths were rare. By the late 19th century, the light- colored moths were rare, and the moths with dark patterns were abundant. The cause of this change was hypothesized to be selective predation by birds (J.W. Tutt, 1896). During the industrial revolution, soot and other wastes from industrial processes killed tree lichens and darkened tree trunks. Thus, prior to the pollution of the industrial revolution, dark moths stood out on light- colored trees and were vulnerable to predators. With the rise of pollution, however, the coloring of moths vulnerable to predators changed to light. Which of the following aspects of Darwin鈥檚 theory of evolution does the story of the peppered moth most clearly illustrate? a. There is competition for resources in an overbred population. b. There is great variability among members of a population. c. There is differential reproduction of individuals with favorable traits. d. The majority of characteristics of organisms are inherited.

Which of the processes described is divergent evolution? a. Groups of organisms evolve in different directions from a common point. b. A new species develops rapidly when an event cuts off a portion of a population. c. Groups of organisms independently evolve to similar forms. d. A species evolves when a few members move to a new geographical area

There are years of drought in a small, relatively isolated community. During the drought, small seeds with thin shells become rare. Large seeds with hard cases become increasingly common. The large, tough seeds are successfully eaten by birds with large and broad beaks. Assuming that the drought continues and the population of birds in the community stays isolated, what predictions for the population can you make under the influence of natural selection? a. The birds with small, thin beaks will grow larger, broader beaks to be able to eat the larger seeds. This will result in subsequent generations having a higher percentage of birds with large, broad beaks. b. There will be more birds with small, thin beaks dying and more birds with large, broad beaks surviving. Differential reproduction of birds with large, broad beaks will result in subsequent generations having a higher percentage of birds with large, broad beaks. c. The species will diverge into two species, one with small, thin beaks and one with large, broad beaks. The two species will then compete for resources. d. There will be neither phenotypic nor genotypic changes in the population.

Populations of a plant species have been found growing in the mountains at altitudes above 2,500 meters. Populations of a plant that appears similar, with slight differences, have been found in the same mountains at altitudes below 2,300 meters. Describe a plan for collecting two kinds of data that could provide a direct answer to the question: do the populations growing above 2,500 meters and the populations growing below 2,300 meters represent a single species? a. Scientists could take the genetic code of a plant from each altitude and determine whether the two sets of DNA are identical. They could also insert genes from one plant into the cells from the other and see if the cells survive b. Scientists could look in the fossil record to find the plants鈥� most recent common ancestor. They could also check the surrounding mountains to determine if the most recent common ancestor is still living. c. Scientists could breed the two groups in the same environment and observe whether, over several generations, they begin to look more similar. They could also switch the groups, growing the high-altitude plants at low altitude and the low-altitude plants at high altitude, and observe whether the former begin to look like low- altitude plants and the latter begin to look like high-altitude plants. d. Scientists could collect seeds and test whether they might be cross- pollinated to produce fertile offspring. They could also investigate the area between 2,500 meters and 2,300 meters to see if fertile hybrid populations might be found living between the two other populations of plants.

Describe a situation where hybrid reproduction would cause two species to fuse into one. a. Separate species cannot interbreed, so hybrid reproduction does not occur in nature b. If the hybrid offspring are more fit than the parents, reproduction would likely continue between both species and the hybrids, eventually bringing all organisms under the umbrella of one species c. Two species that have recently diverged from each other can reproduce with each other, creating hybrid individuals that belong to the species of the parents鈥� common ancestor. d. If two species occupy the same niche in the same area, they can either compete or they can collaborate and reproduce with each other, eventually fusing into a single species.
See all solutions

Recommended explanations on Biology Textbooks

Biology Experiments

Read Explanation

Ecological Levels

Read Explanation

Genetic Information

Read Explanation

Ecology

Read Explanation

Responding to Change

Read Explanation

Substance Exchange

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.