Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

CONCEPT QUESTION Read the Chapter Concepts liston page 412 All these pertain to the principles of population genetics and the evolution of species. Write a short essay describing the roles of mutation, migration, and selection in bringing about speciation.

Short Answer

Expert verified
Title: The Roles of Mutation, Migration, and Selection in Speciation Introduction: Population genetics focuses on understanding the genetic composition of populations and its changes over time. It is crucial for studying the evolution of species, with mutation, migration, and selection playing a major role in speciation, the process of developing new species. Mutation: Mutations are changes in the genetic code of an organism that can occur during DNA replication. While most mutations are neutral or harmful, some may lead to advantageous changes in an organism's traits. This genetic variation enables natural selection to occur and increases an individual's chances of survival and reproduction. Migration: Migration, or gene flow, is essential to the evolution of species as it involves the movement of individuals between populations, leading to the exchange of genetic material. This process not only increases genetic diversity within a population but also introduces new alleles, allowing for the development of new traits and potentially new species. Selection: Natural selection is the process in which individuals with advantageous genetic traits are more likely to survive and reproduce. Over time, the frequency of these advantageous alleles in a population increases, leading to the evolution of new traits and, potentially, contributing to speciation. Speciation: Mutation, migration, and selection work together to drive speciation, as genetic variation created by mutation and migration allow natural selection to act upon. Geographic isolation of populations can lead to the divergence of populations, causing them to evolve separately and eventually develop distinct species. Conclusion: Understanding the roles of mutation, migration, and selection in speciation is vital for gaining a deeper insight into population genetics and species evolution. These mechanisms work collectively to create and maintain the diverse range of life on Earth.

Step by step solution

01

Introduction

Begin by introducing the topic of your essay. Explain that population genetics deals with the study of the genetic composition of populations and how it changes over time. This field of study is essential for understanding the evolution of species, and its main forces include mutation, migration, and selection. These mechanisms contribute to speciation, which is the process by which new species arise over time.
02

Mutation

Explain that mutation is a change in an organism's genetic code, resulting from errors that can occur during DNA replication. Although most mutations are neutral or harmful, some can lead to advantageous changes in an organism's characteristics. These beneficial mutations may increase an individual's chances of survival and reproduction, allowing the advantageous traits to spread through a population over time. Also, mutations can create genetic variation within a population, which is necessary for natural selection to occur.
03

Migration

Discuss the role of migration in population genetics and the evolution of species. Migration (or gene flow) is the movement of individuals between populations, resulting in the exchange of genetic material. This process can lead to an increase in genetic diversity within a population, making it more resilient to environmental changes. Additionally, migration can introduce new alleles into a population, enabling the evolution of new traits and characteristics, which might lead to the development of a new species over time.
04

Selection

Describe the process of selection and its role in speciation. Natural selection is the differential survival and reproduction of individuals within a population based on their genetic traits. Those with advantageous traits are more likely to survive and reproduce, passing on their favorable genes to the next generation. Over time, the frequency of these advantageous alleles will increase in a population, leading to the evolution of new traits and potentially contributing to speciation.
05

Speciation

Now, explain how these forces collectively contribute to speciation. Genetic variation, created by mutation and augmented by migration, provides the raw material for natural selection to act upon. Over time, selection will favor certain traits and characteristics, leading to the divergence of populations and the emergence of new species. Speciation typically occurs when populations become geographically isolated, preventing gene flow between them. As a result, mutations, migration, and selection act independently in each population, causing them to evolve separately and eventually leading to the development of distinct species.
06

Conclusion

Wrap up your essay by summarizing the importance of mutation, migration, and selection in bringing about speciation. Emphasize that understanding these processes is crucial for gaining a deeper insight into the principles of population genetics and the evolution of species. These mechanisms work collectively to create and maintain the diversity of life on Earth.

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 Vaia!

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

A recent study examining the mutation rates of 5669 mammalian genes \((17,208\) sequences) indicates that, contrary to popular belief, mutation rates among lineages with vastly different generation lengths and physiological attributes are remarkably constant [Kumar, S., and Subramanian, S. \((2002) .\) Proc. Natl. Acad. Sci.USA99:803-808|.Theaveragerateisestimatedat12.2 \(\times 10^{-9}\) perbp per year. What is the significance of this finding in terms of mammalian evolution?

A form of dwarfism known as Ellis-van Creveld syndrome was first discovered in the late 1930 s, when Richard Ellis and simon van Creveld shared a train compartment on the way to a pediatrics meeting. In the course of conversation, they discovered that they each had a patient with this syndrome. They published a description of the syndrome in \(1940 .\) Individuals with this syndrome have a short-limbed form of dwarfism and often have defects of the lips and teeth, and polydactyly (extra fingers). The largest pedigree for the condition was reported in an Old Order Amish population in eastern Pennsylvania by Victor McKusick and his colleagues \((1964) .\) In that population of \(8000,\) the observed frequency is 2 per \(1000 .\) In all cases, parents of children with the syndrome were unaffected, and all cases can be traced to Samuel King and his wife, who arrived in the area in \(1774 .\) It is known that neither King nor his wife was affected with the disorder. There are no cases of the disorder in other Amish communities, such as those in Ohio or Indiana. (a) From the information provided, derive the most likely mode of inheritance of this disorder. Using the Hardy-Weinberg law, calculate the frequency of the mutant allele in the population and the frequency of heterozygotes, assuming Hardy-Weinberg conditions. (b) What is the most likely explanation for the high frequency of the disorder in the Pennsylvania Amish community and its absence in other Amish communities?

HOW DO WE KNOW? Population geneticists study changes in the nature and amount of genetic variation in populations, the distribution of different genotypes, and how forces such as selection and drift act on genetic variation to bring about evolutionary change in populations and the formation of new species. From the explanation given in the chapter, what answers would you propose to the following fundamental questions? (a) How do we know how much genetic variation is in a population? (b) How do geneticists detect the presence of genetic variation as different alleles in a population? (c) How do we know whether the genetic structure of a population is static or dynamic? (d) How do we know when populations have diverged to the point that they form two different species? (e) How do we know the age of the last common ancestor shared by two species?

Some critics have warned that the use of gene therapy to correct genetic disorders will affect the course of human evolution. Evaluate this criticism in light of what you know about population genetics and evolution, distinguishing between somatic gene therapy and germ-line gene therapy.

The original source of new alleles, upon which selection operates, is mutation, a random event that occurs without regard to selectional value in the organism. Although many model organisms have been used to study mutational events in populations, some investigators have developed abiotic molecular models. Soll et al. (2006. Genetics 175:267-275) examined one such model to study the relationship between both deleterious and advantageous mutations and population size in a ligase molecule composed of RNA (a ribozyme). Soll found that the smaller the population of molecules, the more likely it was that not only deleterious mutations but also advantageous mutations would disappear. Why would population size influence the survival of both types of mutations (deleterious and advantageous) in populations?

See all solutions

Recommended explanations on Biology Textbooks

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.

Sign-up for free