An Introduction to Methods and Models in Ecology, Evolution, and Conservation Biology - Softcover

Softcover

ISBN 10: 0691127247 ISBN 13: 9780691127248

Verlag: Princeton University Press, 2010

Inhaltsangabe

This unique textbook introduces undergraduate students to quantitative models and methods in ecology, behavioral ecology, evolutionary biology, and conservation. It explores the core concepts shared by these related fields using tools and practical skills such as experimental design, generating phylogenies, basic statistical inference, and persuasive grant writing. And contributors use examples from their own cutting-edge research, providing diverse views to engage students and broaden their understanding. This is the only textbook on the subject featuring a collaborative "active learning" approach that emphasizes hands-on learning. Every chapter has exercises that enable students to work directly with the material at their own pace and in small groups. Each problem includes data presented in a rich array of formats, which students use to answer questions that illustrate patterns, principles, and methods. Topics range from Hardy-Weinberg equilibrium and population effective size to optimal foraging and indices of biodiversity. The book also includes a comprehensive glossary. In addition to the editors, the contributors are James Beck, Cawas Behram Engineer, John Gaskin, Luke Harmon, Jon Hess, Jason Kolbe, Kenneth H. Kozak, Robert J. Robertson, Emily Silverman, Beth Sparks-Jackson, and Anton Weisstein. * Provides experience with hypothesis testing, experimental design, and scientific reasoning * Covers core quantitative models and methods in ecology, behavioral ecology, evolutionary biology, and conservation * Turns "discussion sections" into "thinking labs" Professors: A supplementary Instructor's Manual is available for this book. It is restricted to teachers using the text in courses. For information on how to obtain a copy, refer to: http://press.princeton.edu/class_use/solutions.html

Über diesen Titel

Über die Autorin bzw. den Autor

Stanton Braude is lecturer in biology at Washington University in St. Louis. Bobbi S. Low is professor of resource ecology at the University of Michigan.

Von der hinteren Coverseite

"Braude and Low combine approaches and methodologies from ecology, evolution, and behavior, and emphasize quantitative exercises. Most other books that I'm familiar with are largely focused on either ecology or evolution. It makes sense to me to combine all of this material under a single cover. I can't think of another book like this one."--Jonathan Shurin, University of British Columbia

"A very worthwhile contribution. The authors expose students to quantitative methods using a very hands-on approach. The exercises increase students' comfort with data analysis and quantitative methods while also helping them to develop independent critical thinking and practical problem-solving skills. I do not know of any other textbook that offers this approach in evolution and ecology."--Suzanne H. Alonzo, Yale University

"This book is designed to teach basic ecological methods to undergraduates using a series of interactive exercises. It promotes real learning as opposed to memorization. It is a significant contribution to the field."--Susan L. Keen, University of California, Davis

"This is an interesting and even entertaining book of lab and field exercises that represent a wealth of personal experience in teaching the essentials of ecology and evolutionary theory, as well as the basics of the scientific method, study design, and analysis. The book includes many gems."--David K. Skelly, Yale University

Auszug. © Genehmigter Nachdruck. Alle Rechte vorbehalten.

AN INTRODUCTION TO METHODS & MODELS IN Ecology, Evolution, & Conservation Biology

PRINCETON UNIVERSITY PRESS

Copyright © 2010 Princeton University Press
All right reserved.
ISBN: 978-0-691-12724-8

Contents

Figures..................................................................................................................................................viiTables...................................................................................................................................................xiPreface..................................................................................................................................................xvAcknowledgments..........................................................................................................................................xviiIntroduction.............................................................................................................................................xix1 Evolution and Pesticide Resistance: Examining Quantitative Trends Visually Stanton Braude and John Gaskin.............................................32 Lizard Ecomorphology: Generating and Testing Hypotheses of Adaptation Kenneth H. Kozak................................................................123 Phylogenetic Inference: Examining Morphological and Molecular Datasets James Beck.....................................................................224 Life History Tradeoffs in Avian Clutch Size: Interpreting Life History Data and Evaluating Alternative Hypotheses Jon Hess............................365 Mimicry: Experimental Design and Scientific Logic James Robertson.....................................................................................516 Life Table Analysis Stanton Braude....................................................................................................................637 Lotka-Volterra Competition Modeling Stanton Braude, Tara Scherer, and Rebecca McGaha..................................................................698 Explosive Population Growth and Invasive Exotic Species Jon Hess and James Robertson..................................................................799 Island Biogeography: Evaluating Correlational Data and Testing Alternative Hypotheses James Robertson.................................................9110 Hardy-Weinberg: Evaluating Disequilibrium Forces Jason J. Kolbe......................................................................................10711 Drift, Demographic Stochasticity, and Extinction in Woggles James Robertson, Anton Weisstein, and Stanton Braude.....................................11712 Conservation of Small Populations: Effective Population Sizes, Inbreeding, and the 50/500 Rule Luke J. Harmon and Stanton Braude.....................12513 Dispersal and Metapopulation Structure James Robertson...............................................................................................13914 Understanding Descriptive Statistics Beth Sparks-Jackson and Emily Silverman.........................................................................15515 Understanding Statistical Inference Emily Silverman and Beth Sparks-Jackson..........................................................................17916 Sampling Wild Populations Stanton Braude and James Robertson.........................................................................................18917 Quantifying Biodiversity Cawas Behram Engineer and Stanton Braude....................................................................................19818 Environmental Predictability and Life History Bobbi S. Low and Stanton Braude........................................................................21419 Modeling Optimal Foraging Stanton Braude and James Robertson.........................................................................................22620 Evaluating Competing Hypotheses of Regional Biodiversity Stanton Braude..............................................................................23521 Preparing and Evaluating Competitive Grant Proposals for Conservation Funding Stanton Braude.........................................................23922 Tracing the History of Scientific Ideas: From Darwin, Connell, or Soule to the Present Bobbi S. Low..................................................245Glossary.................................................................................................................................................251Contributors.............................................................................................................................................263Index....................................................................................................................................................265

Chapter One

Evolution and Pesticide Resistance: Examining Quantitative Trends Visually Stanton Braude and John Gaskin

Introduction and Background

Evolution and natural selection have always been central concepts in the study of ecology. When German biologist Ernst Haekel coined the term "ecology" in the 1860s, he envisioned studying the forces of nature that were selective forces in the Darwinian sense. Darwin is popularly associated with the rise of evolutionary thought in biology; his major contribution was explaining natural selection—and the concept is so rich that we still find it fascinating to explore today.

Evolution is the term we use for changes in gene frequencies in populations or species over time. It is not the same as natural selection; in fact, evolution results from mutation, recombination, and drift, which generate variation but are not predictable, as well as from natural selection. So what is natural selection? It is the mechanism that drives adaptive evolution; the result of the simple fact that in any environment, depending on the conditions of that environment, some variants—individuals with specified genetic traits—survive and reproduce better than others. If we understand how any environment shapes traits, favoring some and disfavoring other individuals who possess those traits, we can predict how traits should match environmental conditions—and how populations will change over time. We will see this throughout this book, especially in this chapter, and in chapters 2, 4, 5, 18, and 19.

Ecology is a very empirical science, so it is not surprising that much ecology of the early twentieth century was descriptive. Ecologists today know that understanding natural selection and evolution is central to understanding important "why" hypotheses—especially today, when we humans change environments (and thus selective pressures) rapidly without necessarily understanding our impacts.

"Why" hypotheses can be of several sorts (Tinbergen, 1963). Hypotheses that explain why phenomena exist in nature are ultimate hypotheses, and those that explain how things work are proximate hypotheses. Both are important, but it is especially crucial not to confuse the two; it is confusing and wrong to offer a proximate answer to an ultimate question. For example: why do birds fly south for the winter? "Because individuals in this species in this region that migrate seasonally survive and reproduce better than those that do not" is an ultimate answer (and you can see all sorts of testable predictions: whether hummingbirds will migrate when seed-eating species will not; whether migration will be associated with seasonal changes, etc.). "Because changing day length causes shifting hormone levels" is a proximate explanation: it tells how the changes are operationalized. Ultimate answers are always about differential survival and/or reproduction; there can be myriad proximate ways that responses are mediated. Depending on your question, you will be more interested in one or the other level.

Pesticide resistance is an example of evolution in action. Pesticide use, in both the United States and worldwide, has increased dramatically over the past 30 years (table 1.1) and farmers today have access to a diverse chemical arsenal to protect their crops (table 1.2). As a result, food productivity is higher now than at any other time in human history. But are there hidden costs, as a result of the selection our pesticides impose, and the resulting evolution of pest species? Have we had impacts we did not foresee?

Agricultural pesticides are typically applied broadly, so they are likely to affect unintended, or nontarget, species. These side effects can harm everything from arthropod predators (e.g., spiders and preying mantises), to birds and fish that feed on dead arthropods, to humans who use contaminated water. Pesticides can have secondary impacts: they can, for example, affect endangered species both directly and indirectly, leading to loss of biodiversity.

The effectiveness of any given pesticide rapidly decreases soon after its first use, regardless of the target pest or the pesticide. Although there are hopes that genetically engineered crops and their associated pesticides will avoid this trend, there are evolutionary reasons to doubt the success of any simple pest-elimination program. One reason that insect pests frequently bounce back in higher numbers after spraying is that insect predator populations are also reduced by insecticides. Predators obviously affect the death rate of prey, which means prey often experience intense mortality. Prey (food) populations affect the birth rate of predators, which means prey (in this case pest) populations recover more rapidly than predators (this phenomenon is called Volterra's principle). This is hardly a desired result, because we lose the natural predators of the pests.

The main cause of a decrease in pesticide effectiveness results from the evolution of resistance to the pesticide as a result of natural selection (figure 1.1). Think of it this way: if a pesticide is 95% effective, it kills 95% of the pest individuals—but the remaining individuals are the resistant ones, and their progeny will be more resistant, on average, than individuals in the parent population. We call this directional selection—selection that favors one extreme (here, pesticide resistance).

Thinking about pesticide use in agriculture (or widespread antibiotic use in medicine) raises some interesting evolutionary questions. Many of our newly developed pesticides and herbicides have natural analogs. In this case, because our target pest species may have had long exposure to the natural compounds, we are not surprised if resistance has evolved in species in which there were alleles that conferred resistance. Resistance-conferring alleles can persist for various reasons, even before we begin treatment. Remember that variation (e.g., in resistance) arises from mutation, drift, and recombination. It also matters whether resistance is expensive. The level of existing resistance ability thus depends on several things: frequency of exposure, cost of developing resistance, cost of being nonresistant, and the generation time. The patterns you see in this chapter are so strong because high initial death rates (see tables below) mean that the cost of not being resistant is very high; and most pests have a fairly short life span (many generations = many chances for variations to arise, and selection to act), so that evolution proceeds quickly.

Objectives of this Exercise

In this exercise you will:

• Examine two case studies of pesticide use and effectiveness

• Evaluate the effect of pesticides as a selective agent driving evolution

• Plot the data to help you identify trends more easily

Case Studies and Data

Read the following two cases, examine the data, and answer questions 1 through 7.

Cotton

Almost 50% of all insecticides applied to crops in the United States are applied to cotton! As a result, most major insect pests of cotton have developed resistance to one or more of these insecticides. Some cotton pests, such as the tobacco budworm (Heliothis virescens) and spider mites (Tetranychus species), are now resistant to most of the insecticides registered for use on cotton in the United States. Our arsenal of effective insecticides for use on cotton is rapidly disappearing. Further, many insecticides are indiscriminate killers, destroying the predatory arthropods (e.g. mud wasps, ladybird beetles, dragonflies) that normally control insect herbivore populations, and giving rise to the problem outlined above.

In the 1930s, vast crops of cotton were grown in southern Texas and northeastern Mexico. Boll weevils, pink bollworms, and cotton flea hoppers were the key pests of the crop. These pests were controlled with calcium arsenate and sulfur dust, which quickly yielded profitable crop harvests. There were sporadic, but not devastating, outbreaks of another cotton pest, the tobacco budworm. Shortly after World War II, new chlorinated hydrocarbon insecticides, such as DDT, became available. These pesticides provided greater crop yields, because they destroyed almost all cotton pests. Some pesticide regimes called for 10–20 DDT applications per growing season, but the future of cotton in southern Texas was looking great!

Unfortunately, these pesticide treatments also decimated the predators who feed on the pest species. Because this led to occasional increases in pest numbers, the dosage of pesticide applications was increased. In the mid-1950s the boll weevil developed resistance to chlorinated hydrocarbon insecticides. By 1960, the pink bollworm and the tobacco budworm had also become difficult to control (even with treatments of 1–2 lb. per acre every 2 days!). By 1965, all of the cotton pests were resistant to DDT and similar pesticides. An organophosphorus pesticide (methyl parathion) was called into use, but by 1968 the tobacco budworm had developed resistance to methyl parathion as well. Cotton farming in northeastern Mexico was reduced 70-fold, from 70,000 acres in the 1960s to less than 1000 acres in 1970. These are examples of two unintended consequences of pesticide application: (1) increasing pesticide resistance through directional selection, and (2) decimating natural predators of the pest species. Table 1.3 shows data for this problem in southern Texas.

Apples

Phytophagous (plant-eating) mites such as Tetranychus mcdanieli [T. mc] and Panonychus ulmi [P. ul] are serious pests of apples in Washington state. The practice of preventive scheduling—pesticides applied whether there was evidence of current pest problems or not—of pesticide application in the past has resulted in eradication of the natural enemies of the mites (which often included other mites such as Metaseiulus occidentalis [M. oc.]). To avoid these difficulties, integrated pest management programs, involving natural predators or a combination of selective pesticides and predators, have been developed to preserve the advantages of natural pest control in artificial ecosystems. Table 1.4 contains data on mite populations in orchards with different treatments.

Questions to Work on Individually Outside of Class

When farmers began using organic pesticides half a century ago, the hope was that we could eradicate pests and not have to share our yields with them. However, as you have seen in the data above, the pests are still there after repeated treatment. So, what is the effect of these pesticides on their intended targets? You should be able to see the effect as you work through the following questions.

1. Describe the effect of methyl parathion dose on budworm kill.

2. Graph the relationship between methyl parathion dose and percent budworm kill. All six cases can be plotted on a single graph, but each of the cases should be plotted as a separate line. Now look back at question 1 and see if you want to revise your answer.

3. How does the density of phytophagous mites change over time for both species, and for both treatments? How does the density of carnivorous mites change over time?

4. Graph the relationship between mite density and time for all three species, and for both treatments. (All six of these lines can be placed on one graph.) Now look back at question 3, and see how you can revise it to make it clearer with reference to your plot.

5. How do insecticides appear to affect the evolution of insect populations? Support your answer with reference to the data and the trends apparent in your graphs. Are there any other data you would want, in order to show that the change was the result of selection?

6. Population growth (whether we are talking about insects, plants, fish, or any species) depends on the balance among birth, immigration, death, and emigration.

(a) When you consider the growth of a prey population, which of these population parameters will be most affected by their interaction with predators? (b) When you consider the growth of predator populations, which of these population parameters will be most affected by the size of the prey base? (c) If a very cold winter wiped out 99% of both the predators and prey in a community one year, how do you expect this to affect the growth of the prey population the following spring? How do you expect it to affect the growth of the predator population the following spring?

7. In the apple mite example, the prey and predator had about the same generation time. This is not always the case: normally, the predator's generation time is longer than that of the prey—which slows down the predator's recovery after spraying even further than the fact that predator birth rates are affected by prey abundance. How could this difference in generation time affect population numbers over time if both predator and prey are present in the orchard at the time of spraying and both are initially susceptible to the chemical sprayed?

Small-Group/In-Class Exercise

When you come to class you may be asked to work on one or both of the following exercises. Bring five pieces of blank 8.5 x 11 paper for the Exercise A option.

Exercise A

In this exercise you will be asked by your teacher to copy a series of diagrams of mites. Follow his/her instructions. The discussion that follows will address concepts of evolution, natural selection, and drift.

Exercise B

In this exercise your group will have approximately one-half hour to outline an argument for or against the Mango Marketing Manifesto (the details are fictional, but your arguments should be based on a real understanding of evolution in response to pesticides). Your group may be asked to take the position expected of one of the following groups: Sierra Club, Monsanto Corporation, Local Farm Cooperative, Center for the Study of Intelligent Design and Creation, Anglers and Fly Fishermen of America, Peach Farmers and Orchardists of America.

Each group will have a few minutes to present their position to the class and you will have time to question each group after their presentation. Try to stay in character, but be sure to cite examples and data where relevant.

Congratulations! Your enrollment in this course has landed you a summer internship in the state capital. Each group of you will represent a different constituency, following your instructor's suggestions. Your first assignment is to review the following proposal, and comment on its scientific merit from your group's perspective. Your group has 30 minutes to discuss the proposal and to organize your presentation. You then have to make a concise five-minute report to the state agriculture committee.

Your predecessor submitted a report that this proposal is based on sound scientific reasoning. He argued that it is similar to the use of antibiotics in medicine. When someone gets a bacterial infection we give a course of antibiotics that totally exterminates the bacterial population in that individual, but we don't give antibiotics to every person in a population.

1. Should we support the proposal or not? 2. Should we make the argument that this is just like an infection and that similar treatment will be a good idea? 3. What are the effects at the population level (over time) of such treatments? 4. Explain why this plan will or will not work.

If this plan will not work, propose an alternative solution to the pest problem. Explain your reasoning and convince your audience with any and all evidence at your disposal (whether they are data you have worked with, or other available data).

Your team will have five minutes to present your argument to the committee, and will then take questions from them. (Note: In preparing for critical questions, you may also find questions that you should pose to other groups.)

Chapter Two

Lizard Ecomorphology: Generating and Testing Hypotheses of Adaptation Kenneth H. Kozak

Introduction and Background

From at least Aristotle's time, naturalists and philosophers have commented that many organisms seem wellsuited to their environments. But Charles Darwin introduced a really novel and exciting twist to our view of this relationship. He began by reviewing what was known at the time (1850) about artificial selection: how we humans have shaped dog breeds, plants we are interested in, and more, by allowing some individuals (those with the traits we liked) to survive and breed, and prohibiting others. He then proposed that natural conditions also might impose selection on organisms. This natural selection, through the differential survival and reproduction of individuals with some traits (characteristics), would lead to the sorts of trait-environment "fit" we see. In the more than 150 years since Darwin, we have learned about the role of genetics, and we have expanded and refined our understanding of evolution, natural selection, and adaptation.

(Continues...)

Excerpted from AN INTRODUCTION TO METHODS & MODELS IN Ecology, Evolution, & Conservation Biology Copyright © 2010 by Princeton University Press. Excerpted by permission of PRINCETON UNIVERSITY PRESS. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.

Details zur Ausgabe

• Verlag: Princeton University Press
• Erscheinungsdatum: 2010
• Sprache: Englisch
• ISBN 10: 0691127247
• ISBN 13: 9780691127248
• Einband: Tapa blanda
• Anzahl der Seiten: 312
• Herausgeber: Braude Stanton, Low Bobbi S.
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: Nicht verfügbar