The Living World

896 Pages·2015·606.802 MB·English

by  George Brooks Johnson

EIGHTH EDITION
George B. Johnson
Washington University
St. Louis, Missouri
joh24218_fm_i-xxii.indd 1 11/14/13 9:31 AM
THE LIVING WORLD, EIGHTH EDITION
Published by McGraw-Hill Education, 2 Penn Plaza, New York, NY 10121. Copyright  2015 by McGraw-Hill
Education. All rights reserved. Printed in the United States of America. Previous editions  2012, 2010, and
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limited to, in any network or other electronic storage or transmission, or broadcast for distance learning.
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United States.
This book is printed on acid-free paper.
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ISBN 978–0–07–802421–4
MHID 0–07–802421–8
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Library of Congress Cataloging-in-Publication Data
Johnson, George B. (George Brooks), 1942-
The living world / George B. Johnson, Washington University. – Eighth edition.
pages cm
Includes index.
ISBN 978–0–07–802421–4—ISBN 0–07–802421–8 (hard copy : alk. paper) 1. Biology. I. Title.
QH308.2.J62 2015
570–dc23
2013037683
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does not indicate an endorsement by the authors or McGraw-Hill Education, and McGraw-Hill Education does
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joh24218_fm_i-xxii.indd 2 11/14/13 9:31 AM
Brief Contents
|
Chapter 0 studying Biology 1 UNIT 5 EVOLUTION OF ANIMALS
Chapter 19 evolution of the Animal Phyla 403
|
UNIT 1 THE STUDy OF LIFE
Chapter 20 History of the Vertebrates 443
Chapter 1 the science of Biology 15 Chapter 21 How Humans evolved 469
UNIT 2 | THE LIVING CELL UNIT 6 | ANIMAL LIFE
Chapter 2 the Chemistry of Life 35 Chapter 22 the Animal Body and How It Moves 483
Chapter 3 Molecules of Life 51 Chapter 23 Circulation 507
Chapter 4 Cells 71 Chapter 24 Respiration 525
Chapter 5 energy and Life 107 Chapter 25 the Path of Food through the
Animal Body 539
Chapter 6 Photosynthesis: Acquiring energy from
the sun 119 Chapter 26 Maintaining the Internal environment 557
Chapter 7 How Cells Harvest energy from Food 137 Chapter 27 How the Animal Body Defends Itself 573
Chapter 28 the nervous system 595
| Chapter 29 the senses 615
UNIT 3 THE CONTINUITy OF LIFE
Chapter 30 Chemical signaling Within the
Chapter 8 Mitosis 155 Animal Body 631
Chapter 9 Meiosis 173 Chapter 31 Reproduction and Development 647
Chapter 10 Foundations of Genetics 187
Chapter 11 DnA: the Genetic Material 221 UNIT 7 | PLANT LIFE
Chapter 12 How Genes Work 239
Chapter 32 evolution of Plants 671
Chapter 13 Genomics and Biotechnology 259
Chapter 33 Plant Form and Function 691
Chapter 34 Plant Reproduction and Growth 709
|
UNIT 4 THE EVOLUTION AND DIVERSITy
OF LIFE
|
UNIT 8 THE LIVING ENVIRONMENT
Chapter 14 evolution and natural selection 285
Chapter 15 How We name Living things 323 Chapter 35 Populations and Communities 729
Chapter 16 Prokaryotes: the First single-Celled Chapter 36 ecosystems 755
Creatures 341
Chapter 37 Behavior and the environment 781
Chapter 17 Protists: Advent of the eukaryotes 363
Chapter 38 Human Infl uences on the
Chapter 18 Fungi Invade the Land 387 Living World 803
BRIeF Contents iii
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Preface
Now in its eighth edition, The Living World has been an in-
tegral part of my teaching life. No one who teaches biol-
ogy today can fail to appreciate how important a subject it has
become for our modern world. From global warming to stem
cell initiatives to teaching intelligent design in classrooms, bi-
ology permeates the news and in large measure will defi ne our
students’ futures. As a teacher, I have stood in front of class-
rooms for over 30 years and attempted to explain biology to
puzzled and sometimes uninterested students, an experience
that has been both fun and frustrating: fun because biology
is a joy to teach, rich in ideas and interesting concepts, and
increasingly key to many important public issues; frustrating
because in every biology class there are always some students
who do not do well, who not only miss out on the fun but also
fail to acquire a tool that will be essential to their futures.
This text, The Living World, is my attempt to address
this problem. It is short enough to use in one semester, without
gets it all on the fi rst pass. To aid in learning the more diffi cult
a lot of technical details to intimidate wary students. I have
material, I have given special attention to key concepts and pro-
tried to write it in an informal, friendly way, to engage as
cesses such as photosynthesis and osmosis that form the core
well as to teach. The focus of the book is on the biology each
of biology. The essential processes of biology are not optional
student ought to know to live as an informed citizen in the
learning. A student must come to understand every one of them
twenty-fi rst century. I have at every stage addressed ideas and
if he or she is to master biology as a science. A student’s learn-
concepts, rather than detailed information, trying to teach how
ing goal should not be simply to memorize a list of terms but
things work and why things happen the way they do, rather
rather to be able to visualize and understand what’s going on.
than merely naming parts or giving defi nitions.
With this goal in mind, I have prepared some four dozen “this
is how it works” Key Biological Process boxes explaining the
Focusing on the Essential
important concepts and processes that students encounter in in-
Concepts troductory biology. Each of these Key Biological Process boxes
walks the student through a complex process, one step at a time,
More than most subjects, biology is at its core a set of ideas, so that the central idea is not lost in the details.
and if students can master these basic ideas, the rest comes
easy. Unfortunately, while most of today’s students are very
Teaching Biology as an
interested in biology, they are put off by the terminology.
When you don’t know what the words mean, it’s easy to slip Evolutionary Journey
into thinking that the matter is diffi cult, when actually the
This text, and its companion text Essentials of The Living
ideas are simple, easy to grasp, and fun to consider. It’s the
World, were the fi rst texts to combine Evolution and Diversity
terms that get in the way, that stand as a wall between students
into one continuous narrative. Traditionally, students had been
and science. With this text, I have tried to turn those walls into
exposed to weeks of evolution before being dragged through a
windows, so that readers can peer in and join the fun.
detailed tour of the animal phyla, the two areas presented as if
Analogies Analogies have been my tool. In writing The Liv- unrelated to each other. I chose instead to combine these two
ing World, I have searched for simple analogies that relate the areas, presenting biological diversity as an evolutionary jour-
matter at hand to things we all know. As science, analogies are ney. This has proven a very powerful way to teach evolution’s
not exact, but I do not count myself compromised. Analogies role in biology, and today you would be hard pressed to fi nd a
trade precision for clarity. If I do my job right, the key idea is text that does not organize the material in this way.
not compromised by the analogy I use to explain it but rather
Evolutionary Explanations Evolution not only organizes
revealed.
biology, it explains it. It is not enough to say that a frog is an
Key Biological Process Boxes There is no way to avoid amphibian, transitional between fi sh and reptiles. This correctly
the fact that some of the important ideas of biology are com- organizes frogs on the evolutionary spectrum but fails to ex-
plex. No student encountering photosynthesis for the fi rst time plain why frogs are the way they are, with a tadpole life stage
iv PReFACe
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and wet skin. Only when the student is taught that amphibians
evolved as highly successful land animals, often as big as po- Biology and Staying Healthy
nies and armor plated, can students get the point: of 37 families
Anabolic Steroids in Sports receptor” proteins in the cell, preventing these receptors from
of amphibians, all but the two that lived in water (frogs and doing their job of causing protein breakdown, the muscle
cell’s way of suppressing infl ammation and promoting
salamanders) were driven extinct with the advent of reptiles. A Abemeno nthg et hcela mss oosft snyonttohreiotiucs h oofr lmipoidnse sin k nreocwennt ayse aanrsa hbaosli c tphreo tuesine opfr opdroutcetiinons faonr dfu ienl hdiubritiningg e txheer cbirseea. kBdyo iwncnr eoaf spinrogt eins
steroids. Since the 1950s, some athletes in muscle cells after workouts, anabolic
frog has evolved to invade water, not escape it. It is in this way have been taking these chemicals to steroids signifi cantly increase the mass of
build muscle and so boost athletic an athlete’s muscle tissue.
that evolution explains biology, and that is how I have tried to pinetrrfionrsmica unncfea. iBrnoethss boefc tahuiss ea onfd t hbeec ause on yIfo uthre b oondlyy wefafse ctto oefn ahnaanbcoel iyco sutre roids
of health risks, the use of anabolic athletic performance by increasing
use evolution in this text, to explain. steroids has been banned in sports for your muscle mass, using them would
decades. Controversy over their use still be wrong, for one very simple and
in professional baseball has recently important reason: fairness. To gain
returned anabolic steroids to the nation’s advantage in competition by concealed
Confronting Evolution’s Critics As evolution continues front pages. use of anabolic steroids—“doping”—is
Anabolic steroids were developed simply cheating. That is why these drugs
to be a controversial subject to the general public, I have pro- icno nthdeit i1o9n3 i0ns wtoh tirceha tt hhey pmoagloen taesdtiessm d,o a a re Tbhaen nuesed oinf aspnoarbtso.l ic steroids by
not produce suffi cient amounts of the athletes and others is not only wrong but
vided students with an explicit consideration of the objections hormone testosterone for normal growth also illegal, because increased muscle
and sexual development. Scientists mass is not the only effect of using these
rsaoi-sceadl lbedy e“vinotleultliiogne’nst cdreitsiicgsn, .f”o Ic ufseienlg s itnro dnegtlayi lt ohnat thneo csltauidmesn to’sf sttthhhooeea yntc fhcdaoeicusmicllioditcv aapetlrer oesdtdd rtu uhtchceeta u gstrr ybeon ywot hfst hletie tgoishctf otvslskyete reaslreiloottneanrelsi ,n g Hwinao 2ms 0ien1 3vru.onlv esldu igng ear sAteleroxi dR ocdornitgruoevze rsy cstsetpheruemrmortii,ndi cssaao tc litsaoh.n naA atom lffso otorhn ltegeh aaaedd dr ooetolsleet spsoccrfeee ntnmhtt esag,it rruao lrnwieva tehbso , lic
muscle in laboratory animals. The word users remain shorter than they would
education in biology is complete without a frank discussion of arendaubcoelidc tmhee aandsd gerdo iwminpga cotr o bf uthildesine gn.e Fwu rcthheemr tiwcaelas koinn g halasvoe a bffeeecnte wd ibthyo sutet rtohied sd irnu gths.e A fdoollloewscienngt sw aanyds. aAdnualbtso alirce
sexual development. More than 100 different anabolic steroids can lead to potentially fatal liver cysts and liver
this contentious issue. steroids have been developed, most of which have to be cancer (the liver is the organ of the body that attempts to
injected to be effective. All require a prescription to be detoxify the blood), cholesterol changes and hypertension
used legally in the United States, and all are banned in (both of which can promote heart attack and stroke), and
professional, college, and high school sports. acne. Other signs of steroid use in men include reduced
Another way to increase the body’s level of size of testicles, balding, and development of breasts. In
Linking Biology to Everyday Life tbeustt oosnteer othnaet itsh teo buosde ya ccohnevmeritcsa tlo t hteastt oiss tneorot nites.e lOf naen abolic wofo tmhee nv,o sicigen, as nindc lcuedssea tthioen g orof wmtehn ostf rfuaactiiaoln h.air, lowering
such chemical is 4-androstenedione, more commonly In the fall of 2003, athletic organizations learned
called “andro.” It was fi rst developed in the 1970s by that some athletes were using a new performance-
East German scientists to try to enhance their athletes’ enhancing anabolic steroid undetectable by standard
One of the principal roles of nonmajors’ biology courses is to Olympic performances. Because andro does not have antidoping tests, tetrahydrogestrinone (THG). The use of
the same side effects as anabolic steroids, it was legally THG was only discovered because an anonymous coach
create educated citizens. In writing The Living World, I have available until 2004. It was used by baseball slugger sent a spent syringe to U.S. antidoping offi cials. THG’s
Mark McGwire, but it is now banned in all sports, and chemical structure is similar to gestrinone, a drug used
possession of andro is a federal crime. to treat a form of pelvic infl ammation, and can be made
endeavored wherever possible to connect what the students Anabolic steroids work by signalling muscle cells from it by simply adding four hydrogen atoms, an easy
to make more protein. They bind to special “androgenic chemical task. THG tends to break down when prepared
are learning to their own everyday lives. rjaecbebpintogr ”th persoet epirnost ewinitsh wini tthh ea cpeollkse or,f tmheu sbcilned tiinssgu pe.r oLdikse t he faonrt aidnoapliynsgis tbeyst ss thaandd afardil emd etaon dse, twechti cith. Nexepwl auirnins ew theyst s for
receptors into action, causing them to activate genes on THG that were developed in 2004 have been used to catch
the cell’s chromosomes that produce muscle tissue proteins, several well-known sports fi gures. Olympic athlete Marion
Connections Throughout The Living World are full-page fea- triggering an increase in protein synthesis. At the same time, Jones and baseball sluggers Alex Rodriguez, Barry Bonds,
the anabolic steroid molecules bind to so-called “cortisol and Mark McGwire have all been involved in steroid use.
tures written by me that make connections between a chapter’s
contents and the everyday world: Biology and Staying Healthy 66 UNIT TWO THE LIVING CELL
discusses health issues that impact each student; Today’s Biolo-
gy examines advances that importantly affect society; A Closer joh24218_ch03_051-070.indd 66 10/15/13 9:25 AM
Look examines interesting points in more detail; and Author’s
Corner takes a more personal view (mine) of how science re-
lates to our personal lives.
Using Art That Teaches The Leaf Surface Now follow the light as it passes into a leaf. The beam of
-
prisingly strong layer of protection. Light passes right through this transparent
Art has always been a core component of this text, as today’s wax and then proceeds to pass right on through a layer of cells immediately
beneath the cuticle called the epidermis. Only one cell thick, this epidermis
acts as the “skin” of the leaf, providing more protection from damage and, very
students are visual learners. To help students learn, The Living importantly, controlling how gases and water enter and leave the leaf. Very little
of the light has been absorbed by the leaf at this point—neither the cuticle nor
World has a clean and simple art style that focuses on concepts the epidermis absorb much.
and minimizes detail. In this edition, I have sought to amplify
Cross-section of leaf
the power of illustrations to teach concepts by linking the in-
terior content of illustrations directly to the text that describes Cuticle
that part of the illustration:
Epidermis
Integrated Art Many topics, such as the introduction to pho- Mesophyll Stoma
tosynthesis (treated on pages 120-123), involve several different Bshuenadtlhe Nucleus
Vascular Vacuole
interacting processes, each explained with its own illustration. bundle
In these instances, bouncing back and forth between illustration Mdiaetesolyp ehnyclol uCnetelrlss laPyaesrs ianfgte trh lraoyuegrh o tfh me eepsoidpehrymlli sc,e tlhles. l Tighhets iem cmelels-
-
and text makes it diffi cult for a student to gain or retain perspec- phyll cells contain numerous chloroplasts, which as you recall
from chapter 4 are organelles found in all plants and algae.
They are visible as green specks in the mesophyll cells
tive, and so I have chosen in these instances to integrate the in the cross section of the leaf above. It is here, within
the mesophyll cells penetrated by the light beam, that
illustrations directly into the text, providing a single narrative. photosynthesis occurs.
Cell wall
Chloroplasts
You will fi nd that this “integrated art” throughout the book—
Mesophyll cell
working art into the text narrative—has become a distinctive Thylakoid Chloroplasts Light penetrates into mesophyll cells. The cell walls
of the mesophyll cells don’t absorb it, nor does the plasma membrane
feature of this text. Inner membrane or nucleus or mitochondria. Why not? Because these elements of the
mesophyll cell contain few, if any, molecules that absorb visible light.
Outer membrane If chloroplasts were not also present in these cells, most of this
Bubble Numbers In complex diagrams where there is a lot Granum lidgehrtm wios.u Bldu pt acshsl orrigohptl atshtrso aurgeh p, rjeusset nats, ilto tpsa ossfe tdh ethmr.o Ougnhe tchhel oerpoi--
plast is highlighted by a box in the mesophyll cell above. Light
going on, I have placed numbers (set off in colored balls) at key Stroma passes into the cell to the chloroplast, and when it reaches the
chloroplast, it passes through the outer and inner membranes
positions, and the same “bubble numbers” at those locations in Chloroplast seteon r eaas cthh et hger etehny ldaiksokisd i nst rthuec tcuuretasw waiyth cihnl othroe pclhalsot rsohpolwasnt, hcelreea.r ly
the text where that element of the illustration is being described. CHAPTER 6 PHOTOSYNTHESIS: ACQUIRING ENERGY FROM THE SUN 121
This makes it much easier for a student to walk through the
complex illustration and see how the parts are related.
PReFACe v
joh24218_fm_i-xxii.indd 5 11/14/13 9:32 AM
Helping Students Learn
Chapter Zero In over thirty years of teaching, I have seen
students do well and others do poorly, and one of the best
Learning Objectives 0
predictors of who would do well has been how well a student
Learning
is prepared to learn. Entering a large freshman course, does a 0.1 1H. oLbwiios tlto otgh ySe tspuuricdncyceispsaful ltlhyi.n gs you will need to do in order to study Studying Biology
student know how to take notes? Does a student know how to 2. Eprxopmlapintl yw. hy it is important to recopy your lecture notes
3. Name two things you can do to slow down the forgetting
use these notes effectively with the textbook? Can a student 4. pLriostc ethsrse.e general means of rehearsal.
5. Describe three strategies to improve studying efficiency.
even read a graph? In The Living World, I have decided to 0.2 AUutshionrg’s CYoorunre rT: ePxutllbinogo akn All-Nighter
1. Describe how your text can be used to reinforce and clarify
tackle this problem head on and have added a Chapter 0 at the 2. wRehvaite ywo uth lee aarsns eisns mlecetnutr teo. ols that the text provides to help you
master the material.
beginning of the text to help students with these very basic but 0.3 1U.s iDnegs cYriobue trh Te efixvet bkoinodks ’osf Iinntteerarcntievte Rqueessotiuonrsc eenscountered in
Connect.
essential learning tools. Learning to take effective notes dur- 2. Dhaevsec rliebaer nheodw. LearnSmart’s assessment tests how well you
ing lecture, to recopy these notes promptly, and to key them P0.u4 ttSincigen Wce hIs aat W Yaoyu o fL Tehainrnki ntgo Work
1. Analyze how biological scientists have come to a conclusion
to the text for effi cient review when studying are skills that when confronted with problems of major public importance.
0.5 How to Read a Graph
1. Define independent variable, and explain why correlation of
will improve students’ performance not only in this course but 2. dDeipscernidmeinnta vtea rbiaebtwleese dno aersi tnhomt eptrico vaen dca luosgaatriiotnh.m ic scales.
3. Explain how a regression line is drawn.
throughout their college careers. Learning how to read a graph 45.. CLiosnt tarnasdt dai slicnues sw tihthe afo huirs tdoigstrianmct. steps scientists use to
analyze a graph.
is a skill that will stand students in good stead throughout their
lives.
Learning Objectives and Outcomes Students learn best Thbiys 3th0o,0u0g0h tlfounlg p qourcilulps.i nTeh, enyi babreli nngo th fios rb dreeackofraastito, nis, caos vaenrye d
animal approaching the porcupine soon learns. The quills are
when they are given a clear idea of what it is they are supposed sphoarrcpu,p ainned atinndy ibnatorb yso cuo!a Ft othrees tti pcsre—attuoruecsh, pthoercmu,p ainneds tlhievye cao smoleit oarfyf tlhifee ,
their woodland habitat increasingly encroached by human progress.
to learn. With this in mind, The Living World begins each chap- The porcupine’s fate, and that of all other creatures of the living
world, will depend critically on the steps we humans take to protect
ter with a list of specifi c learning objectives, keyed to that chap- awnidll pprreosveirdvee yoouur wwiotrhl da’ sk ecyli mtoaotle t oan hde lrpe.s oYuoruc easr.e Y aobuoru st ttuod lye aopf biniotolo tghye
study of molecules, cells, and intricate body processes, of evolution
ter’s numbered segments. A learning objective is the intended and ecology. Rich with new ideas unknown to many of you, biology is
a science course full of promise. This short “Chapter Zero” is intended
to provide you with the tools to make the leap more strongly and with
result of study, a specifi c statement of what a student should be greater confidence. Good luck.
able to do when he or she successfully learns the material cov-
1
ered in that chapter segment. Learning objectives are typically
discrete and quite specifi c—the small building blocks with
which a student constructs understanding.
In this edition, each learning objective is repeated at the
point that material appears in the text, again in the review at
chapter’s end, and again in the list of questions that end the
Structure and Function of Plant Tissues
chapter. This “learning path” guides the student through the key 33.1 Organization Apical meristem Terminal bud
elements of each chapter, assessing how well each is mastered. of a Vascular Plant Pzorinmeary growth PBVeelatinidoele Leaf
Axillary bud
At the end of each numbered chapter segment, I have
The Plant Body Lateral
meristems
also placed one or more Key Learning Outcomes. Said simply, La epalrannitn.g Objective 33.1.1 Diagram the basic body plan of Internode Node
a learning outcome is a realized set of learning objectives, a Most plants possess the same fundamental architecture and the Shoot
same three major groups of organs: roots, stems, and leaves.
concrete statement of what a student should have learned after Vcoansdcuulcatrs pwlaantetrs, hmavinee wrailtsh, iann tdh efioro sdt etmhrso uvagshcouulta rth teis psulaen, tw. hich
A vascular plant is organized along a vertical axis
mastering that chapter segment. (figure 33.1). The part belowground is called the root, and
the part aboveground is called the shoot (although in some
Learning objectives and outcomes together provide a isnhsotoantsc ecsa,n reoxotetsn dm baeylo wex tiet)n. dA latbhoovueg ht hroeo tgsr oaunndd s,h oaontds dsoifmfeer Vascular system Pith
in their basic structure, growth at the tips throughout the life
student with a powerful learning tool. Learning objectives othfe t hseo iiln dainvdi daubaslo irsb csh waraatcetre rainstdic v oafr ibooutsh .m Tihnee rraolos,t pwehniecthr aateres Lateral root
crucial for plant nutrition. It also anchors the plant. The shoot
help the student focus on the important points as they read consists of stem and leaves. The stem serves as a framework
a chapter section, and end-of-chapter testing of each specifi c ftaokr etsh pe lpacoes.i tTiohnei nagrr aonfg tehme elneat,v seisz,e ,w ahnedr es hmapoes to pf hthoeto lseyanvtehse asries Root
critically important in the plant’s production of food. Flowers,
and ultimately fruits and seeds, are also formed on the shoot. Primary root
learning objective provides the student a very pointed indica-
Meristems Primary growth zone
tor of how well he or she has mastered the objectives that were Learning Objective 33.1.2 Distinguish between primary and Apical meristem
secondary growth. Figure 33.1 The body of a plant.
the target of their learning. When an animal grows taller, all parts of its body lengthen— The body of this dicot plant consists of an aboveground portion
when you grew taller as a child, your arms and legs length- called the shoot (stems and leaves) and a belowground portion
Assessing Progress The series of questions that appears at eIgnnrseetwde,a ldiak,n eidt t ahsdiosd ,ds y itodisu syru oleeusgr stot ow trhoseou .lt diAp gs e potl fal onitnts g dreooroe atssnn da’t ny dgo rusohrw oho ettahsdi.s It faw lylaoeyru., ctgoaarfe kltelehensed a p ptrlhelaaaecn ser)t o w,d osihtov.e -iEcdnlae ocl nlaleugtd satt hseteireocs n eoonn fod dcfs aet rohllyfse tgcpharleoal lwnreodttho, tts,h sot ea-ac knaaepdlsli e tcphdal ealp mcsretieme imrnais srtt.hye T megh rlsiao c(twkleiemtrhnae,il n g
while the central portion of your body would not change. meristems (yellow areas) of the stem, allowing the plant to increase in
the end of every chapter provides a student with a powerful Why do plants grow in this way? The plant body con- girth like letting out a belt.
tains growth zones of unspecialized cells called meristems.
aboqseuusgteecissnotsinmominneessgn wtao strfo i tatoth elre net oscau hts laetthp eort eehf reo t whhleea v vwesetle uslb dloe etfehn nset o’ tslpr eahsantirussntfdiiocnyra.gm t Tiooehbndej, e ialncicttsioctv o eilrnesd caialrnutng dit nhetoges acaMpisumstnoltp,eaeee dmimon rrc itnimtamsoas etIgltt oe oei ntcrcmmhnml oe,pee wl pecsl wlcar p autdaenhhitllrsihalat iveltslbnwrsee i, ut da mae pftrtebvyu herssaoisnaei ,dl tdm sc sooero yotfe wnia,tg og hcgrciirnieevteoyeoh rnesn n m sg uetairusris licu negtso oticxfuegiwnfrhv paeeg tet alorse hllletc iy iystsn kttwi soi serdvtip eo h oieidlpv“ nan acilsictif.need ttfeelittniella hnmisrlgtes ge.erd h yn Oodcic tvw teeimnahaillettsleltah s seitmryo”.h e t a nesIhmsinne anhttdal ith avtp i aharrnecseentisso s s bi. on mm suywTctol reatctmhai hrlubiaysineer--t,, aiuotacrhsoccaefteo tcdmeti tumhv vsbdmeia iaitGa uvysutpncimir llocdsouaa i,f wtlno ts iatfihtonhtsrr hoosn be o ucoms olife atand os ,tmt wy f.htec .hbes hroTeiiiaiclrucchol kmoch ermnene r,ael eddelrws rsaiasy sirh,rrseey eeits lc setxlethhoumwcy ewlolgtos esn oi, m vi kdupwneit ra sahneifr mnridirycg dsilah usa grpoe yrairh fleeroty l erolow3 as i ce 3tn utyoem.h ll1rfttih,a ,i.n b m leaidT an nmate rvhdhktroeee si trc llo hoivcyksneofe et t senmbnch mtooiitienchnrtsrhkgek--:
at the tips of roots and shoots, colored lime green in fig-
Batleo konmo’ws lteadxgoen oamndy c oofm leparrenhienngs cioante, gqoureiestsi:o qnus etshtaiot nchs athllaetn egvea tlhue- utimhtr aefeod e3rexm3 ut.es1p n. w osTifhoh atneht egoi srfp o krtwihnmetoha wp roynlfa tnatihsts esbtushoeeed s my.p.er iArmissat erthmye sp blraeonsdtuy lb ttosi dppy re,i mlwoanhrgiicalyhte iisns, gKagrr evooyawu sLptcheiuna lzgaro rnon ipfen ltsagu cn baOtel uslies tc dcao o mncmnoenerecit s3titni3enum.g1o s ur.osTo shttsre u tboco tluderyae vo,e fas , with
student to carry out application and analysis, and questions that 692 UNIT SEVEN PLANT LIFE
require synthesis and evaluation.
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Connect and LearnSmart Every year, more and more stu-
dents using The Living World do so on their laptop computers
or iPads. This use opens up an exciting potential: the text can
be interactive. Embedded throughout the eBook version of The
Living World 8e are animations and videos that a student can
use to explore certain topics further. The interactivity also al-
lows students to be in one-to-one contact with their instructors,
which helps in clarifying schedules and taking exams.
Every bit as important, an interactive text using the Con-
nectPlus text-integrated assessment program allows both the
instructor and student to assess progress through each chap-
ter’s learning path. In Connect, instructors assign a class a
series of interactive questions. As the student complete these
interactives, Connect grades each answer. If a student has
trouble with a question, the program connects that question
to the learning objective in the eBook where the question is
answered. By the time a student has successfully navigated
the series of instructor-assigned questions, he or she will be
well on the way to mastering the assignment.
Connect-assigned quizzes are instructor-driven, typical- A Connect question.
ly with the same set of questions selected by the instructor for
the entire class. However, not all students come to a freshman
biology class equally well prepared. For many, it is their fi rst
science course. For others, high school science class seems
in the distant past. For still others, they are right on top of the
material and eager to charge ahead.
LearnSmart, which is delivered through Connect, ad-
&
dresses this problem in a direct way, tailoring its questions to
each student individually. Using artifi cial intelligence, Learn- I N Q U I RYY AA N A LY S I S
Smart examines a student’s answers to a series of questions, Are Island Populations of Song Effects of Population Size on Songbird Success
Sparrows Density Dependent? 0.9
pinpoints concepts and information the student does not yet
unneeddesrs ttoa nleda, rann. dT hmea ppos woeurt oaf sLtueadryn pSlmana rfto’sr awphparot atchha ti ss ttuhdaet nitt Wvoginnirpusoflhpimwtueooebntrrhntes ui rcsfrsnelra ao iotttnmehfy d iei tns o opr dta aohtiftevpfeeseiur dtca lputtateho atwdeiplo shubd nwiylecsa gi hittartih seori tieensn giistz sroa,eo o t .wlpwh aAoehst yp eipbcd uopeh,lpc ra roaauetvu iclpoaiesdonetiveip oit iunaennnlcng’asrd teans iatiotozotsn re ea’ dscc atinv e Juvenile mortality 0000....5768
adapts directly to each particular student. As a student moves dofe pdleeateth a bvya idlaebplreiv raetsioounr.c Aesl,s ole, apdriendga ttoor as nte inndc rteoa fsoecdu rsi sk 0.4
their attention on common prey, resulting in increasing 0 20 40 60 80 100 120 140
through his or her individualized study plan, “timeouts” take rkantoews oinf gm tohratta lai tpy oapsu plaotpiounla itsio dnesc rgeraoswin. Hg oinw nevuemr, bseimrs pdloye s Number of breeding adults
not tell you that the decrease has been caused by the size b. How many populations were observed to have
the student to the appropriate eBook text page to sharpen hazy of the population. Many factors, such as severe weather, juvenile mortality rates below this average value?
volcanic eruption, and human disturbance, can influence What is the average size of these populations?
understanding. A student and LearnSmart constitute an indi- islanTdh pe ogprualpahti oton t shieze rsi,g thoto d.isplays data collected from 13 cju. vHenoiwle mmaonrtya pliotyp uralatetiso anbso wvee rteh iosb asveervraegde t ov ahlauvee?
song sparrow populations on Mandarte Island (see map What is the average size of these populations?
vidualized biology course, with a learning path contoured to a below). In an attempt to gauge the impact of population 3. Making Inferences Are the populations with
size on the evolutionary success of these populations, lower juvenile mortality bigger or smaller than the
each population was censused and its juvenile mortality populations with higher juvenile mortality?
student’s particular needs and speed of learning. rate estimated. On the graph, these juvenile mortality 4. Drawing Conclusions Do the population sizes
rates have been plotted against the number of breeding of these song sparrows support the hypothesis of
adults in each population. Although the data appear density dependence?
scattered, the “best-fit” regression line is statistically 5. Further Analysis
significant (statistically significant means that there is a. The fact that the song sparrow populations with
Teaching Science As a Process abe ltewsse ethna dne p5e%n dcehnatn acen dth iantd tehpeerned ies,n itn v faarciat,b nleos )c.orrelation ltohwoseer wjuivthen hilieg hmero rjutavleitnyi laer me ao rdtaiflfietrye ndot essiz ne otht, ainn
1. Applying Concepts itself, establish that the difference is statistically
a. Variable. In the graph, what is the dependent significant. How would you go about testing these
variable? data to see if the relationship between juvenile
Inquiry and Analysis One of the most useful things a stu- bth. eA sonnagl yszpianrrgo wSc paotpteurlaetdio Dn a(btaas. edW ohna tb irse ethdein sgiz aed ouf lts) mb.o Wrtahlaitty w aonudl dp oyopuu leaxtipoenc ts itzoe h isa prepaeln? if the
with the least juvenile mortality? With the most? researchers supplemented the food available to the
dent can take away from his or her biology class is the ability 2. Ian. tWerhparte itsi tnhge Davaetraage juvenile mortality of all 13 bc.i rdWs?h aEtx wploauinld. you expect to happen if the researchers
populations, estimated from the 13 points on the removed individuals from populations with more than
to judge scientifi c claims that they encounter as citizens, long graph? 100 breeding adults, reducing each to 100?
after college is over. As a way of teaching that important skill, N B.C.
Vancouver
every chapter now ends with an Inquiry and Analysis feature, a CANADA
U.S.A.
full-page presentation of an actual scientifi c investigation that VIsalanncdouver MIasnladnadrte
Sidney
requires the student to analyze the data and reach conclusions.
Victoria
Few pages in this text provide more bang for the buck in learn-
ing that lasts. 752 UNIT EIGHT THE LIVING ENVIRONMENT
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New to This Edition of all major groups, it is possible to sort through the many
protistan classes and families, and identify who is related to
Presentation A major effort has been made in this edition to who. Chapter 17 presents the current clear picture of King-
improve The Living World as a learning tool. The focus of this dom Protista, identifying the ancestors of plants, animals, and
effort has been to identify in each chapter those elements on (for the fi rst time) fungi.
which you should target your attention—learning objectives, in The fungi themselves have been the target of consider-
the parlance of education specialists. Every chapter opens with able genomic analysis. To a taxonomist, fungi present a spe-
a list of the learning objectives you should attempt to master. cial problem: fungi are traditionally classifi ed by how they
While by no means all that you can or should learn from the reproduce as being members of one of three groups: Zygomy-
chapter, they provide very useful guideposts of what is impor- cetes, Ascomycetes, and Basidiomycetes. The problem is that
tant. As you proceed through the chapter, you will again en- reproduction has not been observed in over a third of fungi; so
counter these learning objectives, each one repeated at the point how do you classify them? Until now, mycologists (biologists
in the text where that material is covered—in effect, placing the who study fungi) have simply put them aside, labeling them
cross-hairs of your attention right on the target. “fungi imperfecti.” Now, with genomes sequenced, it is possi-
Thus, in this edition learning objectives serve as markers ble to assign each kind of fungus to a phylogenetic group—to
to defi ne your “learning path” through the text. Each objective classify fungi not by how they reproduce, but by the similarity
is identifi ed in the end-of-chapter summary and then individu- of their genomes. Chapter 18 presents for the fi rst time a clear
ally assessed with one or more questions at the end of the chap- picture of Kingdom Fungi, which turns out to include some
ter. Following the path marked by a chapter’s learning objec- forms we had thought to be protists!
tives will take you a long way toward learning its key content. The widespread use of high-speed genome sequencing
Content Many chapters of this revision of The Living World technology has had other major impacts on biology. One of
have been updated to refl ect scientifi c advances. In particular, the most surprising and important came out of a study in 2012
the impact of new gene sequencing technologies on biology has of genetic variation in Iceland. Researchers interested in iden-
been enormous since the last edition. To give but one example: tifying genes contributing to autism set out to sequence the
In the previous edition on page 466, the discovery of an ancient entire genomes of a large number of individuals from Iceland.
human fi ngerbone in 2010 is described. Found in Siberia, re- In Iceland, precise records have been kept for many genera-
searchers were able to sequence portions of the mitochondrial tions of births and marriages, so it is possible to ascertain not
DNA recovered from the bone cells—the DNA had been pre- only which mutations an individual possesses, but also from
served in the cold for thousands of years. It was a human se- which parent they were inherited, and how old that parent was
quence, but unlike either Neanderthal or modern humans—a at the child’s conception. As we recount in chapter 11, an un-
new species of human. In the following two years, new DNA anticipated fi nding leaps out from the data: the great majority
sequencing technologies coupled to powerful computer analy- of the new mutations arise in fathers, and the older the father
sis has allowed researchers to sequence the entire genome of at conception, the greater the likelihood of mutation. We are
this new human species, all from a fi ngerbone! used to worrying about the mother’s age at conception if she is
A major focus of research in biology over the last few much over 30, as advanced maternal age is highly correlated
years has been epigenetics, the inheritance of gene regulatory with Down syndrome and other problems of chromosome as-
information that does not involve changes to DNA. This sort sortment in meiosis. Now, it seems, the father’s age is at least
of inheritance of acquired characteristics, famously proposed as big an issue.
by Lamarck, has been considered impossible by biologists Genomics has continued to alter our understanding of
since Mendel. But not quite, it turns out. As we discuss in things we thought were settled biology. We used to teach stu-
chapter 10 of this edition, epigenetic inheritance from one cell dents, for example, that the human Y chromosome is largely
generation to the next is widespread. The nucleus in each of devoid of translated genes. As you will see in chapter 10, the
your body cells has all of your genes, but different cells use full nucleotide sequence of the Y chromosome reveals the
different ones, and these instructions—determining which presence of quite a few functional genes, many of them play-
gene is ON and which is OFF—are passed down from one cell ing key roles in sex determination and reproduction. Compar-
generation to the next during your development and growth: ing the Y chromosome to its homolog the X, men are more
Epigenetics. The 2012 Nobel Prize for Medicine was awarded different from women in expressed genes than men are from
to Japanese researcher Shinya Yamanaka for discovering the male chimpanzees!
molecular signals used in the epigenetic modifi cation of hu- Many other advances in biology have crept into The
man cells as they proceed through development. Living World 8e, by no means all of them involving genom-
In two places in The Living World, the widespread use of ics. The effects of human population growth and of the AIDS
genome sequencing has led to major revisions of our under- epidemics continue, and their discussions in this edition have
standing. The fi rst is in the way biologists classify the protists. been updated to refl ect this. Prions, famous as the agents of
By far the most diverse of the six kingdoms, the protists have mad cow disease, are now explored for a full page in chapter
until now defi ed the best efforts of taxonomists to sort out 3. Often treated in chapters devoted to viruses, prions are in
relationships. Kingdom Protista has been presented as simply fact misfolded proteins, not some sort of simplifi ed viruses,
a grab bag of all eukaryotes that were not plants, fungi, or ani- and are best examined while a student is learning about pro-
mals. Now all that has changed. With full genome sequences tein folding.
viii PReFACe
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Giving Biology a Personal Perspective
The author has written full-page boxed readings to help students make connections
to the everyday world.
Author’s Corner essays take a more personal
view of how science relates to our everyday lives. Author’s Corner
Pulling an All-Nighter p. 5 The Author Works Out is flexible but weak, but like the epoxy of fiberglass, it
acts to spread any stress over many crystals, making
bone resistant to fracture. As a result, bone is both strong
Where Are All My Socks Going? p. 27 No one seeing the ring of fat decorating my middle and flexible.
would take me for a runner. Only in my memory do I When you subject a bone in your body to stress—
get up with the robins, lace up say, by running—the bone grows
Are Bird-Killing Cats Nature’s Way of Making mthye frruonnnt idnogo srh, oaensd, bruonu nthcee osturte ets swoo arks ltooa wd.i tHhostwa nddo etsh teh ger ebaotneer
around Washington University “know” just where to add more
Better Birds? p. 316 before going to work. Now my 5-K material? When stress deforms
runs are 30-year-old memories. the collagen fibers of a leg bone,
Any mention I make of my the interior of the collagen fibers
The Author Works Out p. 501 running in a race only evokes becomes exposed, like opening
screams of laughter from my your jacket and exposing your
daughters and an arch look from shirt. The fiber interior produces
my wife. Memory is cruelest when a minute electrical charge. Cells
it is accurate. called fibroblasts are attracted to
I remember clearly the day I the electricity like bugs to night
stopped running. It was a cool fall lights and secrete more collagen
morning in 1978, and I was part there. As a result, new collagen
of a mob running a 5-K (that’s fibers are laid down on a bone
5 kilometers for the uninitiated) along the lines of stress. Slowly,
race, winding around the hills over months, calcium phosphate
near the university. I started to get crystals convert the new collagen
flashes of pain in my legs below the to new bone. In your legs, the new
knees—like shin splints but much bone forms along the long stress
worse. Imagine fire pouring on your lines that curve down along the
bones. Did I stop running? No. Like shank of the bone.
a bonehead, I kept going, “working Now go back 30 years and
through the pain,” and finished the race. I have never run a visualize me pounding happily
race since. down the concrete pavement each morning. I had only
I had pulled a muscle in my thigh, which caused part recently begun to run on the sidewalk and for an hour or
of the pain. But that wasn’t all. The pain in my lower legs more at a stretch. Every stride I took those mornings was a
wasn’t shin splints and didn’t go away. A trip to the doctor blow to my shinbones, a stress to which my bones no doubt
revealed multiple stress fractures in both legs. The X rays of began to respond by forming collagen along the spiral lines
my legs looked like tiny threads had been wrapped around of stress. Had I run on a softer surface, the daily stress would
the shaft of each bone, like the red stripe on a barber’s pole. have been far less severe. Had I gradually increased my
It was summer before I could walk without pain. running, new bone would have had time to form properly
What went wrong? Isn’t running supposed to in response to the added stress. I gave my leg bones a lot of
be GOOD for you? Not if you run improperly. In my stress and no time to respond to it. I pushed them too hard,
enthusiasm to be healthy, I ignored some simple rules too fast, and they gave way.
aanndd ppaaiidd tthhee pprriiccee.. TThhee bbiioollooggyy lleessssoonn II iiggnnoorreedd hhaadd ttoo ddoo NNoorr wwaass mmyy iimmpprrooppeerr rruunnnniinngg lliimmiitteedd ttoo oovveerrssttrreesssseedd
Today’s Biology closely examines important wmiathd eh oofw s tboonnee, ss oglriodw a. nTdh ep elormnga nboennte.s T ohf eyyo aurre l edgysn aarme inco t leexgc ebsosnivees .e Rneethmmueesmmiabbsmeerr ,tt Ihh naaett vppeuurll llweedda rttmmhhiieeggddhh uu mmpp uubbsseeccffllooeerr??ee II IInn rr mmaannyy..
structures, constantly being re-formed and strengthened I was having too much fun to worryy aabboouutt ssuucchh ddeettaaiillss..
advances in science and medicine. Today’s Bini roespolnose gto thye stresses to which you subject them. Wiser now,, II aamm ssuurree tthhee ppuulllleedd tthhiigghh mmuussccllee wwaass aa ddiirreecctt
To understand how bone grows, we first need to result of failing to properly stretch before running.
recall a bit about what bone is like. Bone, as you have I was reminded of that pulled muscle recently,
learned in this chapter, is made of fibers of a flexible listening to a good friend of my wife’ss ddeessccrriibbee hhooww
The Father’s Apgroete iAn cfaflelecd tcosll atghene s tuRciks tkog ether to form cartilage. she sets out early each mornniinngg ffoorr aa lloonngg rruunn wwiitthhoouutt
APMCrcoieioldmdn -RsbT aoraialnnend rea MnpDt.ae 4Cdfe64 Cc Ptohsw oC taDonsis yCenaatshuees esi sDp .i s5pe9a. s1e3 3p. 82 oWcsat btgeryhei acrsnhfnrthido hdgionilmMnrt meaoioI ionoanlfimeons dsdcuIgo aeacv oymh,leant f, tla anatahcar vsehcnrlestes iei uadse laidbkda,smog es rvmrfeoeecpaen nnrhartocti y etmtfoafoe rotcnnsrrehra .n d nh fegrWAipaNa otmea terhf lrshfevmane h u opawegye teilbsriigh elo rrsrpeerrrneau eetegie pha rtatcercisnita aek s oenohlama rnetearan aeed tdsetrbu nes,sl ummsc iy. duttt nhlnaa uUst btas w o trrem(nsbrrjienatioqiyoioo n tg eibrkuonh“dwngi iee,eftdso y g arpetn.paq,s ii n cdtointcolgu stlh eeo”wy oi ceyvdlve)f,osri e o ei kt tnenctnrfoiluehvfaooeosg u reederirnpD dlr t dbbe ssfiyoentull, oo eeatrwetlnnhec-lghwsn dteeiehe s s d g aiceanrpo ertleeaold at mb gscotearrnyndese netfi. ag Number of mutations transmitted toobTltfeshh a child by a particular parent rceo.sa fCcbr crtoe8426iayllc0000lsaloactgamigueles.emn esseesdetenyniFMrdaaeaetto,hhrr,tt thcccshbuuCehhhheussHr ireiioonnaaA ffmdgssP ggttl TiiaeoooEccdyrR oo gg wdduf2aaa p2azzhhi ereleew mmlltTaalloaeeHllii tt rnnfiEpphhm ggnooA.. lduuuuUUNy nnpp InnioMtdd..ll. nee AiiIInn ss Lcctssggh aa Bss ennddhhO ooceeDssoww eeYuuoeenn ssA lhheee Nttssreehh Drrmmmee iiHppnnoooOaarrr mmnneeWvv iieess yynnIeemm Tggnnmm sseeMss,,iinnee nnOOOaa ttttdd VVVnnhhii’’nnEEE ssaaSSS nn 555II 0001
Does Environment Affect I.Q.? p. 201 novo mutations—mutations arising in egg or sperm cells. 0
To help filter out artifacts, the researchers first 15 20 25 30 35 40
sequenced 1,859 Icelanders to develop a profile of Age of transmitting parent at
The Y Chromosome–Men Really Are variation in the population. The researchers then started child’s conception (yrs)
their analysis by examining two-generation families (the
child of a trio has gone on to have children), where it is (a)
Different p. 210 pmoustsaibtiloe nto i nd eat ecrhmilidn. eT thheey p waerreen at bolfe o troig ainn aolfy ezae cshix d seu ncohv o 100
DTDhNNeMAA Fu aFattinanhdtgei oert’nhrsp eAr Iigpnne.tn i 2onA3cgf2fe enccptes. 2tPh3roe1 jeRcistk opf . 267 cetop t24mathrhhaf20mra oeeeci--tnlyy strohdfnheaseean rmnucenaaAetghrhtmrrsni e m--mittte oodlhsbrardo all .ieeaddni tnnnrcDstb d ieagmfs onioa t m mddcfhtugto h hehmei ttetatthe ih e se4lufus rde ermr0e1p t mrort a a5 eprsmumtagtni.iert xineanCuroa t ae nsncttholg raimehswsfroeeatm a i ntiithlrmcohtphdl iosinyttehcre ooms8e hsy. ttp n 9ahh t itaaohn ,obeem rfrea gor eehbt u un cahf2iuchrtstnte2o loa i1k ccd-nlmtdyh1o di toeowe nr?i mfltain n hdtbhTtrrsou,hiuhei-; cvbo wt eteaohfaiul a hnd m trmt4cti eigehaof0lus u aentm-ieut onyttraaslha, eetc. t t tseaar ihAi foeroranre a n-onr dosresms lei dssi kn Number of mutations transmitted toa child by either parent 527055 ASOucthhtiesizrmophrenia
A DNA Timeline p. 273 g reatlTy haiss tihneit ifaalt hsteurd ayg tehs.u s suggests the male parent 0 15 20 25 30 35 40
makes a disproportionate contribution to the next Age of father at child’s conception (years)
Darwin and Moby Dick p. 295 gaegne erreastuioltns 'isn m aunt aatvioernasg. eE vinercyre aadsed iotifo tnwaol myeuatra otifo pnast ienrn al (b)
offspring, while the number of mutations transmitted by
DNA “Bar Codes” p. 332 t he mWothitehr tdhoise sk enyo tr einsuclrte ains eh saignndi,fi tchaen rtelsye waricthh eargs et.hen pderovdeluocpemd efrnotm, w shteilme scheell sis e satrillly iinn hthere mcoouthrseer 'os fw hoemr bbo. dy's
sequenced the entire genomes of 78 trios, a total of 219 They remain there, partway through meiosis, until they
Has Life Evolved Elsewhere? p. 345 dainsatilnycsti si nhdaidv iaduutaislsm. F(oarutyti somf t shpee cchtriuldmre dni ssoerledcetre, dA fSoDr ), aderee pa-cftrieveaztee.d T fhoer movuutlaattiioonns. tThhaitn akc ocuf imt ausla at ep ihny tshioel oDgNicAa l
and 21 were schizophrenic. As in a trio, it is not possible of the eggs during this long storage phase will affect the
Meet Our Hobbit Cousin p. 477 tmo udteatteiromn itnoe t whehiirc chh piladr;e anltl cdoen ntorvibou mteudt aat ipoanrst iicnu laa rc hild etemnbdr tyoo h thavaet tmheo reeg cgh biledcroemn ewsi (tthh caht rios mwohsyo omldael rp mroobtlhemerss
were considered together. Based on the results of the like Down syndrome). But the mutations do not affect the
Race and Medicine p. 479 finrusmt sbtuerd oy f( dgera npohvo a m), uthtae trieosnesa trrcahnesrms aitnteadly tzoe dch tihlde rteonta al s a sdteefmec tcse allrse t hnaott cpraesasteedd othne t oe gfugstu, sroe gtheenseer achtiroonms.o Aso fmatahle r's
function of the father’s age at the child’s conception. The sperm, by contrast, are made continuously throughout his
Invasion of the Killer Bees p. 750 r esultsC cleaanr lbye t sheee nag ien ogfr athpeh f ba.ther at conception has lhifaes, aa nrids ke aocf hD dNivAi srieopnl iocaf ttihoen s mtemist ackelelss. tAhsa tt hper omduance a tgheesm,
a huge impact on the number of new mutations these mutations accumulate in his stem cell line and are
The Global Decline in Amphibians p. 809 transmitted to offspring. Why? A woman's eggs are all passed on to the next generation.
232 UNIT THREE THE CONTINUITY OF LIFE
GIVING BIOLOGY A PERSONAL PERSPECTIVE ix
joh24218_fm_i-xxii.indd 9 11/15/13 3:29 PM