Genetic management of fragmented animal and plant populations

426 Pages·2017·6.663 MB·English

by  Richard Frankham, Jonathan D. Ballou, Katherine Ralls, Mark Eldridge, Michele R. Dudash, Charles B. Fenster, Robert C. Lacy, Paul Sunnucks

GeneticManagementofFragmentedAnimalandPlantPopulations

Genetic Management
of Fragmented Animal
and Plant Populations
RichardFrankham
MacquarieUniversityandAustralianMuseum,Sydney,NSW,Australia
JonathanD.Ballou&KatherineRalls
SmithsonianInstitution,Washington,DC,USA
MarkD.B.Eldridge
AustralianMuseum,Sydney,NSW,Australia
MicheleR.Dudash&CharlesB.Fenster
SouthDakotaStateUniversity,Brookings,SD,USA
RobertC.Lacy
ChicagoZoologicalSociety,Brookfield,IL,USA
PaulSunnucks
MonashUniversity,Clayton,Vic,Australia
LinedrawingsbyKarinaMcInnes,Melbourne,Vic,Australia
1
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©RichardFrankham,JonathanD.Ballou,KatherineRalls,MarkD.B.Eldridge,Michele
R.Dudash,CharlesB.Fenster,RobertC.Lacy&PaulSunnucks2017
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Contents
Preface xi
Acknowledgments xv
ListofSymbols xix
1 Introduction 1
Whyshouldweconservegeneticdiversity? 2
Whatgeneticproblemsoccurinfragmentedpopulations? 5
Canwereversetheadverseeffectsofpopulationfragmentation? 6
Howimportantisgeneticmanagementoffragmentedpopulations? 8
Howshouldwegeneticallymanagefragmentedpopulations? 11
Summary 13
FurtherReading 14
SectionI Geneticproblemsinsmallisolatedpopulations 15
2 Evolutionarygeneticsofsmallpopulations 17
Background 18
Whatfactorscontroltheevolutionofsmallpopulations? 18
Whatgeneticmarkersareusedinconservationgenetics? 26
Howdowemeasureanddescribegeneticdiversity? 27
Howmuchstandinggeneticdiversitydospeciesandpopulationscontain? 28
Howdowemeasurepopulationsize? 31
Whyisinbreedingimportantinconservation? 34
Whydoweusecomputersimulationsinconservationgenetics? 37
Summary 39
FurtherReading 39
Software 40
3 Inbreedingreducesreproductivefitness 41
Whyisinbreedinganimportantissueinconservation? 42
Whyisinbreedingharmful? 43
Whatfactorsaffectthemagnitudeofinbreedingdepression? 44
Howlargearetheimpactsofinbreedingontotalfitness? 53
Doesinbreedingincreaseextinctionrisks? 54
Howdowedetectinbreedingdepression? 58
Howdowequantifyinbreedingdepression? 58
v
Contents
Whatismutationalmeltdown? 62
Whataretherelationshipsbetweenharmfulmutation,drift,
inbreeding,fixation,andfitnessdecline? 62
Canwereverseinbreedingdepressionandmutationalaccumulation? 63
Summary 64
FurtherReading 64
Software 64
4 Lossofgeneticdiversityreducesabilitytoadapt 65
Whyshouldwebeconcernedaboutconservingtheability
ofspeciestoadapt? 66
Howcommonisevolutionaryadaptation? 67
Howrapidlydoesadaptationoccur? 67
Howlargeareadaptiveevolutionarychanges? 69
Whatdeterminestheabilitytoundergoadaptiveevolution? 71
Howcanwemeasureevolutionarypotential? 84
Canwerestoretheabilitytoevolve? 85
Summary 85
FurtherReading 86
Software 86
5 Populationfragmentationcausesinadequategeneflowandincreases
extinctionrisk 87
Whyispopulationfragmentationimportantinconservation? 88
Howfrequentlyarethereproblemsduetoinadequategeneflow? 91
Whatarethegeneticconsequencesofcompletelyisolatedfragments? 91
Whataretheconsequencesofgeneflowamongfragments? 97
Whataretheconsequencesofdifferentfragmentedpopulation
structures? 100
Complexrelationshipsamongvariablesinrealfragmentedpopulations 104
Howdowemeasuregeneticdifferentiationamongpopulations? 106
Summary 111
FurtherReading 112
Software 112
SectionII Rescueandrisk 113
6 Geneticrescuebyaugmentinggeneflow 115
Whataretheproblemsofgeneticerosioninsmallisolated
populationfragments? 116
Canwereverseinbreedingandlossofgeneticdiversity? 117
Doescrossinghavebeneficialorharmfuleffectsonfitness? 118
Areimmigrantallelesataselectiveadvantage? 131
vi
Contents
Howlargeandconsistentareevolutionaryrescueeffects? 132
Summary 134
FurtherReading 134
7 Outbreedingdepressionisuncommonandpredictable 135
Whyareweconcernedaboutharmfulcrosses? 136
Whatmechanismsgenerateoutbreedingdepression? 140
Howmanygenerationsdoesittaketodevelopoutbreedingdepression? 149
Canwepredicttheriskofoutbreedingdepression? 150
Atwhatgenerationaftercrossingisoutbreedingdepressionevident? 153
Canpopulationsrecoverfromoutbreedingdepression? 154
Summary 154
FurtherReading 155
8 Modifiedrescueandriskexpectationsforspecieswithdiversemating
systemsandmodesofinheritance 156
Whydoweneedtoconsiderdiversematingsystemsandmodes
ofinheritance? 157
Howaregeneticrescueandriskexpectationsmodifiedfordifferent
matingsystems? 158
Howcanweidentifymatingsystems? 166
Howaregeneticrescueandriskexpectationsmodifiedfordifferent
modesofinheritance? 169
Howdoweidentifymodesofinheritance? 175
Summary 176
FurtherReading 177
Software 178
SectionIII Developingmanagementdecisions 179
9 Isthetaxonomyappropriate?Delineatingspeciesforconservation
purposes 181
Whatistheroleofspeciesdelineationinconservation? 182
Whatisourobjective? 182
Howdowecharacterizepopulationgeneticdifferentiationintaxonomy? 182
Whatproblemsoccurwithspeciesdelineations? 184
Whichspeciesdefinitionsareappropriateforconservationpurposes? 196
Howdowedecidewhethertaxonomicrevisionisrequired? 200
Howshouldataxonomicre-evaluationbeconductedifrequired? 201
Conclusions 201
Summary 201
FurtherReading 202
Software 202
vii
Contents
10 Determiningthenumberandlocationofgeneticallydifferentiated
populationfragments 203
Whatareourobjectives? 204
Howdoweidentifythenumberofgeneticallydifferentiated
populations? 205
Howdowelocategeneticallydifferentiatedpopulationsinthe
landscape? 209
Arecurrentunitswithinspeciessuitableforgeneticmanagement
purposes? 211
Whatisthecurrentrecommendationwhengeneticallydifferentiated
populationsareidentified? 214
Howshouldweproceedwhentherearegeneticallydiverged
populations? 216
Howcanwemeasuregeneflowamongpopulationfragments? 217
Summary 221
FurtherReading 222
Software 222
11 Aretherepopulationssufferinggeneticerosionthatwouldbenefit
fromaugmentedgeneflow? 223
Whatareourobjectives? 224
Arethereguidelinesforgeneticrescues? 226
Whatquestionsdoweneedtoanswer? 229
Areanypopulationssufferinggeneticerosion? 229
Isthereanotherpopulationtowhichitcanbecrossed? 233
Willcrossingresultinoutbreedingdepression? 233
Willcrossingresultinworthwhilegeneticrescue? 239
Howdowecopewithsimultaneousharmfulandbeneficialeffects
ofcrossing? 243
Summary 243
FurtherReading 243
Software 244
12 Managinggeneflowamongisolatedpopulationfragments.
I.Limitedinformation 245
Whydoweneedtomanagegeneflow? 246
Howcanweaugmentgeneflow? 248
Whatistheobjectiveofgeneticmanagementforisolated
populationfragments? 249
Geneticmanagementwithdifferentamountsofinformation 250
Whatcanbedonewithlittleornogeneticinformation? 251
Geneticswamping 263
Summary 264
FurtherReading 265
Software 265
viii
Contents
13 Managinggeneflowamongisolatedpopulationfragments.
II.Managementbasedonkinship 266
Howdoesdetailedgeneticinformationaidmanagementofgeneflow? 267
Whatpopulationgeneticparametershouldwemanage? 270
Howdowemanageusingmeankinship? 272
Populationmeankinship 277
Kinshipsattheindividuallevel 281
Managinggeneflowattheindividuallevel 283
Whentocease? 287
Whatgeneticmonitoringisneeded? 287
Integratinggeneticrescuewithothermanagementconsiderations 288
Summary 288
FurtherReading 289
Software 289
14 Globalclimatechangeincreasestheneedforgeneticmanagement 291
Whatistheproblem? 292
Whydoesglobalclimatechangeincreasetheneedforgenetic
management? 294
Howhavespeciesrespondedtoglobalclimatechange? 296
Whatgeneticmanagementoptionsdowehaveforpopulationsthat
cannotmoveoradaptsufficiently? 298
Howdoweimplementgeneticmanagementtoassistadaptation? 300
Howdowedecidewhatpopulationsandspeciesneedtranslocation
toavoidextinction? 303
Howshouldwegeneticallymanagetranslocationstocopewith
climatechange? 304
Summary 310
FurtherReading 311
Software 311
15 Takehomemessages 312
Finalmessagesformanagersofwildanimalandplantpopulations 313
Glossary 315
References 327
Index 391
APPENDICES (availableonlineatwww.oup.co.uk/companion/frankham) A1
1 Geneticmarkersforconservationpurposes A1
2 VORTEXsimulationsoftwareforpopulationviabilityanalysis A7
3 Howshouldataxonomicre-evaluationbeconductedifrequired? A12
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