T. RYAN GREGORY -- ALTERNATE VERSION

TABLE OF CONTENTS

VOLUME ONE

Chapter One: The evolution of genome size: a historical, conceptual, and terminological review

    Abstract    2

    Introduction: a word about words    3

    A brief history of DNA    4

    The DNA constancy hypothesis    7
        “Une remarkable constance”    7
        Constancy questioned    8
        Constancy confirmed    11
        “C” is for class!    14

    Exceptions to the rule (?)    17
        Polyteny and gene amplification    18
        Chromatin diminution    20
        Intraspecific variation    21

    The evolution of “genome size”    25
        From pangens to genomes    25
        Genome size, C-value, and polyploidy    28
        Cryptopolyploidy    34

    The paradox that was    35
        The C-value paradox    35
        Of genes and genomes    39
        Multiple strands and multiplied genes    42

    The puzzle that is    43
        Death of a paradox    43
        The C-value enigma    45

    Single-copy DNA    47
        Introns    49

    Types of chromatin    51

    Satellite DNA    52

    Transposable elements    54
        Retroposons: LINEs and SINEs    56
        LTR retrotransposons    58
        DNA transposons    59

    Pseudogenes    60
        Processed pseudogenes    61
        Classical pseudogenes    62
        Numts    63

    Junk DNA    64
        The origin of junk DNA    64
        Junk DNA and non-function    66
        From pseudogenes to everything    67
        Should “junk” be thrown out?    69
        The new noun “nuon” and its nuances (an exercise in confusion)    71
        The primacy of “secondary”    73

    Selfish DNA    74
        The origin(s) of selfish DNA    74
        The origin(s) of selfish DNA (again)    79
        Selfish genes and abstract elephants    80
        Objections to selfish DNA    82
        From parasitism to mutualism    84
        Junk versus selfish    86

    Mutation pressure theories    88
        The junk DNA theory    88
        The selfish DNA theory    89
        The DNA loss hypothesis    90

    The desperate search for function    91

    Cell size and optimal DNA    94
        The nucleoskeletal theory    94
        The nucleotypic theory    95

    Concluding remarks    97


Chapter Two: DNA content and the cellular phenotype

    Abstract    108

    Introduction: the importance of cell size    109

    DNA content and cell size    110
        The karyoplasmic ratio    110
        Polyploidy and cell size    110

    Genome size and cell size    111
        Reptiles    112
        Amphibians    113
        Fishes    114
        Birds    116
        Mammals    119

    Coincidence?    125
        Size-dependent threshold    126
        Overall increase in DNA content    127
        Inability to delete extra DNA    128

    Coevolution?    131
        Nuclear size and the nucleoskeleton    132
        Nuclear pores and RNA transport    134
        Return and reversal of the karyoplasmic ratio hypothesis    135
        The pros and cons of coevolution    139

    Causation?    142
        Challenges to the nucleotypic theory    143
        In support of the nucleotype    145

    Previous models of nucleotypic influence    149
        The nucleotide sequestration model    149
        The division-initiation model    151

    The gene-nucleus interaction model    153
        Eukaryotic cell cycle regulation    154
        DNA content and cell cycle length    156
        DNA content and cell cycle control    160
        Issues awaiting resolution    166

    Concluding remarks    169
        Effect versus function    169


Chapter Three: Genome sizes of mammals and birds

    Abstract    194

    Introduction    195

    Summary of the dataset    196

    Patterns of variation    197

    A digression on regression    200

    Genome size and chromosome number    202

    Genome size, cell size, and metabolism in mammals    204
        Mammalian metabolism: analysis and results    205
        Mammalian metabolism: discussion    208

    Genome size, cell size, and metabolism in birds    209

    Avian metabolism: analysis and results    211
        Avian metabolism: discussion    212

    Genome size and flight    214
        A causal connection?    214
        Genomic baggage: lost or never loaded?    216

    Genome size and developmental parameters    220
        Sources of data    223
        Avian development: dataset #1    224
        Avian development: dataset #2    225
        Mammalian development    228
        Genome size, development, and body size in homeotherms    229

    Concluding remarks    230


Chapter Four: Genome sizes of amphibians and reptiles

    Abstract    244

    Introduction    245

    Summary of the dataset    245

    Patterns of variation    246

    Genome size and chromosome number    249

    Genome size, cell size, and development (a reply to Pagel and Johnstone)    252

    What Pagel and Johnstone did, didn’t, and couldn’t say    253
        Summary of the study    253
        A statistical aside    255
        Difficulties with the data    256
        Negating the nucleoskeleton?    258
        Neglecting the nucleotype    259

    Genome size, cell size, and metabolic rate (a reply to Cavalier-Smith)    261
        Cell size and cellular metabolism    261
        Genome size and metabolic rate    262
        Cell size and metabolic rate    264

    Genome size and developmental complexity    266

    The threshold concept: genome size and development in plants    267

    Developmental complexity in amphibians    271
        Developmental rate and constant complexity    272
        Developmental process: direct development    275
        Developmental process: neoteny    278
        Developmental products: big genomes and simple brains    285
        Development in amphibians: a summary    288

    Amphibian genome size and the hierarchy of evolution    289


Chapter Five: Genome sizes of fishes

    Abstract    305

    Introduction    306

    Summary of the dataset and patterns of variation    306
        Agnathans    307
        Chondrychthyes    307
        Chondrosteans    308
        Teleosts    309
        Sarcopterygians    312

    Genome size, chromosome number, and polyploidy    313

    Genome size, metabolism, and swimming performance    315

    Hinegardner’s rule and developmental complexity    318

    Other factors that may (or may not) affect fish genome sizes    322

    Genome size evolution in vertebrates: a summary    324


References for Volume One    341


VOLUME TWO

Chapter Six: Is DNA loss rate a determinant of genome size?

    Abstract    432

    Introduction    433

    The DNA loss hypothesis    433
        Of mice and men    436
        Relative versus absolute rates of loss    437
        Deletion rate versus deletion size    438

    Comparisons of related taxa    439
        Example #1: Mammals    439
        Example #2: Drosophila    441
        Example #3: Nematodes    443
        Example #4: Barley and maize    444
        Example #5: Bacteria    449

    Swapping junk for trash?    451

    Alternative explanations    452
        Selection for small genome size    452
        Rapid replication and sloppy slippage    454
        Unequal patterns of unequal crossing-over    455
        Is Drosophila just a freak?    457

    Concluding remarks    458


Chapter Seven: DNA quantification by Feulgen image analysis densitometry

    Abstract    466

    Introduction    467

    DNA quantification: past and present    468
        Densitometry    468
        Fluorometry    471

    Image analysis densitometry    473
        Basic concepts    474

    Guidelines for specimen preparation: vertebrates    475
        Fishes    477
        Amphibians    477
        Reptiles    478
        Birds    479
        Mammals    479

    Guidelines for specimen preparation: invertebrates    481
        Crustaceans    481
        Insects    483
        Arachnids    487
        Myriapods    489
        Annelids    489
        Molluscs    491
        Echinoderms    492
        Flatworms    493
        Nematodes    493
        Cnidarians    494
        Miscellaneous invertebrates    494

    Staining methods    495
        The Feulgen reaction    495
        Stain preparation    496
        Staining protocol    497

    Measurement protocol    498
        Hardware and software    498
        Microscope set-up and image capture    499
        Choice of standards and calculation of genome size    500

    Concluding remarks    501


Chapter Eight: DNA content modulation and the evolution of the Crustacea

    Abstract    517

    Introduction    518

    Genome size variation in crustaceans    518
        Summary of the dataset    518
        Patterns of variation    519
        Intraspecific variation in genome size    520
        Cryptopolyploidy, polyteny, and quantum shifts    522

    The significance of genome size variation    523
        Genome size and body size    523
        Genome size and developmental rate    525
        Rapid evolution by quantum shifts in genome size    527
        Other ecological and evolutionary considerations    528

    Good old-fashioned polyploidy    531
        The prominence of polyploidy    531
        Ecological significance of polyploidy    532

    Endopolyploidy    533
        Patterns of endopolyploidization    534
        Ecological significance of endopolyploidy    536

    Chromatin diminution    537
        Characteristics of chromatin diminution in copepods    537
        On the adaptive value of chromatin diminution    539
        Chromatin diminution and rapid development: mechanistic aspects    541
        Endoreduplication, chromatin diminution (or not), and quantum shifts    542

    Summary and concluding remarks    545
   

Chapter Nine: Genome sizes of insects

    Abstract    558

    Introduction    559

    Summary of the dataset(s)    559
        Previously published data    559
        New genome size estimates    560

    Patterns of variation    560
        Blattaria    561
        Coleoptera    562
        Collembola    567
        Dermaptera    568
        Diptera    568
        Embiidina    572
        Ephemeroptera    572
        Hemiptera    573
        Hymenoptera    576
        Isoptera    576
        Lepidoptera    577
        Mantodea    578
        Odonata    578
        Orthoptera    578
        Phasmida    581
        Plecoptera    583
        Siphonaptera    583
        Thysanura    583
        Trichoptera    584

    Endopolyploidy and polyteny    584
        Classic examples    584
        Dosage compensation in Hymenoptera    585
        Nurse cells    586

    Developmental complexity in insects: more on metamorphosis    590

    Concluding remarks    594


Chapter Ten: Genome sizes of spiders

Abstract    609

    Introduction    610

    Summary of the dataset    611
        Spiders    611
        Other arachnids    612

    Patterns of variation    613
        General patterns in spiders    613
        A note on the spider mite    615

    Prospects for future work    615
        Comparisons with other arachnids    616
        Developmental and ecological lifestyle    616
        Endopolyploidy    617


Chapter Eleven: Genome sizes of miscellaneous invertebrates

    Abstract    621

    Introduction    622

    Summary of the dataset(s)    622
        Previously published data    622
        New genome size estimates    622

    Patterns of variation    623
        Molluscs    623
        Annelids    628
        Flatworms    634
        Echinoderms    636
        Nematodes    637
        Tardigrades    639
        Gastrotrichs    640
        Myriapods    640
        Cnidarians    641
        Rotifers    642
        Sponges    643
        Miscellaneous invertebrates    643

    Genome size evolution in invertebrates: a summary    645


Chapter Twelve: Macroevolution, hierarchy theory, and the C-value enigma

    Abstract    654

    Introduction    655

    Macroevolutionary theory for neontologists    656
        What is macroevolution?    656
        Critiques of the Modern Synthesis    658
        Reductionism in biology    664
        Group selection: new and improved and no longer naïve    667
        The concept of individuality    670
        Punctuated equilibria and species as individuals    673
        Species selection in principle and in practice    676
        Aggregate versus emergent characters    678
        Emergent fitness versus the effect hypothesis (the Lloyd-Vrba debate)    680
        Selection versus sorting    683
        Hierarchical macroevolutionary theory: a summary    685

    Molecular macroevolution    688
        Are genomes “individuals”?    688

    The necessity of hierarchy theory for understanding genomes (and vice versa)    692
        Group selection and the origin of the genome    692
        Selfish DNA and the necessity of hierarchy    695

    The C-value enigma from a hierarchical perspective    699
        Genomes as phenotypes and genotypes    699
        The evolution and ecology of transposable elements    703
        Selection, sorting, and genome size    708
        Stasis and DNA constancy    709

    Genome-level processes and the major transitions in evolution    713

    Concluding remarks    722



References for Volume Two    725



VOLUME THREE

Appendix 2.1: Erythrocyte sizes of reptiles    786
Appendix 2.2: Erythrocyte sizes of amphibians    789
Appendix 2.3: Erythrocyte sizes of fishes    799
Appendix 2.4: Erythrocyte sizes of birds    810
Appendix 2.5: Erythrocyte sizes of mammals    827

Appendix 3.1: Genome sizes of mammals    849
Appendix 3.2: Genome sizes of birds    880

Appendix 4.1: Genome sizes of amphibians    896
Appendix 4.2: Genome sizes of reptiles    943

Appendix 5.1: Genome sizes of fishes    969

Appendix 8.1: Genome sizes of crustaceans    1063

Appendix 9.1: Genome sizes of insects (database)    1083
Appendix 9.2: Genome sizes of insects (original data)    1105

Appendix 10.1: Genome sizes of spiders    1123

Appendix 11.1: Genome sizes of miscellaneous invertebrates (original data)    1131
Appendix 11.2: Genome sizes of molluscs    1137
Appendix 11.3: Genome sizes of annelids (database)    1152
Appendix 11.4: Genome sizes of annelids (original data)    1161
Appendix 11.5: Genome sizes of flatworms    1165
Appendix 11.6: Genome sizes of echinoderms    1168
Appendix 11.7: Genome sizes of nematodes    1172
Appendix 11.8: Genome sizes of miscellaneous invertebrates (database)    1174


References for Volume Three    1179