Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

So far in this course we have dealt entirely with the evolution of characters that are controlled by simple Mendelian inheritance at a single locus. There are notes on the course website about gametic disequilibrium and how allele frequencies change at two loci simultaneously, but we didn’t discuss them. In every example we’ve considered we’ve imagined that we could understand something about evolution by examining the evolution of a single gene. That’s the domain of classical population genetics. For the next few weeks we’re going to be exploring a field that’s actually older than classical population genetics, although the approach we’ll be taking to it involves the use of population genetic machinery. If you know a little about the history of evolutionary biology, you may know that after the rediscovery of Mendel’s work in 1900 there was a heated debate between the “biometricians” (e.g., Galton and Pearson) and the “Mendelians” (e.g., de Vries, Correns, Bateson, and Morgan). Biometricians asserted that the really important variation in evolution didn’t follow Mendelian rules. Height, weight, skin color, and similar traits seemed to

Human biochemical genetics

Global climate has fluctuated greatly during the past three million years, leading to the recent major ice ages. An inescapable consequence for most living organisms is great changes in their distribution, which are expressed differently in boreal, temperate and tropical zones. Such range changes can be expected to have genetic consequences, and the advent of DNA technology provides most suitable markers to examine these. Several good data sets are now available, which provide tests of expectations, insights into species colonization and unexpected genetic subdivision and mixture of species. The genetic structure of human populations may be viewed in the same context. The present genetic structure of populations, species and communities has been mainly formed by Quaternary ice ages, and genetic, fossil and physical data combined can greatly help our understanding of how organisms were so affected.

http://webpages.icav.up.pt/PTDC/BIA-BEC/105083/2008/hewitt2000.pdf

The genetic legacy of the Quaternary ice ages

Conflicts between animals of the same species usually are of “limited war” type, not causing serious injury. This is often explained as due to group or species selection for behaviour benefiting the species rather than individuals. Game theory and computer simulation analyses show, however, that a “limited war” strategy benefits individual animals as well as the species.

The Logic of Animal Conflict

Recent studies suggest that populations and species often exhibit behavioral syndromes; that is, suites of correlated behaviors across situations. An example is an aggression syndrome where some individuals are more aggressive, whereas others are less aggressive across a range of situations and contexts. The existence of behavioral syndromes focuses the attention of behavioral ecologists on limited (less than optimal) behavioral plasticity and behavioral carryovers across situations, rather than on optimal plasticity in each isolated situation. Behavioral syndromes can explain behaviors that appear strikingly non-adaptive in an isolated context (e.g. inappropriately high activity when predators are present, or excessive sexual cannibalism). Behavioral syndromes can also help to explain the maintenance of individual variation in behavioral types, a phenomenon that is ubiquitous, but often ignored. Recent studies suggest that the behavioral type of an individual, population or species can have important ecological and evolutionary implications, including major effects on species distributions, on the relative tendencies of species to be invasive or to respond well to environmental change, and on speciation rates. Although most studies of behavioral syndromes to date have focused on a few organisms, mainly in the laboratory, further work on other species, particularly in the field, should yield numerous new insights.

/pdf/behavioral-syndromes-an-ecological-and-evolutionary-overview-53ct6xj1u3.pdf

Behavioral syndromes: an ecological and evolutionary overview.

PART ONE: MIGRATION AND METHODS FOR ITS STUDY PART TWO: PROXIMATE FACTORS IN MIGRATION PART THREE: MIGRATORY LIFE HISTORIES AND THEIR EVOLUTION PART FOUR: MIGRATION AND HUMAN BIOLOGY

Migration: The Biology of Life on the Move

We outline a general scheme for migration that applies across taxa, incorporates the several varieties of migration, and includes all levels of biological organization, from genes to populations. The scheme links the environment, pathways, traits, and genes, and highlights the selective forces that shape and maintain migratory adaptation. We endorse an individual-based behavioral definition of migration that allows an objective distinction between migration and other forms of movement. We recognize migration as an adaptation to resources that fluctuate spatiotemporally either seasonally or less predictably, and note that it is often preemptive. Migration plays a central role in the spatial dynamics of mobile populations, and is largely distinct in both form and function from the within-population mixing arising from postnatal dispersal and from the interpatch movements characteristic of metapopulations. We call for more interaction between biologists studying different taxa and different forms of movement, and between behaviorists and population ecologists.

https://www.jstor.org/stable/10.1641/B570206

What Is Migration

Natural selection can occur when phenotypic variation in a trait related to fitness is heritable (26, 39). The trait can be simple (e.g. appendage length) or complex (e.g. shape, reaction norms), but as long as individuals vary in their expression, and such variance is genetically based, natural selection can act. If over several generations natural selection is consistent and unconstrained by other factors such as antagonistic pleiotropy (145) or physiological thresholds (170), then a population will evolve. Although selection acts upon phenotypic variation, the resulting changes in genotypic frequencies affect evolution. Thus, the developmental mechanisms linking phenotype to genotype are of fundamental concern to an understand­ ing of evolutionary change. Because development is an elaborative process and adult phenotype is a summation of activities accrued over the life span of the individual, developmental events occurring early in the life cycle can significantly influence the phenotype at later stages. In some cases, such developmental variation will be dampened as a result of homeostatic mech­ anisms [e.g. targeted growth of body size in mice (136), brain size allometry (135), or developmental programming (183)], while in others developmental

Maternal Effects in Insect Life Histories

Evolution of insect migration and diapause

Physiological and ecological results from a variety of species are consistent with what seem to be valid general statements concerning insect migration These are as follows: (i)During migration locomotory functions are enhanced and vegetative functions such as feeding and reproduction are suppressed (ii) Migration usually occurs prereproductively in the life of the adult insect (the oogenesis-flight syndrome) (iii)Since migrant individuals are usually prereproductive, their reproductive values, and hence colonizing abilities, are at or near maximum (iv) Migrants usually reside in temporary habitats (v)Migrants have a high potential for population increase, r, which is also advantageous for colonizers (vi)Both the physiological and ecological parameters of migration are modifiable by environmental factors (that is, phenotypically modifiable)to suit the prevailing conditions Taken together, these criteria establish a comprehensive theory and adumbrate the basic strategy for migrant insects This basic strategy is modified to suit the ecological requirements of individual species Comparative studies of these modifications are of considerable theoretical and practical interest, the more so since most economically important insects are migrants No satisfactory general statements can as yet be made with respect to the genotype and migration Certainly we expect colonizing populiations to possess genotypes favoring a high r, but genotypic variation in r depends on the heritabilities of life table statistics, and such measurements are yet to be made (10, 53) The fact that flight duration can be increased by appropriate selection in Oncopeltus fasciatus, and the demonstration of additive genetic variance for this trait in Lygaeus kalmii, suggest that heritability studies of migratory behavior would also be worth pursuing Most interesting of course, will be possible genetic correlations between migration and life history parameters Also, migration often transports genotypes across long distances with considerable mixing of populations An understanding of its operation therefore carries with it implications for population genetics, zoogeography, and evolutionary theory Finally, at least parts of the above general theory would seem to be applicable to forms other than insects Bird and insect migrations, for example, are in many respects ecologically and physiologically similar Birds, like insects, emphasize locomotory as opposed to vegetative functions during long-distance flight; the well-known Zugenruhe or migratory restlessness is a case in point Further, many birds migrateat nigt at a time when they would ordinarily roost(vegetative activity) Because their life spans exceed single seasons, bird migrants are not prereproductive in the same sense that insect migrants are, and hence reproductive values do not have the same meaning(but note that some insects are also interreproductive migrants) The situaion is complicated further by the fact that in many birds adult survivorship is virtually independent of age so that colonizing ability tends to be also (10, 54) Nevertheless, birds arrive on their nesting grounds in reproductive condition with the result that migration is a colonizing episode It is also phenotypically modifiable by environmental factors, some of which, for example, photoperiod, influence insects as well (55) The similarities between birds and insects thus seem sufficient to indicate, at least provisionally, that the theory developed for insects applies also to birds with appropriate modifications for longer life span and more complex social behavior; comparisons between insects and fish (56) lead to the same conclusion In birds especially, and also in other forms, various functions accessory to migration such as reproductive endocrinology, energy budgets, and orientation mechanisms have been studied extensively (55, 56) But there is need in vertebrates for more data andtheoy on the ecology and physiology of migratory behavior per se in order tobetter understand its evolution and its role in ecosystem function (5, 57) Migration in any animal cannot be understood until viewed in its entirety as a physiological, behavioral, and ecological syndrome

https://science.sciencemag.org/content/sci/175/4028/1327.full.pdf

Hugh Dingle

Papers

Migration: The Biology of Life on the Move

What Is Migration

Maternal Effects in Insect Life Histories

Evolution of insect migration and diapause

Migration strategies of insects.