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

Senescence in natural populations of animals: Widespread evidence and its implications for bio-gerontology

The innate immune system in insects is composed of a large variety of specific and non-specific responses that are activated in response to the presence of foreign agents. One important element in such responses is the enzyme phenoloxidase (PO). Here, we review recent progress in PO research and discuss new applications in the emerging field of ecological immunology. Phenoloxidase produces indole groups, which are subsequently polymerized to melanin. The enzymatic reactions in turn produce a set of intermediate products such as quinones, diphenols, superoxide, hydrogen peroxide, and reactive nitrogen intermediates, which are important during defense against bacterial (gram+ and )), fungal, and viral agents. Phenoloxidase requires a complex system of activation and inhibition that involves various cell types, PO zymogens, inhibitor enzymes, and signaling molecules. Finally, research in evolutionary ecology has studied the costs of PO in terms of resource use and pleiotropic relations with other key traits and functions. These studies indicate that PO is a costly trait, whose production and maintenance have fitness costs for hosts. Phenoloxidase does not seem to be anindicatorofresistancebut rather ofhostcondition. Finally, we putforwardsome basicdirectionsforfutureinvestigationofPOaimedatexplainingitsactivatingsystem,itssubstrates,itscoordination with other immune components to fight off pathogens, and variation in PO in relation to gender,lifestages, seasonality, andacross different host species.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1570-7458.2011.01187.x

Phenoloxidase: a key component of the insect immune system

This is the oldest English language journal in genetics. Founded by W. Bateson and R. C. Punnett in 1910, the Journal of Genetics was later edited by J. B. S. Haldane; later, Haldane and his wife, Helen Spurway brought the journal with them to India. After his death in 1964, Mrs. Haldane continued publication of the journal, with Madhav Gadgil and H. Sharat Chandra (Indian Institute of Science, Bangalore) and Suresh Jayakar (Laboratorio de Genetica Biochimica ed Evoluzionistica, Pavia) as editors, until her own death in 1977. In 1985, with the permission of Haldane’s heirs, the Indian Academy of Sciences resumed publication of the journal. The journal retains its traditional interest in evolutionary research that is of relevance to geneticists, even if not explicitly genetic in nature.

The journal of genetics

The idea that resources are limited and animals can maximise fitness by trading costly activities off against one another forms the basis of life-history theory. Although investment in reproduction or growth negatively affects survival, the mechanisms underlying such trade-offs remain obscure. One plausible mechanism is oxidative damage to proteins, lipids, and nucleic acids caused by reactive oxygen species (ROS). Here, we critically evaluate the premise that ROS-induced oxidative damage shapes life history, focussing on birds and mammals, and highlight the importance of ecological studies examining free-living animals within this experimental framework. We conclude by emphasising the value of using multiple assays to determine oxidative protection and damage. We also highlight the importance of using standardised and appropriate protocols, and discuss future research directions.

/pdf/oxidative-damage-ageing-and-life-history-evolution-where-now-36coo7tdk3.pdf

Oxidative damage, ageing, and life-history evolution: where now?

We review the studies of evolution and ecology in the Calopterygidae. Adults are easily distinguished for their pigmented wings and territorial behaviour. Three genera have been well studied: Hetaerina, Calopteryx and Mnais. Larvae develop in riverine aquatic environments. Selection operates at this stage to produce large muscle mass for adults. The adult spends some days until sexually ready. During this time, it feeds extensively to produce muscle fat for egg production and flight. However, gregarine parasites may ingest the fat reserves. Males may use two mating tactics or strategies that may be genetically (Mnais) or environmentally (Calopteryx and Hetaerina) determined: territoriality and nonterritoriality. In Mnais, these strategies appear balanced in fitness terms. Males of Calopteryx, Mnais and Phaon show a precopulatory courtship that is not the case for Hetaerina. Male wing pigmentation seems to signal how good the male is to deal immunologically with parasites to females during the male courtship. During copulation, males displace the sperm the female has stored in the storage organs from previous matings. There is an enormous variation in male sperm displacement mechanisms and ability, and in genitalic morphology in both sexes. This variation possibly results from a coevolutionary game between the sexes to control stored sperm. After copulation, males guard females apparently to avoid that other males take the female in copulation. Our review suggests sources for research in this family.

/pdf/evolution-and-ecology-of-calopterygidae-zygoptera-odonata-4oghsel7i0.pdf

Evolution and ecology of Calopterygidae (Zygoptera: Odonata): status of knowledge and research perspectives

Continental islands offer an excellent opportunity to investigate adaptive processes and to time microevolutionary changes that precede macroevolutionary events. We performed a population genetic study of the fire salamander (Salamandra salamandra), a species that displays unique intraspecific diversity of reproductive strategies, to address the microevolutionary processes leading to phenotypic and genetic differentiation of island, coastal and interior populations. We used eight microsatellite markers to estimate genetic diversity, population structure and demographic parameters in viviparous insular populations and ovoviviparous coastal and interior populations. Our results show considerable genetic differentiation (FST range: 0.06–0.27), and no clear signs of gene flow among populations, except between the large and admixed interior populations. We find no support for island colonization by rafting or intentional/accidental anthropogenic introductions, indicating that rising sea levels were responsible for isolation of the island populations approximately 9000 years ago. Our study provides evidence of rapid genetic differentiation between island and coastal populations, and rapid evolution of viviparity driven by climatic selective pressures on island populations, geographic isolation with genetic drift, or a combination of these factors. Studies of these viviparous island populations in early stages of divergence help us better understand the microevolutionary processes involved in rapid phenotypic shifts.

/pdf/genetic-drift-and-rapid-evolution-of-viviparity-in-insular-5cjdmq0z1r.pdf

Genetic drift and rapid evolution of viviparity in insular fire salamanders ( Salamandra salamandra )

Species that exhibit colour polymorphism, the simultaneous occurrence of two or more discrete phenotypes with a genetic basis, are ideal for studying the microevolutionary forces that maintain genetic variation in nature. One very intriguing type of genetically determined polymorphism is the co-existence of several discrete morphs within only the male, or within only the female, sex. These morphs typically differ in body coloration and sometimes behaviour, with one morph often resembling the opposite sex. In males, this resemblance often allows access to receptive females, whereas in females the polymorphism appears related to avoiding excessive male sexual harassment. One might wonder why natural selection does not simply give rise to a single best male and female type for each species. Odonates are good candidate species to address this type of question because sex-limited polymorphism is widespread within the group, facilitating hypothesis testing through comparative analyses. Odonates are also widely distributed geographically and they are convenient to work with from a methodological perspective because they can be studied over their lifetime on an individual basis under either natural or arti! cial conditions. The phenomenon of sex-limited polymorphisms provides an important opportunity to test contemporary ideas relating to sexual selection and sexual con" ict, and the diversity of polymorphisms that have arisen in odonates clearly offers one of the best natural systems for among-species comparative research.

/pdf/the-evolution-of-sex-limited-colour-polymorphisms-w1grkq3t7q.pdf

The evolution of sex-limited colour polymorphisms

The pace-of-life syndrome (POLS) hypothesis integrates covariation of life-history traits along a fast-slow continuum and covariation of behavioural traits along a proactive-reactive personality continuum. Few studies have investigated these predicted life-history/personality associations among species and between sexes. Furthermore, whether and how contaminants interfere with POLS patterns remains unexplored. We tested for covariation patterns in life history and in behaviour, and for life-history/personality covariation among species, among individuals within species and between sexes. Moreover, we investigated whether pesticide exposure affects covariation between life history and behaviour and whether species and sexes with a faster POLS strategy have a higher sensitivity to pesticides. We reared larvae of four species of Ischnura damselflies in a common garden experiment with an insecticide treatment (chlorpyrifos absent/present) in the final instar. We measured four life-history traits (larval growth rate during the pesticide treatment, larval development time, adult mass and life span) and two behavioural traits (larval feeding activity and boldness, each before and after the pesticide treatment). At the individual level, life-history traits and behavioural traits aligned along a fast-slow and a proactive-reactive continuum, respectively. Species-specific differences in life history, with fast-lived species having a faster larval growth and development, a lower mass at emergence and a shorter life span, suggested that time constraints in the larval stage were predictably driving life-history evolution both in the larval stage and across metamorphosis in the adult stage. Across species, females were consistently more slow-lived than males, reflecting that a large body size and a long life span are generally more important for females. In contrast to the POLS hypothesis, there was only little evidence for the expected positive coupling between life-history pace and proactivity. Pesticide exposure decreased larval growth rate and affected life-history/personality covariation in the most fast-lived species. Our study supports the existence of life-history and behavioural continua with limited support for life-history/personality covariation. Variation in digestive physiology may explain this decoupling of life history and behaviour and provide valuable mechanistic insights to understand and predict the occurrence of life-history/personality covariation patterns.

https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2656.12499

Integrating the pace-of-life syndrome across species, sexes and individuals: covariation of life history and personality under pesticide exposure.

Reproductive isolation is the defining characteristic of a biological species, and a common, but often untested prediction is a positive correlation between reproductive isolation and genetic divergence. Here, we test for this correlation in odonates, an order characterized by strong sexual selection. First, we measure reproductive isolation and genetic divergence in eight damselfly genera (30 species pairs) and test for a positive correlation. Second, we estimate the genetic threshold preventing hybrid formation and empirically test this threshold using wild populations of species within the Ischnura genus. Our results indicate a positive and strong correlation between reproductive isolation and genetic distance using both mitochondrial and nuclear genes cytochrome oxidase II (COII: r=0.781 and 18S-28S: r=0.658). Hybridization thresholds range from -0.43 to 1.78% for COII and -0.052-0.71% for 18S-28S, and both F-1-hybrids and backcrosses were detected in wild populations of two pairs of Ischnura species with overlapping thresholds. Our study suggests that threshold values are suitable to identify species prone to hybridization and that positive isolation-divergence relationships are taxonomically widespread. (Less)

Adolfo Cordero-Rivera

Papers

Evolution and ecology of Calopterygidae (Zygoptera: Odonata): status of knowledge and research perspectives

Genetic drift and rapid evolution of viviparity in insular fire salamanders ( Salamandra salamandra )

The evolution of sex-limited colour polymorphisms

Integrating the pace-of-life syndrome across species, sexes and individuals: covariation of life history and personality under pesticide exposure.

Genetic divergence predicts reproductive isolation in damselflies