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

Thereisgrowinginterestinthepossiblehealththreatposedbyendocrine-disruptingchemicals (EDCs), which are substances in our environment, food, and consumer products that interfere with hormone biosynthesis, metabolism, or action resulting in a deviation from normal homeostatic control or reproduction. In this first Scientific Statement of The Endocrine Society, we present the evidence that endocrine disruptors have effects on male and female reproduction, breast development and cancer, prostate cancer, neuroendocrinology, thyroid, metabolism and obesity, and cardiovascular endocrinology. Results from animal models, human clinical observations, and epidemiological studies converge to implicate EDCs as a significant concern to public health. The mechanisms of EDCs involve divergent pathways including (but not limited to) estrogenic, antiandrogenic, thyroid, peroxisome proliferator-activated receptor , retinoid, and actions through other nuclear receptors; steroidogenic enzymes; neurotransmitter receptors and systems; and many other pathways that are highly conserved in wildlife and humans, and which can be modeled in laboratory in vitro and in vivo models. Furthermore, EDCs represent a broad class of molecules such as organochlorinated pesticides and industrial chemicals, plastics and plasticizers, fuels, and many other chemicals that are present in the environment or are in widespread use. We make a number of recommendations to increase understanding of effects of EDCs, including enhancing increased basic and clinical research, invoking the precautionary principle, and advocating involvement of individual and scientific society stakeholders in communicating and implementing changes in public policy and awareness. (Endocrine Reviews 30: 293–342, 2009)

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Endocrine-Disrupting Chemicals: An Endocrine Society Scientific Statement

For decades, studies of endocrine-disrupting chemicals (EDCs) have challenged traditional concepts in toxicology, in particular the dogma of “the dose makes the poison,” because EDCs can have effects at low doses that are not predicted by effects at higher doses. Here, we review two major concepts in EDC studies: low dose and nonmonotonicity. Low-dose effects were defined by the National Toxicology Program as those that occur in the range of human exposures or effects observed at doses below those used for traditional toxicological studies. We review the mechanistic data for low-dose effects and use a weight-of-evidence approach to analyze five examples from the EDC literature. Additionally, we explore nonmonotonic dose-response curves, defined as a nonlinear relationship between dose and effect where the slope of the curve changes sign somewhere within the range of doses examined. We provide a detailed discussion of the mechanisms responsible for generating these phenomena, plus hundreds of examples from...

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Hormones and endocrine-disrupting chemicals: Low-dose effects and nonmonotonic dose responses

Human exposure to bisphenol A (BPA).

Plastics have transformed everyday life; usage is increasing and annual production is likely to exceed 300 million tonnes by 2010. In this concluding paper to the Theme Issue on Plastics, the Environment and Human Health, we synthesize current understanding of the benefits and concerns surrounding the use of plastics and look to future priorities, challenges and opportunities. It is evident that plastics bring many societal benefits and offer future technological and medical advances. However, concerns about usage and disposal are diverse and include accumulation of waste in landfills and in natural habitats, physical problems for wildlife resulting from ingestion or entanglement in plastic, the leaching of chemicals from plastic products and the potential for plastics to transfer chemicals to wildlife and humans. However, perhaps the most important overriding concern, which is implicit throughout this volume, is that our current usage is not sustainable. Around 4 per cent of world oil production is used as a feedstock to make plastics and a similar amount is used as energy in the process. Yet over a third of current production is used to make items of packaging, which are then rapidly discarded. Given our declining reserves of fossil fuels, and finite capacity for disposal of waste to landfill, this linear use of hydrocarbons, via packaging and other short-lived applications of plastic, is simply not sustainable. There are solutions, including material reduction, design for end-of-life recyclability, increased recycling capacity, development of bio-based feedstocks, strategies to reduce littering, the application of green chemistry life-cycle analyses and revised risk assessment approaches. Such measures will be most effective through the combined actions of the public, industry, scientists and policymakers. There is some urgency, as the quantity of plastics produced in the first 10 years of the current century is likely to approach the quantity produced in the entire century that preceded.

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Plastics, the environment and human health: current consensus and future trends.

The ability of urine from female mice to delay puberty in test females was directly related to the density and duration of grouping of females. When females were removed from group housing their urine lost its ability to delay puberty within 10 days. No interactive effects were observed between duration and density of grouping on the onset of pheromone release after grouping or on the persistence of pheromone release after re-isolation. Urine from grouped females lost its ability to delay puberty in test females after 7 days of exposure to air.

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Effect of density, duration of grouping and age of urine stimulus on the puberty delay pheromone in female mice.

Two experiments were performed to test putative puberty-accelerating pheromones. In the first experiment, 37 weanling female house mice of the ICR strain were exposed to 1 of the following 3 treatments: an airborne mixture of 0.05 M isoamylamine and 0.05 M isobutylamine, fresh male mouse urine, or distilled water, as the control. Neither the amine mixture nor the male urine accelerated first estrus in the mice following airborne exposure to these compounds. In the second experiment, 37 weanling female mice of the same strain were exposed to the same chemicals as in the first experiment by direct contact to the oro-nasal groove. The mixture of isoamylamine and isobutylamine did not accelerate puberty, but direct contact with the male urine accelerated puberty as evidenced by uterine weights. © 1992 Wiley-Liss, Inc.

Analysis of puberty-accelerating pheromones.

In laboratory strains of mice, reproductive maturation is influenced by both the fetal and the peripubertal social environments experienced by females. Intrauterine position (IUP) for female fetuses is identified by the number of adjacent males; where 0M have zero, 1M have one, and 2M have two male neighbors. We sought to confirm, using wild-type female house mice (Mus musculus), the previous finding in the CF-1 strain of laboratory mouse that males prefer 0M over 2M females as mates. We recorded the age at first reproduction for females of known IUP housed either individually with a male or in a group of 6 females and a male. In neither housing condition were there significant differences in age of first reproduction among females of different IUPs, but 0M females that were group housed had perforate vaginas at an earlier age than other group-housed females. Mean (+/- SE) age at first reproduction was 58.1 (+/- 3.3) for paired and 126.6 (+/- 5.1) for group-housed females. The reproductive suppression observed in the grouped females was probably due to the interaction of inhibitory urinary chemosignals, low body weights, and female dominance hierarchies.

Effect of intrauterine position and social density on age of first reproduction in wild-type female house mice (Mus musculus)

The rate of organ and system development in mammals, including humans, is most rapid during the prenatal period. Perturbations of the endocrine system during this period can have profound effects on later anatomy, physiology, behavior, and the onset of disease. Endocrine-disrupting compounds can cause perturbations during fetal development by mimicking or blocking natural hormones. In experimental studies, compounds that mimic estrogens and those that block androgen action have been shown to have a number of long-term effects. Among these effects are the acceleration of puberty onset, increased incidence of adult cancers such as vaginal and prostate cancers, and alterations in sexually dimorphic anatomy, physiology, and behavior. Laboratory animal models continue to play a crucial role in identifying endocrine disruptors, determining their mode of action, and demonstrating their consequences.

Animal models and studies of in utero endocrine disruptor effects.

Selection to obtain mating opportunities is hypothesized to be a major factor in dispersal. Thus, if individuals move to another group or switch nests to maximize their reproductive opportunities, they should move to groups or sites where they minimize competition for resources or mates and where they can find potential mates. We examined movement of pine voles (Microtus pinetorum) in an orchard habitat. Males dispersed later than females, but the two sexes showed similar patterns of movement with respect to conspecifics. Males and females immigrated to territories that contained some opposite-sex conspecifics; they also immigrated to territories without same-sex conspecifics. The latter suggests that they may avoid competitors and move to territories where an opening exists. When female breeders were removed from a social group, a replacement female arrived and began to breed relatively rapidly. In control groups where breeding females were not removed, no replacement females appeared. These results sugg...

John G. Vandenbergh

Papers

Effect of density, duration of grouping and age of urine stimulus on the puberty delay pheromone in female mice.

Analysis of puberty-accelerating pheromones.

Effect of intrauterine position and social density on age of first reproduction in wild-type female house mice (Mus musculus)

Animal models and studies of in utero endocrine disruptor effects.

Social influences on intergroup transfer by pine voles (Microtus pinetorum)