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

It is suggested that local animal species diversity is related to the number of predators in the system and their efficiency in preventing single species from monopolizing some important, limiting, requisite. In the marine rocky intertidal this requisite usually is space. Where predators capable of preventing monopolies are missing, or are experimentally removed, the systems become less diverse. On a local scale, no relationship between latitude (10⚬ to 49⚬ N.) and diversity was found. On a geographic scale, an increased stability of annual production may lead to an increased capacity for systems to support higher-level carnivores. Hence tropical, or other, ecosystems are more diverse, and are characterized by disproportionately more carnivores.

/pdf/food-web-complexity-and-species-diversity-59eo6z6mqe.pdf

Food Web Complexity and Species Diversity

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

An understanding of community structure should be based on evidence that the growth and regulation of the component populations in the community are affected in a predictable manner by natural physical disturbances and by interactions with other species in the community. This study presents an experimental evaluation of the effects of such disturbances and competitive interactions on populations of sessile organisms in the rocky intertidal community, for which space can be demonstrated to be the most important limiting resource. This research was carried out at eight stations on the Washington coastline which have been ranked according to an exposure/desiccation gradient and subjected to comparable manipulation and observation. Physical variables such as wave exposure, battering by drift logs, and desiccation have important effects on the distribution and abundance of many of the sessile species in the community. In particular, wave exposure and desiccation have a major influence on the distribution patterns of all the algae and of the anemone Anthopleura elegantissima. The probability of damage from drift logs is very high in areas where logs have accumulated along the intertidal. Log damage and wave exposure have complementary effects in the provision of free space in a mussel bed, as wave shock enlarges a patch created by log damage by wrenching the mussels from the substratum at the periphery of the bare patch. Competition for primary space results in clear dominance hierarchies, in which barnacles are dominant over algae. Among the barnacles, Balanus cariosus is dominant over both B. glandula and Chthamalus dalli; B. glandula is dominant over C. dalli. The mussel Mytilus californianus requires secondary space (certain algae, barnacles, or byssal threads) for larval settlement, but is capable of growing over all other sessile species and potentially is the competitive dominant of space in the community.

Competition, Disturbance, and Community Organization: The Provision and Subsequent Utilization of Space in a Rocky Intertidal Community

Fish, like other living systems, must conform to the laws of thermodynamics. Fish gain matter and energy in food, and they lose absorbed matter and energy as a result of catabolism—which provides energy for maintenance and activity—and the elaboration of reproductive products. Physiological energetics, or animal bioenergetics, concerns the rates of energy expenditure, the losses and gains, and the efficiencies of energy transformation, as functional relations of the whole organism. The majority of such presentations commence with an energy-flow diagram indicating the main steps that the energy of food intake follows through the organism, and the paths of energy distribution. Each of these steps with their appropriate values is subject to quantitative change, depending on many biotic and abiotic factors. With the thought that the basis of these energy exchanges needs to be elaborated first, it was deemed more fitting to conclude with a quantitatively expressed flow diagram. An understanding of the physical, chemical, and biological basis on which the energetics is built, and the equivalents employed, constitutes the opening section of this chapter. Some necessary distinctions between mammalian and nonmammalian systems are made. An adequately nutritious diet is assumed; the basic source of fuel for the fire of life is solely derived from the food.

6 – Physiological Energetics

An overview of marine chemical ecology is presented. Emphasis is placed on antipredation, invertebrate-toxic host relationships, antifouling, competition for space, species dominance, and the chemistry of ecological interactions.

Chemical ecology of marine organisms: An overview.

Seventy-three percent of all exposed common coral reef invertebrates, from four phyla (42 species) tested, are toxic to fish. This represents the first evidence of the high incidence to toxicity in the marine tropics among several phyletic groups comprising dominant species. Most of the remaining exposed species have structural defense mechanisms against predation by fish. Of cryptic invertebrates, 25 percent are toxic to fish. The relation between toxicity, fish feeding behavior, community structure, and evolutionary theory is discussed.

Chemical Defense Mechanisms on the Great Barrier Reef, Australia

Toxicity in sponges and holothurians is inversely related to latitude and may reach 100 percent for holothurians in high-diversity coral reefs. Evidence from approximately 700 experiments and from underwater observations suggests that predation by fish has resulted in natural selection for noxious and toxic chemical compounds in species within these taxa.

http://science.sciencemag.org/content/sci/185/4155/951.full.pdf

Toxicity in Sponges and Holothurians: A Geographic Pattern

Extracts of marine species from Baja California and the Caribbean have been examined on shipboard for a variety of bioactlvities and their constituents studied there by gas chromatography! mass spectrometry. A very high proportion of the extracts has been shown to be cytotoxic, a high proportion to be antibacterial or antifungal and a surprisingly large number to be antiviral. Many of these activities have been confirmed in more extensive assays against tumor cells, pathogenic microorganisms and a battery of viruses. A number of the compounds responsible for the activities have been identified, including several new compounds. Of special current interest are the didemnins, depsipeptides isolated from a didemnid tunicate, which inhibit a number of RNA and DNA viruses and exhibit potent cytotoxicity vs. tumor cell lines. Systematic studies of marine natural products can be directed toward a particular phylum, such as sponges (Ref. 1), toward a particular class of compounds, such as sterols (Ref. 2), toward a class of compounds in a phylum, such as terpenes in gorgonians (Ref. 3), or toward a particular bioactivity, such as antineoplastic activity (Ref. 4). Our own interest in marine natural products arose initially out of our continuing studies on antibiotics (Ref. 5), and has been directed toward compounds possessing antimicrobial (antibacterial or antifungal) or, more recently, antiviral or antineoplastic activity. In the first instance, we sought to determine whether such activities are widely distributed among the marine phyla and, in the second instance, to ascertain whether the compounds responsible for the activities are of novel Or useful structural types. The primary collecting of marine species for examination was carried out during two expeditions (in 1974 and 1978) aboard the R/V Alpha Helix, a research vessel with laboratory space designed for marine biology and biochemistry studies and sponsored by the U.S. National Science Foundation. During each of these expeditions a comprehensive survey of specific bioactivities was carried out on shipboard, with assays designed to use small samples of the marine species (to avoid ecological disruption) on site (to allow recollection of species with significant activity). The first of these expeditions (AHBE 1974) examined the antimicrobial activities of some 831 species along the west coast of Baja California and in the *This paper is dedicated to the memory of Werner Bergmann, a pioneer in studies of marine natural products and an inspiring teacher of Yale students.

Gerald J. Bakus

Papers

Chemical ecology of marine organisms: An overview.

Chemical Defense Mechanisms on the Great Barrier Reef, Australia

Toxicity in Sponges and Holothurians: A Geographic Pattern

Marine natural products as sources of antiviral, antimicrobial, and antineoplastic agents

Energetics and Feeding in Shallow Marine Waters