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

Metabolism provides a basis for using first principles of physics, chemistry, and biology to link the biology of individual organisms to the ecology of populations, communities, and ecosystems. Metabolic rate, the rate at which organisms take up, transform, and expend energy and materials, is the most fundamental biological rate. We have developed a quantitative theory for how metabolic rate varies with body size and temperature. Metabolic theory predicts how metabolic rate, by setting the rates of resource uptake from the environment and resource allocation to survival, growth, and reproduction, controls ecological processes at all levels of organization from individuals to the biosphere. Examples include: (1) life history attributes, including devel- opment rate, mortality rate, age at maturity, life span, and population growth rate; (2) population interactions, including carrying capacity, rates of competition and predation, and patterns of species diversity; and (3) ecosystem processes, including rates of biomass production and respiration and patterns of trophic dynamics. Data compiled from the ecological literature strongly support the theoretical predictions. Even- tually, metabolic theory may provide a conceptual foundation for much of ecology, just as genetic theory provides a foundation for much of evolutionary biology.

/pdf/toward-a-metabolic-theory-of-ecology-1dxmg8xr3n.pdf

Toward a metabolic theory of ecology

When a person looks at an object while exploring it with their hand, vision and touch both provide information for estimating the properties of the object. Vision frequently dominates the integrated visual-haptic percept, for example when judging size, shape or position, but in some circumstances the percept is clearly affected by haptics. Here we propose that a general principle, which minimizes variance in the final estimate, determines the degree to which vision or haptics dominates. This principle is realized by using maximum-likelihood estimation to combine the inputs. To investigate cue combination quantitatively, we first measured the variances associated with visual and haptic estimation of height. We then used these measurements to construct a maximum-likelihood integrator. This model behaved very similarly to humans in a visual-haptic task. Thus, the nervous system seems to combine visual and haptic information in a fashion that is similar to a maximum-likelihood integrator. Visual dominance occurs when the variance associated with visual estimation is lower than that associated with haptic estimation.

Humans integrate visual and haptic information in a statistically optimal fashion.

One of the most ubiquitous and long-lasting recent changes to the surface of our planet is the accumulation and fragmentation of plastics. Within just a few decades since mass production of plastic...

/pdf/accumulation-and-fragmentation-of-plastic-debris-in-global-2ayi1pcd8z.pdf

Accumulation and fragmentation of plastic debris in global environments.

ilbstract. Autocorrelation is a very general statistical property of ecological variables observed across geographic space; its most common forms are patches and gradients. Spatial autocorrelation. which comes either from the physical forcing of environmental variables or from community processes, presents a problem for statistical testing because autocorrelated data violate the assumption of independence of most standard statistical procedures. The paper discusses first how autocorrelation in ecological variables can be described and measured. with emphasis on mapping techniques. Then. proper statistical testing in the presence of autocorrelation is briefly discussed. Finally. ways are presented of explicitly introducing spatial structures into ecological models. Two approaches are proposed: in the raw-data approach, the spatial structure takes the form of a polynomial of the x and .v geographic coordinates of the sampling stations; in the matrix approach. the spatial structure is introduced in the form of a geographic distance matrix among locations. These two approaches are compared in the concluding section. A table provides a list of computer programs available for spatial analysis.

https://www.jstor.org/stable/pdfplus/1939924.pdf

Spatial Autocorrelation: Trouble or New Paradigm?

Although bacteria can be associated with animals in a wide variety of ways, nutritional interactions are by far the most ubiquitous. We define them simply and inclusively as interactions in which proximity allows nutrient transfer in one or both directions, with the most obvious associations involving the alimentary tract and feces, and food just prior to ingestion. Transient or indigenous, attached or free-living bacteria may be obligately or facultatively associated with their animal counterparts. Obligate interactions of economic importance, e.g. in ruminant and termite guts, are clearly the best studied. A few other strong interactions, such as competition for food between bacteria and carnivores, are reasonably well understood intuitively. We purposely choose here a system marine detritivory in which intuition is a less adequate guide, and mutualism, competition, and predation all are suggested interactions. Because marine detrivores ingest bacteria-covered particles, interactions are virtually assured; we look for some methodical approach by which their existence and importance can be predicted and analyzed. The one we adopt for this review is a cost-benefit analysis that adapts and integrates disparate approaches developed for other applications. We evaluate its predictions through literature review. Then we evaluate the ecosystem consequences of our tentatively concluded interactions

Digestive associations between marine detritivores and bacteria

Physical constraints on marine osmotrophy in an optimal foraging context

Spatial autocorrelation with RUM (Remote Underwater Manipulator): vertical and horizontal structure of a bathyal benthic community☆

Burrowing by benthic infauna mixes both sediment grains and interstitial fluids, affect- ing sedimentary redox conditions and determining fates of organic matter and pollutants. Explicit, quantitative analyses of material properties of sediments, however, have been applied only recently to understand mechanisms of burrowing. Muds are elastic solids that fracture under small tensile forces exerted by burrowers, and are dominated by adhesive forces between sediment grains and the surrounding mucopolymeric gel and (or) by cohesion of this gel. By contrast, in clean sands behaving as granular materials, gravity is a much more significant force holding grains together than is adhesion or cohesion. Burrowers in muds have diverse structures that act as wedges to propagate cracks and elongate their burrows. In sands, increased rugosity on a small, and lique- faction on a larger scale, facilitate displacement of the grains that carry compressive forces along distinct force chains or arches. The classic dual-anchor system described for burrowers is reinter- preted as having several additional functions. The characteristic dilations or expansions function primarily as wedges that exert lateral tensile forces to propagate cracks forward, secondarily as double O-ring seals holding fluid pressure in the advancing burrow (maintaining tensile stresses needed to open a crack), and thirdly as anchors (to pull the shell along in bivalves in particular). Burrowing bivalves are wedges. In the case of burrowing gammarid amphipods, the dorsal exo- skeleton mirrors the shape of half a sedimentary bubble and constitutes a wedge. A great many anatomical features of burrowers can now be understood analogously. The identification of the mechanisms of burrowing by crack propagation suggests that a substantial revision of the previously described feeding guilds of polychaetes is required.

Macrofaunal burrowing : The medium is the message

Fecal pellets of benthic animals are important in sediment transport processes, yet few quantitative data are available on their salient physical characteristics. We measured, directly and independently, the densities (specific gravities), sizes, and settling velocities of pellets produced by Amphicteis scuphobrunchiata, a deposit-feeding polychaete worm. Pellet density was measured by an isosmotic density gradient technique. Densities ranged from 1.086 to 1.282 gacm-3 and settling velocities from 3.03 to 5.94 cmes-I. Pellets transported as bedload for variable distances; the oldest pellets tested (6 h after production) traveled a median distance of 3.1 m, while freshly egested pellets traveled 9.5 m before disintegrating. Worms would reingest disaggregated pellets, but feeding rates correlated positively with pellet age, consistent with previous findings that this species feeds at a faster rate on energetically more profitable sediment. These results suggest substantial interactions among benthic animals, fecal pellets, and sediment transport processes. Fecal pellets produced by aquatic organisms affect sedimentary processes in two ways. Because fecal pellets are aggregates of particles, pellet sinking rates can be much greater than the rates of their smaller constituents (Haven and Morales-Alamo 1968; McCall 1979). Thus, pellets enhance material fluxes through the water column by increasing sedimentation rates; this can also lead to deposition of particles that, because of hydrodynamic or chemical characteristics, otherwise might not be deposited in a given environment (Haven and MoralesAlamo 1968; Smayda 1969; Small et al. 1979; Robison and Bailey 198 1; Silver and Bruland 198 1). Most interest in such vertical sedimentation processes has focused on pellets of planktonic origin. Fecal pellets also play a role in sediment transport processes operating within the benthic boundary layer. Deposit feeders comprise the dominant trophic group in softbottom environments and ingest and package ambient sediment particles during their feeding activities. Although it has been recognized for some time that pellets can affect sediment transport via both bedload and suspended load transport modes (Rhoads

https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1984.29.1.0064

Peter A. Jumars

Papers

Digestive associations between marine detritivores and bacteria

Physical constraints on marine osmotrophy in an optimal foraging context

Spatial autocorrelation with RUM (Remote Underwater Manipulator): vertical and horizontal structure of a bathyal benthic community☆

Macrofaunal burrowing : The medium is the message

Transport and breakdown of fecal pellets: Biological and sedimentological consequences1