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?

Until now, the analysis of burrowing mechanics has neglected the mechanical properties of impeding, muddy, cohesive sediments, which behave like elastic solids. Here we show that burrowers can progress through such sediments by using a mechanically efficient, previously unsuspected mechanism--crack propagation--in which an alternating 'anchor' system of burrowing serves as a wedge to extend the crack-shaped burrow. The force required to propagate cracks through sediment in this way is relatively small: we find that the force exerted by the annelid worm Nereis virens in making and moving into such a burrow amounts to less than one-tenth of the force it needs to use against rigid aquarium walls.

Burrowing mechanics: burrow extension by crack propagation.

of energy and nutrient gain. According to the principles of dynamic programming, a method for formulating and solving optimization problems (Bellman 1957), the entire process is optimized only if digestion follows an optimal path constrained by the food items actually ingested. An animal feeding on a variety of foods should thus exhibit the flexibility to adjust digestion with respect to that range of food types. Conversely, the net rate of gain to an animal lacking such flexibility will be maximized over a restricted set of food types, making it a dietary specialist. To test these general predictions and to formulate more specific ones, we must identify the operating variables for each stage. Many foraging theories exist (e.g., Charnov 1976, Orians and Pearson 1979, Pyke 1984, Schoener 1971), but there are only rudiments of an optimal digestion theory (Milton 1981, Sibly 1981, Taghon 1981, Troyer 1984). Without such a theory, studies of digestive systems (e.g. gut anatomy, histology, or enzymology) tend to be static, piecemeal, and most often nonpredic-

Chemical Reactor Analysis and Optimal DigestionAn optimal digestion theory can be readily derived from basic principles of chemical reactor analysis and design

A feeding model for a generalized, benthic deposit feeder is derived from a filter-feeding model and used to predict how such a deposit feeder would adjust its feeding to maximize its net energy gain. Under the assumption that deposit feeders are utilizing the bacterial fraction of the sediment or other surface organic coatings as food, the model predicts that the smallest particles should always be ingested, while the selection of larger particles depends on several parameters, including gut passage time and assimilation efficiency of the deposit feeder. The model also predicts relationships among particle size selection, assimilation efficiency, gut passage time, gut volume, and particle rejection costs.

https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1978.23.4.0752

Predicting particle selection by deposit feeders: A model and its implications 1

Five 0.25-m2 box cores (four open cores and one vegematic core subdivided in situ into 25 contiguous lo- x lo-cm subcores) reveal that populations of benthic agglutinated Foraminifera in the central North Pacific are extremely abundant and diverse. As many as 120 species and 10,310 total fragments occur in a single open core, and the Foraminifera outnumber all metazoan taxa combined by at least an order of magnitude. Significant patchiness occurs on both the between-core scale of kilometers and the within-core scale of centimeters. Few species occurred in all cores and those that did were not abundant. Hierarchical classification an d multiple discriminant analysis on the resultant subcore groups in the vegematic core suggest potential interactions between certain species of Foraminifera and such external variables as surface deposit feeders, subsurface deposit feeders, carnivores, filter feeders, biogenic surface structure, and manganese nodules. Multiple regressions of foraminiferan species against all the external variables substantiate the existence of patterns of association. Foraminifera are important components of the benthic fauna, acting, among other things, as predators and disturbance agents. It may well be that they have a more significant effect on the structure and dynamics of deep-sea benthic communities than have any of the metazoan macrofaunal taxa that are the usual objects of deep-sea studies.

https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1978.23.3.0401

Spatial dispersion of benthic Foraminifera in the abyssal central North Pacific 1

Controls on bacterial abundance in marine sediments remain poorly understood despite the importance to biogeochemical processes, benthic ecology, and in situ bioremediation. We report an analysis of direct microscopic counts of widely distributed surficial marine sediments, using a new approach of scaling abundance to the fluid volume of pore water within the sediments (bacteria FV -1 ). The analysis identified a greater constancy in benthic bacterial abundance than has been appreciated previously. Whether tested as a combined dataset or separately according to geographic region, less variance was observed when abundance was scaled to fluid volume rather than the traditional dimension of dry sediment mass. The decrease in variance suggests that the primary controls on abundance, such as nutrient acquisition or predator encounter rate, may also scale with porewater fluid volume. With values centered around 10 9 bacteria ml -1 FV, regulation must differ fundamentally from the water column, where values average 10 5 -10 6 bacteria ml -1 FV.

https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1998.43.5.0976

Peter A. Jumars

Papers

Burrowing mechanics: burrow extension by crack propagation.

Chemical Reactor Analysis and Optimal DigestionAn optimal digestion theory can be readily derived from basic principles of chemical reactor analysis and design

Predicting particle selection by deposit feeders: A model and its implications 1

Spatial dispersion of benthic Foraminifera in the abyssal central North Pacific 1

Constancy of bacterial abundance in surficial marine sediments