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

Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

25. Multiple Imputation for Nonresponse in Surveys. By D. B. Rubin. ISBN 0 471 08705 X. Wiley, Chichester, 1987. 258 pp. £30.25.

Multiple Imputation for Nonresponse in Surveys

The harmful effects of close inbreeding have been noticed for many centuries (34, 35, 165). With the rise of Mendelian genetics, it was realized that the main genetic consequence of inbreeding is homozygosis (165, Ch. 2). Two main theories were early proposed to account for inbreeding depression and its converse, heterosis (the increase in vigor observed in an F1 between two inbred lines). These are the overdominance and partial dominance hypotheses, discussed in more detail below. Research into this question has continued up to the present, and this is one of the topics that we discuss. Darwin (35, 36) was the first to point out that the evident adaptations of many plants for ensuring outcrossing could be understood in terms of the selective advantage of avoiding inbreeding depression. We review the evidence that the evolution of breeding systems of animals and plants has been significantly influenced by the occurrence of inbreeding depression. In order to do this, we consider the contemporary genetic theory of inbreeding depression and heterosis, and the experimental data concerning the strength of inbreeding depression. We emphasize data and theory relevant to natural, rather than domesticated, populations as we are chiefly concerned to evaluate the evolutionary significance of inbreeding depression. We do not attempt to give a complete bibliography of this very extensive field but try to concentrate on what seem to be the most significant findings in relation to this aim.

https://www.jstor.org/stable/pdf/2097132.pdf

Inbreeding depression and its evolutionary consequences

Conservation biology has two threads: the small-population paradigm which deals with the erect of smallness on the persistence of a population, and the declining-population paradigm which deals with the cause of smallness and its cure. The processes relevant to the small-population paradigm are amenable to theoretical examination because they generalize across species and are subsumed by an inclusive higher category: stochasticity. In contrast, the processes relevant to the declining-population paradigm are essentially humdrum, being not one but many. So far they have defied tight generalization and hence are of scant theoretical interest. The small-population paradigm has not yet contributed significantly to conserving endangered species in the wild because it treats an erect (smallness) as if it were a cause

Directions in conservation biology

For the measurements of outcrossing rates in plant populations, current electrophoretic procedures permit many loci to be scored per individual progeny. Given that the total experimental effort or cost is limited, the choice exists then between assaying a large number of loci on a restricted number of individuals, or assaying a large number of individuals at a few loci. Using simple models and the criterion of minimising the variance of the estimate, several factors which affect this choice are considered (levels of polymorphism, heterozygosity, linkage disequilibrium, pollen or outcrossing heterogeneity). The general conclusion is that the actual level of outcrossing is a major factor in determining experimental strategy. Maximum efficiency for estimating outcrossing in predominantly inbreeding plants comes from large samples assayed for few polymorphic loci. In contrast, in predominantly outcrossing plants, more loci should be assayed at the expense of sample size for improved statistical efficiency.

Optimum number of marker loci for estimating outcrossing in plant populations.

Three new Australian diploid species in Glycine Willd. are described. Two of these (Glycine gracei B.E.Pfeil & Craven and Glycine montis-douglas B.E.Pfeil & Craven) are endemic to the Northern Territory whereas the third (Glycine syndetika B.E.Pfeil & Craven) is endemic to Queensland. G. montis-douglas is only known from one locality. The genetic affinities of G. gracei and G. syndetika are with other A genome species. The species G. syndetika is the closest relative of a diploid parent of the T2 allotetraploid race of the G. tomentella s.l. Hayata species complex, as well as of allotetraploid G. pescadrensis Hayata, which is here formally reinstated from synonymy. Images are included of the leaflet venation for several species discussed in the paper. Thus, the treatment incorporates evidence from morphology, cytology, DNA sequences and crossing experiments. A key to the subgenera and to the species within Glycine subgenus Glycine is provided, which includes all 25 described Australian taxa.

Three new species of northern Australian Glycine (Fabaceae, Phaseolae), G. gracei, G. montis-douglas and G. syndetika

Principles and strategies of evaluation.

The charge state model of Ohta & Kimura (1973) for the number of electrophoretically detectable alleles in a finite population, is extended to include mutations of both one and two charge changes. The effective number of alleles (ne) is increased only slightly by this extension. Electrophoretic profiles of neutral variants are shown on average to be leptokurtic and have their odd central moments equal to zero. The expected frequency distribution of pairs of gametes which differ by 1,2,3,… charge units can be obtained as the sum of the appropriate terms from two geometric series.

Anthony H. D. Brown

Papers

Optimum number of marker loci for estimating outcrossing in plant populations.

Three new species of northern Australian Glycine (Fabaceae, Phaseolae), G. gracei, G. montis-douglas and G. syndetika

Principles and strategies of evaluation.

Profiles of electrophoretic alleles in natural populations.

In vitro conservation and germplasm utilisation.