Showing papers in "Theoretical Population Biology in 1978"

TL;DR: Analysis of allozymic variation in natural populations of plants, animals, and humans based on studies published prior to early 1976 and involving 243 species, suggests that the amounts of genetic polymorphism and heterozygosity vary nonrandomly between loci, populations, species, habitats, and life zones, and are correlated with ecological heterogeneity.

TL;DR: A model is developed that predicts when an insect should oviposit on a potential larval host plant when it is encountered and how this behavior is modeled for conditions in which the host either does or does not fluctuate in density.

TL;DR: The general conclusion arrived at is that the foraging of a generalist herbivore can be predicted in a quantitative manner, at least in this case, as has been shown for other types of consumers (carnivores and granivores).

TL;DR: It is shown that, for a given net rate of arrisal of deleterious mutations, the more the rate of beneficial mutation, the greater the chance that beneficial mutations will accumulate.

TL;DR: Nectar-collecting bumblebees are hypothesized to employ rules of movement which result in the maximum net rate of energy gain (i.e., are optimal), and predicted patterns of movement are compared with field observations to support the hypothesis.

TL;DR: The sensitivity of population growth to small changes in birth, growth, survival, and migration probabilities for an arbitrary population classification is considered and is shown to be proportional to the product of the reproductive value of stage i and the abundance of stage j in the stable stage distribution.

TL;DR: The threshold criterion obtained for the nonlinear differential equation model can be used to determine the immunization rates which will cause the disease to die out.

TL;DR: The relationship between the risk to helper and benefit to recipient which allows altruism to evolve is shown to depend on the kinship coefficient between helper and helped, the particular fitness function proposed and the degree of dominance of the altruism.

TL;DR: A model is derived for the optimal spatial allocation of foraging effort for an animal returning with food to a central place in a uniform habitat and shows that the allocation of search has been optimal if and only if the “marginal cost” of additional food is equal throughout the foraging area when the period has elapsed.

TL;DR: Data is collected on the moose's ability to utilize each of the forage plants and the population densities of moose in different years (1972–1974) in two forest types to examine energy flow within each ofThe populations and determine in what manner energy limits the moosing population.

TL;DR: This paper shows by example that May's qualitative stability criterion does not ensure stability in any sense unless restrictive conditions on the form of the model are satisfied and alternative methods of analysis are proposed.

TL;DR: This study shall present a number of models that treat ESSs from a dynamic viewpoint, and shall attempt to generalize conventional competition theory by permitting the competing parties to adjust their strategies.

TL;DR: The model predicts an optimal territory size where the territory holder's net energy intake is maximized, on a daily or seasonal time scale, in general agreement with observed relationships in a wide variety of animals.

TL;DR: A model to describe the coevolution of a two-species predator-victim ecosystem is developed and it is shown that for many such systems, there is a value of J, J ∗, at which the rate of predator evolution exactly equals the rates of victim evolution.

TL;DR: The theoretical basis is developed for a population model which allows the use of constant temperature experimental data in predicting the size of an insect population for any variable temperature environment and the key concept in the model is the utilization of a physiological time scale.

TL;DR: The practical conclusion is that migration must be very small in order for the release of sterile males to be effective on suppressing numbers of adults, while more migration can be tolerated if, as in many agricultural pests, immature stages are the object of concern.

TL;DR: A simple model of logistic growth with additive Poisson disasters of fixed magnitude is considered and the dependence of the persistence time of a colonizing species on the parameters of the model is discussed.

TL;DR: A model for two competing prey and one predator in an environment consisting of many discrete, identical patches is developed and it is predicted that intermediate levels of predation give the greatest chance of coexistence.

TL;DR: This paper illustrates by an example that, when population and genetic dynamics are included in a model, the outcome in a competitive situation can be quite different from that deduced from the corresponding static model.

TL;DR: Sigmoid functional responses are known to stabilize the differential Lotka-Volterra predator-prey model, but it is found that they have no such effect in a comparable discrete generation model.

TL;DR: A family of two-species competition models in which density-restricted rates of food enounter are explicitly incorporated generates the following results: a new model for sigmoidal single-species growth, but one whose inflection point always falls below half the carrying capacity.

TL;DR: It is shown that coevolution tends to oppose the destabilization that results from the enrichment itself, but in the circumstance that the victims' r and K are proportional, gradual enrichment followed by coev evolutionary adjustment actually enhances ecosystem stability.

TL;DR: It is shown that under natural selection the deviation between the population sex ratio and Fisher's optimum value evolves to a minimum.

TL;DR: It is suggested that observations consistent with Hardy-Weinberg equilibrium states cannot preclude ipso facto certain forms of selection forces, including mating patterns and some natural selection structures.

TL;DR: Conditions involving both “selfish” and “altruistic” predator characteristics are shown to be necessary and sufficient for group selection predominance in this class of patch-structured models.

TL;DR: The models are fitted to published data on the mating success of male Drosophila at varying frequencies and provide an explanation of the “rare male” effect in which less common males gain a mating advantage.

TL;DR: It is argued that massive linkage disequilibria, of the kind found by Franklin and Lewontin (1970) in their simulations, are unlikely to characterize the genetic structure of natural populations of random mating organisms.

TL;DR: Some new results for diffusion models in population genetics of the “infinite-alleles” type are derived, including expected values for times which may be interpreted either as the age of the kth oldest allele or the time to extinction of the "kth-to-last" allele.