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A numerical analysis of a model in which selfing rate is controlled by a single locus having two alleles, designated A and a, was conducted. The selfing rates of genotypes AA, Aa and aa were designated s1,s2 and s3. One limitation of the model is that it did not allow for the joint evolution of inbreeding depression as selfing rate evolved. Results demonstrate that relaxing the assumption of equal inbreeding-depression effects greatly changes the dynamics of mating system evolution by permitting evolutionary stability of mixed-mating systems.

Simulated grazing can have a positive effect on the lifetime seed production of the strict biennial herb Gentianella campestris. It is shown that overcompensation occurs in populations exposed to a high risk of damage but not in those wherein the risk of damage is predictably low. Overcompensation pertains to higher vegetative productivity and seed yield as a consequence of natural or simulated grazing. These and previous results show that the capacity for overcompensation is an adaptive trait with an evolutionary history associated with habitats with a high and predictable risk of damage.

A study of the reproductive biology of outliers and of rare plants reveals that they produce lesser seeds per flower than plants within local populations but are capable of interbreeding over long distances. Outliers from large gatherings of interbreeding plants are the major sources of extrinsic pollen and seeds, disturbing the spacing of local populations forming the nuclei for new populations. Outliers serve as interpopulation links for pathogens and herbivores.

Observations of the evolutionarily stable allocation of reproductive effort in perennial plants to assess the effect of limited pollen availability, plants' survival and sex allocation indicate that pollen availability affects plant fertility. In cases of long-term pollen supply, where limitations are caused by climatic and ecological changes, the effects are similar in dioecious and hermaphroditic plants.

Analysis of postpollination selection and male fitness in plants examines pre- and post-fertilization selection to determine their influence on variations in mating success. The influence of postpollination mechanisms on male reproductive success is not evident. Although male reproductive success is determined by male-by-female interactions and females choose mates producing healthy offspring, only variations in donors can elucidate the evolutionary significance of post-pollination events.

Pollination efficiency of plants controls their success in mating and determines the influence of environmental and genetic variations on mating success. Male-male competition is common during plant pollination and reduces the male fertility average, though individuals can benefit from asymmetrical competition. Availability and dispersion of pollinators and fertilizable ovules influence male mating success.

A.J. Bateman's explanation of animal mating methods is a basis for analyzing sexual selection in hermaphrodites and plants. The link between mating success and fertility enables the females or female part of plants and hermaphrodites to undergo sexual selection. Analysis of female animals and hermaphrodites is essential to understand that sexual selection is a part of fertility selection.

Sexual selection theory helps study reproduction in plants, though the term 'sexual selection' has not been used due to controversy regarding its applicability to plants. Scientists are unsure about using the term for plant reproduction, which occurs anytime between courtship and pre-natal periods.

Analysis of the differences in theoretical models of sexual selection for hermaphrodites and species with separate sexes reveals that hermaphroditism does not restrict the application of sexual selection theory. The main features of sexual reproduction apply both to hermaphrodites and species with separate sexes, although hermaphroditism stunts sex-specific trait expression. This restricts the origin and stability of traits determined by sex, due to which viability choice equalizes the average selection that determines male and female fertility during neutrality.

Analysis of physiological reproduction in perennial plant species involves comparing two individual groups of the latest reproductive investment, to determine the best indicator of further reproduction. Dynamic measurement involves several processes such as nectar production, reproduction nutrient resorption, reproductive photosynthesis and respiration. Dynamic measurements of nutrient use accurately predict future reproductive efforts and are good indicators of physiological reproduction costs.

The primary hypothesis involving animal-pollinated plant species is tested using structural equation modelling and path analysis. The investigation reveals that the pollinator, which is mostly an insect, is influenced by the characteristic feature of the plant. The pollinator behavior is important for the pollination and reproduction of plants.

Studies on postpollination reproductive traits in plants led to the development of four models that are effective with regard to diallele and equivalent reciprocal crossing designs. The models are useful in studying evolutionary hypotheses and leave confounded genetic and non-genetic effects on reproductive traits. The models A, B and D are useful in the study of animal reproduction also.

Pollen level effects on fruit size and seed number were investigated in the ground cherry, Physalis longifolia to determine resource and pollen limitation in the plant. Results indicate that large individuals are limited by both pollen and resource levels. These plants allocate resources in a way that maximizes production of seeds. On the other hand, small individuals are limitedonly by pollen levels.

Statistical techniques suitable for the interpretation of seedling recruitment data are presented. Application of the methods on a data collection indicate that seed banks do notexhibit a negative exponential decay pattern and that a number of recruitment models exist. Recruitment patterns that are age-specific are particularly difficult to interpret because of individual variation in viability and unobserved mortality. A model describing the recruitment process is developed.

A model was developed to show the relation parental resource status and optimal offspring size. The model demonstrated that individual variation in parental resources could give rise to positive correlations between size and number, even when there exists a resource trade-off between number of offspring within individuals. These results imply that the resource status of the parent influences the fitness-maximizing offspring size.