Birds exhibit a remarkable diversity of different reproductive strategies both between and within species. Species such as the zebra finch (Taeniopygia guttata) may evolve the flexible use of alternative reproductive strategies, as well as benefit from prior breeding experience, which allows them to adaptively respond to unpredictable environments. In birds, the flexible use of alternative repr...

The Neolithic demographic transition remains a paradox, because it is associated with both higher rates of population growth and increased morbidity and mortality rates. Here we reconcile the conflicting evidence by proposing that the spread of agriculture involved a life history quality-quantity trade-off whereby mothers traded offspring survival for increased fertility, achieving greater repr...

Theoretical and empirical literature asserts that the sex ratio (i.e. M/F) at birth gauges the strength of selection in utero and cohort quality of males that survive to birth. We report the first individual-level test in humans, using detailed life-history data, of the 'culled cohort' hypothesis that males born to low annual sex ratio cohorts show lower than expected infant mortality and great...

Executive Summary The outputs from mathematical and statistical models can be influenced by uncertainty in the estimates of the parameters used (known as parameter uncertainty) and to the methods and assumptions used to construct and link parameters in a model (known as structural uncertainty). Sensitivity analysis was applied to the current bigeye stock assessment to ascertain the influence of...

The evolution of reproductive barriers is of central importance for speciation. Here, we investigated three components of postzygotic isolation-embryo mortality, hybrid inviability, and hybrid sterility-in a group of food-deceptive Mediterranean orchids from the genera Anacamptis, Neotinea, and Orchis. In these orchids, pollinator-mediated isolation is weak, which suggests that postpollination ...

BACKGROUND The fifth Millennium Development Goal (MDG-5) aimed to improve maternal health, targeting a maternal mortality ratio (MMR) reduction of 75% between 1990 and 2015. The objective of this study was to identify all maternal deaths in Suriname, determine the extent of underreporting, estimate the reduction, audit the maternal deaths and assess underlying causes and substandard care factor...

BACKGROUND The maternal mortality ratio in Sudan was estimated at 750/100,000 live births. Sudan was one of eleven countries that are responsible for 65% of global maternal deaths according to a recent World Health Organization (WHO) estimate. Maternal mortality in Kassala State was high in national demographic surveys. This study was conducted to investigate the causes and contributing factors...

The classic evolutionary theory of aging explains why mortality rises with age: as individuals grow older, less lifetime fertility remains, so continued survival contributes less to reproductive fitness. However, successful reproduction often involves intergenerational transfers as well as fertility. In the formal theory offered here, age-specific selective pressure on mortality depends on a we...

Mogilevkina I. (2003) Some reproductive health indicators in Ukraine. A study with special emphasis on factors behind induced abortion and perinatal mortality. Acta Universitatis Upsaliensis, Comprehensive Summaries of Uppsala dissertations from the Faculty of Medicine 1215, 50 pp. Uppsala. ISBN 91-554-5487-9. Objectives: To study indicators specifically reflecting the reproductive health of Uk...

Iodine deficiency disorders affect reproductive performance in the afflicted populations. Environmental iodine deficiency (ID) and goitrogens are important in their aetiology. We observed earlier that chronic maternal dietary ID but not goitrogen feeding altered the blood-brain barrier nutrient transport in adult rats. Whether similar differences exist in their effects on reproduction of dams a...