Evolutionary models of human reproduction argue that variation in fertility can be understood as the local optimization of a life-history trade-off between offspring quantity and 'quality'. Child survival is a fundamental dimension of quality in these models as early-life mortality represents a crucial selective bottleneck in human evolution. This perspective is well-rehearsed, but current lite...

Human reproductive patterns have been well studied, but the mechanisms by which physiology, ecology and existing kin interact to affect the life history need quantification. Here, we create a model to investigate how age-specific interbirth intervals adapt to environmental and intrinsic mortality, and how birth patterns can be shaped by competition and help between siblings. The model provides ...

I want to offer a new approach to the history of American ethnic intermarriage--to ask new questions and exploit newly available evidence. Intermarriage patterns have always been important in this country, but in present-day America there is a renewed attention to such patterns, for two reasons. First, new waves of immigrants lead observers to ask whether or not the future of American ethnic li...

Basic concept of managing knowledge is not a new one, even though knowledge management is a new discipline it has emerged only recently and, given its newness is still developing its theoretical home. Knowledge management has always been conducted in one way or another, e.g. apprenticeships, colleagues chatting or a parent handing over her/his business to the offspring. E-learning is one of the...

We show that an infinite Galton-Watson tree, conditioned on its martingale limit being smaller than ε, converges as ε ↓ 0 in law to the regular μ-ary tree, where μ is the essential minimum of the offspring distribution. This gives an example of entropic repulsion where the limit has no entropy.

Maternal smoking during pregnancy is associated with a variety of adverse neonatal outcomes including altered reproductive performance. Herein we provide molecular evidence for a pathway involved in the elimination of the female germline due to prepregnancy and/or lactational exposure to polycyclic aromatic hydrocarbons (PAHs), environmental toxicants found in cigarette smoke. We show that ovar...

Infertility affects around 15% of human couples and in many countries approximately 1-4% of babies are born following Assisted Reproductive Technologies (ART). Several ART techniques are used and these differentially affect the sex ratio of offspring successfully produced. These direct effects on sex ratio also have the potential to influence, indirectly, the sex ratios of offspring born to unt...

objective(s): the effect of maternal voluntary exercise on hippocampal bdnf level in rat offspring was studied. in addition, the possible role of hippocampal bdnf receptors in maternal exercise induced enhancement of learning in the rat pups was investigated.   materials and methods: pregnant rats have been randomly assigned to sedentary control or voluntary exercise groups. each of the exercis...

Parent-offspring birth weight correlations are presented by sex of parent and infant. They range from .14 to .16, except for the mother-daughter correlation, which is .32. This pattern of parent-offspring correlations varies when the parity of the infant, the size of the mother, and the mother's drinking and smoking status are considered. All parent-offspring correlations are higher when the in...

Maternal smoking and micronutrient intake during pregnancy are two strong biological candidates for impacting the developing epigenome. The extent to which DNA methylation in offspring is modified by these intrauterine exposures has not been presented in parallel. In this review, we summarize human studies which have investigated genome-wide DNA methylation in the offspring in relation to mater...