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Report that delayed motherhood decreases life expectancy of mouse offspring

The June 2005 issue of Biology of Reproduction includes a special paper by a team of Spanish scientists indicating that delayed motherhood in mice results in shorter life expectancy and reduced body weight in their offspring. Negative effects of late maternal age in women, such as abnormal numbers of chromosomes in their children, are well known. However, other potential negative effects o...

Males with elevated levels of testosterone lead shorter lives but have more success siring offspring

Comparative studies have studied testosterone levels and related them to mating systems and aggression, but very few studies have attempted to relate testosterone to fitness, that is, the combination of lifetime reproductive success and survival, in the wild or experimentally. Over nine breeding seasons, Wendy Reed (North Dakota State University) and her colleagues followed a group of dark-eyed j...

'Empty nester' parent birds use recruitment calls to extend offspring care

By studying a habituated population of pied babblers (Turdoides bicolor) in the Kalahari Desert, researchers have discovered a surprising new way in which parent birds can extend the period of their care of offspring. The findings are reported by Andrew Radford of the University of Cambridge and Amanda Ridley of the University of Cape Town and appear in the September 5th issue of Current Biology,...

The price of vanity: Mating with showy males may reduce offspring's ability to fight off pathogens

In many animals, males advertise to potential mates with showy traits, many of which are linked to testosterone levels. However, a new study suggests that, in fish, choosing a flashier mate may cause future generations to be more susceptible to pathogens. In the January 2007 issue of The American Naturalist, a new study by Judith Mank (Uppsala University, Sweden) finds that mating with ma...

Turn-ons and turn-offs for neurons

Our brain consists of billions of nerve cells enabling to learn, remember and reason. Every time we think and experience, touch, smell or fear, millions of neurons in our brain becomes active. These nerve cells communicate with each other by chemical and electrical impulses to compute incoming sensory information and integrate it via distinct brain regions. With 20,000 - 25,000 genes in our ge...

Cigarette smoke alters DNA in sperm, genetic damage could pass to offspring

Canadian researchers have demonstrated in mice that smoking can cause changes in the DNA sequence of sperm cells, alterations that could potentially be inherited by offspring. The results of their study are published in the June 1 issu...