20 SEP 2011 by ideonexus
Postmating Competition
Sexual selection doesn’t end with the sex act itself: males can continue
to compete even after mating. In many species, females mate with more
than one male over a short period of time. After a male inseminates a
female, how can he prevent other males from fertilizing her and stealing
his paternity? This postmating competition has produced some of the
most intriguing features built by sexual selection. Sometimes a male
hangs around after mating, guarding his female against other suitors.
Wh... 1 
notes
notesVarious evolutionary strategies males of different species keep a female from mating with other males after sex.
19 JUL 2011 by ideonexus
Effects of Caffeine on the Developing Fetus
Caffeine crosses the placenta and may even concentrate in the fetal circulation. Concern about its effect on fetal development stems from animal studies, where it has been found to be teratogenic when fed to pregnant rats in high doses; a dose equivalent to 150 cups of strong coffee per day causes malformations in rodents such as missing limbs and digits. However, caffeine does not appear to be a teratogen in h humans. The average pregnant woman is estimated to consume 144 milligrams per day ... 1 notes
notesModerate consumption of Caffeine appears to have no impact on a child's IQ; however, massive consumption causes deformities in rats.
08 JUN 2011 by ideonexus
Prenatal Influences as Information for the Fetus
The notion of prenatal influences may conjure up frivolous attempts to enrich the fetus, like playing Mozart through headphones placed on a pregnant belly. In reality, the nine-month-long process of shaping and molding that goes on in the womb is far more visceral and consequential than that. Much of what a pregnant woman encounters in her daily life—the air she breathes, the food and drink she consumes, the emotions she feels, the chemicals she’s exposed to—are shared in some fashion w...Folksonomies: pregnancy fetal development
Folksonomies: pregnancy fetal development
2 
2 Diet and other environmental factors are data for the fetus about the conditions of the world outside the womb and influence its development to be best adapted to that environment.
03 MAY 2011 by ideonexus
Orgasms and Sperm Retention
t. Baker and Bellis discovered that the amount of sperm that is retained in a woman's vagina after sex varies according to whether she had an orgasm and when. It also depends on how long it was since she last had sex: The longer the period, the more sperm stays in, unless she has what the scientists call "a noncopulatory orgasm" in between.
So far none of this contained great surprises; these facts were unknown before Baker and Bellis did their work (which consisted of samples collected by ... 1 notes
notesWomen retain more sperm when they have an orgasm, but they are also more likely to be unfaithful when most fertile.
