June 7, 1996 |
Expanding on evidence that environmental chemicals could be altering sex hormones, scientists have discovered that some pesticides with weak potential to imitate estrogen on their own become hundreds of times more potent when two are combined.
March 14, 1989 |
In a case where the new world of reproductive technology comes up against the old world of law and human frailty, a Tennessee couple who are getting a divorce are at odds over who should have control of their frozen embryos. Junior Lewis Davis, who initiated the divorce action, says the embryos are potential children and that he should have the right to decide whether he wants to become a father.
October 3, 1994 |
"Every man sitting in this room today is half the man his grandfather was. And the question is, are our children going to be half the men we are?" In all likelihood, that alarming testimony--from a reproductive biologist at a congressional hearing on the hazards of pesticides--is hyperbole. Even so, it readily dramatizes the fears of many scientists that environmental pollution could be warping human sexual development.
May 26, 2007 |
Female sharks can fertilize their own eggs and give birth without sperm from males, according to a study published Wednesday in the British journal Biology Letters. The joint Northern Ireland-U.S. research analyzed the DNA of a shark born in 2001 at the Henry Doorly Zoo in Omaha. Analysis of the baby shark's DNA found no trace of any chromosomal contribution from a male. Shark experts said this was the first confirmed case in a shark of parthenogenesis, or "virgin birth."
CALIFORNIA | LOCAL
September 9, 1992 |
A sophisticated reproductive technique that has enabled some menopausal women to bear children appears to work as well in women over 40 as in younger women, according to a new report by USC researchers. The study of 100 patients suggests that the technique, which involves the use of eggs from younger women, can in some instances reverse the normal age-related decline in human fertility. The underlying problem may be the age of the egg, not the age of the other reproductive organs.
CALIFORNIA | LOCAL
April 1, 1991 |
A new clue to how mammalian eggs attract sperm may lead to new treatments for infertility. Follicle cells in the reproductive tract, and presumably the eggs themselves, emit a chemical that causes sperm to migrate toward the egg, researchers from the Weizmann Institute of Science in Rehovot, Israel, report in today's edition of the Proceedings of the National Academy of Sciences.
October 2, 1994 |
In the gender-bending waters of Lake Apopka, alligators aren't quite male. They aren't quite female either. They may be both. Or neither. This sexual confusion in the wild, discovered in this steamy Florida swamp last year, is so disturbing to scientists that they keep performing test after test on the scaly reptiles, trying to prove themselves wrong. But the more they look, the more evidence they find.
March 10, 2007 |
A study of spiders' copulation techniques found that males leave part of their sex organ inside females as a sort of "chastity belt" to deter rivals. "Males can reduce sperm competition and thereby increase their paternity success," Bonn University researchers wrote in the journal Behavioral Ecology. A male only has only seconds to have sex before the larger female kills him. In more than 80% of cases, the tip of the male's genital organ breaks off inside the female.
CALIFORNIA | LOCAL
March 15, 2006 |
In the final analysis, the federal watchdogs had to make a no-win choice about the bald eagles of Santa Catalina Island. The birds' eggs were still cracking because of the ravages of DDT. The chances of reproducing on their own, at least in the foreseeable future, seemed dubious at best.
September 22, 1989 |
In a decision that could have far-reaching ethical, medical and legal implications, a Tennessee judge Thursday awarded custody of seven frozen embryos to a wife embroiled in a divorce case, ruling that "human life begins at conception." Circuit Court Judge W. Dale Young ruled the fertilized eggs should go to Mary Sue Davis, who wants to implant them and carry them to term--against the wishes of her estranged husband, Junior Lewis Davis. At a news conference in Titusville, Fla.