(For the latest Human Nature columns on Terri Schiavo, mandatory pregnancy, and more, click here.)
The American Medical Association proposed to ban teenagers from using indoor tanning equipment. The issue is skin cancer. Some states already require parental consent for tanning salons.
A day of abstinence improves male fertility. A study suggests sperm quantity and quality peak after a day off but decline if you wait longer.
Brain size correlates with intelligence-test scores. To comfort small-headed people, researchers point out that Einstein's brain wasn't very big.
A solar-powered spacecraft crashed during launch due to a failed booster rocket. Pre-launch press reports hailed it as the first privately funded spacecraft. Then they hailed it as the first solar-propelled spacecraft. Now it's $4 million worth of junk.
The government is funding the search for a male birth control pill. One study has found a compound that makes male rats temporarily infertile; researchers aim to find a half-dozen more such chemicals.
Political scientists tried to quantify the role of genes in politics. Using twin studies, they deduced that genes caused about 40 percent of ideological differences over school prayer, the Moral Majority, capitalism, and property taxes, but genes explained only 14 percent of differences in party affiliation. The researchers suggest politics will become more polarized as people seek like-minded mates.
Chess computers are beating grandmasters. Three machines outscored three grandmasters last fall (one of the humans tied one of the machines; he lost to the other two machines); two more matches begin this week. Grandmasters used to boast about beating the machines; now they say the goal is just to do your best.
Michael Schiavo buried his wife. The gravestone says she "Departed this Earth" on the day she suffered massive brain damage in 1990. It says she was "at peace" on the day she officially died in 2005.
Florida Gov. Jeb Bush ordered an investigation into whether Michael Schiavo delayed calling 911 when his wife collapsed. The incident happened 15 years ago; last week's autopsy report found no evidence to support rumors that Schiavo strangled his wife, broke her bones, or neglected her after she suffered brain damage.
Prosthetic limbs are becoming robotic. Sensors, chips, and hydraulics are improving them to such a degree that some amputees now flaunt them, and the military is exploring ways to put robotic attachments on non-amputees.
Senate Majority Leader Bill Frist revised his medical assessment of Terri Schiavo. He previously said on the Senate floor, speaking "as a physician," that she was not in a persistent vegetative state. Now that she's been autopsied, he says, "I never, never, on the floor of the Senate, made a diagnosis." (For Human Nature's takes, click here and here.)
Doctors are keeping a brain-dead woman alive so her fetus can develop. This is the 12th such case reported in the U.S. in three decades. The average survival time for such women is 10 weeks, which would get this baby to 25 weeks gestation.
Terri Schiavo's autopsy vindicated her husband. Examiners concluded that 1) her brain was irreversibly damaged and had shrunk to half the appropriate size; 2) her bone damage was the result of immobility, not violence; 3) there was no evidence of strangulation; and 4) an MRI, which critics faulted her husband for not authorizing, might have harmed her because she had an implanted stimulator in her brain.
A religious right leader conceded that "nature" makes some people gay. Rev. Rob Schenk says he'll tell fellow evangelicals that gay sex is Biblically forbidden but that homosexuality is "deeply rooted."
Conservatives challenged a study that suggested virginity pledges fail to reduce sexually transmitted diseases. The Heritage Foundation applied different methods to the same data and concluded that the pledges worked. The original study's authors say Heritage is wrong to rely on self-reporting of STDs.
Italy's IVF law survived a referendum. The law bans sperm donation and surrogate motherhood and requires women to implant simultaneously all the embryos they create. (For Human Nature's take, click here.)
Astronomers found the smallest planet so far detected outside our solar system. It has seven times the Earth's mass, is made of the same stuff, and might have an atmosphere. This is as small a planet as we can detect with present technology, so there's no evidence that Earth-sized planets won't be found as our instruments improve.
New evidence suggests that fat makes you age faster. Obesity adds about nine years to your biological age, as measured by cellular deterioration.
Psychiatrists are debating whether too many people are being classified as mentally ill. Some say over-diagnosis is diverting resources from seriously ill people to those with mild problems. Others say it's better to catch the mild cases before they become serious.
IVF kids are taller and have more good cholesterol than naturally conceived kids. The height difference seems related to more growth hormones, not parental size. The study's author thinks the difference is caused by IVF-induced genetic change, not by eugenics.
Latest Human Nature columns: 1) The lesson of the Schiavo autopsy. 2) Mandatory pregnancy: A true story. 3) Abortion and responsibility. 4) The coming war over IVF. 5) Bush's hypocrisy on stem cells and the death penalty. 6) The evolution of creationism. 7) Why GPS tracking is good for felons. 8) If steroids are cheating, why isn't LASIK? 9) The case for raising the retirement age.