Health & Science
How high will the seas rise?; Where did whales come from?; The effect of nurture on IQ; A vaccine for cocaine addicts
How high will the seas rise?Climatologists last year estimated that sea levels will rise about 2 feet over the next century as a result of global warming—a prediction they conceded was merely a best guess. But a group of scientists has discovered that the last time the Earth warmed as much as computer models predict it will by 2100, sea levels rose by 20 feet. By examining ancient sea sediments, the scientists were able to reconstruct conditions between the last two ice ages, 124,000 years ago. During this period, temperatures rose by about 4 degrees Fahrenheit, and ice in the arctic regions melted rapidly, adding vast quantities of water to the oceans. Today, a sea-level rise of that magnitude would be catastrophic; even an increase of a few feet would flood coastal cities and recreation areas, and require massive new efforts to hold back the sea. Climatologist William Thompson of the Woods Hole Oceanographic Institution in Massachusetts, who did not participate in the new study, tells Science that while it remains unclear how much seas will rise in coming decades, the findings indicate that last year’s estimate was probably “too conservative.”
Where did whales come from?Whales and dolphins evolved from a tiny, deer-like mammal that took to the water to avoid being hunted, a newly discovered fossil suggests. Scientists have long known that whales evolved from a creature that once lived on land, with the most likely candidate being a hippopotamus-like creature that waded in the water for food. But the new fossil, of a raccoon-size mammal called the Indohyus, shows similarities to whales and dolphins that researchers say indicate that it is actually the “missing link” in cetacean evolution. The Indohyus had a peculiar, thickened middle-ear bone found in all modern cetaceans and in no other mammal, and had dense limb bones that helped it stay rooted in the water while foraging for aquatic plants. The mammal lived in Asia about 50 million years ago, and slowly evolved to swim and live in the water to pursue food sources and escape predators, says researcher Hans Thewissen of Northeastern Ohio Universities College of Medicine. Other experts say the evidence is intriguing but not conclusive. “To suggest that this fossil somehow is closer than hippos, that’s a big deal,’’ evolutionary biologist Annalisa Berta tells Scientific American. “I’m just not convinced.”
The effect of nurture on IQIs IQ strictly the product of genetics, or does it also reflect experience and nurture? That controversial question continues to divide geneticists, but a new study of orphans strongly suggests that how a child is raised plays a major role in his IQ. Researchers working in Romania gave intelligence tests to two groups of the country’s orphans. One group of kids had been placed in foster families early in life, while the other grew up in orphanages. When scientists tracked the mental development of these children over time, they found that the kids raised in institutions scored abnormally low on IQ tests—they averaged a 73 at age 4½. Kids who had been raised in foster families scored an average of 81 at the same age, with higher scores for the children who had switched from institutional care to foster care as infants. Children raised from birth by their own biological parents have average IQ scores of 109. The findings, Dr. Seth Pollak tells The New York Times, indicate that IQ is very much affected by interaction between a child and a parent. “The evidence seems to say that for humans, we need a lot of responsive care giving,” Pollak says.
A vaccine for cocaine addictsCocaine addiction is one of the toughest to kick, but scientists are now working on a vaccine that may prevent addicts from getting a high from the drug. The vaccine, designed by psychiatrist Tom Kosten of the Baylor University College of Medicine, contains inactivated cocaine molecules attached to bits of the inactivated cholera virus. When injected into the body, this combination trains the body’s immune system to perceive the drug as an invader. So if a vaccinated coke addict ingests the drug, antibodies surround and attach themselves to the cocaine molecules, preventing them from reaching the brain to produce a high. “At some point, most users will give in to temptation and relapse,” Kosten tells the Associated Press. “For people who have a desire to stop using, the vaccine should be very useful.”Another reason to hate cell phones Next time you’re stuck in traffic, blame cell phones. Motorists who are blabbing on cell phones, even hands-free devices, invariably slow down slightly, and don’t pay attention to the flow of traffic, a new study found. They fail to change lanes appropriately, and tend to bunch up behind slow-moving cars, slowing down everyone around them. “Your frontal cortex can handle only so many tasks at one time, so you slow down,’’ researcher David Strayer of the University of Utah tells the Associated Press. Since one in 10 drivers is on the phone at any one time, those delays really add up. Strayer estimates that drivers who use cell phones add up to 10 percent to the time of an average person’s commute.