Q. Which of the following is the deadliest predator of people on the planet? A. sharks B. lions and other big cats C. human beings D. mosquitoes E. dogs
A. Mosquitoes (D). “Sharks kill fewer than 10 people annually, whereas the average yearly mosquito-related death toll over the past two decades is about two million,” says Steve Mirsky in “Scientific American” magazine, drawing on Timothy Winegard’s book, “The Mosquito: A Human History of Our Deadliest Predator.” What makes humans particularly attractive are carbon dioxide exhalations that the insects can detect up to 200 feet away.
Some 110 trillion mosquitoes are alive at any one time, but only the female bites. Writes Winegard, “it is the toxic and highly evolved diseases she transmits that cause an endless barrage of desolation and death.” Of the more than 15 diseases mosquitoes transmit, the deadliest is malaria, and the book argues that malaria diseases played a critical role in the American colonists’ underdog win against the British in the Revolutionary War. George Washington, himself a malaria sufferer, commanded troops already exposed to the disease, whereas the British troops were unprotected from “the kill-buzz.”
FYI, the runner-up killer of human beings is human beings, Winegard says, with the annual toll reaching about 475,000 deaths on average over the past two decades.
Q. Why were new Moms asked to wear the same cotton T-shirt to bed for three consecutive nights?
A. They were part of a study to test whether a familiar scent can sooth Baby, as some midwives have advised, says Layal Liverpool in “New Scientist” magazine. Moms were told to use their normal shampoo, soap and deodorant but not add any new products. Then researcher Sarah Jessen showed photos of happy and fearful faces to seven-month-old babies — the age by which the fear response has developed. “Each of the 76 infants viewed the photos while being exposed to either the familiar smell of their mother, a stranger’s odor, or no specific odor.” The infants were fitted with an EEG cap, which would measure a specific pattern of electrical activity in the brain, indicative of a fear response.
Jessen found those babies that could smell their mother didn’t have this pattern, but those exposed to the other two situations did. Her conclusion? Babies’ experiences, including those of smell, can influence fear processing in the brain. Next, she plans to investigate whether babies have a similar response to their father’s scent or the scent of other caregivers. Stay tuned!
Q. As the old cowboy song intones: “Here on the range I belong/ Drifting along with the tumbling tumbleweeds.” What’s wrong with this picture?
A. “Those dried-up, grey and brown tangles of ‘salsola’ plants have blown through many a Western movie, but they actually aren’t all that Western,” says Susan Milius in “Science News” magazine. According to evolutionary ecologist Shana Welles, the tumbleweed species isn’t even native to North America, reportedly having been brought as “impure” flaxseed from Russia to South Dakota in the 1870s. The adaptable “S. tragus” can now be found in at least 45 U.S. states, including Louisiana, Maine and Hawaii, and thrives in places like California’s Central Valley, where 5’8” Welles recounted standing next to tumbleweeds that were taller than she was.
In its one year of life, a single plant can create more than 100,000 lentil-sized fruits. When fruit and seeds form, a tissue layer weakens the main stem at the base for the wind to snap off the entire structure to blow where it will. As Milius puts it, “A tumbleweed is just a maternal corpse giving her living seeds a chance of a good life somewhere new.”