Snippets from Science

• “Caterpillars follow scent trails left by their fellows. Paint the ground with an invisible circle of scent molecules and put a few caterpillars down on it. Like locomotives on a circular track, they’ll go around and around forever – or at least until they drop from exhaustion. What, if anything, is the caterpillar thinking?” Probably not a lot, for their tiny brains are wired to follow instinct, not reason. In nature, species don’t lay circular trails (unless they are deranged). (from Shadows of Forgotten Ancestors, by Sagan and Druyan)

• Evidence continues to grow that “caloric restriction,” or eating less, minimizes age-related diseases and results in extended life. At the U. of Wisconsin, researchers completed a 20-year old study on 76 young adult rhesus monkeys. The animals were divided into two groups. One group was fed a moderate calorie-restricted diet. The other group, the control group, was fed the “normal” monkey diet. In the calorie-restricted group, the incidence of age-related diseases, such as diabetes, cancer, heart disease, and brain atrophy was substantially reduced. At the end of the study, only 50 percent of the control animals (i.e., animals fed a “normal” caloric diet) survived, while 80 percent of the animals on the restricted diet remained alive. Similar results have been obtained in other animals eating a healthy but restricted diet. (Colman et al, 2009, in the July issue of Science)

• Concussions sustained in contact sports, such as football, can result in permanent brain damage. The more concussions, the more likely the individual is to experience confused thinking, memory loss, and depression later in life. One neurologist examined the brains of nine former pro football players and found that eight of them showed signs of degeneration. This doesn’t mean that every football player will suffer mental loss, but many will, especially after a number of concussions. (Science, August, 2009)

• How much do IQ scores differ between twins and their siblings? For identical twins, the average IQ difference is six points. Between fraternal twins, the average is ten points. Between twins and their siblings, fourteen points. Evidence indicates that genetics plays a substantial role in determining our intelligence, but other factors also influence IQ scores. (Nancy Segal, Entwined Lives, 2000)

• The Common Green Darner (Anax junius) is one of Door County’s largest dragonflies, with a wingspan of about 4 inches and a body length of about 2 3/4 inches. These darners have a green thorax and a bluish abdomen (the thorax is the part bearing the six legs and four wings). Don’t call the long segmented abdomen a “tail,” for it isn’t. Some of these Green Darners are migratory, arriving from the south in late April or early May. Others, appearing later in the season, are resident dragonflies. Scientists have tracked migration of the Green Darner using tiny radio transmitters weighing 0.01 ounce. They stop and feed along the way, as we do on auto trips, but for them it’s a one-way journey. After arriving in Door County, mating, and depositing eggs in ponds and marshes, they die. Their eggs develop into aquatic larvae that, after a few years, emerge and become airborne – and fly south.