A new study indicates that Americans gained up to 15 IQ points after the addition of iodine to salt became mandatory. In an effort to prevent goiter related to iodine deficiency, authorities ruled that iodine be added to U.S. salt products in 1924. The iodine, in addition to eliminating goiter, appears to have had an unexpected result: smarter Americans.
At peak lactation a black bear cub consumes about 30 ounces of milk a day, and a brown bear cub takes about 45 ounces. Thatâs per cub, so a mom with a litter of two or three cubs could be producing three or four quarts per day â a difficult metabolic feat to sustain.
Bears have the smallest young in relation to the motherâs body size of any higher mammal. Typically bear cubs weigh between one three-hundredth and one five-hundredth as much as their mother. On average a newborn black bear cub weighs little more than 10.5 ounces (300 g) and is 9 inches (23 cm) long. Brown bear and polar bear cubs are marginally larger, about 17.5 to 28 ounces (500-800 g) in weight and 12 inches (30 cm) in length. If a newborn human infant were that small in comparison, it would weigh between 3.6 and 6 ounces (100-170 g), the weight of a 14 to 16 week old fetus.