Anopheles stephensi: a new and important menace to South America?

Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.

Many human characteristics, like height, are shaped by both nature—in other words, by our genes—and by nurture, or our environment. For example, chronic stress during childhood inhibits the production of growth hormones and consequently reduces bone growth and height. Scientists estimate that 70-90% of variation in height is due to genetic differences among individuals, and 10-30% of variation in height is due to differences in the environments that individuals experience,...