Guppies are small fish found in streams in venezuela. male guppies are brightly colored, with black, red, blue and iridescent spots. males cannot be too brightly colored or they will be seen and consumed by predators, but if they are too plain, females will choose other males. natural selection and sexual selection push in opposite directions. when a guppy population lives in a stream in the absence of predators, the proportion of males that are bright and flashy increases in the population. if a few aggressive predators are added to the same stream, the proportion of bright-colored males decreases within about 5 months (3-4 generations). the effects of predators on guppy coloration have been studied in artificial ponds with mild, aggressive, and no predators, and by similar manipulations of natural stream environments (endler, 1980). a typical natural population of guppies consists of hundreds of guppies. which statement best describes the guppies of a single species in an isolation population? the guppies share all of the same characteristics and are identical to each other. a.