Darwin hypothesized that there are definite steps to natural selection. consider the model for natural selection. describe a scenario that represents this model of natural selection according to darwin.

Examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. polyploidy is creating new species. the two populations are not interbreeding freely. hybrid offspring of the two populations begin to appear. one species will increase into a population size twice as large as the other species.

New york city has 2,181 inhabitants per square mile. the state of alaska has 1.03 inhabitants per square mile. ecologists would say alaska has a low exponential growth population density birth rate carrying capacity

1. mendel observed that pea plants had traits, such as color, that were either “one or the other,” never something in between. discuss the correlation between mendel’s factors, what they might be, and why pea plant traits come in one form or another—e. g., gray or dark red—rather than blended.