In europe , three lineages of bears evolved in a common ancestor. two of those lineages led to present-day black bears and brown bears. the third lineages led to cave bears that went extinct 24,000 years ago. which of the following could explain why only one group of bears were extinct?

Afarmer has applied a pesticide to control a pest population that is affecting her crops. the pest population has reacted as shown below. which best describes the process that the pest population has experienced due to this environmental change? a genetic diversity b natural selection c natural resistance d genetic resistance

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

The pacific plate is an oceanic tectonic plate. how did a hot and the pacific plate interact to form the hawaiian islands?