A broken section of Earth's outermost layer that slowly moves while carrying continental or oceanic crust

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.

What is the inability of an individual or a society to achieve a minimum standard of living known as ?

In which of the following relationships is one organism always benefited while the other organism is always harmed