Camilla and Kevin were debating how waves travel through matter. Kevin said that all waves must travel through some kind of matter. This is why there is no sound in space. Because there is no matter in space (that is called a vacuum). Camilla disagreed with Kevin and argued that while some waves need matter to travel, not all of them do.

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.

List two limitations of natural selection

If a robot fixed another robot is it a engineer or doctor?