What’s the following have contributed to historical increases in the global human population? A.) increases in the number of deaths
B.) unavailability of clean water
C.) decreases in the birth rate
D.)Advances in hygiene

Three reasons of the deaths of native americans: new illnesses that their immune systems couldn't cope with. genocides so the settlers could have the good land.starvation from lack of rations and poor infertile land on resevations