Question

historically, what contributed to the zero population growth of humans?
lack of diseases that affected humans
environmental resistance and biotic potential
abundant food supplies everywhere
no clean water sources

Explanation:

To determine the answer, we analyze each option:

• "lack of diseases that affected humans" is incorrect because historically, diseases were prevalent and not a reason for zero population growth.
• "environmental resistance and biotic potential" aligns with the concept that environmental resistance (like limited resources, harsh climates) and biotic potential (population growth capacity) interacted to keep population growth at zero historically, as per the context about environmental checks on biotic potential.
• "abundant food supplies everywhere" is incorrect as historical conditions had limited food resources, not abundant ones.
• "no clean water sources" is too narrow and not the main factor; environmental resistance includes multiple factors, not just water.

Answer:

B. environmental resistance and biotic potential