The 'Single Origin' Theory of Humankind's Invasion of the World

question 18

Multiple Choice

The 'single origin' theory of humankind's invasion of the world:

• A) is the same as the Australian Model.
• B) states that all humans are descendants of a shared common ancestor in Africa.
• C) states that all humans are descendants of a shared common ancestor in the Americas.
• D) is the same as the Multiple Origins Model.
• E) explains how the evolutionary paths of a number of versions of Homo came together or converged eventually.

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Definitions:

Semilunar Valves

Heart valves located between the ventricles and the major arteries, preventing backflow of blood into the heart chambers.

Intraventricular Pressure

The pressure within the ventricles of the heart, which varies during different stages of the cardiac cycle.

Incompetent Mitral Valve

A condition where the mitral valve in the heart does not close properly, leading to backward flow of blood from the left ventricle into the left atrium, affecting heart efficiency.

Left Atrium

The heart chamber that receives oxygenated blood from the lungs and pumps it to the left ventricle.