The species theory, polygenism, held that human races were of different lineages and suggested a hierarchy outlined in the Chain of Being that positioned Africans between man and lower primates.
No, they are involved in the Circulatory System which is responsible for pumping and channelling blood to and from the body and lungs with heart, blood and blood vessels. no veins are not considered an organ because they are a grouping of different tissues like a organ.
1 Veins carry deoxygenated blood and wastes from the tissues to the liver and heart. 2  The lympathic vessels also empty into the veins thereby returning any excess fluid in the tissue spaces back into the circulation. 3  Capillaries allow for gas, nutrient and waste exchange between the blood and tissue spaces.