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.
Arteries,veins and capillaries are the blood vessels which help in transporting blood from one organ to another organ.nswered by The Community. Making the world better, one answer at a time. veins are unique because they connect to the capillaries and return oxygen-rich blood to the right atria of the heart so that blood can exchange carbon dioxide for fresh oxygen in the lungs.