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.
Best Answer: An organ is a body part made up of 2 or more tissue types. A tissue is a group of cells specialized to perform a specific function. A capillary is made of one tissue type, endothelial cells. Endothelial cells are shaped like potato chips.