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.
An organ is a specialized grouâ¦p of tissues that performs a particular function, and often more than one function. Examples of organs are the brain, heart, eyes, bones, intestines, pancreas, rectum, lymph nodes, ears, stomach, liver, and gallbladder. We have close to seventy-eight organs in our body. Organs may work together to form a body system.