Part 1: Medical Abolitionists and Adaptation
Before the civil war, pro-slavery scientists such as Louis Agassiz worked with politicians like Secretary of State John Calhoun to promote the concept of polygenesis. In polygenesis, there is no adaptation of animals to their environment. Races of animals, including humans, were created separately in specific locations for specific purposes. Black people were created to be enslaved, and whites to rule from above.
Opposing this view were medical scientists such as H. Ingersoll Bowditch, president of the American Medical Association, and James McCune Smith, the first African American M.D. They had an important friend in common: famed abolitionist Frederick Douglass. This network of medical abolitionists promoted the concept of monogenesis. In monogenesis all humans started as one race in the same place, then gradually spread around the world. As they encountered different climates they adapted by changing features. Taller bodies lose heat faster, and darker skin protects from the sun better, so taller darker bodies are found in Africa, and shorter people with lighter skin in Europe.
In his 1854 address at a university in Ohio, Frederick Douglass pointed out how southern politicians were using the theory of polygenesis to justify slavery. He explained the alternative, adaptationist view:
Outward circumstances may have something to do with modifying the various phases of humanity... color itself is at the control of the world's climate and its various concomitants.
After the civil war, the adaptation concept found new support when Bowditch’s nephew H. Pickering Bowditch became the dean of Harvard Medical School. Pickering saw that the same old racism that had been applied during slavery had taken a new form, “eugenics,” and was now used against immigrants. He used statistics to show that poor nutrition, not genetics, was the cause of low birth weight and other problems among the poor. The body was always adjusting itself to survive. His student Walter Cannon invented the term homeostasis to explain how living things can adapt with negative feedback.
Cannon was especially interested in the heart’s feedback loops (he coined the term “fight or flight”). For example, when blood pressure rises, the “baroreceptor” in the carotid artery in your neck sends a signal to your brain. That loops back to the heart, causing it to beat faster.
Explore the heart simulation here. Click the green flag in the upper right corner once it's loaded to run the program.
Is there a lag? If so, why, and how might the loop to the brain be involved? Take notes about what you found, and use them to help assemble the blocks in your feedback flowchart. (Click and drag the blocks to form a flowchart)