Asking Questions in Biology: Discovery versus Knowledge

Not all scientists are right!

Galen and Vesalius

Galen was a prominent Roman physician c 129-200 and has been regarded by some as one of the most influential writers on medical subjects. He performed dissections on pigs and monkeys since he was not allowed to use humans. Galen used the information he uncovered through these dissections to make conclusions about human anatomy. Galen's contributions dominated medicine for nearly two millennia. Then about 1500 years later another physician named Vesalius (1514-1564) came along and performed dissections on human cadavers. He produced a seven volume text that contained accurate illustrations of internal human anatomy. One of Galen's errors was that he thought the human jaw bone was made up of two bones, like a dog's. Also, the human breast bone is made up three segments, not the seven that Galen thought. He believed the humerus, upper arm bone, was the second longest bone in the body while Vesalius proved that the tibia and fibula located in the lower leg are longer, making the humerus the fourth longest. Vesalius began to notice other inconsistencies and studied Galen's work more closely when he realized that Galen had not performed dissections using humans. He then set out to produce a more accurate understanding and spent four years developing his seven volume text, commonly known as Fabrica. This text changed the way physicians looked at the work of others and trusted only observations. Vesalius's investigations led to the development of comparative anatomy. Researchers studied animals to find similarities and differences and gradually began to recognize humans share common traits with other animals. Darwin used this knowledge to help him construct his research on evolution.

The Planet Vulcan

Mathematician Urbain Jean Joseph Le Verrier proposed that there was a planet that existed between the Sun and Mercury. He made this proposition based on the irregular orbit of Mercury that was difficult to explain with existing knowledge. Le Verrier argued that the irregularity had to be caused by another celestial body, like a small planet. He named this planet Vulcan after the Roman god of fire. Other astronomers ready to become a part of this new discovery claimed to see this new planet, which propagated the inaccuracy. After Le Verrier died in 1877, many notable astronomers began to doubt its existence. When Einstein's theory of relativity helped to explain Mercury's odd orbit, the search for the planet Vulcan was dropped. ³

Phrenology

Phrenology, in its day, was one of the most popular and well-studied branches of neuroscience! Believers in phrenology thought that certain character traits could be localized to specific parts of the brain. Phrenologists would study the shape and size of a person's head to determine what type of personality based on the lumps and bumps. A map of the brain was produced to show 27 different areas. A person who had a large bump in the area of music would be thought to show expertise in this area. True scientists of this time often scoffed at this belief but it was finally debunked when modern advances showed that personality traits were not traceable to specific areas of the brain. ⁴

Spontaneous Generation

Aristotle, a famous Greek philosopher (384Bc-322BC), studied from other prominent Greek philosophers, like Hippolytus. These philosophers believed that life could spontaneously come into being from inanimate matter like mud or slime when it was exposed to sunlight. His ideas were confirmed by his studies of maggots and how they appeared to generate out of dead animal carcasses. This theory persisted for hundreds of years until the scientific method was adopted and tests began. Louis Pasteur proved that maggots would not appear if meat was kept in a sealed container. After the invention of the microscope, it was proven that life was formed by a seed, egg or some other form of reproduction. ⁵

All of these examples will help my students to see that the joy of science is in the journey not in the outcome. As technology increases, understanding increases. Yet as understanding increases, the irony becomes that we realize how much we still don't know. What is a cutting edge, fantastic discovery today, may be disproven by a better microscope or different filtering system tomorrow. My message to students is, "Begin anywhere" then we will see where the journey takes you.