The house where modern biology was born is a short walk from my office. There are actually two houses, one behind the other. The first is the Hunt-Morgan House, built by one of the first wealthy men in the region, John Wesley Hunt. His great grandson, Thomas Hunt Morgan, was born in the first house and raised in the second. Thomas Hunt Morgan was to become the most important biologist of his time, and laid the foundations for all of modern biology. His life and accomplishments have a great deal to do with how we address the challenges of climate change.
Thomas Hunt Morgan was born in his great-grandfather’s house only a year after the end of the Civil War. His family included some of the most illustrious – or notorious depending on where you are from – members of the Confederate army, including the raider John Hunt Morgan. Thomas’ own father was a member of Morgan’s Raiders. It is quite remarkable to note that the span from a civil war soldier to a founder of modern biology was a single generation.
Thomas Hunt Morgan grew up in the white house just behind his great grandfather’s house, known today as the Thomas Hunt Morgan house. As a young student, Morgan proved an adept naturalist and excellent student. He earned his degrees from the University of Kentucky and Johns Hopkins University, and spent 24 years on the faculty of Bryn Mawr College. All this time, he engaged in pioneering research in embryology. In 1904, he joined the faculty at Columbia University, where he was to lay the groundwork of modern biology. (Read his biography at the Nobel Prize site, or read a non-technical description of his fly research at Nature. )
There are two major threads that form modern biology: Darwin’s discovery of evolution through natural selection, and Gregor Mendel’s discovery of genetics. Mendel’s work was lost for almost 30 years before its rediscovery in 1900. Morgan understood the reality of evolution, but did not believe that Darwin’s explanation of its mechanism – natural selection – could be true. He was also skeptical of Mendelian genetics. But Morgan was a brilliant experimental scientist. At Columbia he developed a sophisticated series of experiments using the lowly fruit fly as a way of understanding the workings of both evolution and genetics.
Morgan did not believe Darwin or Mendel because he could not see a mechanism either for natural selection or for Mendelian inheritance. He had a life-long aversion to anything that could not be explained by experiment.
That is the great strength of Morgan as a scientist – he was an experimentalist, not a theoretician. Although it is common to divide some disciplines into theoretical and experimental branches, physics being the most obvious example, biology before Morgan was heavy on theory, even speculation, and light on rigorous experimentation. Morgan did not invent the experimental method, which had been around for at least 200 years, but he brought it to the forefront of the new biology.
Beginning with two years of work leading to the discovery of the sex-linked white eye mutant in fruit flies, Morgan and his fly boys, as his staff was known, spent 17 years gradually teasing apart the relationships between chromosomes and inheritance. The success of the fly lab was due not only to Morgan’s insight and intelligence, but to his perseverance as a bench scientist. For this work, from 1910 to 1928, Morgan was awarded the Nobel Prize in Physiology or Medicine.
Morgan is a key figure in modern science not just because of his accomplishments, but because of his underlying skepticism. He did not believe any biological theory unless he could test it. But once he had thoroughly tested it over and over to his own satisfaction, he yielded his skepticism. One of his earliest books was a resounding criticism of Darwin’s theory of evolution through natural selection. Thirteen years later, he wrote another book defending natural selection. He was constantly learning from his own work and that of others, and this allowed him to change his mind once the experiments convinced him that he must.
This may seem ordinary to a biologist today, but it was not so in Morgan’s day. Most biological research was anecdotal, not experimental, the kind of science that Ernest Rutherford called “stamp collecting.” The application of a rigorous experimental approach to biology was not Morgan’s invention, but he was the star of the experimental approach. In 1928, Morgan was lured to California to begin a new biology program at California Institute of Technology (Caltech). He recruited students and faculty who were devoted to his experimental approach to biology, and an amazing number of highly accomplished students trained at Caltech. These students went on to start outstanding programs at other universities and in industry. His influence has spread throughout the biological world.
Almost every biological scientist working today is the beneficiary of Thomas Hunt Morgan’s approach to research. We are deeply trained to be skeptical – skeptical of untested hypotheses, skeptical of other scientists’ work, and most important of all, skeptical of our own work. I remember sitting in Folke Skoog’s lab at Wisconsin tearing apart work by scientists of great reputation, with Skoog egging us on. It is no coincidence that Skoog was a product of Morgan’s Caltech program.
It is that deep skepticism that has allowed us to make so much progress in understanding the impacts of climate change. The general public has a perception that scientists develop ideas and set out to prove them – I don’t use the term hypotheses here, because few outside of science know what that means. In fact, the opposite is true. We set out to disprove other people’s ideas and even our own. That is what leads to good science. The most profound statement that can come out of an experiment is “Well, that’s strange,” because our experiments generally don’t come out the way we expect. Science is about making mistakes, not about getting things right. We learn to understand nature the way Morgan did – by repeatedly making mistakes, modifying our approach, testing our hypotheses. It took the fly boys two years of fumbling about breeding flies before the first white-eyed mutant opened the door to modern genetics. This is the real joy of science – fumbling our way to new understanding. It is why, I think, scientists have trouble communicating the real and deep pleasure of science.
Morgan and the fly boys had the luxury of carefully controlled experiments in a laboratory setting. Many of the greatest challenges in biology now can’t be done in the lab, and nothing illustrates this more than climate change. Controlled growth chamber experiments with rising carbon dioxide or temperatures have proven to have limited utility. Biologists have had to adapt the experimental approach to field worl. The rise of sophisticated statistics and computer-based models has helped us to overcome some of the limitations of field work. However, the same deep skepticism of our own work and the work of others is what has allowed us to make so much progress in understanding how greenhouse gases are changing our world.