The Stubborn Gene

NOT-SO-FAMOUS CHANNELIZERS IN GENETICS

There have been many scientists who were not accepted by the scientific community in their times even when their theories deduced from their experiments were actually true, take the now-famous Mendel for an example. Similar to Mendel, there were many more scientists who helped channelize "genetics" from the day of its birth up till the "modern genetics" we know today.

Mendel's results implied that some "things" were transmitted from generation to generation. But what was the nature of these things? At about Mendel's death, it was already 15 years left to the completion of 19th century and scientists using ever-improving optics to study the minute architecture of cells coined the term "chromosome" to describe the long stringy bodies in the cell nucleus. But it was not until the early 20th century that Mendel's work and chromosomes came together.

An american medical student, Walter Sutton, realized that chromosomes had a lot in common with Mendel's mysterious factors. Studying Grasshopper chromosomes, Sutton noticed that they double-up almost always - just like mendel's paired factors. Sutton also identified one type of cell in which chromosomes were not paired: the sex cells. Now in his time, DeVries-Correns-Tschermak had already proved Mendel's work to be true and prevalent.; so this was exactly what Mendel had described: his pea plant sperm cells (pollens) also only carried a single copy of each of the factors. Thus, it was interpreted that Mendel's factors, now called genes, must be on the chromosomes.

In Germany, Theodor Boveri independently came to the same conclusions as Sutton, and so the biological revolution began. Their work came to be called the Sutton-Boveri chromosome theory of inheritance. Suddenly genes were real. They were on chromosomes, and you could actually see chromosomes through the microscope.

But not everyone bought the Sutton-Boveri theory, looking down the microscope at those stringy chromosomes, one could not see how they could account for all the changes that occur from one generation to the next. if all the genes were arranged along chromosomes, and all chromosomes were transmitted intact from one generation to the next, then surely many characteristics would be inherited together. But since evidence showed this not to be the case, the chromosomal theory of inheritance seemed insufficient to explain the variation observed in nature. So came by the famous Thomas Morgan, who turned to the fruit fly, Drosophila melanogaster, a little fly that, ever since Morgan, has been so beloved by geneticists.