Mendel: The Father of Genetics

In 1857, Austrian monk Gregor Mendel decided to breed pea plants in the large monastery garden of Brunn. He loved botany (studying plants) and he had very much wanted to become a high school teacher. Unfortunately, he had failed the teaching exam three times, so he had to be content with living as a monk.

Mendel noticed that all of his pea plants had different characteristics: some had green seeds, others had yellow; some had tall stems, and others had short, and so on. He was curious why this was true, especially when he noticed that sometimes the offspring portrayed characteristics of the parent(s) and sometimes they did not. He decided to experiment with the pea plants (which are excellent for such experiments because they can self replicate) to discover why.

The first trait Mendel tested was height. When he took several short plants and self pollinated them, they produced seeds that all grew to be short, just like the parents - that is, they all bred true. Then, he self pollinated several tall plants and the resulting seeds (called the F1 generation) all grew to be tall, meaning they also bred true. The results of this experiment seem obvious and logical, that short parents have short offspring and tall parents have tall offspring; hence, Mendel wasn't surprised at all by his findings. He was surprised, however, when he bred a new batch of tall plants with short plants and found that all the offspring were tall. Not a single seed of this F1 generation grew to be short. At first, Mendel believed that the shortness characteristic had disappeared, but when he self pollinated the F1 offspring, the second generation (called the F2 generation) had a mix of both tall and short plants. Apparently, the shortness hadn't just disappeared after all!

After conducting more experiments and breeding more plants, Mendel figured out that in the F2 generation, there were three tall plants for every short one (a 3:1 ratio). From this, he concluded that traits, or characteristics, come in pairs - one from each parent - and that one trait will have dominance over the other (tall is dominant over short, for example). The idea was simple, but very ingenious for its time.

Mendel studied other traits besides height, including the color of the seeds and seed coats, the position of the flowers on the stems, and the shape and color of the pea pods. It took him eight years and 30,000 pea plants to discover these natural laws of heredity (now known as the Mendelian Laws). Afterwards, Mendel wished to publish his findings, but feared that no one would listen to him because he was only a monk and not even qualified to teach high school! Nevertheless, he sent his reports to the most famous botanist in Europe, Karl Wilhelm von Nageli of Switzerland, hoping to gain his sponsorship (support of his work). von Nageli ignored Mendel's work, though, and sent it back to him. Mendel was able to get his paper published in a scientific journal several years later, but - just as he had feared - no one acknowledged it because he was an unsponsored amateur. Saddened, he gave up botany and devoted his days to monastic life. Mendel died in 1884. It was nearly forty years later when his writings and research were rediscovered and found to be true.