In 1865 an Austrian monk, Gregor Mendel, presented the results of painstaking experiments on the inheritance of the garden pea. Those results were heard, but not understood, by Mendel's audience. In 1866, Mendel published his results in an obscure German journal. The result of this was that Mendel's work was ignored and forgotten. Mendel died in 1884 without knowing the pivotal role his work would play in founding the modern discipline of genetics.
By 1899, some geneticists were beginning to realize the necessity of mathematically analyzing inheritance in order to understand how evolution might work (Bateson, 1899). They did not realize that Mendel had already solved this problem. Then, in 1900, three leading scientists of the day, Hugo de Vries, Carl Correns, and Erik von Tschermak, simultaneously rediscovered Mendel's paper and realized how important it was. With the rediscovery of Mendel’s principles, genetics as a scientific discipline exploded into activity. Within two years, the first human study of inheritance (Garrod, 1902), describing the Mendelian inheritance of alkaptonuria, was published. This paper, too, was far ahead of its time, the importance of which would only be recognized as the one gene-one polypeptide principle was developed in the latter part of this century.
Now, more than a century later, Mendel's work seems elementary to modern-day geneticists, but its importance cannot be overstated. The principles generated by Mendel's pioneering experimentation are the foundation for genetic counseling so important today to families with health disorders having a genetic basis. It's also the framework for the modern research that is making in roads in treating diseases previously believed to be incurable. In this era of genetic engineering - the incorporation of foreign DNA into chromosomes of unrelated species - it is easy to lose sight of the basics of the process that makes it all possible.