Mendel, Gregor Johann

Austrian biologist who founded genetics. His experiments with successive generations of peas gave the basis for his theory of particulate inheritance rather than blending, involving dominant and recessive characters; see Mendelism. His results, published 1865–69, remained unrecognized until the early 20th century.

Mendel formulated two laws now recognized as fundamental laws of heredity: the law of segregation and the law of independent assortment of characters. Mendel concluded that each parent plant contributes a ‘factor’ to its offspring for determining a particular trait. These are what we now recognize as genes or alleles. He showed that the pairs of factors in the offspring do not give rise to a blend of traits.

Much of his work was performed on the edible pea Pisum, which he grew in the monastery garden. He carefully self-pollinated and wrapped (to prevent accidental pollination by insects) each individual plant, collected the seeds produced by the plants, and studied the offspring of these seeds. Seeing that some plants bred true and others not, he worked out the pattern of inheritance of various traits.

He reported his findings in ‘Experiments with Plant Hybrids’ (1866), but the importance of his work was not recognized at the time, even by the eminent botanist Karl Wilhelm von Naegeli, to whom Mendel sent a copy of his paper. It was not until 1900, when his work was rediscovered by Hugo De Vries, Carl Erich Correns, and Erich Tschermak von Seysenegg, that Mendel achieved fame – 16 years after his death.