Mendel’s work was pretty much ignored, but by 1900 or 1901
Hugo de Vries, Erich von Tschermak, Carl Correns, and William Jasper Spillman
separately rediscovered it.
The laws of inheritance are so important that everyone who
is the result of generic inheritance should know them:
Some plant and animal species reproduce without sex, but
single-parent transmission does not follow the Mendelian laws of
inheritance. Some species alternate between asexual and sexual
reproduction. Inquiring minds want to know why plants do it, or as
Cole Porter wrote, birds do it, bees do it, even educated fleas do
it, why don’t we do it? Sexual reproduction increases
genetic variation, which, for example, makes a species less
susceptible to disease.
See also in The book of science:
Readings on wikipedia: