Laws of inheritance

1865

Laws of inheritance

The book of science

Tom Sharp

Gregor Johann Mendel genetics

Laws of inheritance

Mendelian factors

Pattern recognition

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:

  1. The law of segregation—Every person has two copies of the genes for each trait and passes only one copy at random to each child. When the copies from each parent are different, one is dominant. Traits are not blended.
  2. The law of independent assortment—Selecting the copy of one gene has nothing to do with selecting the copy of another gene.

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: