Genetics SitesHuman Genome Project
DNA Learning Center
ReferencesHenderson's Dictionary of Biological Terms. 10th Ed. John Wiley & Sons.
Before the development of genetics, our understanding of heredity came from farming, agriculture, and the breeding of animals, such as dogs, for certain desirable traits. Many breeds of dogs, for example, were developed during the Middle Ages. In the 1790s, the British farmer T.A. Knight bred varieties of garden peas. In his work, he noticed that everytime he bred peas with white flowers to those with violet flowers, the offspring were always violet. Knight explained this phenomena by stating that the violet flowers had a "stronger tendency" to appear than white flowers. The idea of a trait having a "stronger tendency" appeared up to the 18th century in phrases that people used, such as "its in the blood", to account for certain traits that appeared quite often in certain families.
But in the 19th the field of Genetics because of the work
of an Austrian named Gregor Mendel. Mendel, through his understanding
of both science and mathematics, developed the foundations from which
Genetics grew. Mendel learned how to predict the probability that future
traits would appeared, based upon knowing what traits and genes that
the parents possessed.