Gene theory is one of the basic principles of the science of biology. It holds that traits are passed from parents to offspring through genes, which are located on chromosomes. Genes are comprised of DNA. Much of the modern understanding of gene theory came through the work of Gregor Mendel.
Gregor Mendel was a monk who spent his time studying crossbreeding of pea plants. Although he published his work in 1866, it was not until the turn of the 20th century that scientists recognized the groundbreaking nature of his empirical data. The scientific understanding of gene theory emerged through the work of embryologists E.B. Wilson, Theodor Boveri, and Thomas Hunt Morgan. They were able to build up Mendel's work following the discovery of chromosomes.
Genes are the unit of biology responsible for transmission of hereditary traits. Gene theory expanded throughout the 20th century to encompass a number of different aspects of biological life. The gene theory of aging maintains that a human's lifespan will be largely determined through one's genetic inheritance. In other words, people whose parents lived to an advanced age are likely to do so themselves.
Biologist Richard Dawkins developed the selfish gene theory, in which he maintained that the gene was the base unit of all evolution. Each gene, according to Dawkins, will act in a way to assure its transmission to the next generation. Natural selection, he claimed, favors genes that create survival mechanisms.