any modern theory of evolution holding that species evolve by natural selection acting on genetic variation
the reappearance in an individual of characteristics of some remote ancestor that have been absent in intervening generations
a mature sexual reproductive cell, such as a sperm or egg, that unites with another cell to form a new organism
the ability of a population to maintain or increase its numbers in succeeding generations
a sudden departure from the parent type an heritable characteristic caused by a change in a gene or a chromosome
natural selection that favors altruistic behavior toward close relatives resulting in an increase in the individual's genetic contribution to the gene pool
late 14c., "made by man" (opposite of natural), from O.Fr. artificial, from L. artificialis "of or belonging to art," from artificium (see artifice). Another early use was in the phrase artificial day "part of the day from sunrise to sunset" (late 14c.). Artificial insemination
dates from 1897. Artificial intelligence "the science and engineering of making intelligent machines" was coined in 1956.