Segregation (aside flock), (1) as used in eugenics means the policy of isolating feeble-minded and other anti-social individuals from the normal population into institutions, colonies, etc., where the two sexes are kept apart. (2) The term is also used technically in genetics, to refer to the discontinuity of the variation of characteristics resulting from the independent distribution of factors before or at the time of formation of the gametes.
Selection (apart pick), the choice (for perpetuation by reproduction) from a mixed population, of the individuals possessing in common a certain character or a certain degree of some character. Two kinds of selection may be distinguished: (1) natural selection, in which choice is made automatically by the failure to reproduce (through death or some other cause) of the individuals who are not "fit" to pass the tests of the environment (vitality, disease resistance, speed, success in mating, or what not); and (2) artificial selection, in which the choice is made consciously by