| any alteration in the structure of an organism resulting from natural selection, by which the organism becomes more able to survive in its environment |
| any modern theory of evolution holding that species evolve by natural selection acting on genetic variation |
monogenesis mon·o·gen·e·sis (mŏn'ə-jěn'ĭ-sĭs)
n.
The theory that all living organisms are descended from a single cell or organism.
The production of similar organisms in successive generations.
Asexual reproduction, as by sporulation or parthenogenesis.
The process of parasitizing a single host, in or on which the entire life cycle of the parasite is passed.