theory of inheritance of characteristic by means of (what now are called) genes, 1903, in reference to the work of Gregor Johann Mendel (1822-1884), Austrian biologist who enunciated the laws of heredity. Related: Mendelian.
1794, "of or pertaining to the work or thought of English Enlightenment thinker Erasmus Darwin;" 1860 in reference to his grandson, Charles, the biologist. As a noun, 1808 in reference to Erasmus; 1869 as "one who favors or accepts the theory of species evolution by natural selection proposed by Charles Darwin." See Darwin. Related: Darwinianism.
"the branch of biology which attempts to deduce the genesis and evolution of a phylum," 1869, from German Phylogenie, coined 1866 by German biologist Ernst Heinrich Haeckel from Greek phylon "race" (from PIE root *bheue- "to be, exist, grow") + -geneia "origin" (from PIE root *gene- "give birth, beget"). Related: Phylogenic.
also bio-genesis, 1870, "theory that living organisms arise only from the agency of pre-existing living organisms," coined by English biologist T.H. Huxley from Greek bios "life" (from PIE root *gwei- "to live") + -genesis "birth, origin, creation." Meaning "the theoretical evolution of living matter from complex inanimate chemicals" is from 1960. Related: Biogenetic; biogenetical.
"history of the development and behavior of living beings as affected by their environment," 1882, coined by English biologist St. George Jackson Mivart (1827-1900) from Greek hexis "a state or habit," from ekhein "to have, hold;" in intransitive use, "be in a given state or condition" (from PIE root *segh- "to hold").
Every living creature has also relations with other living creatures, which may tend to destroy it, or indirectly to aid it, and the various physical forces and conditions exercise their several influences upon it. The study of all these complex relations to time, space, physical forces, other organisms, and to surrounding conditions generally, constitutes the science of hexicology (hexiology?). [Mivart]