1824 in biology, "science of the outer form and inner structure of animals and plants," from German Morphologie (1817); see morpho- "shape" + -logy "study of." By 1869 in philology, "science of structure or forms in language." General sense of "shape, form, external structure or arrangement" is by 1890. Related: Morphological; morphologist. Related: Morphologist.
"plurality of origins," in biology, "generation or origination from several separate and often independent germs; as a doctrine, equivalent to special creation; originally and often specifically in reference to the view that the human race consists of several distinct species, 1858, from poly- + -genesis "birth, origin, creation." Also see polygeny.
1540s, in reference to property, qualities, etc., "descent by natural or due succession," agent noun from devolve. Meaning "act of transferring or handing over" is from 1620s. Etymological sense "act of rolling down" (1620s) was rare in English and is archaic or obsolete. In biology, as "degeneration, the opposite of evolution," it is attested by 1882.
1845, in reference to the doctrine of French anarchist/socialist Pierre-Joseph Proudhon (1809-1865) that individual and collective well-being is attainable only by mutual dependence, from French mutuellisme. In biology, "a symbiosis in which two organisms living together mutually and permanently help and support one another," from 1876, from mutual + -ism.
"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.
used from 18c. in various senses in English in anatomy and biology, from Latin capitulum, literally "little head," diminutive of caput "head," also "leader, guide, chief person; summit; capital city; origin, source, spring," figuratively "life, physical life;" in writing "a division, paragraph;" of money, "the principal sum" (from PIE root *kaput- "head").
1938, in biology, "a graded series of differences within a species," a back-formation from incline or from a Latinized form of Greek klinein "to slope, to lean" (from PIE root *klei- "to lean"). Earlier, but now obsolete, was a verb cline, from Middle English clinen "to bend, bow," from Old French cliner, from Latin clinare.