polyphyletic theory — noun : a theory in physiology: the several cellular elements of the blood originate in two or more distinct stem cells compare monophyletic theory … Useful english dictionary
polyphyletic — 1. Derived from more than one source, or having several lines of descent, in contrast to monophyletic. 2. In hematology, relating to polyphyletism. * * * poly·phy·let·ic .päl i (.)fī let ik adj of or relating to more than one stock specif derived … Medical dictionary
theory — A reasoned explanation of known facts or phenomena that serves as a basis of investigation by which to seek the truth. SEE ALSO: hypothesis, postulate. [G. theoria, a beholding, speculation, t., fr. theoros, a beholder] adsorption t. of narcosis… … Medical dictionary
monophyletic theory — n a theory in physiology: all the cellular elements of the blood derive from a common stem cell compare POLYPHYLETIC THEORY * * * the theory that all forms of blood cells have their origin in a single type of cell, the blast cell (which develops… … Medical dictionary
monophyletic theory — noun : a theory in physiology: all the cellular elements of the blood derive from a common stem cell compare polyphyletic theory … Useful english dictionary
dualistic theory — a variant of the polyphyletic theory that holds that blood cells arise from two distinct types of stem cells, the myeloblasts and lymphoblasts. Cf. monophyletic t. and trialistic t. Called also dualism … Medical dictionary
trialistic theory — a variant of the polyphyletic theory that holds that blood cells arise from three distinct types of stem cells, the myeloblasts, lymphoblasts, and monocytes. Cf. dualistic t. and monophyletic t. Called also trialism … Medical dictionary
polyphyletism — In hematology, the theory that blood cells are derived from several different stem cells, depending on the particular cell type. SYN: polyphyletic theory. [poly + G. phyle, tribe] * * * poly·phy·le·tism .päl i fī lə .tiz əm n … Medical dictionary
polyphyletist — poly·phy·le·tist (pol″le fiґlə tist) an adherent of the polyphyletic theory; see under theory … Medical dictionary
Cladistics — For the scientific journal, see Cladistics (journal). Part of a series on Evolutionary Biology … Wikipedia