BioConcepts

divergenceDivergenz (ger.)

• The departure from each other of two phylogenetic paths.  
  category phylogenesis

  1857

  principle of divergence

  Darwin, C. (1857). Letter to  A. Gray, Sept. 5th 1857 (Correspondence, vol. 6, Cambridge 1991, 445-449): 448.

  1859

  Divergence of Character.—The principle, which I have designated by this term, is of high importance on my theory, and explains, as I believe, several important facts. [...]

  we see in man's productions [in breeding] the action of what may be called the principle of divergence, causing differences, at first barely appreciable, steadily to increase, and the breeds to diverge in character both from each other and from their common parent.

  But how, it may be asked, can any analogous principle apply in nature? I believe it can and does apply most efficiently, from the simple circumstance that the more diversified the descendents from any one species become in structure, constitution, and habits, by so much will they be better enabled to seize on many and widely diversified places in the polity of nature, and so be enabled to increase in numbers.

  Darwin, C. (1859). On the Origin of Species (London 1985): 111; 112; cf. 6th ed. 1872: 86-7; Lefèvre, W. (1984). Die Entstehung der biologischen Evolutionstheorie: 245ff.

  1945

  The almost universal absence of continuous record of the earliest stages of branching between important phyla constitutes a more serious difficulty, but the problems can usually be solved with reasonable probability because of the fairly obvious and simple criteria for convergence, divergence, homology, and conservation provided by the preserved sequences. If the early members of two groups are more alike than the later, their later dissimilarities are divergent.

  Simpson, G.G. (1945). The principles of classification and a classification of mammals. Bull. Amer. Mus. Nat. Hist. 85: 12.