For the common progenitor of a whole family, now broken up by extinction into distinct groups and subgroups, will have transmitted some of its characters, modified in various ways and degrees, to all the species; and they will consequently be related to each other by circuitous lines of affinity of various lengths (as may be seen in the diagram so often referred to), mounting up through many predecessors.
eta hauek, ondorioz, elkarrekin erlazionaturik egonen dira luzera ezberdineko kidetasun-lerro korapilatsuei esker, arbaso askorengandik datozen lerroak berauek, hain sarri aipatu dugun diagraman ikus daitekeenez.