the sporophyte) and is conventionally characterized as a conflict between theories of antithetic and homologous alternation of generations.
Celakovsky's (1874) purpose was to present an accurate classification of the alternation of generations (Generationswechsel).
Pringsheim (1876b) presented a contrary interpretation of the connection between alternation of generations in thallophytes and mosses.
Bower (1890) viewed the alternation of generations of archegoniates as arising from the adaptation of an initially aquatic organism for the land.
Here, Scott referred to recent discoveries that had shaken a strictly morphological interpretation of the alternation of generations, and that had "dropped as a bombshell" (Bower, 1935; p.
Brown (1935: 657-658) clearly believed, however, that "it is doubtful if any alternation of generations .
An argument often put forward in favor of the homologous theory of alternation of generations (and sporophyte origin) is the alleged "evidence" of algae with isomorphic (morphologically identical or very similar) gametophytes and sporophytes, such as Ulva, Cladophora suhriana, Chaetomorpha (cf.
246) presented an easy-to-follow "flow diagram" of the evolution of meiosis, life cycles, alternation of generations, and so forth; their tracings led first to eukaryotes (after the development of mitosis and meiosis), and then to several major eukaryotic lineages and sublineages, including land plants based on the timing of meiosis in the life cycle and the supposed development of alternating generations.
South and Whittick speculated that this alternation of generations in algae, connecting to land-plant origins, would be heteromorphic (they did not name a specific group of algae).
The total paleobotancial evidence, though, as previously discussed, does not support either theory of alternation of generations conclusively; put another way, the existing evidence could be argued to support both theories more or less equally.