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NONPHOTOSYNTHETIC PROTISTS
Author(s) -
Grell Karl
Publication year - 1974
Publication title -
taxon
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 81
eISSN - 1996-8175
pISSN - 0040-0262
DOI - 10.1002/j.1996-8175.1974.tb02807.x
Subject(s) - biology , phylogenetic tree , evolutionary biology , homology (biology) , heterokaryon , taxonomy (biology) , zoology , genetics , gene , mutant
Nuclear dualism, i.e. the occurrence of two nuclei, different in structure and function within the same cell, is a phenomenon restricted to the heterokaryotic Foraminifera and to the ciliates. Though interesting similarities exist, there is no doubt that the phenomenon developed independently in both groups. In the Foraminifera whose taxonomy is still based exclusively on the morphology of the shells, nuclear dualism is a striking “bridge of homology” connecting certain genera and species of the family Rotaliidae. As will be demonstrated, its variable expression gives some insight into the evolutionary process. However, other features such as the mode of sexual reproduction have to be considered too, if an attempt is made to clarify phylogenetic relationships.