Abstract Some 50 clones belonging to a rather homogeneous, presumably monophyletic, section of genusEuplotes proved to be distributed between two clear-cut subgroups on the basis of cell size and relative peristome length. These subgroups are referred to asvannus andminuta morphotypes. Withinvannus morphotype, theE. vannus complex of 5 sibling species was previously defined on the basis of interfertility criterion. Electrophoretical studies revealed clear-cut biochemical differences between theE. vannus complex and theminuta morphotype. A multivariate analysis concerning 6 characters shows that the 5 species in the complex are closely similar. Nevertheless, the results of discriminant analysis suggest that a morphological discrimination could be possible. The status of one peculiar clone remains somewhat obscure. It belongs undoubtedly to thevannus morphotype, but shows no mating reaction with any of the 5 species ofE. vannus complex and is electrophoretically related tominuta morphotype. The following interpretation is suggested. In this section of genusEuplotes, two stable adaptive zones are available, corresponding to the two morphotypes. Speciation and change of adaptive zone are more or less independent evolutionary events. For example, the 5 species of thevannus complex have been generated by speciation without change of adaptive zone. Conversely, the exceptional clone may be phyletically related to theminuta morphotype through a rather recent jump from one adaptive zone to the other.
A biometrical analysis of morphological variation within a section of genusEuplotes (ciliata, hypotrichida), with special reference to theE. vannus complex of sibling species
Origins of life ; 13 , 3-4
1984
Aufsatz (Zeitschrift)
Englisch
Lokalklassifikation TIB: | 535/3908/4290 | |
BKL: | 44.71 Verkehrsmedizin |