Cladistic analysis of blue‐green procaryote interrelationships and chloroplast origin based on 16S rRNA oligonucleotide catalogues

Abstract

Oligonucleotide catalogues from 16s rRNA have been a major source of information for phylogenetic reconstruction among procaryotes. Several large procaryote groups have been analyzed and phylogenies presented. Catalogues are also available for many chloroplasts. The hypotheses of phylogeny are derived mainly from similarity (phenetic) comparisons of the catalogues and the extent of the homoplasy (parallelisms and reversals) involved has not been estimated properly. Although catalogues are currently being superseded by complete sequence data, an evaluation of the strength of catalogue data, and hence of the strength of the extensive phylogenetic hypotheses derived from them, is in order. Cladistic analysis of 16s rRNA oligonucleotide catalogues from three blue-green procaryotes, Prochloron, and chloroplasts of a red alga, Euglenu, a green alga and two flowering plants shows that there is extensive homoplasy in the catalogues and several phylogenetic trees are possible. The corresponding consensus trees indicate that little or nothing can be said about interrelationships and chloroplast origin on the basis of these particular catalogues, except that Prochloron may be more closely related to the blue-greens than to chloroplasts. AnalysisMacromolecular sequence data are potentially important sources of information for phylogenetic reconstruction. Because of its ubiquitous distribution in procaryotes and plants, its conservative nature and its considerable size, 16s ribosomal RNA is 13

The Suitability of Molecular and Morphological Evidence in Reconstructing Plant Phylogeny

“…In some cases, the result is an almost complete lack of resolution, especially when trees in the neighborhood of the most parsimonious cladogram(s) are taken into consideration. This has been demonstrated by Bremer (1988) for amino acid data on angiosperm families (also see Archie, 1989b), and by Bremer and Bremer (1989) for rRNA oligonucleotide catalog data on blue-green algae. Lack of resolution of some clades is also apparent in many studies with cpDNA restriction site data, even when there is little homoplasy (Olmstead et al, 1990).…”

Rna Sequence Data in Phylogenetic Reconstruction: Testing the Limits of Its Resolution

“…This identified three equally parsimonious solutions of 163 steps. However, the results from the echinoid analyses presented above suggest that trees within about 17; of the most parsimonious result cannot be rejected, and Bremer ( 1988) and Bremer and Bremer (1989) have argued a similar case for amino acid and nucleotide sequences of plants and prokaryotes.…”

“…There has been little direct testing of how morphological and molecular phylogenies compare at different evolutionary distances, or how robust molecular phylogenies actually are. Only Bremer and Bremer (1989) have specifically examined rRNA phylogenies, which they found to be largely uninformative about distant evolutionary relationships because of extensive homoplasy and reversals in the sequence data. Other workers have looked a t other kinds of molecular data, comparing morphological and molecular phylogenies of mammals (Penny and Hendy, 1986;Shoshani, 1986;Wyss et al, 1987), or have used artificially created data (Sourdis and Krimbas, 1987).…”

Macroevolutionary Patterns of Morphological Diversification Among Parasitic Flatworms (Platyhelminthes: Cercomeria)

“…Also once again, we do not have the necessary sister-group data. We do, however, have evidence that high levels ofmorphological homoplasy exist among a variety ofgroups offree-living organisms, including prokaryotes (Bremer and Bremer, 1989); fungi (Heiland, 1987;Crisci et al, 1988); angiosperms (Crane, 1985;Freire, 1987;Bremer, 1987); opisthobranch molluscs (Gosliner and Ghiselin, 1984); amphipods (Myers, 1988); nemerteans (Sundberg, 1989); insects (Throckmorton, 1965;Saether, 1977); and vertebrates (Hecht and Edwards, 1976;Butler, 1982; Begle, 1991). Thus, while we cannot make the precise comparisons we would like, we can assess whether the parasitic platyhelminths fall into the "high homoplasy" group of taxa.…”