Protists – A textbook example for a paraphyletic taxon☆

Schlegel, Martin; Hülsmann, Norbert

doi:10.1016/j.ode.2006.11.001

Cited by 22 publications

(11 citation statements)

References 40 publications

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“…37,322 One cautionary note with regard to the use of GFP-ATG8 in protists is that these organisms display some "nonclassical" variations in their ATG proteins (see LC3-associated apicoplast) and possibly a wide phylogenetic variation since they constitute a paraphyletic taxon. 1407 For example, Leishmania contains many apparent ATG8-like proteins (the number varying per species; e.g., up to 25 in L. major) grouped in 4 families, but only one labels true autophagosomes even though the others form puncta, 287 and ATG12 requires truncation to provide the C-terminal glycine before it functions in the canonical way. Unusual variants in protein structures also exist in other protists, including apicomplexan parasites, for example, the malaria parasite Plasmodium spp.…”

Section: Protistsmentioning

confidence: 99%

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Klionsky¹,

Abdelmohsen²,

Abe³

et al. 2016

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Section: Protistsmentioning

confidence: 99%

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Klionsky¹,

Abdelmohsen²,

Abe³

et al. 2016

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“…At the deepest levels of time, protists may represent an example for a paraphyletic group (Schlegel & Hülsmann, 2007). The term protist is often used to describe eukaryotes with a unicellular level of organisation, without cell differentiation into tissues.…”

Section: Examples Of Paraphyly At Different Levels Of the Taxonomic Hmentioning

confidence: 99%

“…Multicellularity evolved several times out of this paraphyletic stem group, and protists therefore can be assigned to six major eukaryotic super-groups (Adl & al., 2005). These authors refrain from a formal recognition of protists, but argue for an informal use, while Schlegel & Hülsmann (2007) proposed a paraphyletic taxon Protista. The question remains whether unicellular eukaryotes ever were holophyletic.…”

Section: Examples Of Paraphyly At Different Levels Of the Taxonomic Hmentioning

confidence: 99%

Paraphyletic groups as natural units of biological classification

Hörandl

Stuessy

2010

TAXON

146

110

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Despite the broad acceptance of phylogenetic principles in biological classification, a fundamental question still exists on how to classify paraphyletic groups. Much of the controversy appears due to (1) historical shifts in terminology and definitions, (2) neglect of focusing on evolutionary processes for understanding origins of natural taxa, (3) a narrow perspective on dimensions involved with reconstructing phylogeny, and (4) acceptance of lower levels of information content and practicability as a trade‐off for ease of arriving at formal classifications. Monophyly in evolutionary biology originally had a broader definition, that of describing a group with common ancestry. This definition thus includes both paraphyletic and monophyletic groups in the sense of Hennig. We advocate returning to a broader definition, supporting use of Ashlock's term holophyly as replacement for monophyly s.str. By reviewing processes involved in the production of phylogenetic patterns (budding, merging, and splitting), we demonstrate that paraphyly is a natural transitional stage in the evolution of taxa, and that it occurs regularly along with holophyly. When a new holophyletic group arises, it usually coexists for some time with its paraphyletic stem group. Paraphyly and holophyly, therefore, represent relational and temporal evolutionary stages. Paraphyletic groups exist at all levels of diversification in all kingdoms of eukaryotes, and they have traditionally been recognized because of their descent‐based similarity. We review different methodological approaches for recognition of monophyletic groups s.l. (i.e., both holophyletic and paraphyletic), which are essential for discriminating from polyphyly that is unacceptable in classification. For arriving at taxonomic decisions, natural processes, information content, and practicability are essential criteria. We stress using shared descent as a primary grouping principle, but also emphasize the importance of degrees of divergence plus similarity (cohesiveness of evolutionary features) as additional criteria for classification.

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“…Nonetheless, biologists are unwilling to abandon long-cherished terminology. Taxonomists who should know better have pleaded to retain obsolete and misleading plesionyms, such as "protist," "protoctista," and "protozoa" on the grounds that doing so will enhance communication and facilitate teaching [95]. They make a fair point, but surely the chief objective of science is to correct misconceptions, not perpetuate them.…”

Section: Class Protoctistamentioning

confidence: 99%

“…In the meantime, therapeutic opportunities for eradicating the so-called protozoal infections, using class-targeted agents, have no doubt been missed [3]. For practical reasons, textbooks still use the term "protozoan," but strictly speaking, Kingdom Protista no longer exists [95].…”

Section: Glossarymentioning

confidence: 99%

Changing how we think about infectious diseases

Berman¹

2019

Taxonomic Guide to Infectious Diseases

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Protists – A textbook example for a paraphyletic taxon☆

Cited by 22 publications

References 40 publications

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

Paraphyletic groups as natural units of biological classification

Changing how we think about infectious diseases

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