Limits...
Evaluating support for the current classification of eukaryotic diversity.

Parfrey LW, Barbero E, Lasser E, Dunthorn M, Bhattacharya D, Patterson DJ, Katz LA - PLoS Genet. (2006)

Bottom Line: We assess three aspects of each supergroup: (1) the stability of its taxonomy, (2) the support for monophyly (single evolutionary origin) in molecular analyses targeting a supergroup, and (3) the support for monophyly when a supergroup is included as an out-group in phylogenetic studies targeting other taxa.Our analysis demonstrates that supergroup taxonomies are unstable and that support for groups varies tremendously, indicating that the current classification scheme of eukaryotes is likely premature.We highlight several trends contributing to the instability and discuss the requirements for establishing robust clades within the eukaryotic tree of life.

View Article: PubMed Central - PubMed

Affiliation: Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, Massachusetts, United States of America.

ABSTRACT
Perspectives on the classification of eukaryotic diversity have changed rapidly in recent years, as the four eukaryotic groups within the five-kingdom classification--plants, animals, fungi, and protists--have been transformed through numerous permutations into the current system of six "supergroups." The intent of the supergroup classification system is to unite microbial and macroscopic eukaryotes based on phylogenetic inference. This supergroup approach is increasing in popularity in the literature and is appearing in introductory biology textbooks. We evaluate the stability and support for the current six-supergroup classification of eukaryotes based on molecular genealogies. We assess three aspects of each supergroup: (1) the stability of its taxonomy, (2) the support for monophyly (single evolutionary origin) in molecular analyses targeting a supergroup, and (3) the support for monophyly when a supergroup is included as an out-group in phylogenetic studies targeting other taxa. Our analysis demonstrates that supergroup taxonomies are unstable and that support for groups varies tremendously, indicating that the current classification scheme of eukaryotes is likely premature. We highlight several trends contributing to the instability and discuss the requirements for establishing robust clades within the eukaryotic tree of life.

Show MeSH

Related in: MedlinePlus

Trends in the Taxonomy of EukaryotesA comparison of four representative taxonomies illustrates trends within eukaryotic taxonomy over the past 50 years [2,5–7]. Movement of taxa is traced from earlier to more recent taxonomies with solid and dashed lines. A solid line indicates all members of a group (left of line) are incorporated into the subsequent group (right of line). Dashed lines indicate that a subset of members (left) is incorporated into subsequent groups (right).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC1713255&req=5

pgen-0020220-g001: Trends in the Taxonomy of EukaryotesA comparison of four representative taxonomies illustrates trends within eukaryotic taxonomy over the past 50 years [2,5–7]. Movement of taxa is traced from earlier to more recent taxonomies with solid and dashed lines. A solid line indicates all members of a group (left of line) are incorporated into the subsequent group (right of line). Dashed lines indicate that a subset of members (left) is incorporated into subsequent groups (right).

Mentions: Higher-level classifications have historically emphasized the visible diversity of large eukaryotes, as reflected by the establishment of the plant, animal, and fungal kingdoms. In these schemes the diverse microbial eukaryotes have generally been placed in one (Protista [2–4] or Protoctista [5]) or two (Protozoa and Chromista [6]) groups (Figure 1; but see also [7,8]). However, this historic distinction between macroscopic and microscopic eukaryotes does not adequately capture their complex evolutionary relationships or the vast diversity within the microbial world.


Evaluating support for the current classification of eukaryotic diversity.

Parfrey LW, Barbero E, Lasser E, Dunthorn M, Bhattacharya D, Patterson DJ, Katz LA - PLoS Genet. (2006)

Trends in the Taxonomy of EukaryotesA comparison of four representative taxonomies illustrates trends within eukaryotic taxonomy over the past 50 years [2,5–7]. Movement of taxa is traced from earlier to more recent taxonomies with solid and dashed lines. A solid line indicates all members of a group (left of line) are incorporated into the subsequent group (right of line). Dashed lines indicate that a subset of members (left) is incorporated into subsequent groups (right).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC1713255&req=5

pgen-0020220-g001: Trends in the Taxonomy of EukaryotesA comparison of four representative taxonomies illustrates trends within eukaryotic taxonomy over the past 50 years [2,5–7]. Movement of taxa is traced from earlier to more recent taxonomies with solid and dashed lines. A solid line indicates all members of a group (left of line) are incorporated into the subsequent group (right of line). Dashed lines indicate that a subset of members (left) is incorporated into subsequent groups (right).
Mentions: Higher-level classifications have historically emphasized the visible diversity of large eukaryotes, as reflected by the establishment of the plant, animal, and fungal kingdoms. In these schemes the diverse microbial eukaryotes have generally been placed in one (Protista [2–4] or Protoctista [5]) or two (Protozoa and Chromista [6]) groups (Figure 1; but see also [7,8]). However, this historic distinction between macroscopic and microscopic eukaryotes does not adequately capture their complex evolutionary relationships or the vast diversity within the microbial world.

Bottom Line: We assess three aspects of each supergroup: (1) the stability of its taxonomy, (2) the support for monophyly (single evolutionary origin) in molecular analyses targeting a supergroup, and (3) the support for monophyly when a supergroup is included as an out-group in phylogenetic studies targeting other taxa.Our analysis demonstrates that supergroup taxonomies are unstable and that support for groups varies tremendously, indicating that the current classification scheme of eukaryotes is likely premature.We highlight several trends contributing to the instability and discuss the requirements for establishing robust clades within the eukaryotic tree of life.

View Article: PubMed Central - PubMed

Affiliation: Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, Massachusetts, United States of America.

ABSTRACT
Perspectives on the classification of eukaryotic diversity have changed rapidly in recent years, as the four eukaryotic groups within the five-kingdom classification--plants, animals, fungi, and protists--have been transformed through numerous permutations into the current system of six "supergroups." The intent of the supergroup classification system is to unite microbial and macroscopic eukaryotes based on phylogenetic inference. This supergroup approach is increasing in popularity in the literature and is appearing in introductory biology textbooks. We evaluate the stability and support for the current six-supergroup classification of eukaryotes based on molecular genealogies. We assess three aspects of each supergroup: (1) the stability of its taxonomy, (2) the support for monophyly (single evolutionary origin) in molecular analyses targeting a supergroup, and (3) the support for monophyly when a supergroup is included as an out-group in phylogenetic studies targeting other taxa. Our analysis demonstrates that supergroup taxonomies are unstable and that support for groups varies tremendously, indicating that the current classification scheme of eukaryotes is likely premature. We highlight several trends contributing to the instability and discuss the requirements for establishing robust clades within the eukaryotic tree of life.

Show MeSH
Related in: MedlinePlus