Diaphoretickes () is a major group of
eukaryotic
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...
organisms, with over 400,000 species. The majority of the earth's biomass that carries out
photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...
belongs to Diaphoretickes.
Diaphoretickes includes:
*
Archaeplastida
The Archaeplastida (or kingdom Plantae ''sensu lato'' "in a broad sense"; pronounced /ɑːrkɪ'plastɪdə/) are a major group of eukaryotes, comprising the photoautotrophic red algae (Rhodophyta), green algae, land plants, and the minor group ...
(comprising
red algae
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority ...
,
glaucophytes
The glaucophytes, also known as glaucocystophytes or glaucocystids, are a small group of unicellular algae found in freshwater and moist terrestrial environments, less common today than they were during the Proterozoic. The stated number of spe ...
, and
green algae & land plants)
*
Cryptista
Cryptista is a clade of algae-like eukaryotes. It is most likely related to Archaeplastida which includes plants and many algae, within the larger group Diaphoretickes.
Although it has sometimes placed along with Haptista in the group Hacrobia, ...
*
Haptista
Haptista is a proposed group of protists made up of centrohelids and haptophytes. Phylogenomic studies indicate that Haptista, together with ''Ancoracysta twista'', forms a sister clade to the SAR+Telonemia supergroup, but it may also be siste ...
*
Hemimastigophora
Hemimastigophora is a group of single-celled eukaryotic organisms with a single family, Spironemidae, first identified in 1988. Over the next 30 years, different authors proposed placing these organisms in various branches of the eukaryotes ...
*
SAR supergroup
The SAR supergroup, also just SAR or Harosa, is a clade that includes stramenopiles (heterokonts), alveolates, and Rhizaria. The name is an acronym derived from the first letters of each of these clades; it has been alternatively spelled "RAS". T ...
(consisting of
stramenopiles
Stramenopile is a clade of organisms distinguished by the presence of stiff tripartite external hairs. In most species, the hairs are attached to flagella, in some they are attached to other areas of the cellular surface, and in some they have be ...
+
alveolates
The alveolates (meaning "pitted like a honeycomb") are a group of protists, considered a major clade and superphylum within Eukarya. They are currently grouped with the stramenopiles and Rhizaria among the protists with tubulocristate mitochond ...
+
Rhizaria
The Rhizaria are an ill-defined but species-rich supergroup of mostly unicellular eukaryotes. Except for the Chlorarachniophytes and three species in the genus Paulinella in the phylum Cercozoa, they are all non-photosynthethic, but many foramini ...
)
*
Telonemia
Telonemia is a phylum of microscopic eukaryote, single-celled organisms. They were formerly classified as protists until that kingdom fell out of general use, and are suggested to have evolutionary significance in being a possible transitional fo ...
Where
Chromista
Chromista is a biological kingdom consisting of single-celled and multicellular eukaryotic species that share similar features in their photosynthetic organelles ( plastids). It includes all protists whose plastids contain chlorophyll ''c'', ...
is used as a taxon, its member groups all fall within Diaphoretickes.
In 2012 Diaphoretickes received the following phylogenetic definition:
:"The most inclusive clade containing ''Bigelowiella natans'' Moestrup & Sengco 2001 (Rhizaria), ''Tetrahymena thermophila'' Nanney & McCoy 1976 (Alveolata), ''Thalassiosira pseudonana'' Cleve 1873 (Stramenopiles), and ''Arabidopsis thaliana'' (Linnaeus) Heynhold, 1842 (Archaeplastida), but not ''Homo sapiens'' Linnaeus 1758 (Opisthokonta), ''Dictyostelium discoideum'' Raper 1935 (Amoebozoa) or ''Euglena gracilis'' Klebs 1883 (Excavata). This is a branch-based definition in which all of the specifiers are extant."
The placement of Hemimastigophora is uncertain. Some studies find it nested within the clades of Diaphoretickes, as the best supported hypothesis or a less-supported one.
[
] Others find it to be the sister group of all other Diaphoretickes,
[ which under the branch-based definition falls within Diaphoretickes.][
]
Taxonomic history
Diaphoretickes was identified by Burki ''et al''. (2008) as the
"plants+HC+SAR megagroup".
because it included plants (Archaeplastida), haptophytes, cryptomonads, and stramenopiles, alveolates, and rhizarians.
Diaphoretickes has also been referred to as the SAR/HA Supergroup or "Corticata with Rhizaria".
According to this description, it includes most of the species engaging in photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...
, except for the Euglenozoa
Euglenozoa are a large group of flagellate Discoba. They include a variety of common free-living species, as well as a few important parasites, some of which infect humans. Euglenozoa are represented by three major clades, i.e., Kinetoplastea, Di ...
and Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...
. It includes all Bikont
A bikont ("two flagella") is any of the eukaryotic organisms classified in the group Bikonta. Many single-celled members of the group, and the presumed ancestor, have two flagella.
Enzymes
Another shared trait of bikonts is the fusion of two ge ...
s that are not excavates and Hemimastigophora
Hemimastigophora is a group of single-celled eukaryotic organisms with a single family, Spironemidae, first identified in 1988. Over the next 30 years, different authors proposed placing these organisms in various branches of the eukaryotes ...
.
The name "Corticata
Corticata ("one with a cortex"), in the classification of eukaryotes (living organisms with a cell nucleus), is a clade suggested by Thomas Cavalier-Smith
to encompass the eukaryote supergroups of the following two groups:
* Plantae, or Archaepl ...
" comes from Cavalier-Smith
Thomas (Tom) Cavalier-Smith, FRS, FRSC, NERC Professorial Fellow (21 October 1942 – 19 March 2021), was a professor of evolutionary biology in the Department of Zoology, at the University of Oxford.
His research has led to disc ...
's hypothesis about the common origin of the cortical alveoli The cortical alveoli (singular: cortical alveolum) are cellular organelles composed of vesicles located under the cytoplasmic membrane, to which they give support. They have been defined as membrane sacs that strengthen the cellular cortex through ...
of glaucophyte
The glaucophytes, also known as glaucocystophytes or glaucocystids, are a small group of unicellular algae found in freshwater and moist terrestrial environments, less common today than they were during the Proterozoic. The stated number of spe ...
s and alveolate
The alveolates (meaning "pitted like a honeycomb") are a group of protists, considered a major clade and Biological classification, superphylum within Eukarya. They are currently grouped with the stramenopiles and Rhizaria among the protists with ...
s.
The megagroup was previously described as the sum of Archaeplastida
The Archaeplastida (or kingdom Plantae ''sensu lato'' "in a broad sense"; pronounced /ɑːrkɪ'plastɪdə/) are a major group of eukaryotes, comprising the photoautotrophic red algae (Rhodophyta), green algae, land plants, and the minor group ...
, Rhizaria
The Rhizaria are an ill-defined but species-rich supergroup of mostly unicellular eukaryotes. Except for the Chlorarachniophytes and three species in the genus Paulinella in the phylum Cercozoa, they are all non-photosynthethic, but many foramini ...
, and chromalveolate
Chromalveolata was a eukaryote supergroup present in a major classification of 2005, then regarded as one of the six major groups within the eukaryotes.
It was a refinement of the kingdom Chromista, first proposed by Thomas Cavalier-Smith in 1 ...
s. However, this description is obsolete, largely due to the discovery that chromalveolata is not monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
.
References
[
]
Bikont unranked clades
{{Bikont-stub