Knowra SAR supergroup SAR supergroup SAR is a major eukaryotic grouping comprising Stramenopiles, Alveolata, and Rhizaria. Its members include organisms with widely varied forms, lifestyles, and ecological roles.
Stramenopiles : A eukaryotic lineage that includes diatoms, brown algae, and oomycetes. The S in SAR; its members range from photosynthetic algae to fungus-like pathogens.
Phylogenetics : The study of evolutionary relationships among organisms using inherited characters and molecular data. SAR is a proposed branch of the eukaryotic tree reconstructed through phylogenetic analysis.
Diatom : A photosynthetic stramenopile microalga enclosed in a silica cell wall. Diatoms make up a major share of marine primary production and form distinctive sediments.
Archaeplastida : A eukaryotic group containing red algae, green plants, and glaucophytes, whose plastids derive from primary endosymbiosis. It is a separate major eukaryotic grouping, despite photosynthetic members also occurring within SAR.
Alveolata : A eukaryotic lineage characterized by membrane-bound sacs beneath the cell surface in many members. The A in SAR; it includes ciliates, dinoflagellates, and apicomplexans.
Molecular phylogenetics : The reconstruction of evolutionary relationships by comparing DNA, RNA, or protein sequences. Sequence comparisons supplied key evidence for joining the three lineages in one supergroup.
Plasmodium : A genus of apicomplexan parasites that causes malaria in humans and other animals. Its placement within alveolates links a major human pathogen to the SAR lineage.
Opisthokonta : A eukaryotic group that includes animals, fungi, and their closest single-celled relatives. Animals and fungi belong to this separate major lineage, not to SAR.
Rhizaria : A diverse eukaryotic lineage that includes many amoebae with thin, branching pseudopodia. The R in SAR; many members extend threadlike projections used in feeding or movement.
Horizontal gene transfer : The movement of genetic material between organisms other than through parent-to-offspring inheritance. Gene histories can conflict with organismal ancestry, complicating reconstruction of deep eukaryotic relationships.
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