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  2. Sister group - Wikipedia

    en.wikipedia.org/wiki/Sister_group

    The term sister group is used in phylogenetic analysis, however, only groups identified in the analysis are labeled as "sister groups".. An example is birds, whose commonly cited living sister group is the crocodiles, but that is true only when discussing extant organisms; [3] [4] when other, extinct groups are considered, the relationship between birds and crocodiles appears distant.

  3. Phylogenetic tree - Wikipedia

    en.wikipedia.org/wiki/Phylogenetic_tree

    The idea of a tree of life arose from ancient notions of a ladder-like progression from lower into higher forms of life (such as in the Great Chain of Being).Early representations of "branching" phylogenetic trees include a "paleontological chart" showing the geological relationships among plants and animals in the book Elementary Geology, by Edward Hitchcock (first edition: 1840).

  4. Harvestman phylogeny - Wikipedia

    en.wikipedia.org/wiki/Harvestman_phylogeny

    Phylogenetic analysis by Garwood et al. (2014) showing the diversification of Opiliones. Harvestmen are an order of arachnids often confused with spiders, though the two orders are not closely related. Research on harvestman phylogeny (that is, the phylogenetic tree) is in a state of flux.

  5. Crown group - Wikipedia

    en.wikipedia.org/wiki/Crown_group

    A stem group is a paraphyletic assemblage composed of the members of a pan-group or total group, above, minus the crown group itself (and therefore minus all living members of the pan-group). This leaves primitive relatives of the crown groups , back along the phylogenetic line to (but not including) the last common ancestor of the crown group ...

  6. Outgroup (cladistics) - Wikipedia

    en.wikipedia.org/wiki/Outgroup_(cladistics)

    A simple cladogram showing the evolutionary relationships between four species: A, B, C, and D. Here, Species A is the outgroup, and Species B, C, and D form the ingroup. In cladistics or phylogenetics, an outgroup [1] is a more distantly related group of organisms that serves as a reference group when determining the evolutionary relationships of the ingroup, the set of organisms under study ...

  7. Basal (phylogenetics) - Wikipedia

    en.wikipedia.org/wiki/Basal_(phylogenetics)

    Amborella trichopoda, the most basal extant angiosperm. The flowering plant family Amborellaceae, restricted to New Caledonia in the southwestern Pacific, [n 9] is a basal clade of extant angiosperms, [13] consisting of the most species, genus, family and order within the group that are sister to all other angiosperms (out of a total of about 250,000 angiosperm species).

  8. Phylogenetic nomenclature - Wikipedia

    en.wikipedia.org/wiki/Phylogenetic_nomenclature

    The diagram shows three common ways of doing this. For previously defined clades A, B, and C, the clade X can be defined as: The three most common ways to define the name of a clade: node-based, branch-based and apomorphy-based definition. The tree represents a phylogenetic hypothesis of the relations of A, B and C.

  9. Clade - Wikipedia

    en.wikipedia.org/wiki/Clade

    The science that tries to reconstruct phylogenetic trees and thus discover clades is called phylogenetics or cladistics, the latter term coined by Ernst Mayr (1965), derived from "clade". The results of phylogenetic/cladistic analyses are tree-shaped diagrams called cladograms; they, and all their branches, are phylogenetic hypotheses. [12]