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outgroup

outgroup

1 8.2
A species used to compare other species and find the root of their family tree
  • noun
  • /ˈaʊtˌɡruːp/
  • Specialized
translation icon : grupo externo
  • Pharmacosycea is the outgroup to all other figs and is strictly Neotropical.
  • used as an outgroup

Examples

  • The VIT dataset was an exception, with several lineages other than the outgroup having high rates.

    Academic text (2018)
  • Lineage-specific rate variation in each dataset was idiosyncratic, with the most extreme variation in the outgroups.

    Academic text (2018)
  • I know how to deal with members of plesiomorphic outgroups like you.

    Blog text (29)
  • Spirometra erinaceieuropaei was used as an outgroup. Scale bar indicates the number of base substitutions per site.

    Academic text (2014)
  • Puumula virus S and M segments were included as outgroups in the phylogenetic reconstructions.

    Academic text (2012)
  • After rooting, branches leading to outgroup sequences (HTVMEL5 and Z46900) were removed from the figure to increase its legibility.

    Academic text (2012)
  • Finally, three outgroup species were included: Lampropholis coggeri, Lampropholis guichenoti, and Pygmaeascincus timlowi, each represented by two samples.

    Academic text (2018)
  • Finally, the eudicot Arabidopsis thaliana and the basal angiosperm Amborella were included to provide outgroups for comparison.

    Academic text (2017)
  • We performed the standard clock test for each ortholog, with outgroup removed, using PAUP* v4.0a151 by calculating the ML score for a gene both with and without assuming a clock, and then performing a likelihood ratio test.

    Academic text (2018)
  • In phylogenetic studies, species like crocodiles often serve as the outgroup for modern birds.

Surface Forms

outgroup singular
outgroups plural

Morphology

outgroup = group (transparent) = out + group

Meaning is directly compositional: a group that is outside the main group; the technical sense is specialized but the components map clearly to the meaning. [Postprocessing: moved 'out' from base_words to prefix]

Etymology

Outgroup is a simple compound of out- 'outside' and group 'group', so you can remember it as a group that is 'outside' the main set. In biology, an outgroup is a species used as a reference to show which traits came first and to find the root of the family tree.