In biology, a reticulation of a single-access identification key connects different branches of the identification tree to improve error tolerance and identification success.
[1][2][3] In a reticulated key, multiple paths lead to the same result; the tree data structure thus changes from a simple tree to a directed acyclic graph.
Two forms of reticulation can be distinguished: Terminal reticulation and inner reticulation.
Reticulations generally improve the usability of a key, but may also diminish the overall probability of correct identification averaged over all taxa.
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