Phylon

A phylon is a segment of a phylogenetic tree that represents a lineage, especially one that has undergone a significant degree of evolutionary change or diversification. The term is often used informally to refer to a distinct group within a larger clade, reflecting a perceived difference in evolutionary trajectory or ecological adaptation.

While not a formally defined taxonomic rank, "phylon" emphasizes the evolutionary history and relationships of organisms within the segment. It highlights the common ancestry and subsequent divergence of the group, often suggesting a period of accelerated evolution, adaptive radiation, or significant ecological shifts.

The usage of "phylon" can be subjective and is often determined by the context of the discussion. It is used to describe a lineage that, while part of a broader phylogenetic grouping, exhibits a certain degree of distinction based on morphological, genetic, or ecological characteristics. Consider it a tool for emphasizing a specific evolutionary story within a larger phylogenetic context. It's important to note that the term is not universally accepted or applied in a standardized manner within the field of phylogenetics.