In cladistics, what happens when a lineage splits?

In cladistics, when a lineage splits, it divides into exactly 2 groups. This splitting is referred to as a bifurcation, which reflects a fundamental aspect of cladistic methodology. Cladistics organizes organisms into clades, which are groups that consist of an ancestor and all its descendants. The split signifies a branching point in evolutionary history, where one lineage diverges into two distinct lineages that may evolve independently over time.

This concept is crucial in understanding the evolutionary relationships among species, as it allows researchers to reconstruct the tree of life based on shared characteristics and common ancestry. The idea that a lineage can split into only two lineages at a time helps to simplify the analysis of evolutionary pathways and promotes clarity in the categorization of organisms. Other options might imply multiple branches or outcomes that do not align with the fundamental principles of cladistics.