what are the three primary methods scientists use to group organisms into monophyletic clades? please provide examples for each. which has caused the major reorganization of phylogenies, i. e. the fall of the kingdoms, and why only recently?

Cladistics (/kləˈdɪstɪks/, from Greek κλάδος, kládos, "branch") is an approach to biological classification in which organisms are categorized in groups ("clades") based on the most recent common ancestor.

Explanation: Modern taxonomists seek to employ classification schemes that are consistent with the underlying evolutionary relationships among species. As shown below, phylogenetic analyses present a way to test existing Linnaean classifications (some of which predate widespread acceptance of the fact of evolution) and to determine which classifications are consistent with evolutionary history, and which require modification.

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.