Cladistics and Clades
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
Cladistics groups organisms into clades, a common ancestor plus every one of its descendants, based on shared homologous traits.
Show
All descendants of the first amniotic-egg-laying ancestor, including every descendant lineage, together form the clade Amniota.
Watch for
A clade must include every descendant of its defining ancestor — omitting even one lineage disqualifies the group as a clade.