<Ul> <Li> A clade located within a clade is said to be nested within that clade . In the diagram, the hominoid clade, i.e. the apes and humans, is nested within the primate clade . </Li> <Li> Two clades are sisters if they have an immediate common ancestor . In the diagram, lemurs and lorises are sister clades, while humans and tarsiers are not . </Li> <Li> A clade A is basal to a clade B if A branches off the lineage leading to B before the first branch leading only to members of B. In the adjacent diagram, the strepsirrhine clade, including the lemurs and lorises, is basal to the hominoids, the apes and humans . Some authors have used "basal" differently, using it to mean a clade that is "more primitive" or less species - rich than its sister clade; others consider this usage to be incorrect . </Li> </Ul> <Li> A clade located within a clade is said to be nested within that clade . In the diagram, the hominoid clade, i.e. the apes and humans, is nested within the primate clade . </Li> <Li> Two clades are sisters if they have an immediate common ancestor . In the diagram, lemurs and lorises are sister clades, while humans and tarsiers are not . </Li> <Li> A clade A is basal to a clade B if A branches off the lineage leading to B before the first branch leading only to members of B. In the adjacent diagram, the strepsirrhine clade, including the lemurs and lorises, is basal to the hominoids, the apes and humans . Some authors have used "basal" differently, using it to mean a clade that is "more primitive" or less species - rich than its sister clade; others consider this usage to be incorrect . </Li>

What is a clade in a phylogenetic tree