Members of genus X,a hypothetical taxon of invertebrates,have antennae with a variable number of segments.Species A and B have 10 segments;species C and D have 9 segments;species E has 8 segments;and species F has 7 segments.In all other genera in this family (including genus Y,the sister genus of genus X),all species have antennae with 10 segments.Which character state most likely is a synapomorphy that would be useful for determining evolutionary relationships within genus X?
A) 10-segment antennae in species A and B
B) 10-segment antennae in genus Y and in two species of genus X
C) Antennae with fewer than 10 segments in species C,D,E,and F
D) 8-segment antennae in species E
E) 7-segment antennae in species F

Question

Quizplus · Accepted Answer

Antennae with fewer than 10 segments in species C, D, E, and F is a derived character state (synapomorphy) that distinguishes these species from those with the ancestral state of 10 segments, thus useful for determining evolutionary relationships within genus X.

Members of Genus X,a Hypothetical Taxon of Invertebrates,have Antennae with a Variable