Question

Members of genus X 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. In all other genera in this family (including genus Y) all species have antennae with 10 segments. Which of the following character states is a synapomorphy that would be useful for determining evolutionary relationships within genes X?

a. 10 segment antennae in species A and B
b. 10 segmented antennae in genus Y and in two species of genus X
c. Antennae with fewer than 10 segments in species C, D, and E
d. 8 segment antennae in species E

Answer 1

The correct synapomorphy within genus X reflecting evolutionary relationships is the presence of antennae with fewer than 10 segments in species C, D, and E, as it is a derived trait that distinguishes them from other genera in the family.

Step-by-step explanation:

The question pertains to identifying a synapomorphy within the genus X that would be helpful for determining evolutionary relationships among its member species. A synapomorphy is a characteristic that is shared by two or more taxa and is derived from their most recent common ancestor. Considering the information provided, the character state that is a synapomorphy for species within genus X would be antennae with fewer than 10 segments in species C, D, and E since this is a shared derived trait that sets them apart from the other genera in the family with a constant 10-segment antennae feature. The presence of 10 segments in species A and B is not unique in this context as it is shared with other genera, and similarly, the 8 segment antennae in species E is a trait unique to that species rather than a shared derived character.