The heliconid butterflies of South America have brightly coloured patterns on their wings. A hybrid between two species, Heliconius cydno and H. melpomene, has wing patterns that are different from both parental species. An investigation was carried out to see whether the hybrid was a new species.

Separate groups of four butterflies, each consisting of a male and female of one of the parental species and a male and female of the hybrid, were placed together and their choices of mates recorded. The results are shown in the table.

a. With reference to the information in the table, explain whether or not the results of the investigation suggest that the hybrid butterfly is a separate species.

b. Suggest how the hybrid could be reproductively isolated from the two parent species of butterfly.

c. Briefly describe how allopatric speciation can occur.

Transcribed Image Text:

Number of matings H. melpomene male hybrid male H. melpomene female 15 hybrid female 15 H. cydno male hybrid male H. cydno female 5 3 hybrid female