The formation of the major Hawaiian Islands began approximately 28 million years ago. These islands have formed as the Pacific Island tectonic plate has moved over a hotspot, which is a fixed area in the Earth's mantle at which magma rises to the crust. As a result of this formation, each of the Hawaiian Islands has a different age.

Question

Researchers examined the history of a group of Drosophila, a type of small fly, on the Hawaiian Islands. The graph below shows the number of subgroups in this group of Drosophila, called the AMC group, over time. The table next to the graph shows the age of the oldest major Hawaiian Islands.

Data courtesy of Lapoint, R.T., Magnacca, K.M., and P. M. O'Grady. 2014. Phylogenetics of the Antopocerus-Modified Tarsus Clade of Hawaiian Drosophila: Diversification across the Hawaiian Islands. PLoS ONE 9(11): e113227. Licensed under CC BY 4.0.

What statement is best supported by the data in the table and the graph?
A.
The change in the diversity of the AMC group of Drosophila is not related to the formation of the Hawaiian islands.
B.
At the time that Necker Island formed, there were no Drosophila of the AMC group present on the Hawaiian islands.
C.
By the time Midway Island had formed, the majority of the AMC Drosophila subgroups had been established.
D.
The formation of the islands of Kauai and Oahu is associated with an increase in the diversity of AMC Drosophila.

Answer 1

Based on the information provided, option D is the best supported statement. The formation of the islands of Kauai and Oahu is indeed associated with an increase in the diversity of the AMC Drosophila, as the age of these islands corresponds with an increase in the number of subgroups observed in the Drosophila population. The other statements are either not supported by the data or lack sufficient evidence.

Therefore, the correct choice is:

D. The formation of the islands of Kauai and Oahu is associated with an increase in the diversity of AMC Drosophila.