[robinzfc]

Seems that the title of the article has it backwards. From the original paper [1]:

"mitochondrial divergence values between H. diadema samples from the Solomon Islands and New Guinea were greater than any observed divergence values between H. diadema and H. dinops samples from within the Solomon Islands"

The paper describes an example of parallel evolution. There is one species of smaller bats (H.dinops) and then on different islands larger ones evolved from it independently. The bigger bats have all been called H. diadema as they look very similar. So the situation is more like "same size, different species" than what the title suggests.

[1] [Parallel evolution in an island archipelago ...](https://academic.oup.com/evolut/advance-article/doi/10.1093/...)