Based on a genetic analysis, an international team of researchers write in the Proceedings of the Royal Society B that humpback whales may actually consist of three subspecies.
As LiveScience reports, researchers led by Oregon State University's Scott Baker used darts to collect small biopsies and DNA from some 2,700 whales in five different ocean regions. Baker and his colleagues then analyzed both the nuclear and mitochondrial DNA from those samples to gauge how various humpback whale populations are related and how the whales have moved about the globe. For instance, Baker and his colleagues noted restricted gene flow between whales in different ocean basins.
"Although female whales have crossed from one hemisphere to another at certain times in the last few thousand years, they generally stay in their ocean of birth. This isolation means they have been evolving semi-independently for a long time," says first author Jennifer Jackson said in a statement.