LA JOLLA, Calif., April 22 (UPI) — A U.S. government study says new gene sequencing technology supports empirical evidence that multiple species of killer whales are likely to exist.
The report by the National Marine Fisheries Service says scientists have found strong genetic evidence supporting the theory there are several species of killer whales (Orcinus orca, also known as orcas) throughout the world’s oceans.
The researchers said it’s been suspected there was more than one species of killer whales because of observed differences in behavior and subtle physical features. But until now DNA analysis has been inconclusive because of the inability to map the entire genome of the whales’ mitochondria — an organelle within the cell inherited from the mother.
“The genetic makeup of mitochondria in killer whales, like other cetaceans, changes very little over time, which makes it difficult to detect any differentiation in recently evolved species without looking at the entire genome,” said geneticist Phillip Morin, lead author of the study at the Southwest Fisheries Science Center in La Jolla, Calif. “But by using a relatively new method called ‘highly parallel sequencing … we were able to see clear differences among the species.”
Morin says determining how many species of killer whales exist is critically important for conservation priorities and to better understand the ecological role of the large and widespread predator in the world’s oceans.
The report appears in the journal Genome Research.
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