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Mother Whale’s Cultural Traditions Shape the Genetics of Offspring

The migratory behaviour of endangered southern right whales, learned from a whale’s mother in its first year of life, has helped to shape the genetics and population recovery of the species.

Prof Robert Harcourt of Macquarie University says the findings, published in Scientific Reports (tinyurl.com/q593osq), offer an insight into how cultural preferences can shape the genetics of a mammalian species.

“Young whales acquire their migration preferences from their parents in a practice known as migratory culture, causing them to follow the same routes to get to their desired destination when they grow older,” Harcourt said. “What is interesting about the findings of this study is that they show that the migratory culture actually has an effect on the genetic patterns that we observe in both the summer feeding and winter calving grounds of Australian southern right whales.”

The international group of researchers involved in the study took up to 20 years to collect enough skin samples from southern right whales in certain regions around Australia and New Zealand, due to their endangered status. They then analysed the unique DNA markers of each whale, which allowed them to build a map of the population structure and relatedness in the species. Microchemical markers revealed the feeding ground preferences of each whale.

“Whales that showed similar feeding ground preferences were more likely to be related, using both maternally inherited and bi-parentally inherited DNA markers,” explained lead author Dr Emma Carroll of the University of St Andrews in the UK. “There were also significant differences in maternally inherited DNA markers among winter calving grounds, consistent with the idea that there is maternally directed learning of these migratory habitats,” she added.

The researchers hope that their study will shed more light on the current issues facing this large, long-lived species of marine mammal, which is still recovering from the effects of whaling even though the practice was terminated in Australia in 1979. “Knowing the current genetic network of this species and their migratory habits means we will be able to monitor them more precisely in the future,” Harcourt explained.