Mutation Rates in Whales are Much Higher than Previously Reported
Published:17 Oct.2023    Source:University of Groningen
An international team of marine scientists, led by the University of Groningen in the Netherlands and the Center for Coastal Studies in the USA, has studied the DNA of family groups from four different whale species to estimate their mutation rates. The results revealed much higher mutation rates than previously thought, and which are similar to those of smaller mammals such as humans, apes, and dolphins. Using the newly determined rates, the group found that the number of humpback whales in the North Atlantic before whaling was 86 percent lower than earlier studies suggested. The study is the first proof that this method can be used to estimate mutation rates in wild populations and was published in the journal Science on 1 September.
 
Mutation rate is a key parameter in genetics and genomics, where it is used to determine rates of evolution and adaptation. It is also used to derive the number of whales in the oceans before they were decimated by large-scale commercial whaling. However, estimating the rate at which new mutations appear in whales, or in any wild species, is difficult.
 

The results showed that the mutation rates in whales are similar to the rates seen in pedigrees in smaller mammals such as humans, apes, and dolphins. In contrast, earlier estimates in whales using the phylogenetic method were much lower compared to these smaller mammals. The newly determined, higher mutation rates were used to infer that the number of whales in the North Atlantic before industrial whaling. The result was 86 percent lower than earlier reported estimates based on phylogenetic mutation rates. This is important information, not only for the conservation of whales but also for our understanding of the state of the oceans before whaling.