Emily Chan
Previously, the hybrids were assumed to be infertile, much like other hybrid animals, such as the mule, a donkey and horse hybrid, or the liger, a lion and tiger hybrid.
However, scientists now know that is not the case, and at least some of the hybrid whales are capable of producing offspring of their own.
The type of DNA transfer the whales have been engaging in is called introgression. Introgression involves the transfer of genetic material from one species to another following hybridization and repeated backcrossing.
It seems that only blue whales are able, or willing, to mate with the hybrids. Studies on fin whales have not uncovered any evidence of the species inheriting blue whale DNA through introgression.
Also, as far as scientists know, introgression between blue whales and fin whales happens only in the North Atlantic. There are few indications that the event is occurring anywhere else in the world.
Concerns have arisen over the continuation of introgression. Some scientists believe it could reduce the amount of blue whale DNA that is present across the population, making the whales less resilient to environmental changes. But so far, there’s been no sign that fin whale DNA in blue whales is impacting them negatively.
