Global warming is dramatically changing the natural habitats of species across the entire world, and it is essential that scientists understand how different species adapt in order to help protect them. An example of an affected yet adaptable species is the ocean-dwelling bottlenose dolphin.
Researchers from the Norwegian University of Science and Technology (NTNU) Science Museum are investigating exactly how bottlenose dolphins adapt so well to changes in their environment.
Bottlenose dolphins were chosen as subjects of the study as they are spread throughout both the north and the south of the equator across both open oceans and coasts. They can survive on a variety of different fish, squid, and crustaceans. Such a broad range of habitats and diets makes the dolphins excellent candidates for rapid adaptation.
Different locations and diets result in greater genetic variation among the dolphins. The research team theorized that the process of natural selection across advantageous genes has promoted excellent adaptation abilities. Until now, however, it has been puzzling as to why bottlenose dolphins are better than other dolphin species at adapting to survive around coastal habitats.
“We discovered the solution in the ancestral genes that the dolphins have. We found that genes that provide benefits for coastal dolphins also appear as genetic variations in dolphins that live far out to sea,” said Marie Louis at the University of St. Andrews. “These ancient genes are not only found in dolphins along the coast, although they are far more common there. When necessary, open ocean dolphins have the genetic potential to adapt to coastal life.”
Ultimately, this means that the ancestral genes of bottlenose dolphins have been triggered and repeated throughout many occasions and places across the history of different groups of the species. “In other words, a species that lives in groups can benefit from both the ecological possibilities in the environment and the genetic variation to adapt to a new habitat over and over again,” explained Louis.
As a result, dolphin species may hold genes essential for survival that are not currently used, yet will be useful for habitat changes hundreds or thousands of years later.
“Through the generations, these beneficial gene variants came to dominate in the coastal dolphins, so much so that they became clearly genetically different from the ones in the open ocean,” said Louis.
The study is published in the journal Science Advances.