The DNA map of two species of sharks at risk of extinction is ready

The DNA of the hammerhead shark and the mako shark, two species at risk of extinction and whose populations have collapsed in the last 250 thousand years, has been mapped. The study has been published in the iScience journal by a group of researchers led by the US Cornell University, who achieved a very high level of definition, even distinguishing the different chromosomes.

The data obtained will help to better target the efforts to protect these animals, but the news is not encouraging: the genetic diversity of these species is very low, a factor that indicates a poor ability to adapt to the profound changes that human activities are bringing to shark environments.

The researchers, led by Michael Stanhope, were able to obtain tissue samples from different hammerhead and mako sharks, from which they then extracted and reassembled the various DNA sequences, a bit like a jigsaw puzzle.

The data were then compared with those available for other shark species, such as the whale shark and the white shark, allowing to reach a very high precision: it was a very difficult task for species like these, which have much larger genomes than the human one.

The results show that the situation is not easy, especially for the hammerhead shark: in addition to the lack of genetic diversity this shark also presents many signs of inbred mating, a fact that can further reduce the survival capacity of a population. Besides revealing the fragility of these two endangered species, the authors of the study hope that the techniques used and the data obtained could become a reference point for other research in the field of conservation of endangered animals.