The DNA map of the hammerhead and mako sharks, two endangered species whose populations have collapsed in the last 250,000 years, has been obtained: the result, published in the journal iScience, is by a group of researchers led by the US Cornell University, who managed to reach a very high level of definition, even distinguishing the different chromosomes.
The data obtained will help to better direct 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 in shark environments.
The researchers led by Michael Stanhope managed to obtain tissue samples from various hammerhead and mako sharks, from which they then extracted and reassembled the various DNA sequences, a bit like a puzzle.
The data were then compared with those available for other shark species, such as the whale shark and the white shark, making it possible to reach a very high precision: it is a very difficult undertaking to tackle, especially for species like these, which they have much larger genomes than humans.
The results show that the situation is not easy, especially for the hammerhead shark: in addition to the low genetic diversity, in fact, this shark also shows many signs of inbreeding, a fact that can further reduce the survival capacity of a population.
In addition to revealing the fragility of these two endangered species, the authors of the study hope that the techniques used and the data obtained can become a point of reference for other research in the field of conservation of endangered animals.