A new study challenges the common assumption that endogamy reduces biodiversity and makes it difficult to recover endangered species.
For many threatened species, population decline to the threshold of extinction leads to the intersection between seemed individualsexposing the species to harmful recessive mutations that severely limit their recovery potential.
But the venom (Pigeon gleaming), endemic of the Ogasawara Islands in Japan, followed a different course.
Although this pigeon population has fallen to Less than 80 individuals In the 2000s, it began to increase sharply after the elimination of an introduced predator – the cat-trail (Felis).
Such a remarkable recovery raised questions about the endogamy And about why harmful mutationsthat could cause endogamic depression or Loss of genetic diversitydid not crash the rebirth of the species.
In an attempt to unravel this biological puzzle, a team of researchers from the University of Kyoto sought to identify the factors that contributed to this unlikely return.
The results were presented in an article recently published in the journal Nature.
“Many threatened species have difficulty recovering, even with intensive conservation measures,” says the first author of the study, Daichi Tsujimoto., in the University of Kyoto.
“O exceptional resurgence This pigeon led us to investigate the genetic reasons underlying his resilience, hoping to realize what makes some threatened species more capable of recovering than others, ”adds the investigator.
The team sequenced and compared the complete genomes of wild and captivity populations of the redhead-like pigeon, as well as a wild population of the japan pigeon.
The analysis allowed to evaluate the degree of endogamy and genetic load Of the threatened species, besides understanding how the historical population dynamics influenced these factors.
The results revealed that the frequency of highly harmful mutations in the red-lined pigeon it was lower than in the most widespread japan pigeon, which suggests that instead of being an obstacle, the success of the species will have been rooted in its long-term persistence in reduced populations before human impact.
Centuries of gradual endogamy in a historically small and isolated population may have allowed the species eliminate harmful mutations of your genome through a process designated by genetic purge.
This process seems to have her endowed with a robust genetic baseallowing the population to survive a population strangulation and dramatically recover only three years after predators removal.
“This unique evolutionary story seems to have conferred on these pigeons a resilience thatIt is observed in other threatened populations”The team leader stresses, Yuji Isagi.
The study challenges the common assumption that endogamy makes recovery difficult by expressing harmful genetic mutations.
Even so, the long -term survival of the population remains at risk. Such a marked loss of genetic diversity may have reduced the species’s ability to adapt to future environmental changes, and a population below historical levels remains vulnerable to additional erosion of genetic diversity and the accumulation of harmful mutations.
Therefore, restoring the pigeon population to historical levels is fundamental.
Ultimately, this new perspective suggests that conservation efforts should not only seek to increase genetic diversity, but also to take into account the unique genetic history of each speciesin order to develop more informed and effective strategies for their long -term survival.
