Читать книгу Fundamentals of Conservation Biology - Malcolm L. Hunter Jr. - Страница 121

We now are approaching a new era in which we can provide endangered species with new traits that enable them to deal with the threats they are facing. For example, scientists have transferred two genes from wheat into the American chestnut, conferring upon the chestnut resistance to a fungal blight that nearly eradicated it across the vast range in which it was a dominant species (Powell 2014). Genetic engineering may also generate novel genes that can be introduced into populations of invasive exotic species so that they limit their own numbers, a distinct possibility now for dealing with the scourge of endemic island species everywhere: black rats (Campbell et al. 2015). Genetic engineering falls within the realm of “synthetic biology” and offers extraordinary opportunities to address some seemingly intractable conservation issues (Piaggio et al. 2017) while also posing new ethical quandaries. Some straightforward applications include transplanting genes for resistance to white‐nose syndrome into bats and to chytrid fungus into amphibians, or giving corals that are vulnerable to bleaching carefully selected genes from nearby corals that are more tolerant of heat and acidity. More controversial would be eliminating populations of feral cats and dogs by producing generations that are genetically programmed to be sterile. The same is envisioned for eradicating mosquitoes without pesticides, including in areas where mosquitoes vector diseases that hobble endangered species, as in the case of birds in Hawaii. Perhaps most daunting, intriguing, and controversial of all is the possibility to resurrect extinct species through synthetic biology, grafting fragments of their DNA harvested from museum specimens into similar, extant surrogate species to recreate admixtures that largely appear and function as the original species once did (Shapiro 2017). This is being done using Asian elephants to snip into their genome functional and distinctive genes from extinct mammoths to recreate something resembling the latter to release upon the Siberian tundra to help clear woody vegetation, deepen penetration of freezing temperatures into the permafrost, and help slow the melting of the Arctic (Campbell and Whittle 2017).