What “Genetic Rescue” Means
- The first level is pure information — finding out what is going on genetically with endangered species that have small populations or special vulnerabilities, such as to disease. Comparing the full genome sequences of a variety of individuals may provide a diagnosis of their situation and suggest ways to treat it. The thorough analysis of the genome of a species (living or extinct) may also yield “paleogenomic” information – clues to past events in its history such as the scale and timing of major changes in population size.
- The second level uses genome editing for living, endangered species. Techniques developed for de-extinction might be used with living small populations to restore genetic diversity, working even with variations of genes that can now only be found in the ancient DNA of museum specimens (“extinct alleles.”) Susceptibility to disease may also be genetically treatable. The techniques proposed so far include sequencing of ancient DNA, gene-function interpretation, cryopreserved cell lines, induced pluripotent stem cells, cloning (somatic cell nuclear transfer), and precision genome editing for trait alteration.
- The third level uses genome editing to revive extinct species. Here the quality of the ancient DNA from museum specimens and fossils is key, along with having a closely related living species. The trick will be to transfer the genes that define the extinct species into the genome of the related species, effectively converting it into a living version of the extinct creature. In addition to the techniques mentioned above, this level involves massive gene transfer, interspecies cloning, surrogate mothers and surrogate parenting.
The goal of each level of genetic rescue is to restore a species to full genetic health. Success is when it can prosper in the wild without further treatment.