Survival of the most variable
As more and more species become highly endangered due to human activity, there is a growing impetus to understand how best to reintroduce or relocate individuals from wild or closed populations. Suggestions range from choosing people from the closest regions to choosing those who may have the best ability to adapt to the new environment. Scott and others. uses long-term data collected during the relocation of turtles in the Mojave Desert, including animals that were previously kept as pets, to test these issues. Although the overall survival rates for all on-site turtles (both reintroduced and native) are extremely low, translocated individuals with the highest heterozygosity survive at much higher levels than those determined to be similar to the target population.
Science, this issue page 1
Anthropogenic environmental modification puts as many as 1 million species at risk of extinction. One management action to reduce the risk of extinction is to move individuals to places from which they have disappeared or to new places where biologists assume they have a high chance of surviving. To maximize this likelihood of survival, it is standard practice to move animals from the closest possible populations that contain supposedly related individuals. In an empirical test of this conventional wisdom, we analyzed a genomic dataset of 166 displaced desert turtles (Gopherus agassizii) who either survived or died over a period of two decades. We used genomic data to infer the geographical origin of the relocated turtles and found that individual heterozygosity predicted the survival of the turtles, while the translocation distance or geographical unit of origin did not. Our results show a relatively simple indicator of the probability of survival of the translocated individual: heterozygosity.