Beginning in the 1930s, and continuing through the 1980s, various threatened populations of land iguanas were relocated from one island habitat to another, or were subject to captive breeding and reintroduction programs. Combined with the eradication of invasive species at some locations, this patchwork of dedicated conservation efforts by the Charles Darwin Foundation and the Galpagos National Park Service has undoubtedly preserved some native species from extinction, but unfortunately the records of these activities were not always detailed. As a result, the genetic diversity of captive and reintroduced populations is uncertain.
Given that genetic diversity within and relationships among populations are crucial for long-term species survival, the authors investigated genetic variation at nine nuclear microsatellite loci among more than 700 land iguanas from six island habitats. For comparison, the information obtained was compared with similar information gathered from 20 marine iguanas. This represents the first time that extensive and modern molecular genetic analyses have been applied to the study of these unique terrestrial reptiles. Results revealed four distinct "clusters" of iguanas, including two potential new species. Results also revealed that, while some populations enjoy robust genetic diversity, others do not. As such, they are at increased risk from any future changes in environmental pressures.
As noted by the authors, "Molecular data could prove of paramount interest for improving management of [off-site] captive populations and for guiding the development of proper [natural habitat] population survival and habitat management plans for this spectacular reptile."
|Contact: Tim Vines|