Abstract

Two main speciation patterns are described in oceanic islands, cladogenesis and anagenesis, the result of these processes is one or more new species with different morphological and genetic characteristics, compared to their continental progenitors. Juan Fernández archipelago, with a 65% of endemism in the vascular flora, is one of the world's mini-hotspots of biological diversity with highest priority for conservation. In Juan Fernández islands a 36% of the species diverged through anagenetic speciation, one of these species is Escallonia callcottiae endemic of Robinson Crusoe Island. Evidence from literature indicates to E. virgata as the most probable parental species on the continent. The main objective of this investigation was to evaluate the genetic consequences of anagenesis in the insular species using amplified fragment length polymorphism molecular technique (AFLPs). Thirteen populations of E. callcottiae and ten populations of E. virgata were analyzed, included a total of 426 individuals and six primers combinations. A total of 551 AFLP bands were obtained, the genetic diversity and divergence values in E. callcottiae are slightly lower than in E. virgata confirming the pattern of an anagenetic species, also evidencing a recent colonization process on Robinson Crusoe Island similar to that proposed for Rhaphithamnus venustus (Verbenaceae). Based on presence of private alleles and high values ​​of genetic diversity three populations with a high priority of conservation are proposed on Robinson Crusoe Island, these are Mirador de Selkirk, Ramplones and Cerro Centinela. FONDECYT Project No. 1160794 and CONAF Juan Fernández Archipelago National Park.