Genomic data suggest no inbreeding and isolation by environment in an endangered bird
摘要
Genetic diversity is the raw material for evolution, and its assessment is crucial for determining the evolutionary potential of populations and species. This is particularly vital for threatened species that inhabit restricted habitats. In this study, we examined the genetic diversity of the Antioquia wren (Thryophilus sernai), an endemic and endangered species that inhabits the highly degraded tropical dry forest of the Cauca River canyon in Antioquia, Colombia. This area has been significantly impacted by the construction of a large hydroelectric dam. Previous assessments of the genetic diversity of this species using microsatellites and adaptive markers have shown very low genetic diversity. Therefore, we sought to explore the genetic diversity of this species using highly informative single nucleotide polymorphism (SNP) markers obtained through double digest Restriction Site Associated DNA (ddRAD) sequencing. We collected samples along the Cauca River canyon spanning a temperature and precipitation gradient. Despite the low population size and highly fragmented habitat, we found moderate levels of genetic diversity and no evidence of inbreeding. Although the data suggest the existence of a single population, we detected moderate population structure, as shown by FSTs and a pattern of isolation by distance and environment. The moderate FSTs are possibly due to the highly fragmented habitat, while our isolation-by-environment analyses suggest that the temperature and precipitation gradients could be driving patterns of genetic diversity, potentially indicating local adaptation in this species. Our findings are discussed in the context of conservation of this species.