Abstract
Biological invasions are a growing threat to native ecosystems, and
genomic studies have become an increasingly useful tool for invasive
species management by providing the ability to identify spatial population
structure in the invaded range. In this study, we compared the spatial
genetic structure of two ecologically distinct non-native lizard species
both established and widespread throughout South Florida, a global hotspot
for reptile invasions. We used an individual-based sampling approach to
collect genetic samples of Agama picticauda, a rock specialist native to
West Africa, and Basiliscus vittatus, a riparian specialist from Central
and South America. We collected specimens across Miami-Dade County (the
original site of introduction) and then genotyped ~4,000 single nucleotide
polymorphisms (SNPs) for each species. Both species exhibited fine-scale
population structure at distances <5 km for A. picticauda and
<10 km for B. vitattus, but at the county scale B. vittatus showed
much stronger spatial structure compared to A. picticauda. Landscape
genomic analysis revealed no significant landscape influence on A.
picticauda genetic differentiation, while for B. vittatus low canopy cover
was the best predictor of genetic connectivity. The genetic structure of
both species may suggest human-aided dispersal is driving long distance
movements, and A. picticauda appear more susceptible to these events
likely due to their affinity for highly urbanized areas. By identifying
variable dispersal patterns among two ecologically distinct species, we
hope that this study will help combat the spread of these or similar
species as they continue to arrive at urban centers across the globe.