Brown Tree Snakes' Genetic Diversity Helped Guam Invasion

A recent study reveals that the brown tree snake invasion that has devastated Guam’s native bird populations may have been aided by hidden genetic diversity within the reptile population. Scientists employed long‑read DNA sequencing to analyze the snakes’ genomes and identified more than 19,000 large genetic differences, many of which cluster in genes associated with immunity and olfactory function. The findings suggest that even a population founded by only a handful of individuals can maintain sufficient genetic variation to avoid inbreeding depression.

The research team highlighted that the identified genetic variants likely provided the snakes with enhanced disease resistance and improved environmental sensing, facilitating rapid adaptation to Guam’s unique ecosystem. These advantages would have enabled the snakes to thrive in a new habitat, reproduce at high rates, and ultimately reach the extraordinary densities that have caused the collapse of local avian communities. The study underscores the importance of genetic diversity in invasive species’ success and offers new insights into managing such ecological threats.