How much do genetics contribute to population declines and extinction?

Rapid environmental changes, such as habitat loss and climate change, threaten the survival of many species. As populations become smaller, they can lose genetic diversity, become more inbred, and accumulate harmful mutations—a process known as genomic erosion. At the Luna Lab, we study how population decline and life at small population sizes shape the genomic architecture of species, and how these genomic changes influence their ability to survive and adapt. We use long-term ecological studies and museum specimens to compare genomes from the past and present, allowing us to track genetic changes through time and connect them to events such as habitat fragmentation and periods of intense overexploitation.

We study species with small and restricted populations, such as the critically endangered Araripe manakin (Chiroxiphia bokermanni) in Brazil, as well as widespread species that have declined rapidly, such as the ruffed grouse (Bonasa umbellus) in North America. By comparing species with different population histories, our research program aims to understand how population decline and evolution in small populations reshape diversity and the distribution of functional variation across the genome. Ultimately, we seek to develop a unified framework determining to what extent changes in genomic composition contribute to species resilience or extinction, elevating genomic erosion from a descriptive metric to a predictive tool for understanding evolutionary resilience and guiding biodiversity conservation.