Defaunation leads to microevolutionary changes in a tropical palm.

Area of Science:

• Ecology
• Evolutionary Biology
• Conservation Biology

Background:

• Global declines in large frugivore populations due to habitat fragmentation and poaching are widespread.
• Defaunation reduces seed dispersal services, impacting plant populations, but long-term microevolutionary effects are understudied.

Purpose of the Study:

• To investigate the microevolutionary consequences of large seed disperser loss on a tropical palm species.
• To determine if frugivore defaunation drives changes in plant allelic frequencies and genetic similarity.

Main Methods:

• Comparative analysis of allelic frequencies in tropical palm populations across defaunated and non-defaunated forest sites.
• Assessment of genetic dissimilarity and similarity among individuals in relation to seed disperser presence.

Main Results:

• Frugivore defaunation was identified as the primary driver of changes in plant allelic frequencies.
• 100% of allelic frequency dissimilarity between sites was attributed to turnover of alleles.
• Palms in defaunated sites exhibited 1.5 times greater genetic similarity compared to those in pristine sites.

Conclusions:

• Defaunation significantly alters microevolutionary trajectories of tropical plants by affecting gene flow and genetic diversity.
• Reduced seed dispersal by large frugivores can lead to dispersal limitation of specific genotypes or gene flow collapse in fragmented landscapes.
• These microevolutionary changes have profound implications for the adaptive potential and persistence of tropical plant species facing environmental change.