How animals shape plant evolution: an ecological and evolutionary synthesis

This review synthesizes current knowledge on how animals shape plant evolution through a complex network of mutualistic and antagonistic interactions operating across ecological and evolutionary timescales. Plant–animal interactions, ranging from pollination and seed dispersal to herbivory and parasitism, generate reciprocal selective pressures that drive diversification in plant reproductive, defensive, and dispersal traits. Coevolutionary dynamics are increasingly understood within a network framework, where indirect interactions and community structure play a critical role in shaping adaptive landscapes. Animal pollinators have been central to the evolution of floral traits, including morphology, color, scent, and phenology, while herbivores impose selection on plant defenses, often leading to trade-offs between reproduction and resistance. Similarly, frugivores influence the evolution of fruit and seed traits, contributing to the emergence of dispersal syndromes and large-scale diversification patterns in angiosperms. Interactions such as synzoochory highlight the continuum between mutualism and antagonism, emphasizing context dependency in ecological outcomes. Recent advances extend classical coevolutionary frameworks to include microbiome-mediated interactions, revealing that plant–animal relationships are frequently embedded within tripartite systems involving microbial communities that modulate signals, rewards, and defenses. Additionally, phenotypic plasticity emerges as a key mechanism enabling rapid plant responses to fluctuating biotic and abiotic environments, often preceding longer-term genetic adaptation. The review also integrates spatial and temporal perspectives, including the geographic mosaic of coevolution, eco-evolutionary feedbacks, and the persistence of evolutionary anachronisms resulting from past interactions. Anthropogenic pressures—such as climate change, habitat fragmentation, and species invasions—are profoundly reshaping plant–animal interactions, altering selection regimes and driving rapid evolutionary responses. Overall, this synthesis highlights that plant evolution cannot be fully understood without considering the dynamic, multi-layered, and context-dependent influences of animal interactions, which operate across scales from genes to ecosystems and from historical legacies to contemporary global change.