Researchers at the University of Michigan have documented a striking evolutionary shift in morning glories, finding that plants facing twin pressures from climate change and pollinator decline are redirecting their evolutionary energy toward attracting remaining pollinators rather than adapting to warming temperatures.
Over a nine-year study period, the team observed a 96% drop in the population's rate of adaptation. This sharp decline suggests morning glories are evolving faster to appeal to pollinators than to cope with shifting climate conditions. The trade-off reveals a fundamental constraint in plant evolution. Resources devoted to developing pollinator-attracting traits leave less evolutionary capacity for climate adaptation.
The findings, published in Evolution Letters, carry practical implications beyond basic biology. Farmers dealing with morning glories as agricultural weeds may see the plant's evolutionary trajectory shift in unexpected ways. A population optimized for pollinator attraction but poorly adapted to new temperature and precipitation regimes could become easier or harder to manage depending on local conditions.
The study illustrates how multiple environmental stressors interact to reshape evolution. Morning glories cannot simultaneously evolve at maximum speed on all fronts. When pollinator availability becomes the immediate survival bottleneck, plants allocate limited genetic variation toward reproductive success through pollinator partnerships. Climate adaptation becomes secondary.
This pattern likely extends beyond morning glories. Many plant species face the same dual crisis. As wild pollinator populations collapse globally, plants may universally experience reduced evolutionary adaptation to warming. Over decades, this could create a mismatch between plant physiology and climate conditions, threatening crop yields and ecosystem stability.
The research also highlights an underappreciated consequence of pollinator decline. The loss of insects reshapes not just current plant reproduction but future plant evolution itself. A warming world combined with fewer bees and butterflies may produce plants that are simultaneously worse at handling heat stress and more dependent on increasingly scarce pollinators.
The nine-year timeframe