Macroevolution of the plant-hummingbird pollination system

Area of Science:

• Ecology
• Evolutionary Biology
• Botany

Background:

• Plant-hummingbird interactions are a classic example of coevolution, with plants relying on hummingbirds for pollination and hummingbirds depending on nectar for food.
• Coevolution involves mutualistic species influencing each other's evolutionary trajectory.

Purpose of the Study:

• To review the macroevolutionary consequences of plant-hummingbird interactions.
• To synthesize studies on the origins and dynamics of hummingbird pollination across angiosperm clades.
• To identify factors influencing shifts to and from hummingbird pollination.

Main Methods:

• Literature synthesis of prior studies on plant-hummingbird pollination.
• Analysis of the timing of hummingbird diversification relative to pollinated plant clades.
• Examination of diversification rates in plant lineages associated with hummingbirds.

Main Results:

• Hummingbird pollination has occurred across diverse angiosperm clades, sometimes involving shifts from insect, bat, or passerine pollination.
• The diversification of hummingbirds and their associated plants often coincides, suggesting co-diversification.
• The impact of hummingbirds on plant diversification is variable, with some lineages showing increased rates and others showing no change or decrease.

Conclusions:

• Shifts to and from hummingbird pollination are complex and influenced by factors beyond the interaction itself, such as climate and isolation.
• Future research should investigate the mechanisms and contexts of hummingbird influence on plant evolution, including species-level traits and behaviors.
• Macroevolutionary studies should incorporate species-level interaction data to better understand the coevolutionary signals of plant-hummingbird mutualism.