Mutualists and antagonists mediate frequency-dependent selection on floral display

Area of Science:

• Evolutionary Biology
• Ecology
• Plant Sciences

Background:

• Alternative reproductive strategies can persist if rare morphs have an advantage.
• Frequency-dependent selection, driven by mutualists and antagonists, is a key mechanism maintaining such strategies.
• Primula farinosa exhibits polymorphism in inflorescence height, presenting a model for studying frequency-dependent selection.

Purpose of the Study:

• To investigate frequency-dependent selection on floral display in Primula farinosa.
• To determine if pollination success and seed predation are influenced by the frequency of different morphs.
• To assess the role of mutualistic and antagonistic interactions in mediating selection pressures.

Main Methods:

• Field experiments and population surveys were conducted on Primula farinosa.
• Floral display polymorphism (inflorescence height: short-scaped and long-scaped morphs) was analyzed.
• Pollination success (fruit and seed initiation) and seed predation rates were quantified in relation to morph frequency.

Main Results:

• Pollination success and seed predation in short-scaped morphs were positively correlated with the frequency of the long-scaped morph.
• The direction and strength of frequency-dependent selection varied across years and populations.
• Evidence suggests both mutualists and antagonists mediate frequency-dependent selection.

Conclusions:

• Frequency-dependent selection can maintain alternative reproductive strategies in plants like Primula farinosa.
• The interplay between mutualistic (pollination) and antagonistic (predation) interactions shapes selection.
• Selection can shift from positive to negative, favoring rare morphs depending on interaction strengths.