Flowers are “giving up on” pollinators and evolving to be less attractive to them as insect numbers decline, researchers have said.
A study has found the flowers of field pansies growing near Paris are 10% smaller and produce 20% less nectar than flowers growing in the same fields 20 to 30 years ago. They are also less frequently visited by insects.
“Our study shows that pansies are evolving to give up on their pollinators,” said Pierre-Olivier Cheptou, one of the study’s authors and a researcher at the French National Centre for Scientific Research. “They are evolving towards self-pollination, where each plant reproduces with itself, which works in the short term but may well limit their capacity to adapt to future environmental changes.”
… or, the latent survival genes that ensure reproduction are switched back on through epigenetic signals when there is a lack of pollinators. Plants do evolve, but not on that short of a time scale.
That’s a good point. If I am reading this correctly, the only molecular argument that they make is the analysis of allelic richness (Table 1), and most of the measured values are within the error bars of each other. Either I am missing something, mis-understanding the significance, or they are not making a compelling case against epigenetic mechanisms.
But I also don’t think it is so unlikely. I think that a plant population could evolve in this way rapidly, especially if the genes are already present in the population and there is a change in the selective pressure for that gene.