A new study claims that plants evolve new defense mechanism as the old ones become obsolete.
A new study hypothesized that during a plant’s evolution, this would stop using defensive measures that have become obsolete. Instead, plants will adapt and develop new methods. Ones based on the predation by herbivorous insects that are not affected by the plant’s previous defensive mechanisms.
This is according to the latest research conducted at the Academy of Natural Sciences, Drexel University. The study examined a specific chemical named pyrrolizidine alkaloids.
During research, it was noted that plants which generated pyrrolizidine alkaloids ceased producing it when confronted with a species of butterfly that was not affected by the chemical.
Useless Defenses Stop as Plants Evolve
Tatyana Livshultz is the lead author of the study analyzing the cessation of the useless defenses. During research, the scientists reviewed the activities of dogbane and milkweed plants. These are both members of the Apocynaceae species.
It was discovered that as the plants learned that the pyrrolizidine alkaloids did not dissuade Danainae or milkweed butterflies, they ceased generating this chemical.
Still, it was noted that not all milkweeds stopped producing the alkaloids. Livshultz hypothesized that this may be due to the fact that the milkweeds in other regions are affected more by other local insects. Ones that live in those regions and that are still dissuaded by the toxic alkaloids.
This study supports the idea that as plants evolve, they stop wasting time and energy on creating defenses that are no longer successful in deterring predators.
“Co-evolution explains how interactions between species can drive the origin of novelty and diversity,” states the study lead.
Livshultz’s team will continue its research. The implications of this new study may extend beyond the plant world and into the lives of humans as well.
The theories of co-evolution and defense de-escalation examined in Livshultz’s work, while popular, require additional study and evidentiary support. Studying this phenomenon is important, as it can have practical uses in multiple fields such as agriculture, environmental protection, and pharmaceuticals.
Current research results were released in a paper in the journal New Phytologist.
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