Clover, Cyanide and Evolution

Evolutionary biologists try to observe, make sense of and explain evolution. Obviously. They want to see it, it's their job. Unfortunately, much of what is called evolution is nothing of the kind. This conflation is misleading, since it implies that the small changes that biologists find are support for molecules-to-man evolution.

Pixabay / JamesDeMers

For example, some forms of clover have a defense mechanism of releasing low-potency cyanide when being munched. Others are missing the gene for this. Not just a mutation, but completely missing. Therefore, evolution. Not hardly.

Clovers come in a wide variety of sizes, and some of them hold interesting surprises. Plant biologists have been studying one trait in particular, and it keeps showing up—or disappearing—in peculiar patterns. Do these patterns illustrate evolutionary changes or does something entirely different switch off this trait?

The trait under scrutiny involves clover-leaf tissue that releases cyanide when crushed. If an insect begins munching, it gets a mouthful of bad taste—not enough to kill, but enough to deter the eater from its clover feast.

The plants use an ingenious system to deploy this poison, only when needed, while protecting their own tissues. Under ordinary conditions, cyanide is safely bonded to sugar molecules that are sequestered in secure pockets inside each plant cell. The enzyme that separates the cyanide from its sugar lies outside that pocket. When an insect chews the clover leaves, the cyanide-sugars and enzymes mix—like bending and shaking a plastic glow stick—and this releases the poisonous cyanide concoction.

To finish reading, click on "Clever Clover: Evidence for Evolution?"