Odds are, if you had any kind of a childhood, you have probably heard of Colonel Mustard. However, rather than being a clean cut military man from an old board game, a new study from the Proceedings of the National Academy of Sciences, PNAS, Colonel Mustard was actually a glucosinolate, a sharp tasting chemical, produced by ancestors of today’s Brassicale order which includes wasabi, horseradish, mustard, cabbage, and kale.
Way back in the day, like 90 million years ago, caterpillars and Brassicales were involved in what the study calls an “evolutionary arms race.” As a result of caterpillars feeding on the ancient plants, these plants developed glucosinolates to fend off the hungry critters. However, rather than finding new plants to feed on, these caterpillars fought back by developing their own chemical defenses against the glucosinolate toxins.
Scientists claim that this chemical evolutionary battle occurred three times in the past 90 million years. The most surprising part of the discovery is not that plants and bugs co-evolved by making small changes to their genes, but rather that they co-evolved by creating entirely new copies of their genes, a process that is said to be rare in the natural world.
Luckily for us, these ancient chemical battles lead to plants developing highly complex glucosinolates that give wasabi, horseradish, mustard, cauliflower, and radishes their distinct flavors. So the next time you open your refrigerator, be sure thank the “seasoned” caterpillar veterans.