Hanson, T. 2015. The Triumph of Seeds. New York (NY): Basic Books. p. 128-160.
I don’t know about you, but I wouldn’t want to come between a mother and her child. There are many stories about hikers coming across giant grizzly bears without happy endings. I never thought about how a plant can protect its offspring in the same way. More specifically, I never considered the protection provided to the pepper plant and coffee plant growing my house.
Like most people, I enjoy adding a little extra spice to my food and probably could not survive without a cup of coffee in the morning. There is an inside joke with my lab mates that I live for drinking coffee and have adapted to have a cup permanently attached to my hand (early morning field days can be rough). Who knew that the things I love most about these plants (e.g. spice and caffeine) were actually evolved to protect them? I love these plants so much that I even decided to grow them!
Spices (including pepper) have fueled greed and change within the world, leading to exploration and the European colonies many of us occupy today. “For centuries the lust for spices shaped history” (p. 134). The economics behind spices took over the world and over 2000 cultivars have been developed from the Capsicum chili pepper (p 133). I know that the world’s economy is driven by food and the control of resources, but I had never thought about what causes my food to taste the way it does.
Chilli peppers are spicy because that’s how they protect their young. Spiciness has evolved through a coevolutionary relationship and “’it all comes down to seed production’” (p 136). Capsaicin is an alkaloid that gives the pepper its spicy flavor. This alkaloid also protects the plants from fungal pathogens and can alter a bird’s digestive system, aiding in dispersal and survival. It also acts as a deterrent for herbivores.
When eaten by mammals, capsaicin tricks your brain into thinking your mouth is on fire! Who would enjoy that? As it turns out, many people enjoy the burning sensation caused by chili peppers, myself included.
The coffee bean is protected in a similar way. I really enjoyed reading about the coffee plants history and how the effects of caffeine have changes the world. Learning about all the famous historians that gathered in coffee houses was fascinating. Voltaire drank 50 cups of coffee a day (p 152)! As I enjoy my daily cup of coffee (or 5), I never questioned why coffee had caffeine in the fist place.
Coffee is a smart plant and has equipped its seed with a good defense system. Caffeine acts as a natural insecticide to protect the seed and growing plant. It also leaches out of the seed to prevent the germination of all other plants around the seed, effectively killing off the competition. The coffee seed is well defended to survive to the next generation.
Caffeine also provides the plant with an addictive agent for pollinators. As it turns out, bees are just as addicted to caffeine as I am! There is small a concentration of caffeine in flower nectar to give the bees a taste, but not a lethal dose. This is really cool. Just as popular coffee chains like Starbucks and Tim Horton’s have discovered, the best way to increase your fitness (make money) is to have a line up of caffeine-addicted bees (or students) at your door.
It’s truly fascinating how a plant protects its seeds, just as a lioness or mother grizzly protects their cubs. I am glad that the human population has been able to take advantage of these protections to change the world. I enjoy my coffee far too much to imagine a world without it.