Just as Starbucks lures you into its coffee shops with the promise of a tasty treat and a nice buzz of energy in pleasant surroundings, many plants offer exactly the same deal to bees.
The only significant difference is that bees don’t pay for the treat with money; they pay by assisting the plants they visit in their sexual activities – i.e. by transporting pollen from one plant to another.
We learned this week that some of their favorite flowers offer bees more than just some tasty, life-enhancing nectar in exchange for their services; they include a little jolt of caffeine at the same time.
Unlike animals, plants don’t move around, so they need another way of exchanging genes with other plants. That’s why they expend much of their energy creating attractive flowers with special scents that make you want to go back for more so that you’ll collect a little more pollen to distribute as you go on your way to the next plant.
Caffeine, like nicotine and other drugs, is toxic to animals. They produce these toxins as a defense against being eaten. But in small doses, they’re safe and can make you feel good. And that’s how many plants have “learned” to use them for other purposes than simple self-defense.
All of this is interesting to know, but we should note it’s the result of invasive experiments on bees. The research team, led by Geraldine Wright, a bee brain specialist, write in the journal Science:
Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times as likely to remember a learned floral scent as were honeybees rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar did not exceed the bees’ bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success.
What we learn most of all is that there’s not that much difference between the brain of a bee and the brain of a human. We’re all basically of one kin, and that means we really shouldn’t be doing this kind of invasive research on unconsenting animals.