It may not seem obvious at first, but the pollination prowess of bees affects much of what, how and why we eat. And it goes far beyond honey served from a jar. Thor Hanson is a biologist and author of the book Buzz: The Nature and Necessity of Bees. Francis Lam talked with Hanson about the importance of bees and honey to not only our food supply, but their greater connection to the evolution of both plants and humans.
Francis Lam: There's something that bee-loving people like to say – and I love the sound of – and that is that bees are responsible for every third bite of food that humans consume. But in your book, you have a decidedly foodie way of illustrating what that actually means. Can you tell us about it?
Thor Hanson: That statistic comes from looking at global crop production and the fact that fully 35 percent of that production either relies on or benefits from bee pollination. But I thought it would be interesting to look at the quality of food, not just the quantity, and try to dissect a meal looking for bee ingredients. And not just any meal – not something that you would see at the farmer's market or the produce aisle – but something a little bit out of the way of the normal bee foods. That was a Big Mac sandwich at McDonald's.
What I found was there were a host of bee products involved in that hamburger. Things like pickles and even the lettuce and the onions get removed. You still have a burger, a meat patty from grass and grain-fed beef. You can still have a bun from wind-pollinated grains, but the sesame seeds had to picked off the bun. Even the special sauce had to go. I started looking at the ingredients and you have a host of things in there – at least five ingredients – that relied on bees, from the paprika to the vegetable oils that give it its rich taste and texture. So, the lesson that it taught me was that, yes, we could eat in a world without bees, but our food would be dull and probably not very nutritious.
Photo: Kathleen Ballard Photography
FL: It goes from two all-beef patties, special sauce, lettuce, cheese, pickles, onion on a sesame seed bun, to like, a sad burger.
TH: Yeah. The jingle would never have caught on. Two all-beef patties, bun. That doesn't work.
FL: So, bees give us a lot. But, in the book you argue that there's more. It all sounds to me that pretty much everything we like in the plant world is because of bees.
TH: The one thing to remember, right off the bat, is how diverse bees are. We tend to immediately think of honey bees, but we're talking about a group that has more species than all of the birds and all of the mammals combined; there’s more than 20,000 species of bees in the world. That diversity stems, in part, from their close relationship with flowers. Bees and flowering plants coevolved together, the diversity of one spurring diversity in the other. Because bees are solely reliant upon flower products for their own food and for the food they feed to their babies – the little larvae there back in the hive or the nest – they want that nectar and that pollen.
From the plant's perspective, they want to attract bee visitors to move pollen among flowers. You have this interesting coevolutionary relationship where each side influences the other. And flowers that we look at have adopted colors specifically to attract bee visitors. Many of the colors that we think of for flowers – blues and purples – fall right in the middle of the bee's visible spectrum, and that is by design. Flowers have evolved to attract bees with not only certain colors but with smells and the shapes, all designed to attract and then manipulate the bees on the flowers so that they move in a particular way that deposits pollen onto the bee and then removes that pollen onto the female parts of the flower or the next flower that the bee visits. A lot of what we see in nature and take for granted is heavily influenced by bees.
FL: That's wild. If there were no bees, what would flowers look like? What would they smell like if they didn't have to attract bees?
TH: You would have to start looking at what some of the other flower visitors are out there. If we get rid of bees the flowers would be much more likely to have coevolved with other insects like wasps and flies, who are attracted to these musky terpenes and rotten flesh smells. You'd have all these dead-meat looking flowers out there. There are a few examples of that in nature where the flowers look and smell like rotten meat to attract, say, particular kinds of flies for pollination. But they're quite rare because the bees are a much better bet. It's a happy accident in nature that the smells, colors and shapes that we find beautiful are the ones that are also attractive to bees.
FL: It's interesting because, again, you're talking about flowering plants. I think it's so important for us to remember that flowering plants aren't just pretty flowers – like tulips – but most of the fruits and vegetables that we eat are actually flowering plants. Oranges flower, apples flower, zucchini flower.
TH: Exactly. It’s a huge range of things that you would see in the produce aisle, and some things that are less intuitive – even nuts. Every almond that you get in a bunch of mixed nuts, that seed comes from a flower that was visited by a bee. It has to be pollinated by bees. Other things are far less intuitive, like vegetable oils. Canola oil comes from mustard plants with big, beautiful yellow flowers visited and pollinated by bees. Even some things like soybeans, which can self-pollinate, do much better if bees are present in those fields with 10 to 40 percent higher yields for bee-visited soybean flowers.
Buzz: The Nature and Necessity of Bees
by Thor Hanson
FL: I want to ask you about a chapter in your book where you talk with a nutritional anthropologist, because this is a conversation that totally blew my mind. She thinks we owe bees some credit for helping us evolve into humans.
TH: This is terrific stuff; it really is. When we talk about the human connection to bees, we often think of our long domestication of honey bees, or even looking for wild honey bee nests and other bees in nature going back thousands of years. But this anthropologist, Alyssa Crittenden at the University of Nevada, Las Vegas, and her colleagues have done fascinating research that suggest that our connection to bees should be measured in the millions of years.
What they've done is study the dietary habits of the Hadza people, a hunter-gathering group still living a very traditional hunter-gatherer subsistence lifestyle of East Africa in the very landscape where our species is thought to have evolved. In doing so they learned how much honey the Hadza people eat. Not just honey, but also the larva and the pollen that's included in those honeycombs. We tend to think of something like that as sort of a sweet, occasional treat, but in interviewing people and observing the foods brought back to those camps at the end of a day's foraging, Alyssa was able to calculate how many of their calories were coming from honey. Over the course of a year, it was a full 15 percent of the calories in their diet. At certain times of year, it’s much higher than that, and even higher for the men who do most of the honey hunting because they eat quite a lot of it before they even come back into camp.
This is a totally fascinating idea because when you put it in an evolutionary context, you then ask the question, “Would our ancestors, living roughly the same lifestyle in the same landscape, have done anything different?” Probably not. The Hadza people of today are still looking for honey on a daily basis; it's their favorite food. They're always searching for the hives of honey bees and at least six other honey-producing species in that area. We know that chimpanzees and other great apes eat honey, so why not Homo habilis and Homo erectus, and even Australopithecus? These are ancient ancestors who would have been in that same area looking for a sweet treat.
It becomes really powerful when you start to think about the impact of all those calories on ancestral humans because the story of human evolution has always been a story of brain size. The brain is what physiologists like to call metabolically expensive. It takes a lot of energy to run brain tissue; fully 20 percent of our daily calories go to fuel the brain, which takes up only two percent or so of our body weight. So, it is expensive to have a big brain. Every surge that we've seen in brain size over the eons of human evolution is thought to have been associated with a surge in calories, whether that be the advent of hunting, better tools for hunting, or the advent of cooking, which provides more accessible calories from the food.
When you start to look at honey in that context, it’s the most energy-rich food in nature. Not only that, but it comes in, a large part, the form of glucose, which is what the brain uses. If you eat other things, your body will turn those starches or whatever into glucose to feed your brain. You can get it straight out of honey. So, this suddenly suggests that our primordial sweet tooth led us to bees and to following them to honey and hives. The calories that we gained from that may indeed have helped bolster an increase in brain size over time. Because all of those same technological and social innovations that could lead to increases in hunting productivity or more calories from cooking – like stone tools – will allow you access into the big hives of honey bees that are in trees. You can chop the trees open and get the honey. If you need to master fire for cooking, that also gives you mastery over smoke, which you can use to pacify bees and get the honey. There are all of these things, now in the context of honey, which suggest it's perhaps not responsible for human evolution, but along with hunting and cooking and other innovations, it is a contributing factor in what makes us who we are.