
Christina Agapakis is a synthetic biologist and postdoctoral research fellow at UCLA who blogs about about biology, engineering, biological engineering, and biologically inspired engineering at Oscillator.
When you factor in the fertilizer needed to grow animal feed and the sheer volume of methane expelled by cows (mostly, though not entirely, from their mouths), a carnivore driving a Prius can contribute more to global warming than a vegan in a Hummer. Given the environmental toll of factory farming it’s easy to see why people get excited about the idea of meat grown in a lab, without fertilizer, feed corn, or burps.
In this vision of the future, our steaks are grown in vats rather than in cows, with layers of cow cells nurtured on complex machinery to create a cruelty-free, sustainable meat alternative. The technology involved is today used mainly to grow cells for pharmaceutical development, but that hasn’t stopped several groups from experimenting with “in vitro meat,” as it’s called, over the last decade. In fact, a team of tissue engineers led by professor Mark Post at Maastricht University in the Netherlands recently announced their goal to make the world’s first in vitro hamburger by October 2012. The price tag is expected to be €250,000 (over $330,000), but we’re assured that as the technology scales up to industrial levels over the next ten years, the cost will scale down to mass-market prices.
Whenever I hear about industrial scaling as a cure-all, my skeptic alarms start going off, because scaling is the deus ex machina of so many scientific proposals, often minimized by scientists (myself included) as simply an “engineering problem.” But when we’re talking about food and sustainability, that scaling is exactly what feeds a large and growing population. Scaling isn’t just an afterthought, it’s often the key factor that determines if a laboratory-proven technology becomes an environmentally and economically sustainable reality. Looking beyond the hype of “sustainable” and “cruelty-free” meat to the details of how cell culture works exposes just how difficult this scaling would be.
by Richard Wrangham, as told to Discover’s Veronique Greenwood. Wrangham is the chair of biological anthropology at Harvard University, where he studies the cultural similarities between humans and chimpanzees—including our unique tendencies to form murderous alliances and engage in recreational sexual activity. He is the author of Catching Fire: How Cooking Made Us Human.
When I was studying the feeding behavior of wild chimpanzees in the early 1970s, I tried surviving on chimpanzee foods for a day at a time. I learned that nothing that chimpanzees ate (at Gombe, in Tanzania, at least) was so poisonous that it would make you ill, but nothing was so palatable that one could easily fill one’s stomach. Having eaten nothing but chimpanzee foods all day, I fell upon regular cooked food in the evenings with relief and delight.
About 25 years later, it occurred to me that my experience in Gombe of being unable to thrive on wild foods likely reflected a general problem for humans that was somehow overcome at some point, possibly through the development of cooking. (Various of our ancestors would have eaten more roots and meat than chimpanzees do, but I had plenty of experience of seeing chimpanzees working very hard to chew their way through tough raw meat—and had even myself tried chewing monkeys killed and discarded by chimpanzees.) In 1999, I published a paper [pdf] with colleagues that argued that the advent of cooking would have marked a turning point in how much energy our ancestors were able to reap from food.
To my surprise, some of the peer commentaries were dismissive of the idea that cooked food provides more energy than raw. The amazing fact is that no experiments had been published directly testing the effects of cooking on net energy gained. It was remarkable, given the abiding interest in calories, that there was a pronounced lack of studies of the effects of cooking on energy gain, even though there were thousands of studies on the effects of cooking on vitamin concentration, and a fair number on its effects on the physical properties of food such as tenderness. But more than a decade later, thanks particularly to the work of Rachel Carmody, a grad student in my lab, we now have a series of experiments that provide a solid base of evidence showing that the skeptics were wrong.
Whether we are talking about plants or meat, eating cooked food provides more calories than eating the same food raw. And that means that the calorie counts we’ve grown so used to consulting are routinely wrong. Read More