Today I would like to share my latest paper for my Behavioral Evolution class, I think you will like it, and I hope you will learn from it! I shall also consider this a review of the book, “Catching Fire, How Cooking Made Us Human” by Dr. Richard Wrangham!
If you enjoy what is discussed here, be sure to pick up you own copy of Catching Fire!
If you are on Academia.edu, do me a favor and check it out on there as well =)
Dr. Christina Campbell
November 17, 2021
Catching Fire, How Cooking Made Us Human, a Review
In “Catching Fire, How Cooking Made Us Human” by Dr. Richard Wrangham, we learn about what is possibly the most important change in human, and pre-human history. Fire changed everything that our ancestors did, from how they digested food, to how they hunted and fended off predators. Fire changed how we viewed the world, it spurred on the formation of culture as we know it today, and led to massive dietary changes that allowed for the explosion in brain size we see between H. habilis and H. erectus in the fossil record. While there is little actual evidence of fire in the fossil record, at least until much more recently, it is difficult to say for sure just exactly how the first hominins came across fire, and how they used it. What possessed them to take something that they knew would be so dangerous, and apply it in the ways that they did? We may never know for sure, but we can look at the biological changes that have brought us to be where we are today, and we can trace the very roots of our many cultures to sitting around the campfire, preparing food. Dr. Wrangham proposes the “Cooking Hypothesis” in this book, which since its publication has been widely accepted, and changed the way we view early Homo. While fire may date back much earlier than we know currently, the basis of its effects remains the same. We would not be the same without fire, it has fueled our evolution and fuels the machine of our modern world. But how?
The book starts, as most books on Human Evolution do, with a recap of the fossil record, who is, and is not a part of our “family tree”. We learn the names of various hominins and specific specimens, and then we get into the biology of it. Discussing how these animals evolved to survive, and what they did to find shelter, safety, and for the purpose of this book, most importantly food. According to current Paleoanthropologic hypotheses, Homo habilis, “Handy Man”, was the first hominin to make and use stone tools. While this idea has been challenged since Wrangham’s book was published, the fact that they were able to scavenge, and eat meat, with the use of said tools, was a huge development in our history. What would soon become clear, was without fire, meat did not have the same effect as it does today. Fire had an important role in our early evolution into Homo. Before habilis, we had the Australopithecines, creatures that were more ape-like than human, but a far departure from our common ancestor with the great apes. They ate hard, tough food, such as roots and tubers, that had little nutrition, it was enough to survive, and our brains grew at a steady rate, but it was nothing spectacular. Soon bone marrow was discovered as a reliable, and easy food source, and that helped us along quite a bit. But because of what we ate, we had to have the right “tools” to do so. We had larger teeth, the massive molars of Zinj, and huge muscles connecting sometimes to a large sagittal crest. We had larger intestines, that were harder to handle bipedally than what we have today. We survived, we continued to evolve, and that is how it was for millions of years. But then, somehow, somewhere on the continent of Africa, lightning struck. Some curious hominin carried this fire back home or used it in situ by some miraculous reason to cook meat. With that, a new age began. Fire allowed us to cook our food, which truly unlocks the potential nutritional value of not only meat but fibrous plants as well. Digestion became a much easier task, requiring less energy. This was diverted to brain growth, and we could walk, and run in more efficient ways as our guts shrank, a more anatomically modern human morphology took place. All of this was brain food, and in what is an extremely short time geologically, our brains exploded in size. Going from around 750cc in an adult male habilis to 1200cc erectus, which very close to our volume. The modern human body was beginning to truly take shape, and with the growth of our brains, many more changes were to come.
With the newly freed up energy from digestion going straight to brain development, many morphological changes occurred to the skull of erectus. As erectus moved around the world, it became more adapted to its environment, which would have been impossible without the nutrients brought on by cooked food. With fire, food became physically easier to chew, which led to smaller teeth than our contemporaries, and smaller chewing muscles as well. This led to a reduction in skull size, and prognathism, which created a more “modern” looking face. Erectus fossils are found around the world. Their behavior, their skills, dare we say their culture dare, was something the planet had never seen before, and this was because of the changes that fire brought to their brains. We can only presume that erectus hunted, with their ability to run long distances. It is supposed they were very like modern-day hunter-gatherers still present in Africa. They would hunt, bring back the food, and cook it. Cooking takes time. The hominins would have to sit around a fire, waiting for the food to be prepared. They had to learn how to be patient, to be social, how to behave, and how to work together to achieve common goals for not only the small family units but for the group as a whole, started to become critically important. A new behavior not seen prior. Erectus went from only being able to be active during the day, the diurnal creatures that they were, but with the introduction of fire, suddenly traveling, and possibly even hunting at night became more plausible, albeit dangerous still. The cultural implications of having fire could very well be what set us on the road to where we are today, as the earth’s most social creatures. Sitting around the fires, we can imagine that storytelling perhaps had its first roots, that language and communication reached a level not seen in other primates, unique to us. Would any of this have happened without fire? Without cooked food?
As discussed previously, fire also had a major effect on our physical bodies from early on. Evolution occurs when there is a need to adapt to a new environment, or challenges in ones environment. With the earth’s ever-changing climate, the fluctuations have been something that we have been dealing with for millions of years and we have learned a trick or two, but it has not by far been easy. Homo erectus had to adapt, culturally and physically if it were to become the most successful hominin, even against us arguably, in the history of the world. Fire fueled that change, that evolution. The bodies of homo erectus were different than anything we had seen before, which was arguably quite more “ape-like” than human. When we look into the orbits of Nariokotome Boy, we see, possibly for the first time, a true sense of humanity as we recognize it today. The expansion of the brain that occurred around 1.5-2 MYA was, proportionately, unheard of in the animal kingdom. Almost doubling in size compared to their predecessors, erectus was able to do things no hominin had ever been able to do. Reaching all through Eurasia, almost into Europe, and down to Polynesia and the tip of the land. They had the brainpower to do it, they had the toolset to make these remarkable treks and changes that would lead them to us. And it all started with cooking, and allowing our bodies to better digest food that we found. We went from being the hunted, who scavenged for food on the ground, to the hunter, with a bountiful supply of prey for an ever-growing brain.
According to the FDA website, an adult human male, ages 30 and up, should consume anywhere between 1800-2500 calories a day to maintain a healthy weight depending on activity level. For an animal of our size, that is a massive amount of energy consumption, and most of it is used by our brains alone, 20% in fact. For early hominins, especially those before eating raw meat, it would have been nearly impossible to achieve such a massive intake, especially in groups. With the discovery of fire, less became more. We could unlock the potential of raw foods, and we took every advantage of this that we could. Our brains could finally be unshackled. We truly became what one could say is recognizably human, compassion, care, possibly love, became possible in erectus with the advanced social and behavioral skills that they would have been forced to develop to survive in the ways that they did. Today, fire heats our homes, indirectly now, but it powers the machine of the city. The Industrial Revolution would never have happened without the discovery and use of fire to its fullest. Our modern world, let alone our modern bodies, would never have existed had we not taken that giant leap, and changed the world forevermore. Fire is sacred in so many cultures around the world, and it’s easy to understand why. Often a gift of knowledge or life, fire is the literal light in the darkness, and it puts warmth in our bellies. Next time you stare into a flame, remember what it has done for you, feel the voices of all those millennia of generations that have gone before who would not have without this magical, dangerous, unpredictable, godly, force. In “Catching Fire…” by Dr. Richard Wrangham, the author truly presents a hypothesis that is hard to counter, and, in my mind one that will one day become an even more recognized theory, as we learn more about our lives and development into anatomically modern humans today.