Today, we’re healthier than ever before in human history—we have higher life expectancy, less malnutrition, and have removed threats from diseases like smallpox, measles and the plague (which used to kill masses of people). Yet, we are getting sick from preventable diseases like osteoporosis, depression, allergies, cancer etc. In the USA alone, more than $2 trillion is spent on healthcare annually, when 70% of the illnesses are preventable. In his book, Daniel Liberman advocates that we should understand our bodies using an evolutionary perspective, so we can develop more effective strategies to prevent and address these diseases. In this free version of The Story of the Human Body summary, you’ll learn some powerful insights into this problem.
The Story of the Human Body: An Overview
The book covers some key ideas such as (a) our biological evolution and how we came to have our present bodies, (b) our cultural evolution and how it transformed the way we live, and (c) why the mismatch between the 2 evolutions has caused many of our modern-day diseases.
Lieberman approach to evolution is built on 2 important perspectives:
• Evolution is an ongoing process of change, rather than just a study of the past. The choices we make today will determine the future of mankind.
• Evolution is not just biological. Cultural/societal changes shape the way we live and use our bodies, and affects how our bodies continue to evolve.
Let’s take a quick look at the 2 types of evolution and how they interact.
In the book, Liberman explains the concept of evolution, and how modern humans (Homo Sapiens) evolved from apes. In a nutshell, there were probably 5 key transitions in our biological evolution:
Transition 1: From Apes to Bipeds
This was the biggest evolutionary step that set homonins (a subset of the apes species) apart from Chimps and Gorillas, and was probably necessitated by major climate change and the need to find increasingly-scarce food. Standing on 2 feet allowed us to forage better for fruits and save energy while traveling to find new food sources. Till today, we’re still the only non-feathered species moving on 2 legs.
Transition 2: Australopiths
About 4 million years ago, the Australopiths emerged. While they were still suited to climb trees, Australopiths started to dig for underground tubers, bulbs and roots, like potatoes and ginger, which gave them an additional food-source that was rich in water, starch and nutrients.
Transition 3: The First Hunter-Gatherers
At the dawn of the Ice Age about 2-3 million years ago, when food became even more scarce, the first hunter-gatherers emerged. They started to consume meat, cooperate, make tools and process food. This combination of behaviours was unique to the human genus–they shaped the ongoing evolution of our bodies, improved the efficiency of food digestion, and increased the amount of calories we could absorb.
Transition 4: Spread of Hunter-Gatherers
During the Ice Age, Hominins continued to spread across the globe, and several sub-species of Archaic Humans emerged. Generally, we developed even bigger brains, bred faster, became fatter, and matured slower.
Transition 5: Birth of modern Homo Sapiens (H. Sapiens)
By the end of the Ice Age, all Homo species had become extinct, except for H. Sapiens. What set H. Sapiens apart were our heads–our prefrontal cortex gave us new abilities to think and organize ourselves, while our vocal tract and tongue brought a leap in modern human speech. This brought a cultural transformation about 50,000 years ago, with an explosion of new tools, weapons and art-forms.
By understanding our biological evolution over millions of years, we can understand why our bodies are designed the way they are… Why the human brain is 5x as large as other mammals (while our guts are half the size), why our bodies require more fat, why we move slower but can run long distances, and can handle tools and weapons unlike any other animals. Our full 14-page version of The Story of the Human Body summary elaborates on the key details of the transitions and how our bodies were adapted to help us survive in those environments.
Culture is the set of learned beliefs, values, and knowledge that shape people’s thinking and behavior. Technically, there should be 2 more transitions in our evolutionary history: the Agricultural Revolution (when we started to farm our food instead of hunting and gathering), and the Industrial Revolution (when we began to use machines to replace human work). These cultural evolutions did not create new species, but they transformed how we eat, live and use our bodies, which indirectly impacts biological evolution.
The Agricultural Revolution
Farming may seem like an old-fashioned way to live, but it’s actually a very recent phenomenon by human evolutionary standards. Farming brought more predictable food supply, but also other challenges, like a more limited range of foods & nutrients, higher risk of famine and food shortages, cavities from starchier foods, and contagion and infections. Every major infectious disease happened after the Agricultural Revolution, and humans actually shrank in size during the revolution.
The Industrial Revolution
It increased the pace of transformation exponentially, with the use of fossil fuels (e.g. coal oil, gas), reorganization of economic and social institutions, and science as an essential driver. Technology significantly reduced our level of physical activity, we sleep less (and less well), and the human population exploded with progress in medicine, sanitation and food storage/safety. While we have much more variety of food than the typical farmer, almost everything we consume today is bred, harvested, processed and shipped by machines, with huge amounts of pesticides, inorganic fertilizers and antibiotics. Processed foods also contain more sugars and starches, and require less energy to break down, causing spikes in blood sugar levels that our bodies aren’t used to.
It took millions of years for the first H. Sapiens to evolve from apes. Yet, in less than 10 generations, we’ve transformed the way we live—to a lifestyle that’s totally different from what our bodies were evolved for. This results in “mismatches” which we’ll touch on below. You can get our detailed version of The Story of the Human Body summary, where we explain the changes and implications in more detail.
Understanding Present and Future Challenges
Many of the diseases or discomforts that we face today (e.g. high blood pressure, cancer, cavities) arise from “mismatches” in our cultural and biological evolution. Mismatches basically occur when the inputs from our environment are (a) too much, (b) too little, or (c) too new for our bodies to handle. Longer life expectancy also means a growing number of people with aging-related diseases and disabilities.
Diseases from Excess
For the first time in human history, we have too much food, most of which are processed foods with little/no fibre, and contain lots of starch and sugars, and such excess energy creates problems for the body.
Diseases of Dis-use
Our bodies adopts the “use it or lose it” concept to use energy wisely. Unfortunately, our modern lifestyle neglects many parts of the body, leading to issues like Osteoporosis, impacted wisdom teeth, and allergies.
Diseases of Novelty
The things that we take for granted in modern societies–e.g. shoes, eyeglasses, and chairs–are comfortable or convenient, but may actually be bad for us because they create a different type of strain for our bodies.
In our complete 14-page summary, we explain (i) more about each of these 3 types of diseases and (ii) what you can do about them.
Getting the Most from The Story of the Human Body
Ready to gain an understanding of our bodies using an evolutionary perspective? Check more details, tips and examples from our complete book summary bundle. This includes an infographic, a 14-page text summary, and a 26-minute audio summary.
This is a very comprehensive book that covers the human body evolution and modern-day diseases in great detail. To truly understand our bodies’ evolution and how the mismatches occur with our modern lifestyle, you can purchase the book here.
Check out our Sapiens summary to learn more about human evolution from a social and cultural perspective. Or, learn more about health and nutrition in The China Study summary, or find out how to Prevent and Reverse Heart Disease.
About the Author of The Story of the Human Body
The Story of the Human Body: Evolution, Health & Disease is written by Daniel E. Lieberman— a paleoanthropologist at Harvard University. There he is the Edwin M Lerner II Professor of Biological Sciences, and chair of the Department of Human Evolutionary Biology. He is best known for his research on the evolution of the human head and the evolution of the human body In his research on the human body, Lieberman combines paleontology, anatomy, physiology and experimental biomechanics in the lab and in the field. His research on running in general, especially barefoot running, was popularized in Chris McDougall’s best-selling book “Born to Run”. Lieberman is an avid marathon runner, often barefoot, which has earned him the nickname The Barefoot Professor.
The Story of the Human Body Quotes
“Knowing your body’s evolutionary history helps to evaluate why your body looks and works as it does, and why you get sick.”
“Human cultural creativity, once unleashed, has been an unstoppable engine of accelerating evolutionary change.”
“Rethink how you use your body, especially what you eat and how you exercise.”
“The human body’s past was molded by the survival of the fitter, but your body’s future depends on how you use it.”
“Cancer is basically a kind of evolution gone wile, in which mutant cells reproduce without restraint in a body.”
“The pace and scope of cultural evolution now vastly exceeds the pace and scope of biological evolution.”
“In much of the development world, the food we eat is now as industrial as the cars we drive and the clothes we wear.”
“Treating symptoms rather than causes of mismatch diseases sometimes provokes a pernicious feedback loop, which I term dysevolution, that allows the disease to persist or even intensify.”
“You may not realize that your body uses energy in a special way, but it really does.”
Understand your body and the path to health today!