I bought The Story Of The Human Body because I thought it would give me a biology lesson on the inner workings of the human body, but instead it was an evolutionary study of human anthropological history. While I did recently post a critique of how evolution has gone off the rails in regard to modern humanity, thanks to rapid advances in culture and technology that we haven’t kept up with, I do accept that evolutionary processes occurred during the history of our species.
The author, Daniel Lieberman, is a paleoanthropologist at Harvard. He has combined the latest human evolutionary research to explain the behavior of our body instead of our minds (that was covered more in the book Mean Genes). I didn’t want to read a book on evolutionary theory, but I didn’t mind getting an update on the current accepted science.
Lieberman begins his principal hypothesis by arguing that our ape ancestors became bipedal to better forage for food in a changing climate. At the same time he brings this hypothesis forth, he admits that the initial change to bipedalism would incur huge disadvantages. The new species would lose speed and agility, severely impacting its ability to hunt and therefore reduce it to more of a scavenger role. They’d gradually lose the skill to climb trees and be sitting ducks for predators. In spite of all this, there was a magical deus ex machina that allowed the bipedal species to survive though its initial jump to bipedalism, even though it’s not clear how that could have happened.
According to current theory, not only did the first bidpedal humans survive these disadvantages, but they managed to successfully evolve to the result you are now living. Bipedalism today is taken for granted, and we are obviously more adept at surviving than our ape cousins, but this change happened before the use of tools, language, and hunting, even with spears. Until we get further evidence that shows how these first bipedals survived, I have to assume it was from some sort of miracle.
…the benefits of foraging far and wide favored further adaptations for more habitual and efficient long-distance walking than we see in Ardi and other earlier hominins. The combination of these adaptations, which were largely driven by the exigencies of climate change, had momentous implications, setting the stage for the evolution of the genus Homo a few million years later and for many important features of the human body.
I bet in 1,000 years, absolutely nothing in the above passage will remain true, especially when explaining the why and how of evolutionary change. The problem with anthropological hypotheses like the one Lieberman provides is that they’re based on a minuscule set of data. They find one partial skeleton for every 100,000 or even 1 million years of human existence, and then re-jigger their entire theory around that skeleton. It’s intellectually dishonest, especially when you consider that a lot can happen in 100,000 years. If the history of humanity was a 1,000 page book, we only have one or two frayed pages of the entire story.
As Africa became cooler and drier many millions of years ago, fruit became more scattered and scarce, favoring those ancestors who were better able to forage by standing and walking upright.
Whenever the australopiths ventured down from trees, they were easy pickings for such carnivores as lions, saber-toothed cats, cheetahs, and hyenas that hunt in open habitats. Perhaps they were able to sweat and thus could wait until midday to move about when these predators would have been unable to cool down as effectively.
Perhaps! Yes, perhaps our guess is correct and we can explain a gigantic hole in figuring out how bipedals, who were slower and less capable of climbing trees, managed to survive at all.
And yet the apes that stayed on all fours continued to do just fine, at least up to recent times when humans finally started figuring out how to dominate its environment. How can natural selection promote the divergence of a species to bipedalism when, for at least a million years, it put them at a grave disadvantage? My argument is not that we couldn’t have evolved from apes, but that the initial jump to bipedalism must have been guaranteed death during the environment of the earth at that time. It would be like if a modern group of humans evolved to walk on their hands instead of feet in order to eat weeds and plants that are on the ground, but still had to compete with existing humans to survive.
The story of the Neanderthals
We’re starting to piece together the story of the Neanderthals, who were already in Europe when modern humans made it out of Africa. There was inter-breeding between them and humans (many non-Africans have Neanderthal genes) until they died out from supposed lack of food or other environmental reasons. My own guess is that they were slaughtered by modern humans. The reason we find their remains in caves is because that was the only place they could hold defensive positions.
It’s also becoming likely that Neanderthals were smarter than humans at that time. I’m guessing they saw new humans as inferiors who could be easily controlled, but when they got out-bred, it was all over for them (the current European migrant crisis is probably a light simulation of exactly how that happened).
…the last time the modern human and Neanderthal lineages belonged to the same ancestral population was about 500,000 to 400,000 years ago. Not surprisingly, human and Neanderthal DNA are extremely similar: only one out of every six hundred of your base pairs differs from a Neanderthal’s.
…all non-Africans have a very small percentage, between 2 and 5 percent, of genes that came from Neanderthals.
My guess is that Neanderthals were extremely smart, but that modern humans are more creative and communicative.
Lieberman has been at Harvard for too long to think it takes “creativity” to destroy an enemy. Modern humans were more numerous (higher fertility) and better at fighting (physically stronger or faster). To Neanderthals, humans must have been a dreaded zombie army that just kept coming from Africa. I can only imagine what the last Neanderthal thought of when he died in his cave fortress.
The transition to agriculture
We have enough data to show that agriculture has actually hurt humans in many ways. Life got more brutish and short after we began working the land and creating permanent settlements.
…a hunter-gatherer’s chances of dying from starvation must be orders of magnitude lower than any farmer’s.
Farmers consume foods that are starchier and contain less fiber, less protein, and fewer vitamins and minerals. Farmers are also more susceptible to eating contaminated food, and they risk famine more regularly and intensely than hunter-gatherers . In terms of diet, humans have paid a high price for the pleasure of enjoying a yearly harvest feast.
For thousands of years after the origin of agriculture, life stank, diarrhea was common, and cholera epidemics were regular occurrences. In spite of being unsanitary death traps, cities became magnets as the agricultural economy progressed. People flocked to cities because urban areas generally had more wealth, more jobs, and more economic opportunities than impoverished rural areas.
…there is little evidence for regular famines during the Stone Age. Hunter-gatherers rarely have massive food surpluses , but they seldom run out of food either, and their body weights fluctuate only modestly between seasons. As chapter 8 reviewed, famines became much more common and severe after farming began.
Lieberman explained how our energy needs have declined greatly since the Industrial Revolution. He used good data from early farm and industrial age workers like coal miners to make comparisons, unlike his earlier guesswork.
Living in cities is decidedly modern, and evolution has not yet created the genetic adaptations that match a sedentary city lifestyle.
In 1800, only 25 million people lived in cities, about 3 percent of the world’s population. In 2010, about 3.3 billion people, half the world’s population, are city dwellers.
Has the industrial era caused a trade-off between lower mortality and an extension of morbidity? To some extent, the answer is unquestionably yes. Because of more food, better sanitation, and better work conditions, fewer people, especially children, contract infectious diseases and suffer from insufficient food, and so they live longer. It is also inevitable that, with age, the chance of cancer-causing mutations increases, arteries harden, bones lose mass, and other functions deteriorate. Many health problems correlate strongly with age, which makes them more prevalent as more populations grow and a larger percentage of them are middle-aged and elderly.
He provides an interesting observation of why more women are affected by cancer in the modern age:
All told, [a woman] can expect to experience approximately 350 to 400 menstrual cycles during her life. In contrast, a typical hunter-gatherer woman starts menstruating when she is sixteen, and she spends the majority of her adult life either pregnant or nursing, often struggling to get enough energy to do so. She thus experiences a total of only about 150 menstrual cycles. Since each cycle floods a woman’s body with powerful hormones, it is not surprising that reproductive cancer rates have multiplied in recent generations as birth control and affluence has spread.
Most problems that you face, including flat-footedness, near-sightedness, back pain, allergies, and digestive ailments are mismatch diseases resulting from the fact that we have put ancestral human bodies in modern environments quicker than evolution has allowed it to adapt. The same thing is happening with technology, where advances in tech are becoming so rapid that we will face increasing psychological suffering and malaise from being forced to stay plugged into the system.
The early parts of the book contained too much speculation. Lieberman was essentially pulling guesses out of thin air. Can you imagine aliens coming to planet Earth in a million years and finding one partial skeleton for the past 10,000 years of humanity, since the dawn of agriculture, and using that alone to create a complete picture of how modern humans lived? It’s absurd. I understand science wants to provide answers, but they’re placing too much confidence on theories from a random and sparse data set.
I can’t decide if it takes more faith to believe in evolutionary theories of early man or believing in the story out of Genesis with Adam and Eve. Nonetheless, if we are to try and base the ideas of humanity on science, the partial-skeleton-every-one-million-years approach must be used, and connecting dots from one skeleton to the next can at least provide the direction of evolution, but I’m hesitant to let scientific guesswork furnish me with answers on my existence.
If you set aside the speculation of the early pages, the book does a good job explaining how our bodies are evolved for hunter-gathering, and how modern living takes us away from that, creating disease and morbidity as we try to jam our bodies in environments that they simply don’t belong in. Overall the book does have reasonable information that could probably assist you with modern living, so it’s worth your time to check out.
Read More: “The Story Of The Human Body” on Amazon