Survival of the Fittest
Can Evolutionary Logic Help Cultivate a Better Future for the Human Body?
All that we can do is to keep steadily in mind that each organic being is striving to increase in a geometrical ratio; that each, at some period of its life, during some season of the year, during each generation, or at intervals, has to struggle for life and to suffer great destruction. When we reflect on this struggle, we may console ourselves with the full belief that the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply.
CHARLES DARWIN, On the Origin of Species.
2. The last few thousand years of cultural evolution have significantly altered the human body’s condition, sometimes for the worse (especially initially), but eventually and mostly for the better. Because of farming, industrialization, sanitation, new technologies, improved social institutions, and other cultural developments, we have more food, more energy, less work, and additional blessings that immeasurably enrich and improve our existence.
3. Billions of people now take for granted a long life and good health. In fact, if you have the good fortune of being born in a wealthy, well-governed country, you can expect to live into your seventies or eighties, rarely if ever suffer from a serious communicable disease, never have to do hard physical labor, always have plenty of tasty food, and beget similarly healthy, pampered children. To those less lucky, such a prognosis must sound like an advertisement for a lifelong vacation.
4. To be honest, the most marked improvements to human health and well-being have occurred from the intense surge of scientific progress, still ongoing, that started in the last few hundred years. Many of these advances solved problems that were deleterious consequences of the Agricultural Revolution. As we have seen, although farmers have more food and can have more children than foragers, they have to labor more intensively, and they experience more famine, malnutrition, and infectious disease.
5. Over the last few generations, we have figured out how to conquer many of the contagions that arose or became epidemic after farming took root. Diseases like smallpox, measles, plague, and even malaria have either been eradicated or can now be cured or prevented with proper measures. Likewise, diseases of malnutrition and poor sanitation that proliferated after people settled into permanent towns and cities exist today in some parts of the world chiefly because of poor government, social inequality, and ignorance.
6. As democracy, information, and economic progress sweep across the globe, people are becoming taller, living longer, and otherwise thriving. Yet of course there are inevitable trade-offs, because everyone must die from something. Not dying young from diarrhea, pneumonia, or malaria means a greater likelihood of dying in old age from cancer or heart disease. Similarly, as bodies accumulate wear and tear over the years, aging inevitably brings increasing decrepitude, even when cars and other technologies permit us to still get around.
7. Our body’s evolutionary journey is also far from over. Natural selection didn’t stop when farming started but instead has continued and continues to adapt populations to changing diets, germs, and environments. Yet the rate and power of cultural evolution has vastly outpaced the rate and power of natural selection, and the bodies we inherited are still adapted to a significant extent to the various and diverse environmental conditions in which we evolved over millions of years. The end product of all that evolution is that we are big-brained, moderately fat bipeds who reproduce relatively rapidly but take a long time to mature.
8. We are also adapted to be physically active endurance athletes who regularly walk and run long distances and who frequently climb, dig, and carry things. We evolved to eat a diverse diet that includes fruits, tubers, wild game, seeds, nuts, and other foods that tend to be low in sugar, simple carbohydrates, and salt but high in protein, complex carbohydrates, fiber, and vitamins.
9. Humans are also marvelously adapted to make and use tools, to communicate effectively, to cooperate intensively, to innovate, and to use culture to cope with a wide range of challenges. These extraordinary cultural capacities enabled Homo sapiens to spread rapidly across the planet and then, paradoxically, cease being hunter-gatherers.
10. The principal trade-off between the novel environments we have created and the bodies we inherited has been mismatch diseases. Adaptation is a tricky concept, and there is no one environment to which the human body was adapted, but our biology remains imperfectly adapted to living at high population densities in permanent settlements amid the filth we create.
11. We are also inadequately adapted to being too physically idle, too well fed, too comfortable, too clean, and more. Despite recent progress in medicine and sanitation, too many of us are getting sick from a wide range of diseases that used to be rare or unknown. Increasingly, these diseases are chronic noninfectious illnesses, many of which arise from having made too much progress.
12. For millions of years, humans struggled to stay in energy balance, but billions of people are now obese from eating more calories (especially from massive doses of sugar) as well as from less physical activity. As we accumulate excess fat in our bellies while fitness dwindles, diseases of affluence are on the rise, especially heart disease, type 2 diabetes, osteoporosis, breast cancer, and colon cancer.
13. In the United States, the rate of type 2 diabetes is rising even among teenagers, with nearly 25 percent now classified as having either prediabetes, diabetes, or other risk factors for cardiovascular disease. Economic progress has also brought more pollution and other potentially harmful environmental changes (too much, too little, too new) that are contributing to rising rates of mismatch diseases, such as certain cancers, allergies, asthma, gout, celiac disease, depression, and more.
14. The next generation of Americans risks being the first generation to live shorter lives than their parents. The ongoing epidemiological transition that is bringing lower mortality and higher morbidity is not just a problem for wealthy nations. The rest of the world is heading in the same direction. India, for example, has achieved dramatic improvements in life expectancy but is now facing a tsunami of type 2 diabetes among the middle class, with the number of cases expected to grow from 50 million in 2010 to more than 100 million by 2030.
15. Economically developed countries are already having problems paying for the rising costs of chronic illness among the young and middle-aged (for example, diabetes doubles the average cost of a person’s health care). How will less wealthy countries, such as India, cope? The big picture we now confront is a paradoxical situation in which the human body is simultaneously doing better in many respects but worse in others.
16. To understand this paradox and what to do requires using the lens of evolution to consider two related processes. The first, summarized above, is that changing environments have made us increasingly prone to diseases from evolutionary mismatches. Understanding why mismatches occur is vital to figuring out how to prevent or treat them, which highlights the importance of the second process, the pernicious feedback loop of dysevolution.
17. Even though many (though not all) mismatch diseases are preventable, we too often fail to address their environmental causes, allowing the diseases to remain prevalent or to intensify when we pass on the same disease-inducing environmental conditions to our children through our culture. The obvious and important exceptions to this feedback loop have been infectious diseases, which we have become fairly skilled at preventing since the development of microbiology and modern sanitation.
18. Diseases caused by malnutrition are also now uncommon when people have good government. But for various reasons outlined in chapters 10 through 12, we seem to be unable to apply the same preventive logic to a wide range of diseases caused by too much energy intake, not enough physiological stress, and other novel aspects of our environments.
19. These mismatch diseases are the ones most likely to disable you, kill you, and cost you money. The United States, for example, spends more than two trillion dollars a year on health care, nearly 20 percent of the country’s gross domestic product, and it is estimated that approximately 70 percent of the illnesses we treat are preventable.
20. In conclusion, although the human body has come a long way over the last 6 million years, its journey is far from over. But what is that future? Will we just muddle along? Will we succeed in developing new technologies to finally cure cancer, solve the obesity epidemic, and make people otherwise healthier and happier?
21. Or are we headed to a future like the one described in the movie WALL-E, in which we balloon into a race of fat, chronically ill weaklings who are dependent on medications, machines, and big corporations to survive? How can an evolutionary perspective help chart a better future for the human body? There is obviously no single approach to this Gordian knot, so let’s look at each of the options using the lens of evolution.
● VOCABULARY
deleterious: harmful often in a subtle or unexpected way
forager: one who look for forage as a food
trade-off: A balance achieved between two desirable but incompatible features; a compromise
decrepitude: the state of wasted and weakened
biped: a two-footed animal
type 2 diabetes: not necessarily but occasionally associated with obesity and the lack of physical activity.
celiac disease: an autoimmune disorder of small intestine caused by ingesting gluten.
morbidity: the condition of being diseased, the rate of disease in a population.
feedback loop of dysevolution: feedback loop itself is not a form of biological evolution ( hereditary) but an interaction between culture and biology, because we pass on the environments and behaviors to the next generation. “dysevolution” is a coined word, a harmful (dys) form of change over time(evolution), but not genetic variation. Type 2 diabetes is one of mismatch diseases of dysevolution.
weakling: a person or animal that is physically weak and frail.
Gordian knot: an extremely difficult or involved problem.
● UNDERSTANDING
1) In Par.4 underlined part: The intense surge of scientific progress in the last few hundred years means mainly “medical progress” and “industrial revolution” , but what are the medical progress and industrial revolution in specific?
ref. inoculation, antibiotics, disinfection, steam engine, locomotive, machinery plant, mass production etc.
2) In Par.9 underlined part: Why did Homo sapiens adopt farming rather than being hunter-gatherers despite the burden of hard work and famine?
3) In Par.17 underlined part: Do you think we can resolve the disease-inducing environment conditions like enticing TV ads on
foods, additives in food, stressful and sedentary work and so on? and how? For example, future advancement in medicine, efforts to educate people about diet and lifestyle, legislation for the public health and technological development are sort of approaches to the environmental causes?
● DISCUSSION
1) It took over 6 million years for the biological evolution of our body, but only several hundred years ( less than 0.01% of biological evolution time) for the drastic advancement of science which mostly blessed us. But as described in par.10, there arises an adverse effect as mismatch diseases. Do you think we can cure the mismatch diseases with the help of other would-be medical breakthrough in the future?
2) Aside from mismatch diseases, we are now facing other serious and imminent problems like environmental pollution, population explosion, widening disparity between rich and poor and so on, mostly derived from cultural evolution-related civilization.
I am wondering if we human beings are smart enough to overcome those Gordian knot difficulties? and how?
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