How Evolution Didn't Prepare Us for Modern Lifestyles

Evolution didn’t prepare our bodies for modern life.

We live in an age of unprecedented abundance, where once-scarce resources are now everywhere.

In much of the world, food and drink are exceedingly plentiful. Interpersonal communication has gone from close-knit families to worldwide social networks. We now get vastly more light in 24 hours than ever before. And as lifespans go up, even time itself has increased.

While such abundance is beneficial, it also creates problems for our bodies and minds, which haven’t had time to catch up.

Overstimulated reward systems. Disrupted circadian rhythms. Undermined social connections. Many of the modern conveniences and artifacts of human progress can negatively impact our well-being. We encounter these issues every day, often without thinking about them. But whether we choose to acknowledge them or not, they do impact us.

While we can’t accelerate human evolution (yet), we can help ourselves out.

Every year new scientific research reveals more about the impact of modern life on our well-being. And every year we learn a bit more about how to prevent and modulate those effects.

We’ve compiled a few of the more common of these effects – the modern lifestyle that impacts our health and well-being on a daily basis. We look at what humanity evolved to handle, where things broke down along the way, and what can be done to help ourselves out.

In summary, these experiences are:

• Drinking alcohol: Our human ancestors evolved to break down the ethanol in rotting fruit during times of scarcity. But now we drink processed alcohol with much higher quantities of ethanol and other byproducts.
• Eating modern food: Early human food consumption was heavily influenced by survival needs that simply don’t exist for most modern communities. Now, we have an abundance of highly palatable foods that tempt our taste buds and over-stimulate our reward system.
• Sleep and artificial light: Our circadian rhythm has evolved over millennia but isn’t adapted for the artificial lights we encounter every day, disrupting our crucial sleep cycles.
• Being social vs. social media: Socialization is a survival tactic, but the human brain can only handle a certain number of meaningful connections. The unfathomable scale, engineered experiences, and forced hierarchies of social media can supplant and break down these connections.
• Aging: Living a longer life has had tremendous benefits to humans, but our bodies were not prepared to age for this long. Of course, longer lifespans are a good goal, so how do we make the most of those added years?

Drinking Alcohol

How We Evolved

Our ability to break down alcohol developed long before we started making beer and wine.

For our primate ancestors, the primary source of ethanol– what we commonly refer to as alcohol – came from fruits. As they were trying to adapt to a terrestrial lifestyle, it was the rotting fruits falling from trees that kept them full when food was scarce on the ground. Because these fruits were undergoing fermentation, they contained small yet meaningful quantities of ethanol. Our ancestors had to develop the ability to break down that ethanol more efficiently, which they did as a result of evolution.

A 2014 study (citation) tested this theory by measuring the ethanol metabolism rates of older and older versions of a common alcohol dehydrogenase enzyme (ADH4) from primate ancestors along a 70 million-year timeline. And indeed, a genetic mutation 10 million years ago conferred on our ancestors the ability to process ethanol particularly efficiently.

Where Things Broke Down

Fast forward to the present day, and even one glass of beer or wine has far more ethanol than the rotting fruit our primate ancestors were eating off the ground. This creates a problem. We evolved the ability to metabolize small amounts of ethanol, but the excess ethanol of human-made beverages creates a burden our bodies are not equipped to deal with.

This in part explains why alcohol – along with its metabolic byproduct acetaldehyde – can be so harmful to our bodies. Alcohol was a relatively uncommon toxin until just a few thousand years ago. Now we drink it regularly.

How We Can Adapt

Despite our bodies’ lack of preparedness, drinking alcohol has become a critical element of human social life. For many people, it fosters our ability to connect with others and remains an essential part of our cultural traditions. So how do we adapt?

The primary answer isn’t surprising: it’s moderation. Striking a balance between social enjoyment and bodily impact requires regulating alcohol consumption to levels that are consistent with healthy living given your own personal situation. That takes deliberate – and sometimes difficult – effort. It may mean not drinking at all. The CDC’s guideline on moderate drinking is a great place to start to learn more.

In addition to moderation, mindful drinking tips like stopping drinking earlier and consuming food with alcohol can help as well. The more we learn about alcohol and its effects on our bodies, the better prepared we are to handle it. And the science is not stagnant in this area. Novel alcohol research continues to this day (citation), with more to come.

Eating Modern Food

How We Evolved

Have you ever felt the urge to peek into your fridge before bedtime for leftovers? You’re not alone. The activity in your brain that creates craving and snacking behavior is innate – having evolved many thousands of years ago to meet the needs of the time.

Under immense pressure to forage for food while trying to evade predators, our early ancestors evolved to crave high-fat foods. They didn’t know when the next meal was coming, and fatty foods would have been beneficial for them to store energy in times of danger and scarcity. Their brains evolved to reward seeking those types of high-fat foods.

Today, we can see how those evolutionary patterns persist. Researchers have shown how high-fat and high-sugar foods can trigger cravings and snacking due to the effect they induce on dopamine, the neuromodulator responsible for making us seek more. A 2020 study published in the journal Current Biology demonstrated this by feeding high-fat and high-calorie foods to mice and comparing their behavior to mice with a healthy diet (citation). The dopaminergic signaling was over-stimulated in the group consuming a fat- and calorie-dense diet. In turn, their eating schedule was disrupted, and they began snacking more frequently.

Where Things Broke Down

In contrast to prehistoric times, a decadent brownie or a bag of barbecue-flavored chips is now just a few steps away in the kitchen. That level of abundance is just not something we evolved to handle. It turns our reward-seeking behavior from a positive to a negative, and it puts the system on overdrive.

Modern foods are specifically engineered to trigger our reward systems with fat, sugar, unnaturally satisfying textures, etc. (citation). These processed foods are so stimulating to our brain’s reward system that they blunt it over time, requiring more and more food to activate it in the future. One study showed a significant decrease in dopamine availability in obese people (citation), supporting the idea that the more frequently and regularly you consume processed food, the less pleasure you get from the same amount, driving you to eat even more.

How We Can Adapt

How can we break this vicious cycle? There is no magic bullet, but we can adjust our eating habits by shifting towards practices proven beneficial by science.

While it’s easier said than done, slight lifestyle changes through diet and exercise help recover the dopaminergic response naturally. For example, protein-rich foods, such as legumes, eggs, turkey, beef, and dairy products, contain the amino acids tyrosine and phenylalanine, known to regulate dopamine production (citation, citation). In addition, removing energy-dense and processed foods from our pantries can help mitigate the consequences of late-night cravings. So too can adhering to healthy dietary practices like eating on a defined schedule and having set mealtimes.

Mindfulness practices are also gaining recognition as a way to alleviate cravings. A set of case studies (citation) employed decentering to demonstrate reduced compulsive eating behavior. When participants objectively observed their own reactions to food stimuli and acknowledged the transient nature of these cravings, the initial impulses were blunted over time. While these studies were conducted on relatively small groups of participants, mindfulness action should be explored further as a potential supplementary method to combine with a healthy diet and exercise.

Sleep and Artificial Light

How We Evolved

If you’ve ever gone camping, you probably experienced feeling sleepy earlier than usual, especially in the absence of your technological gadgets. This is your body reverting to the factory settings of its biological clock.

Humans harbor a distinct circadian rhythm with biochemical feedback loops that regulate levels of wakefulness in a little-over-24-hour loop, depending on the natural lighting in the environment. Basically, our biological clocks program us to be awake in daylight and sleepy at night under normal circumstances.

At least two theories have been proposed as to why we evolved to have our distinct biological clock. The restorative theory (citation) suggests that our ancestors needed sufficient sleep to minimize energy demand and expenditure at night simply because finding resources would have been more challenging in darkness. The adaptive theory (citation) describes sleep as an adaptive function to remain silent and inactive at night when we are most vulnerable to predatory attacks.

Where Things Broke Down

Unlike the prehistoric times, the present day is abundant in resources and relatively safer at night. We are also surrounded by artificial light from our phones, laptops, TV, and so on. Our interaction with technology means our light exposure is irregular, but there is substantial evidence that artificial light at night suppresses the secretion of melatonin, which disrupts our sleep cycle (citation). Many of us are in the near-constant presence of artificial light, deprived of the rejuvenating functions of sleep and with a disrupted circadian rhythm.

How We Can Adapt

While our bodies have not yet evolved to compensate for that prolonged disruption, regulating exposure to light (especially the blue wavelength that matters for the circadian rhythm) can help restore a healthy sleep and wake cycle. This can help you stay alert and focused during the first half of the day and more relaxed and ready for rest in the second half. We can achieve this by viewing sunlight early in the morning and minimizing artificial light exposure at least one hour before bed (citation).

Being Social vs. Social Media

How We Evolved

Social interactions have always been integral to our well-being. A multitude of research (citation) and systematic reviews (citation) indicate a strong correlation between social isolation and overall health and lifespan, mainly due to a neuropeptide called tachykinin that disrupts neural circuit function when upregulated (citation).

Clearly, the human brain adapted to socializing as a survival tactic. A study in the scientific journal Nature proposed a model suggesting the need for primates to become social beings with the mindset of “safety in numbers” (citation). As they switched from nocturnal life to diurnality, they became vulnerable to a wide range of predators and thus had to live in packs. According to another Nature study, as hominids continuously evolved language and communication skills, they were able to share ideas and develop tools fit for a terrestrial lifestyle (citation).

While the brain adapted to exhibit prosocial behavior in small to moderate groups, its ability to interact with large groups remained limited. Evolutionary psychologist Robin Dunbar conducted pioneering research in this field by correlating the brain size of various primates and their interaction quota, resulting in Dunbar’s number, suggesting that the human brain is roughly limited to 150 meaningful connections. In other words, humans struggle to cooperate and maintain groups larger than 150.

According to evolutionary psychologists Sarah Hill and David Buss (citation), socialization also served a function for our ancestors to determine their status in the group hierarchy and strive to avoid being abandoned by the group.

Where Things Broke Down

How do these facts relate to the social lives we lead today? While comparison helped our ancestors strive to improve in order to maintain their place in constricted social circles, our brain runs the same comparison with the millions of people we could potentially follow on social media. The technology gathers an astronomical number of people – who would not have been able to coexist seamlessly in nature – on a virtual platform. While it certainly does open our eyes to new and diverse experiences, the downside is that our brain primitively compares us to far too many others than we can handle. Viewing so many other people’s lives all at once – exacerbated by the unrealistic curation inherent in social media and influencer culture – leads to anxiety, feelings of inadequacy, and depression (citation).

How We Can Adapt

Fortunately, we can reverse the harmful effects of social media by regulating how much time we allocate to it and the type of content we expose ourselves to. If we do this, we might be able to use social media in a positive way: as a means of accessing helpful information and connecting with people.

The obvious solution is to limit our time on social media. The data bears this out. A 2018 study reports significant improvement in feelings of loneliness and depression in participants who limited social media time to 30 minutes per day for three weeks (citation).

In addition to time management, though, regulating the content you follow can also materially improve your mental health. Recognize what type of content evokes uncomfortable feelings and replace that with more positive and uplifting content.

Finally, employing a conscientious “name it to claim it” mentality can be helpful as well. By explicitly telling yourself that the people you are following on social media are not an actual representation of a social group to compare yourself to, you can disrupt feelings of inadequacy that may arise from subconscious comparison.

Aging

How We Evolved

Humans did not have a long life expectancy until recently. Predators, exposure, disease, malnutrition, and more all kept life expectancy low for a long time.

And even though it rose relatively steadily for the last few thousand years, it’s only very recently that life expectancy has truly exploded. In the 20th century alone, the US saw a sharp increase in average life expectancy: from 46 to 74 in men and 48 to 79 in women.

Where Things Broke Down

While it’s definitely a common wish to lead longer lives, the human body is still relatively new to the concept. That’s why the body hasn’t evolved the machinery to maintain its integrity for that long.

The result is a general decline in health around 30 years, which has been shown to particularly impact hearing (citation), visual acuity (citation), muscle strength (citation), and the immune system (citation). In addition, the implications of the items we previously discussed could accumulate in the body and manifest at later stages of life in the form of cardiovascular diseases (citation), hypertension (citation), osteoarthritis (citation), and diabetes (citation).

How We Can Adapt

Obviously, there is no magic elixir to keep our biological age at 20-30 indefinitely, but we can do things to better utilize the limited time we have to lead a fulfilling life. Fortunately, science is constantly working to reveal how our bodies process substances and stimuli, which can help solve health problems previously deemed unsolvable.

Health decline is a natural process, but we can significantly slow down that decline by establishing healthy habits and moderating practices that have harmful long-term effects. This heavily relies on our lifestyle choices and daily habits, including the previously-mentioned science-based suggestions regarding diet, sleep, exercise, social interactions, and regulating alcohol consumption.

Making conscious choices to implement healthy practices is easier thanks to reliable and accessible scientific research. We can significantly improve our overall health and lifespan by keeping up to date with scientific information. Indeed, evolution endowed us with the cognitive skills to put that information to use. So let’s go out and use it.