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Craig Van's Deep Dives
AI Deep Dives on developing ourselves through health, wealth, and connection. This is the easiest way for me to listen to the AI Deep Dives that I generate before diving deeper into a field of knowledge, or alongside. If you find them interesting and useful too, enjoy.
Craig Van's Deep Dives
Darwinian Medicine: Your Body is Smarter Than You Think, Even When It's Sick | Ep10
Through the lens of evolution and natural selection, we explore why our bodies function—and sometimes malfunction—the way they do, offering a transformative new perspective on health optimization.
• Our bodies represent ingenious evolutionary compromises, not design flaws
• Symptoms like fever and pain often serve as sophisticated defense mechanisms rather than malfunctions
• The "smoke detector principle" explains why our defense systems sometimes overreact—better safe than sorry
• Many modern health problems stem from the mismatch between our Stone Age biology and contemporary lifestyles
• Understanding our dietary vulnerabilities as adaptations to ancestral food scarcity
• Iron withholding during infection as an example of the body's sophisticated pathogen-fighting strategies
• The accelerated evolution of pathogens creates a constant arms race affecting antibiotic effectiveness
• Mental health challenges gain new context when viewed through an evolutionary lens
• Physical "design quirks" like our choking risk and back problems represent evolutionary trade-offs
• Health optimization requires working with our evolved nature rather than fighting against it
Consider how your health decisions might change if you always asked not just what a symptom is, but how it might have contributed to survival in our evolutionary past, and how it interacts with your specific modern environment.
You work hard to be well-informed, right To understand the world around you and especially well to optimize your health. But even for those of you really deep into health stuff, what if the very reasons we get sick, the fundamental design of our bodies, actually holds a surprising key to feeling better? Today, we're diving deep into something truly fascinating. It's the intersection of Charles Darwin's theory of natural selection and human health. Intersection of Charles Darwin's theory of natural selection and human health. Our source for this exploration is a really foundational text in well, what's become a burgeoning field is called why we Get Sick the New Science of Darwinian Medicine, by Randolph Nessa and George Williams. Okay, so let's unpack this. Our mission today is basically discover why understanding our evolutionary past isn't just some academic thing, you know. It's actually a vital and often overlooked tool for understanding, improving and yeah, optimizing your own health and well-being.
Speaker 2:Exactly, and a key insight I think that comes out of this perspective is how it just fundamentally shifts your view of disease. It's not just seeing it as, oh, a malfunction, you know something breaking down in the system. It's seeing it as something deeply rooted in our evolutionary history. It sort of makes us ask questions that conventional medicine maybe doesn't focus on as much Like why hasn't natural selection just eliminated all this susceptibility to disease? Why do we age? Why this inevitable decline?
Speaker 2:And the answers, as Nessie Williams really detailed, often point to these careful biological compromises, these ingenious tradeoffs made over millennia. They're not just simple design flaws, and recognizing these compromises is absolutely crucial if you're serious about modern health optimization. Now, this deep dive, it isn't about giving specific medical advice, let's be clear on that. It's more about providing you with maybe a transformative new way of thinking about your body and illness. Like the authors themselves say that every expectation, that the pursuit of evolutionary questions will demonstrably improve human health. So this book it really aims to stimulate a different kind of curiosity about illness, you know, to encourage you to ask those deeper why questions and to engage critically with your health rather than just sort of accepting a diagnosis at face value.
Speaker 1:Right and one of the most, I guess, profound ideas, but also kind of liberating from this evolutionary view, is that our bodies aren't perfect machines, they're not flawlessly engineered for eternal health. In fact the authors, they highlight that the body is really a bundle of careful compromises and that immediately challenges that common assumption we often have that you know, natural selection is so powerful, it should have perfected us somehow, it should have eliminated every vulnerability, every little ape, every susceptibility to getting sick. We tend to think well, if evolution is so great, why are we still so fragile? Why do we still get sick so much?
Speaker 2:Yeah, it's a natural question.
Speaker 1:Think about something like our bones. They seem so robust, so impeccably designed right. The source even calls their designs exquisite, unmatched by anything humans have created. They're engineered with this tubular structure which maximizes strength to weight ratio. They're actually stronger than solid steel bars, pound for pound, which is amazing.
Speaker 2:It really is incredible engineering.
Speaker 1:And they're masterfully shaped for their specific functions. Thicker at the vulnerable ends where they bear weight, studded with these precise bumps for muscles and ligaments to attach, Even grooved to provide safe pathways for nerves and arteries. And the hollow space the marrow, that's a critical factory for new blood cells. But here's the catch, this intricate design it's optimized for survival and reproduction across our early life, not necessarily for perfect, disease-free function deep into old age. So if our bones are these masterpieces, why do we still get things like osteoporosis or brittle bones later in life, sometimes even after our reproductive years are over?
Speaker 2:You've really hit on a powerful almost, you could say, a brutal truth that this book reveals. Say a brutal truth that this book reveals when we look at the bigger picture. This whole idea of compromise is absolutely central to understanding why we still experience so many diseases, especially as we get older. Natural selection it isn't optimizing for a perfectly healthy, you know, super resilient 100-year-old. That's not its goal. It's optimizing purely for reproductive success. It's like a ruthless accountant, always weighing the benefits against the drawbacks, strictly in terms of passing on genes.
Speaker 1:Strictly passing on genes, yeah.
Speaker 2:So a gene that gives you a significant advantage for survival and reproduction in your early life, say up to maybe age 30 or 40, that gene will be strongly favored, even if it carries some kind of cost or vulnerability that only shows up much later, maybe it's 70 or 80. That's the core compromise, and it forces us to completely rethink what we even mean by a design flaw. It might not be a flaw at all from evolution's perspective.
Speaker 1:That's a huge shift in thinking.
Speaker 2:It really is. Think about the rabbit example. The authors use A gene that makes a rabbit more fearful, helps it avoid foxes. Fantastic for immediate survival right.
Speaker 1:Yeah.
Speaker 2:Helps it reproduce Makes sense, but that same heightened fearfulness might mean the rabbit doesn't forage as much, and that could lead to higher starvation rates during a harsh winter. It's a classic tradeoff Short-term survival benefit versus a potential long-term environmental cost. Wow, and this applies directly to us too. How so Well, even the traits that cause aging, the whole process of senescence. They might've had powerful benefits earlier in life. Scientists are now studying these pleiotropic effects. That means a single gene affecting multiple, seemingly unrelated traits at different life stages.
Speaker 1:Okay, like one gene doing multiple jobs.
Speaker 2:Exactly, and the source gives a really compelling example. With the DR3 gene. It increases your susceptibility to diabetes later in life, but paradoxically, it seems to provide a significant advantage in utero. It enhances the mother's ability to provision the fetus, making a successful birth more likely.
Speaker 1:Wow. So a trade-off right there Better chance of being born, higher chance of diabetes later.
Speaker 2:Precisely so. While it leads to a serious disease decades later, its early benefit for reproductive success was apparently so profound that it's been kept in our gene pool. This just highlights that our bodies aren't about perfect, infallible design. They're about optimal trade-offs in a complex, changing ancestral world.
Speaker 1:Okay. So the really important question then becomes how does understanding these evolutionary compromises actually change how we approach health optimization today? What's the practical takeaway?
Speaker 2:Well, it fundamentally shifts our perspective. It means recognizing that some vulnerabilities we experience they are just flaws to be fixed or eradicated. They might actually be fundamental, maybe even ingenious parts of our biological design that were selected for other critical reasons. So, instead of trying to fight against our evolutionary history as if it's just a list of defects, which is kind of how we often approach it, isn't it Like fix this broken part?
Speaker 2:Exactly. Instead, we're prompted to work with it to understand its logic. For instance, if aging is partly a byproduct of genes that helped us when we were young, our focus shifts. It's not about an unrealistic attempt to cure aging itself. It becomes more about understanding and strategically mitigating its downstream effects, like the various diseases that come with aging. We sort of accept that our bodies aren't immortal machines, but rather these incredibly clever bundles of compromises, and when you understand them through this evolutionary lens, it can guide us toward more effective, more proactive, maybe more holistic health strategies.
Speaker 1:So it's about maximizing well-being within the constraints of our evolved blueprint.
Speaker 2:Exactly Embracing our biological past to inform a healthier future. It's about working smarter with our biology, not just harder against it.
Speaker 1:OK, that makes sense. So, building on that idea of our evolutionary blueprint, let's talk about something else that's really counterintuitive, which is that many common symptoms we experience the things we rush to suppress with pills might actually be sophisticated, evolved defenses.
Speaker 2:Ah yes, this is a critical point.
Speaker 1:This deep dive reveals that sometimes what we see as the problem, our body actually sees as the solution, or at least part of the solution, a key part of its ancient defensive toolkit. And this, I think, profoundly impacts how we might approach health optimization Absolutely. Let's take fever. That's a perfect example. We instinctively reach for the Tylenol or ibuprofen, right Right, you feel like a high temperature is just bad, full stop. But the source makes a really compelling case that fever is actually a powerful, evolved defense against infection.
Speaker 2:Remobilizes the immune system, makes the environment hostile for pathogens.
Speaker 1:Exactly, and they cite specific studies. Pathogens Exactly, and they cite specific studies, like children with chickenpox who were given acetaminophen, that's Tylenol, took on average a full day longer to recover than kids on a placebo A whole day longer.
Speaker 2:That's significant.
Speaker 1:And another amazing study. Fifty-six volunteers were deliberately given common colds. The group that got a placebo, letting their natural fever response happen. They had a significantly higher antibody response, less nasal stuffiness and even spread the virus for a slightly shorter time.
Speaker 2:Wow, so the fever was actually helping them fight it off more effectively.
Speaker 1:It seems so, and Dr Dennis Stevens, a professor of medicine, is even quoted citing evidence that treating a fever in certain circumstances actually may make it more likely the patient will develop septic shock.
Speaker 2:Septic shock. That's incredibly serious.
Speaker 1:Right. It really makes you rethink the standard approach, doesn't it? Our bodies aren't just overheating randomly. They're actively creating a hostile environment for germs, using temperature like a weapon. So for health optimization. Maybe the first question shouldn't be how do I get rid of this fever, but why is my body doing this?
Speaker 2:That's a crucial shift in thinking.
Speaker 1:Or think about iron withholding. This is maybe even more subtle but incredibly clever A defense most people have no idea about. When we get an infection, our bodies intentionally actively lower the levels of iron in our blood.
Speaker 2:Why do they do that?
Speaker 1:Because iron is a crucial and scarce resource for bacteria. By cutting off the supply, our bodies are basically trying to starve out the invaders.
Speaker 2:Like cutting off their fuel line.
Speaker 1:Exactly, and the authors give some striking examples A patient with chronic TB whose infection got much worse after getting an iron supplement. They contrast Zulu men, who traditionally drink beer from iron pots and often get serious liver infections, with Maasai tribesmen who drink milk and rarely get amoebic infections. And when those Maasais were given iron supplements, a staggering 88% quickly developed an amoebic infection 88%.
Speaker 2:That's unbelievable. Just from adding iron.
Speaker 1:It really highlights the body's strategy. Unbelievable Just from adding iron. It really highlights the body's strategy, even those little changes in food preferences when you have the flu, craving low-ion stuff like tea and toast instead of a steak.
Speaker 2:Yeah, you never really feel like eating rich food when you're sick.
Speaker 1:That's part of this sophisticated strategy Is our body's ancient wisdom deliberately trying to starve the bugs. So what does this all mean for optimizing our health? It means we need to deeply rethink how we manage symptoms. Is our first impulse suppressant immediately, always the best move?
Speaker 2:And putting this in a broader context. What's really fascinating about these defenses is what the authors call the smoke detector principle.
Speaker 1:The smoke detector principle. Ok, explain that.
Speaker 2:Think about a smoke detector in your kitchen. It goes off all the time from a smoky toaster burned popcorn. Right, it's annoying.
Speaker 1:Definitely annoying.
Speaker 2:But it's absolutely crucial for withing you about a real fire. Our body's defense systems. They seem to operate in a very similar way. They're designed to err on the side of caution, to be oversensitive.
Speaker 1:So better safe than sorry, essentially, Exactly.
Speaker 2:They might trigger a strong, uncomfortable defense, even when the threat is relatively minor, because the cost of not reacting to a major threat could be catastrophic, Lethal even. Take allergies, for example Many individual allergic reactions, while they cause us misery or even severe distress, they're part of a system, our IgE antibody system. This system seems generally adaptive, maybe as a defense against potent toxins or parasitic worms, which are huge threats ancestrally, Even if its individual activations are sometimes an overreaction to something harmless today, like pollen or cat dander. The underlying system is still valuable, even if specific reactions feel like a mistake.
Speaker 1:Okay, so the system's good, even if it sometimes misfires on minor things.
Speaker 2:That seems to be the idea and this smoke detector logic. It applies profoundly to pain and fear too. The book emphasizes they are normal components of the body's defenses, not diseases themselves. They're critical alarm systems.
Speaker 1:Alarm systems okay.
Speaker 2:The source notes that people born without the ability to feel pain often die by age 30. They just don't get the warnings about injury. Imagine someone with a condition like syringomyelia, where they lose pain sensation in their hands. They might pick up a scalding coffee cup and burn themselves badly without even realizing it, because that critical pain signal is just missing.
Speaker 1:That's a terrifying thought.
Speaker 2:And fear. Similarly, it warns us of danger. It motivates us to escape or avoid threats. Blocking these fundamental signals without addressing the underlying cause can be really detrimental.
Speaker 1:So the million-dollar question then if these are such vital defenses, should we just let them run wild? Should we never suppress them?
Speaker 2:Well, that's the nuance. The authors definitely caution against, say, an unbending policy of encouraging fever. They acknowledge it has real costs. Fever depletes nutrient reserves much faster, about 20% faster. It can cause temporary male sterility and at high levels it can lead to delirium seizures, even lasting tissue damage.
Speaker 1:OK, so it's not harmless.
Speaker 2:No, it's definitely not harmless. It's about finding a sophisticated balance For health optimization. This means engaging in some deep critical thinking. Ask why your body is doing what it's doing. When is a fever actually beneficial, helping fight infection, and when does its cost start to outweigh its benefit, maybe becoming dangerous in itself?
Speaker 1:Right when is pain a useful warning and when is it chronic pain that's just debilitating and needs intervention.
Speaker 2:Exactly this perspective encourages a more nuanced approach. Sometimes you support the body's natural defenses, other times you intervene, but hopefully with a better understanding. You intervene when the costs of the defense are too high or when the defense system itself gets dysregulated and becomes harmful.
Speaker 1:So it's about informed decision making, not just automatic symptom suppression.
Speaker 2:Precisely this kind of critical inquiry, based on evolutionary understanding, can lead to more informed, more effective and definitely more personalized health practices.
Speaker 1:OK, that leads perfectly into the next big idea from Darwinian medicine, maybe one of the most impactful the concept of the modern mismatch, the idea that our bodies are, for the most part, designed for a Stone Age world, a world vastly different from the one we live in today.
Speaker 2:Yes, this is huge.
Speaker 1:And this radical difference, this mismatch between our ancient biology and our modern lives leads to what the authors call diseases of civilization. Let's break this down.
Speaker 2:Please do. It explains so much.
Speaker 1:Our pervasive dietary problems are just a glaring example. For almost all of our evolutionary history, things like fat, sugar and salt were scarce. They were precious, so it was always adaptive to crave them, to seek them out, even obsessively. Your ancestors who really went after every calorie, every bit of fat. They had a crucial survival edge in a world of scarcity.
Speaker 2:Absolutely Finding those energy-dense foods was key.
Speaker 1:But now, in modern societies, these things aren't just abundant, they're hyper accessible. They're engineered to be irresistible, they're everywhere, and the source states it bluntly An overwhelming amount of preventable disease in modern societies results from the devastating effects of a high fat diet.
Speaker 2:There's a direct consequence of that mismatch.
Speaker 1:Cancer, strokes, heart attacks, diabetes they're all tightly linked to these excesses that our bodies weren't designed to handle constantly. Think about this Hunter gatherers typically got less than 20% of their calories from fat. The average American diet today it's around 40%.
Speaker 2:Double. That's a massive difference.
Speaker 1:So this intense craving, which was once a lifesaver, it's now a major health liability. It fuels all these chronic conditions. So for health optimization, just understanding that deeply ingrained evolutionary craving is maybe the first step toward managing it in our modern food environment.
Speaker 2:Knowing why you crave it helps you deal with the craving.
Speaker 1:Exactly. And the mismatch isn't just about big metabolic diseases. It shows up in common, seemingly minor things too, like dental cavities. They were incredibly rare before agriculture, almost unheard of. They only became common when people started eating lots of maize and later with widespread sugar. Our teeth just didn't evolve to handle the constant acid bath from sugars and carbs, which are basically an environmental novelty at this scale. Our ancient mouth bacteria weren't ready for it. Our poor teeth. What about toxins? We actually evolved incredibly sophisticated ways to detoxify lots of natural plant toxins things in grasses, even dilute poisons in flower nectar that plants use.
Speaker 2:Our livers are pretty amazing. Detoxifiers for natural stuff.
Speaker 1:Right, but these novel toxins from things like PCBs, organic mercury, they're chemically very different. The authors say we have no enzymatic machinery designed to deal with many of them.
Speaker 2:Our bodies just don't recognize them as threats.
Speaker 1:in the same way, and we don't have a natural aversion. They don't necessarily smell or taste bad. To warn us off, you can't taste DDT or radioactive fallout, for example. So modern detox becomes a whole new ballgame for health optimization.
Speaker 2:A challenge our ancestors never faced.
Speaker 1:And this brings us to something really interesting about pregnancy, pregnancy, nausea, you know, morning sickness. It affects so many women. The book proposes it's actually a powerful adaptive defense.
Speaker 2:A defense how so?
Speaker 1:It suggested. It protects the developing fetus from toxins in the environment, especially in early pregnancy, when the fetus is most vulnerable to things that cause birth defects.
Speaker 2:That makes intuitive sense actually protecting the baby.
Speaker 1:A researcher mentioned. Margie Prophet gathered compelling evidence, including this really striking observation Women who don't experience pregnancy nausea are actually more likely to miscarry or to bear children with birth defects.
Speaker 2:Wow. So the unpleasant symptom is actually doing a vital protective job.
Speaker 1:Seems like it, a remarkable adaptation that causes discomfort but gives a huge survival advantage to the next generation, even something like myopia nearsightedness it's linked to modern life. Myopia nearsightedness it's linked to modern life. Arctic natives historically were rarely nearsighted, but when their kids started going to school, stuck in classrooms, reading books, doing close-up work, up to 25% became myopic.
Speaker 2:Just from schooling.
Speaker 1:Yeah, our eyes, they argue, simply weren't designed for prolonged confinement to classrooms and constant close work. They evolved for standing wide, open spaces Another mismatch.
Speaker 2:It's fascinating how deep these mismatches go and, placing this in the broader picture, they extend right into our life cycles, our fundamental biology For women. A really striking example is the link between modern menstrual patterns and cancer risk. The source is quite direct the more menstrual cycles a woman has, the more likely she is to get a reproductive system cancer.
Speaker 1:More cycles, higher risk. Why is that?
Speaker 2:Well, historically, women would have had far fewer cycles over their lifetime because of frequent pregnancies and long periods of breastfeeding. These breaks, these interruptions in the cycle, they seem to provide compensating repairs for the reproductive tissues. Time to heal and regenerate.
Speaker 1:Okay, like downtime for the system.
Speaker 2:Exactly, but modern conditions of your pregnancies, having kids later, shorter breastfeeding mean women now might have three or 400 menstrual cycles in a lifetime. That's an unprecedented number evolutionarily speaking, and this constant cycling without those normal breaks seems to impose a significant biological cost, contributing to higher rates of reproductive cancers.
Speaker 1:That's a really sobering thought. So how do we optimize health when our ancient biology is clashing so hard with our modern world? What do the authors suggest?
Speaker 2:Well for cancer risk related to cycles. They suggest diligently searching for artificial means of achieving the low cancer rates that come naturally to women in hunter-gatherer societies. It means understanding why those protective brakes exist at pregnancy, lactation, and finding ways to maybe replicate their benefits today, rather than just treating the cancer later.
Speaker 1:Proactive based on evolutionary insight.
Speaker 2:Precisely. And for diet, the advice stemming from that mismatch is clear and direct. The single thing most people can do to most improve their health is to cut the fat content of their diets. It's not just about calories. It's about getting our macronutrient balance closer to what our bodies are actually adapted for.
Speaker 1:Back towards that ancestral pattern.
Speaker 2:Right, and this mismatch perspective also sheds light on things like food restriction or dieting and using artificial sweeteners. Sheds light on things like food restriction or dieting and using artificial sweeteners. Our bodies might interpret deliberate dieting as a famine, triggering a metabolic slowdown and intense hunger and adaptive response to scarcity, making dieting even harder.
Speaker 2:Potentially yes, and artificial sweeteners they can trick the body. Sweetness always signaled sugar prompting metabolic preparation. If that signal is a lie, if no glucose arrives, it might mess up blood sugar responses and actually intensify hunger later, especially for quick energy. These subtle things show how our evolved responses can backfire in novel environments.
Speaker 1:So even seemingly healthy choices need evolutionary consideration for optimal health.
Speaker 2:They really do. Addiction is another profound example of a disease of civilization. Yes there are genetic predispositions, these genetic quirks, but these were likely a relatively modest problem before the reliable availability of beverages with at least several percent alcohol. Naturally occurring alcohol was rare low concentration.
Speaker 1:Right, you didn't have distilled spirits in the Stone Age.
Speaker 2:Exactly, and those genes that might predispose someone to addiction today. They might even have had positive effects ancestrally Perhaps a tendency to continue pursuing sources of reward despite difficulties. Great for persisting in hunting or forging, maybe, but potentially disastrous when faced with easily accessible, highly concentrated addictive substances.
Speaker 1:So again, the context changes everything.
Speaker 2:It does For health optimization. Just labeling addiction a defect misses that deeper biological context. Understanding the interaction between genes and the modern environment is key.
Speaker 1:But what about allergies? They seem to be skyrocketing. Is that a mismatch too?
Speaker 2:It looks like it. One clue is modern indoor living carpets, drapes creating breeding grounds for dust mites, increasing exposure. But another really compelling idea is the hygiene hypothesis. The thought is that our super sterile modern environments we don't get enough exposure to everyday microbes and minor toxins, so our immune systems and detox enzymes might be sort of unprepared or maybe miscalibrated, making us overreact when we do encounter something.
Speaker 1:Like the immune system is bored and looking for trouble.
Speaker 2:That's one way to think about it. The smoke detector principle applies again. The IgE system is useful, possibly against toxins or worms, but maybe it gets trigger happy in our clean world. So for optimizing health regarding allergies, it might involve not just symptom relief, but maybe environmental tweaks or even finding safe ways to train our immune systems better.
Speaker 1:Fascinating. Okay, let's shift gears a bit. We often think of evolution as slow right Millennia, but for pathogens, bacteria, viruses, evolution is happening incredibly fast, like warp speed compared to us.
Speaker 2:Oh, absolutely. It's a completely different timescale.
Speaker 1:And this creates a constant, relentless arms race that deeply impacts our health. Pathogen evolution is critical for health optimization strategies today. Bacteria, for instance they can evolve as much in a single day as we humans can in a thousand years. A thousand years in a day. That puts us at a massive disadvantage, a grossly unfair handicap, as the book says, we just can't adapt biologically nearly fast enough.
Speaker 2:So we rely on medicine and behavior instead.
Speaker 1:Exactly, and let's look at what this means practically the rise of antibiotic resistance. It's a stark, frankly, terrifying example of this arms race playing out right now. Think about this 1941, basically all Staphylococcus aureus that common bug causing wound infections, were vulnerable to penicillin. Just three years later, 1944, some strains had already evolved enzymes to break penicillin down, made it useless against them.
Speaker 2:Three years, that's incredibly fast.
Speaker 1:And today something like 95% of staph strains show resistance to penicillin. The story just repeats. Methicillin comes along in the 50s to fight resistance strains.
Speaker 2:And then we get MRSA, methicillin-resistant Staph, agurus.
Speaker 1:Exactly. Ciprofloxacin, introduced in the mid-80s with high hopes, now faces widespread resistance. One Oregon hospital saw resistance jump from under 5% to over 80% in a single year.
Speaker 2:In one year. That's evolution happening right in the hospital ward.
Speaker 1:It's happening in real time, constantly eroding our defenses, and even viruses like HIV, which evolve slower than bacteria. They still show this relentless adaptation. They evolve resistance to drugs like AZT. It might take months or years, not weeks like bacteria, but the principle is the same.
Speaker 2:Constant pressure, constant adaptation.
Speaker 1:Right Within one infected person, hiv replicates. Mutates, undergoes selection. The strains that can best overcome the drugs become dominant. The virus inside you can actually evolve to become more resistant or even more virulent during the infection.
Speaker 2:It's a battle within the body.
Speaker 1:A relentless battle where the pathogens are constantly adapting to whatever we throw at them. It forces us to constantly innovate, just to keep pace.
Speaker 2:And what's really striking about this battle, this arms race, is how selection can happen, not just between hosts, but really powerfully within a single host, and this often favors more virulent strains, ones that reproduce faster and cause more harm, because they're competing aggressively for your body's resources.
Speaker 1:Wait so they don't always evolve to be less harmful. I thought that was the conventional wisdom.
Speaker 2:That was the conventional wisdom, the idea that it's not in the pathogen's interest to kill its host too quickly. But that view is too simple. Simple If you have multiple strains competing inside you, the one that exploits your resources most ruthlessly and multiplies fastest might spread more copies of itself before you die or recover.
Speaker 1:So being more aggressive can be an advantage within the host.
Speaker 2:Yes, Selection within the host can favor higher virulence. Selection between hosts like if being too sick prevents you from spreading it might favor lower virulence. It's a complex balance.
Speaker 1:Okay, that makes sense. It's not just one simple direction.
Speaker 2:Definitely not. And this leads to the critical question what are the health optimization implications of this constant arms race? What should we be doing?
Speaker 1:Right. What's the takeaway?
Speaker 2:It means we have to be incredibly strategic and careful with antibiotics. It means we have to be incredibly strategic and careful with antibiotics. The authors suggest if one antibiotic doesn't alleviate your disease, it may be better to try another, instead of simply increasing the dose of the first.
Speaker 1:Trying a different weapon instead of just hitting harder with the same one.
Speaker 2:Exactly and crucially, we must avoid long-term exposure to antibiotics whenever possible. That practice directly selects for resistant strains, making them stronger and more common everywhere in the environment and in us.
Speaker 1:Like taking daily penicillin for years, even for a good reason like preventing heart valve infections.
Speaker 2:That constantly promotes resistant bacteria and we're often unknowingly exposed through the food chain to farm animals given antibiotics routinely.
Speaker 1:So it's not just the pills we take ourselves.
Speaker 2:No, it's a much bigger system. This constant evolutionary pressure requires us to adapt our medical strategies continuously. Pathogens aren't static targets, so for health optimization we have to acknowledge this dynamism. Use interventions like antibiotics judiciously. Support public health efforts that account for evolution. Invest in new ways to fight these adapting threats.
Speaker 1:It really underscores that health isn't just personal, it's ecological, it's evolutionary.
Speaker 2:Beautifully put. It absolutely is.
Speaker 1:Okay. So beyond physical health and germs, this evolutionary lens also gives us really profound insights into our mental well-being. It suggests it's not always just about broken parts or simple chemical imbalances. It's also about understanding the adaptive functions of our minds and emotions.
Speaker 1:A much needed perspective in mental health, just like pain and fear are seen as defenses for the body, maybe other emotions, like sadness or even what we call depression, have or had adaptive roles, roles the authors propose depression might be a dysregulation of a normal capacity, or maybe even an involuntary signal of submissiveness in social hierarchies, a way to avoid conflict or conserve energy when things seem hopeless.
Speaker 2:Reframing it from pure pathology to potentially dysregulated adaptation.
Speaker 1:Right, which could radically reshape how we view mental health challenges, moving beyond just it's broken to considering an evolved, albeit maybe now problematic, function.
Speaker 2:Yeah, and this brings us to a really crucial point. Especially now, with modern drugs, with psychotropic medications, we're gaining this unprecedented power to adjust mood as we choose.
Speaker 1:We can dial up happiness, dial down sadness, potentially, Potentially.
Speaker 2:But the huge question this raises for health optimization is is it wise to eliminate normal low mood If sadness actually serves a function, maybe signaling that we need to pull back from something unprofitable, leading us to reevaluate, or just conserving energy during stress or loss?
Speaker 1:Then suppressing it might have hidden costs.
Speaker 2:It might. People intuitively feel it's wrong to just artificially change mud in some situations, but we need a strong medical argument against the appeal of instant relief. The only sound medical reason not to use such drugs is if they interfere with some useful adaptive capacity.
Speaker 1:So it's a major ethical and practical question for mental health optimization when does alleviating suffering cross the line into interfering with an adaptive process?
Speaker 2:A very tricky question.
Speaker 1:And it's not just mental health. Even our physical bodies are very structured, carries, these evolutionary legacies that, while amazing overall, lead to some common problems. The quirks, the scars of evolution.
Speaker 2:Ah yes, the tradeoffs made visible.
Speaker 1:Like our choking hazard. It's bizarre right that every particle of food and drink has to pass over the orifice of the trachea, our windpipe.
Speaker 2:Food and air crossing paths Seems like a bad design.
Speaker 1:And it's apparently aggravated by modifications to facilitate speech. Other mammals their passages don't cross like that. Human babies can drink and breathe, but once we start talking the larynx drops, increasing choking risk for the huge benefit of complex speech.
Speaker 2:A trade-off for language Fascinating.
Speaker 1:Or the blind spot in our eye. Light has to pass through nerves and blood vessels before hitting the light-sensitive cells. This weird inside-out retina creates a blind spot where the optic nerve leaves.
Speaker 2:Our brain cleverly fills it in, but it's still an imperfection.
Speaker 1:Definitely. Then there's the appendix Basically a leftover, a vestige of a larger digestive organ from early ancestors who ate tough plants.
Speaker 2:Doesn't do much for us now.
Speaker 1:Except, as the book says, it enables us to have appendicitis, a potentially deadly inflammation from an evolutionary remnant. Thanks evolution and back pain so incredibly common. Thanks, Evolution and back pain so incredibly common. It's a direct result of turning a horizontal four-footed animal into an upright two-footed one.
Speaker 2:Standing tall has its price.
Speaker 1:All that weight compressing the lower spine, the pelvis-resisting forces it wasn't originally designed for. It's a massive strain from a relatively rapid evolutionary shift. These are deep legacies.
Speaker 2:And connecting this back to the bigger picture, shift. These are deep legacies and connecting this back to the bigger picture. Understanding the adaptive functions even of unpleasant emotions is absolutely vital for psychiatry, for mental health optimization. Just like knowing why we cough or vomit helps internal medicine treat things better, understanding the evolutionary roots of emotions gives us a crucial framework in which pathopsychology could be studied, like pathophysiology.
Speaker 1:Studying disordered minds like disordered bodies with an understanding of normal function.
Speaker 2:Exactly. It helps us try to distinguish between true disorders, where something is genuinely broken, and dysregulations of normal, albeit perhaps unpleasant, adaptive responses. For instance, many excessive fears or anxieties today seem deeply related to these prepared fears of ancient dangers Darkness, snakes, spiders, heights being alone.
Speaker 1:Things that were genuinely life-threatening for our ancestors.
Speaker 2:Right. But now, in our relatively safe modern world, these ancient fears mainly cause unwanted anxiety and distress. Understanding their origin helps contextualize them.
Speaker 1:That leads to another question what about sleep? How does that optimize health? From an evolutionary view, seems like just wasted time, vulnerable time.
Speaker 2:Ah, but it's far from just inactivity. Sleep seems crucial for complex cellular maintenance like DNA repair, and maybe for sophisticated memory work, consolidating important stuff, purging the irrelevant. Some theories suggest these deep maintenance tasks work better when the brain isn't busy processing the outside world, so it gets confined more and more to sleep.
Speaker 1:Doing essential housekeeping while offline.
Speaker 2:Kind of, and its importance is underlined by the fact that depriving animals like cats in experiments of dreaming sleep causes severe psychopathology. They became hyperactive, hypersexual, their lives shortened.
Speaker 1:So REM sleep is doing something critical.
Speaker 2:Absolutely so. If sleep evolved for these vital active functions, understanding them is key to optimizing our rest for overall health, mental and physical.
Speaker 1:Makes sense Now. The book even touches on really sensitive topics like child abuse through an evolutionary lens. How does that work?
Speaker 2:Yes, it's a difficult but important area. Studies by psychologists Daly and Wilson found a really striking, statistically significant pattern the risk of fatal child abuse for kids living with one non-genetic parent, a step-parent, is 70 times higher than for kids with both biological parents 70 times.
Speaker 1:That's enormous.
Speaker 2:It is, and this holds even when controlling for things like poverty or mental illness. It strongly suggests that kinship, our evolved sense of relatedness, plays a powerful underlying role in parental investment and protection.
Speaker 1:Even if it's deeply uncomfortable to acknowledge.
Speaker 2:Extremely uncomfortable and this perspective absolutely does not justify the behavior in any way. Let's be crystal clear. But it does provide a potential biological angle for understanding a complex social problem. It might offer insights into underlying risk factors which could perhaps inform prevention strategies for health optimization in that broader sense.
Speaker 1:Understanding the roots, to better address the problem.
Speaker 2:Potentially. And despite dwelling on these imperfections the choking risk, the appendix, back pain, the author's stress we shouldn't overlook the truly remarkable excellence of our adaptations overall. Our oversized brains yeah, they made childbirth harder, but they also made us the dominant species cognitively, enabling everything we do. Our longevity is impressive compared to other mammals our size.
Speaker 1:Good point. We shouldn't just focus on the flaws.
Speaker 2:No, this evolutionary perspective really urges us to appreciate the intricate, often brilliant design of our bodies, not as flawless, but as marvels of compromise and adaptation, shaped by natural selection and recognizing this inherent biology. It's like a powerful compass. It guides us to work with our evolved nature for optimal health and well-being in this modern world we've created.
Speaker 1:Okay, so, wrapping this all up, what does this really mean for you, the listener, and how you approach your health? We've taken quite a journey, haven't we, into the origins of sickness and health through this Darwinian medicine lens, exploring how our bodies are, this testament to trade-offs, amazing adaptations and these ongoing arms races.
Speaker 2:It's a rich perspective.
Speaker 1:From rethinking symptoms like fever and pain as defenses, to understanding the deep roots of diseases of civilization, diet issues, allergies, even mental health challenges. This evolutionary view gives us a powerful new framework. It shifts our focus, doesn't it, from just treating symptoms to understanding their purpose, from blaming our bodies for flaws to appreciating their ancient, often brilliant design. And maybe from seeking perfect, impossible health to striving for optimal adaptation and resilience in our modern lives.
Speaker 2:Exactly, and I think a key insight from this whole deep dive is just the sheer power of this framework for actual human health optimization. It really suggests that by recognizing the evolutionary pressures that shaped us, we can make significantly more informed choices about our lifestyles, our medical treatments, even how we relate to our own bodies and their sometimes weird response.
Speaker 1:Our own choices, yeah.
Speaker 2:The authors of why we Get Sick. They can see that science is full of people proving things impossible right before they happen, especially regarding lifespan extension. They're cautious about radical life extension claims, but they strongly emphasize the very real likelihood of postponing or preventing many diseases of senescence, the illnesses of old age, simply by better understanding our evolutionary heritage.
Speaker 1:So maybe not living forever, but living healthier for longer by understanding our past.
Speaker 2:That's the core message. I think. Understanding our biological past allows us to better navigate our present and future health challenges, not just react blindly to them.
Speaker 1:So, as we wrap up this deep dive, here's maybe a final thought for you to consider, something to mull over. How might your daily health choices, and maybe even your conversations with your doctor, how might they fundamentally change if you always ask not just what is the symptom or condition or what's it for physiologically, but also ask how might this trait or this vulnerability have actually contributed to reproductive success way back in our evolutionary past? And how does it interact with my specific modern environment right now?
Speaker 2:That's a powerful pair of questions.
Speaker 1:It's challenging, right, but ultimately, maybe really empowering. A way to think about your well-being that invites you to see your body not as just a collection of parts that break, but as this masterpiece of evolutionary engineering, perfectly adapted maybe for a world that's gone, but wonderfully capable of thriving in the world we have now, if we just understand it better.