Weekly Digest: Our Evolutionary Past Is Killing Us Now and more

Added: 2026-05-11

[00:00:00]Natural selection has made us who we are, a species that's extraordinarily well adapted to the environment that we live in. Then we began to rapidly change our environment faster than we can adapt to it. Now our natural abilities no longer make us fit to live in the world we've created. Biologists call this the environmental mismatch hypothesis. In a new paper that just appeared, a group has collected the evidence that this is actually true. Let's have a look.

[00:00:33]Natural selection works by small changes in genetic codes. The changes that result in better chances of reproduction are more likely to pass on to the next generation. Over many generations, the species therefore becomes good at reproducing and so it becomes more numerous. And it does so by finding better ways to use nature for its purposes. We still adapt to our environment, but this genetic adaptation takes many generations to have noticeable effects. For example, that most Europeans can digest cow milk goes back to a genetic mutation that happened only about 10,000 years ago. Blue eyes, too, likely go back to a mutation that happened only 10 to 15,000 years ago, and light skin color about 5,000 years.

[00:01:20]Both are believed to aid the body to absorb sunlight. Parts of the African population have developed immunity to malaria and some populations have genetically adapted to living at high altitudes. But it takes thousands of years for such mutations to spread to a significant part of the population. The problem is now that we are changing our environment much faster than we can possibly adapt to it and we've changed it dramatically. Big parts of the world population now live in cities. We're surrounded by concrete rather than vegetation. The nights are no longer dark. The days are no longer quiet. The air carries all kinds of pollutants from car exhaust to nanoscopic plastic particles. And our ways of living today are entirely unnatural if you compare them with what our bodies evolve to do.

[00:02:12]Humans evolved to hunt and gather, not sit at a desk 10 hours a day, except for the breaks to doom scroll on the toilet.

[00:02:20]We evolved to chew and digest natural food, not heavily processed goo that contains god knows what. Women, the ones with uteruses, evolve to have babies, not to impress other women on Instagram.

[00:02:34]Our brains don't know how to deal with networks that connect millions of people. mine barely copes with group chats. So on the one hand, the environmental mismatch hypothesis sounds all too plausible. On the other hand, the plausible hypothesis are the ones we should be most skeptical of. In this case, it's because humans don't just adapt genetically. We also adapt epigenetically or just socially. For example, you could interpret the trend to working from home and more flexible working hours as a social adaptation that aligns us better with our environment. The authors of the new paper now collect the existing evidence across several areas. The first evidence is a decline in reproductive capability, especially in men. Multiple large studies have found declines in sperm count and sperm quality since the midentth century. These trends are statistically robust and have been reported by independent research groups.

[00:03:36]A second line of evidence is a decline in immune function. People in highly industrialized environment show higher rates of allergies, autoimmune conditions, and chronic inflammatory diseases. The third area is stress and brain function. Laboratory and field studies consistently show that urban environments increase physiological stress markers compared to natural settings. Chronic activation of stress responses is known to suppress reproductive hormones, impair immune responses, and affect cognition. These links are well established in physiology and neuroscience. The authors conclude that a growing body of empirical evidence suggests that environmental industrialization negatively impacts human biology, suppressing key biological functions essential for survival, reproduction, and therefore evolutionary fitness. I find this an interesting summary because a lot of people are concerned about the falling reproduction rate in the developed world, but we hear far less about the overarching problem of genetic maladaptation that affects our physical and mental health. I think the evidence is quite convincing, but what does it mean? It's not that humans are doomed, that modern life is inherently bad, or that we need to go back to the good old days when women popped out a baby each year, whether they wanted to or not.

[00:04:59]It's just that we aren't paying enough attention to our physical limits. We either have to restructure modern life so that it's better aligned with human well-being or we find a way to speed up human adaptation by genetic engineering until we're finally able to win a fight against exel sheets. The Fermy paradox is a question of why we haven't heard from any extraterrestrial species. The Milky Way has had billions of years to produce civilizations. So where is everybody? You can turn this question around and ask, given that we have not heard from any other species, what does this silence tell us? Well, the authors of a new paper just crunched the numbers and arrived at a slightly horrifying conclusion. The starting point in all discussions about the Fermy products is the Drake equation. That's an estimate for the number of actively communicating technological civilizations in our galaxy. The estimate comes from multiplying a bunch of factors like how many suitable planets exist, how often life begins, how often intelligence evolves, how often it becomes technological and then you multiply by how long such a civilization lasts. The authors of the new paper now instead ask given that we have not yet detected any signals from other civilizations, how long does a civilization last on the average? They plug in the best current numbers we have for the number of planets in habitable zones and so on.

[00:06:29]Then they calculate how long civilizations persist and the result is about 5,000 years. Yes, that's right.

[00:06:37]They say put in our estimates for the other numbers and you have to conclude that civilizations only keep up their space signaling activity for a few thousand years. If they're right, we may currently be in what historians will later call the final season. They also give a second more observationally flavored argument. Electromagnetic signals cross the galaxy in about a 100,000 years. So if civilizations last longer than this and broadcast detectably for a meaningful fraction of that time, we should have seen something by now. So this estimate is slightly more optimistic, but still it's rather depressing. Why might this be the case?

[00:07:15]What could be the reason why technological civilizations go dark so quickly? Scientists have proposed basically three different reasons. The first is self-inflicted extinction or near extinction. That might be war, accidentally released pandemics or environmental destruction that eventually erodess the capability of the species to survive at high technological standard. I think that this problem almost certainly befalls a lot of civilizations. They just fail to grow beyond a certain level of complexity.

[00:07:48]The second possibility is that there is some sort of external risk factor that we don't know of. Maybe supernovi explosions are much more frequent and more fatal than we thought. Maybe tiny black holes exist after all and eat up more stars than we thought, though I think this is unlikely. The third possible explanation is that civilizations survive, but they lose interest in space exploration. They spend all their time in virtual reality or they have crossed over to a post scarcity economy and can't be bothered lifting a finger if they have fingers.

[00:08:22]Of course, the problem might actually appear earlier. It seems that somewhere between having a habitable planet and having a truly interstellar civilization, there's a subtlet that almost no species completes it. This has been dubbed the great filter by Robin Hansen. the great filter might be because the origin of life is so unlikely. Personally, I think that's not the case. Indeed, in the past years, we've seen that complex chemical cycles that lead to reproduction seem to actually be quite common. However, the great filter might come at a later stage. The issue might be that for a species to reach a high level of technological sophistication, its members must be intelligent enough to coordinate their actions. As I said in a recent video, I doubt that humans are intelligent enough to jump that bar unless possibly we manage to use artificially intelligent systems to our advantage. In any case, what are we to make of this somewhat depressing paper?

[00:09:21]First of all, it must be said that the authors use optimistic values for the other parameters in the Drake equation.

[00:09:27]They take for example a large number of earthlike habitable planets in the Milky Way around 1 million and they take the probability that such a planet produces a technological civilization to be close to one. It's only then that you get the pessimistic constraints on the survival of a technological civilization though personally I think that these values are close to the correct ones. The point where I disagree with the authors is simply the question of what such a technological civilization would be communicating with. The authors as pretty much everyone else assume that technological civilizations would of course communicate with electromagnetic signals that we can measure. But I strongly doubt that we have yet developed the technology that an advanced species would be using. I think it's possible to communicate faster than the speed of light. And of course, if that's possible, that's what the aliens use to signal. We could be sitting right in the middle of a cosmic broadband stream and wouldn't know because no one on this planet believes faster than light signaling is even possible. I give this paper a five out of 10 rating on the meter. It's not wrong, but the authors do once again miss the obvious explanation for the silence, which is that we have not yet developed the right technology to receive the signals. And somewhere out there, an alien scientist is currently giving a lecture titled the Earth Paradox. Why haven't they answered? A few days ago, physicists at CERN announced that something isn't quite right. Yes, we have a new anomaly which hasn't happened for years. Or rather, it's the return of an anomaly that doesn't want to go away.

[00:11:19]Just what is the anomaly and what does it mean? I have a quick summary.

[00:11:24]Particle physicists biggest hope is currently that they'll find something wrong with the standard model of particle physics, which contains all the known particles, electrons, quarks, nutrinos, and so on, and the interactions between them. Because if that was so, if the standard model made a prediction that was clearly wrong, then we'd know there must be something else, something new to find. As it stands though, the standard model is holding up stubbornly, which strongly suggests that particle physics is basically over the end. This is why particle physicists pray there is some anomaly in the data, and now we have one. The new paper comes from the LHCB collaboration at CERN. They study the decay of a particle called a B meison.

[00:12:12]This is a short-lived composite particle made of two quarks which is sometimes produced in the collisions at the LHC.

[00:12:19]The B meison is unstable and decays after about a picoscond. This decay can happen in many ways. For this experiment, they look for a specific and rare decay channel in which the bottom quark that's contained in the B meon turns into a strange quark and produces two lepttons, usually muons. This type of decay is interesting because it involves virtual particles, which means that there are particles that appear temporarily but then disappear again.

[00:12:49]They're never measured in the detector, but they still contribute to the result.

[00:12:54]Any real particle like the ones in the standard model can also appear as a virtual particle. But if there are any further particles, these could contribute as virtual particles in the decay as well. And then the result would not be what the standard model predicts.

[00:13:12]To check this, they measure three things. how often the decay happens, how the decay products are distributed in space, and whether the behavior is the same for different types of lepttons like electrons and muons. Over the past decade, all three of these have shown small discrepancies with the standard model. These lingered around two to four sigma depending on how you look at it.

[00:13:36]Then a couple of years ago, this anomaly seemed to have gone away. And now it's back. But elsewhere, they find that the angular distribution of the decay products doesn't quite fit. And the discrepancy is at a statistical significance of four sigma. This is below the discovery standard, but it's more than an oddity. It's a proper anomaly. It's also about the same significance as the muon anomaly used to be. Yet, this was finally laid to rest properly this week. So, what are we to make of this? What could it be? The first and most exciting option would, of course, be that it's a hint of a new particle. Theorists have come up with two major explanations that fit the observations. They're called lepto quarks or Z prime bosons. These are not particles in the standard model. and if we found evidence for their existence that it strongly suggests that there are likely even more new particles out there. The second possibility is that this is a real anomaly. But the problem is that the prediction from the standard model isn't correct. Something is wrong with the calculation. So in this case, we wouldn't need new physics. Just fix the calculations. This is basically what happened with the muon anomaly. The third possibility is that it's just a data fluke that will go away. Particle physicists have found oddities with this decay sector for a decade or so. But the more you search for oddities in the data, the more you'll find. Personally, I think it's a case like this, the statistical significance isn't actually that high. It's artificially inflated because they're trying really hard to squeeze an anomaly out of the data. Yet on the other hand, maybe the reason they keep seeing odd things in this particular decay sector is that there is really something anomalous there. And if there is something new to find, if there really is new physics beyond the standard model, this is how you'd expect it to show up. This paper gets a five out of 10 on the meter. The data itself is almost certainly fine.

[00:15:49]When it comes to the statistical significance, well, seek and you will find. Basically, four sigma and particle physics is a bit like four stars on an online review. It sounds good, but you should read the comments. Thanks for watching. See you tomorrow.