If true that it enhances healthy people, I wonder why we didn't evolve to produce more of it? Why didn't mice?
Maybe side effects? Maybe being too smart is an evolutional disadvantage on an individual level or in small groups? Maybe producing the hormone is too costly?
Seems like too easy of a "hack" to improve such highly optimized systems such as humans or mice.
I think there's a fallacy there: the joint assumptions that evolution has "already happened" and has produced fully optimized systems.
If we adopt a flawed "evolution as agent" model, there is zero evidence that it has tried everything, or even most things, in order to optimize species.
If we adopt a more accurate model, evolution doesn't optimize or produce optimized systems. It can (but does not always) produce reliable (as in reproduction/survival) systems. There are plenty of ways Klotho could be beneficial but not produced by selection: mutations which increase production of this chemical may have occurred but had negative effects on fitness, or may have happened to occur along with other mutations with negative effects; there may not be any mutations which increased production (it's tempting to think of e.g. hormone levels as "knobs" for which there are mutations that turn up/down output, but that metaphor completely fails in many cases); beneficial mutations to increase Klotho production may be possible but not have occurred in nature because of chance or complexity of changes required to actually manifest the "right" change.
The article mentions people who produce more Klotho, so clearly that variation has occurred:
> Some people carry a genetic variation that causes them to produce higher levels of Klotho than average in their bodies. Dr. Dubal and her colleagues identified a group of healthy old people with the variant and tested their cognition.
> They scored better than people who make an average level of Klotho. “It’s not like they didn’t undergo cognitive decline,” said Dr. Dubal. “It’s just that they started off higher.”
I'm a bit torn between your perspective and the parent comment. I accept the logic of your argument.
But that doesn't mean the parent comment couldn't be correct. Klotho could have side effects (doesn't everything have side effects?) and that could be why we (and mice) don't produce more of it. I don't think that's a bad hypothesis.
Of course it's just a hypothesis and, as you point out, it doesn't logically follow that our production of Klotho is perfectly optimized (Optimized for what? Fitness? Fitness is a moving target). But, on the whole, I'm skeptical of a hormone that makes us smarter and wards off brain degeneration but does nothing else.
There might also be a mob-reaction against beeing gambled too much, resulting in conspiracy theorys and goverments built to execute those framed in those in conspiracies.
In other word, hacking your fellow mens livelihood might shorten your longterm survival.
If you are smart, you do not work hard.
Instead, it turns into a sort of competition, who has to work the least, to extract the most benefits and do the least amount of work. Hacking in that regard, is a competition of parasites.
My pet theory is, that having suffered for nearly 10.000 years under castes of priests and noble men unwilling to lift a finger, humanity has developed a near instinctive hatred for "parasitic" entitys, who ledge themselves to society extracting value without returning anything to society.
The moment, external circumstances in such a system create a down turn, the whole thing explodes, viciously attacking the non-contributors, trying to exterminate them and redistribute there ill gathered gains back to society.
Take a look at france during the revolution for example. Sometimes the parasites, manage to redirect the hatred towards internal or external outgroups, like the jews in germany during ww2, but in the end, the mobrule undoes most of the parasitic growth anyway by sheer brute force and endurance of turmoil.
Why haven't we evolved photosynthetic skin? Why haven't we evolved the ability to regrow lost limbs and organs? Why haven't we evolved a better defensive system, delivering us from sickness and cancer?
The answers to all those questions are the same: evolution doesn't "care" about you being comfortable, or optimized. I quoted "care" because evolution is a process; it lacks a conscience and thus it cannot "care". But it has drives. Regarding you, evolution's drives are that you pass your genetic material down to your offspring, that you have as many offspring as possible, and that they repeat the cycle after you are gone.
All the benefits that you as an individual get from are either a direct consequence those drives, or a happy random accident, because there's a high degree of randomness involved.
The fact that there's randomness, plus the fact that individual comfort or productivity is not a drive, means that there could be places where us humans can "supplement" evolution - that's one of the roles of modern medicine. I'm not saying this particular compound will work as advertised; just that the room for improvement exists.
I agree. Personally, I'm very annoyed with myself at times at the tendencies that drive me that are constantly at odds with productivity or good health etc etc. as like you said it, evolution does not have the capacity to care about the desires of humans. In a macro-scale sense, humans figuring out how to overcome this is a type of evolution via intellect possibly as our intellect results in tools etc. via evolution.
It might also be something like limited resources as a driver in environmental pressure such as food being available to older members that did not pull their weight and a tribe had a better survivability if these individuals naturally died off earlier than later.
Bad examples. Increasing the amount of some substance produced vs re-growing limbs?
Evolution is an optimization process. It can get stuck on a local maxima, but it's not a local maxima, if it can be trivially improved upon with no harmful side-effects. And it's not like producing more Klotho requires complicated mutations that are unlikely to happen. We know they happen.
So - asking why it's not already widespread is perfectly reasonable. It probably involves some trade-offs.
Although I also disagree with the GP, I think phrasing evolution as an optimization process is a mistake. Evolution is a diversification process that exploits variation within a population to make the population as a whole more resilient to changes in the fitness function.
The net result is the same -- even if Klotho production is neutral in the fitness landscape, you would expect it to be quite common. For it to be naturally as rare as it is probably implies a significant fitness cost in other ways.
It could very well be, however, that the particular problems with Klotho production are factors which are no longer relevant in the current fitness landscape, but we (and other animals) evolved a certain resistance to Klotho production that has yet to be overcome by the irrelevance of the underlying costs. For example, if Klotho production significantly reduced reaction times or the time it takes to ramp up adrenaline production, then it might be that we are at a point where the downsides are no longer as relevant as they once were.
> Regarding you, evolution's drives are that you pass your genetic material down to your offspring, that you have as many offspring as possible, and that they repeat the cycle after you are gone.
It also doesn't help that lower IQ correlates to higher offspring, according to some studies.
That’s only true since the 1800’s. From the dawn of agriculture to industrial civilisation there might have been very weak selection for intelligence. It can’t have been strong because otherwise we’d all be Von Neumanns.
Gregory Clark's work on social mobility is fascinating if you find this topic interesting. Start with either A Farewell to Alms or The Son Also Rises.
"It can’t have been strong because otherwise we’d all be Von Neumanns."
But the type of intelligence that secures safety and access to reproductive opportunities is the sort which wages war and waits for the right time to backstab and/or do away with one's rivals.
With agriculture you get the monopolization of surplus resources which greatly increases the rewards for autocratic and oligarchic formations.
Funny that you mention von Neumann. His background is Hungarian Jewish, a trait he shares with a number of other super-geniuses. In fact, von Neumann went to the same Budapest high school as Edward Teller and Eugene Wigner. Quite a few other geniuses and Nobel laureates hail from Budapest. Scott Alexander has a fascinating write-up on this phenomenon [1].
Unfair conparison. Growing titanium bones is most likely unfeasible, if even possible. Producing Klotho is not infeasible, it is being done in our bodies. The question is the amount, which I assume should be already finetuned. That's why I called it too easy of a "hack".
to me I conceptualize evolution as just a process like water filtering through a sieve is. So I don't see why using the word 'drives' is justified either.
The only thing evolution by natural selection tends towards is survival of genes (by definition). In order to assume evolution was open-endedly optimizing for greater intelligence, one would first have to make a strong argument that such greater intelligence would result in greater genetic success.
I think many people view humans and intelligence as something evolution has always been working towards, following a gradient like a river meandering to the sea. The reality is that such intelligence satisfied a niche adaptational advantage.
It's not a far fetched idea. At least up to a certain point, higher intelligence means a higher chance of survival and thus better chance of passing on the genes.
That's why I said open-endedly optimizing. Obviously some amount of intelligence is beneficial to humans' survival, procreation and protection of offspring, but only to a point. If evolution tended towards ever greater intelligence, you'd expect to see the most intelligent individuals having on average a greater number of offspring. Instead, studies generally show a negative correlation between intelligence and fertility. This would instead suggest that evolutionary pressure on intelligence was not open-ended, but in equilibrium.
> If we compare the smartest people in the world now like Terence Tao to the smartest people of more than half a century ago like John von Neumann, there seems to be little difference. Eliezer Yudkowsky expands the thought out in his essay “Algernon’s Law”, stating it as:
>> Any simple major enhancement to human intelligence is a net evolutionary disadvantage.
...
> COSTS
Intelligence is an almost unalloyed good when we look at correlations in the real-world for income, longevity, happiness, contributions to science or medicine, criminality, favoring of free speech etc18. Why is it, then, that we can find quotes like “the rule that human beings seem to follow is to engage the brain only when all else fails - and usually not even then”19 or “In effect, all animals are under stringent selection pressure to be as stupid as they can get away with”20? Why does so much psychological research, especially heuristics & biases, seem to boil down to a dichotomy of a slow accurate way of thinking and a fast less-accurate way of thinking (“system I” vs “system II” being just one of the innumerable pairs coined by researchers21)?
Because thinking is expensive and slow, and while it may be an unalloyed good, it is subject to diminishing returns like anything else (if it is profitable at all in a particular niche: no bacteria needs sophisticated cognitive skills, nor most mammals) and other things become more valuable. Just another tradeoff.
Because that's not how evolution works. Depending on the environment, initial conditions, boundary conditions, some traits may arise and some may not simply because of random chance. Evolution doesn't have a goal, if something survives because of some mutation and propagates, then it might be seen in future generations.
A lot of the replies are making true statements, but not getting to the core of your point.
First, there is a whole class of improvements that evolution can't do because they involve a non-local refactoring that therefore can't happen through random variation plus selection.
But you're right, as a general rule, any simple local improvement that turbocharges capability like you've described is something we should expect evolution to have already done. There's a name for that heuristic, but I can't find it at the moment. That's why it's so hard to find a single chemical that costlessly improves intelligence.
I tend to think like this too. If the change is small/easy evolution probably tried it already. A standard guess for a "downside" would be increased energy expenditure (but only a guess). Also, Klotho seems to decline with age, and old people are not as well optimized by evolution, since they don't procreate (directly).
I hope to formalize my thoughts on this in the future but this is precisely my hypothesis- that as a whole we have reached peak intelligence; any smarter and we will start "seeing" the futility of life and just be more prone to suicide or other acts. It can also go the other way where no fully intelligent individual sees the need to cooperate and you end up with a lot of extremely selfish intelligent individuals killing each other.
I also think that's why traits like intelligence are not completely genetically determined within our species. It looks like evolution has programmed stochasticity into intelligence so that the distribution is kept intact within the population while no individual lineage gets an unfair advantage.
Maybe side effects? Maybe being too smart is an evolutional disadvantage on an individual level or in small groups? Maybe producing the hormone is too costly?
Seems like too easy of a "hack" to improve such highly optimized systems such as humans or mice.