Comment by londons_explore
1 day ago
I am worried about the long term impact of research involving human conception, IVF, etc.
The reason is that genetics/evolution don't yet seem to fully explain how humans exist. A computer genetic algorithm run for a billion generations doesn't lead to anything anywhere near the the complexity of a human.
I suspect there are as-yet undiscovered effects which shape the next generation. Whether that be DNA methylation, gut bacteria passing from mother to child, selection of the 'correct' egg or sperm out of millions, or something new and un-discovered etc.
And if those effects are bypassed with artificial conception, we might end up with humans which aren't as strong, aren't as smart, aren't as well adapted to a changing environment, etc.
The effect will be small for each generation, but after 5-10 generations of a combination of artificial and natural conception you could end up with meaningful loss of fitness - or perhaps a lack of gain of fitness that would have otherwise occurred.
Having gone through IVF multiple times, there’s usually a pretty rigorous process and it is highly regulated in many countries. In some places you need genetic screenings when using donors. I was unaware that I was carrying a mutation for a difficult to diagnose, fatal but relatively easy to treat disease if caught early, which explained at least two cases in my family history. If the donor happened to carry the same mutation, the chances of having an offspring with the disease was around 25%. So in my view, IVF if done right, could actually make healthier humans. And yes, this genetic screenings are available to anyone not only IVF patients, but it is extremely unlikely that people will use them when conceiving naturally, because first, they aren’t cheap and secondly there’s some sort of tabu about asking your partner for genetic testing, and even if the test comes back positive for some type of disease, what would people do anyway?
25% of humans died before reaching 5 in 1800s US, today it is <1%. Its been at least 5 generations since this value dropped dramatically.
We have not ended up with "humans which aren't as strong, aren't as smart, aren't as well adapted to a changing environment, etc."
> We have not ended up with "humans which aren't as strong, aren't as smart, aren't as well adapted to a changing environment, etc."
Haven't we?
Objectively we’ve only become smarter (IQs have increased), stronger (fitness records continue to be broken), etc. since infant mortality shrank. If you believe otherwise please provide evidence.
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This line of reasoning leads to “some people are weak and unworthy of life because they are impure.” I don’t think rolling back our work to end infant mortality to prevent weak people from living is the right answer.
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Probably throwing quite the grenade here, but around 29% of pregnancies end in termination globally. Absent cultural considerations, it's questionable whether life expectancy has improved in absolute terms in modern times
Child mortality rates are rapidly dropping globally as well
https://ourworldindata.org/child-mortality
https://ourworldindata.org/children-saved-global-health
I don't think it's a grenade unless you are implicitly trying to mean it that life begins before birth, which ultimately is a definition game since it's actually quite hard to define life, hard enough that calling it "life" is a matter of personal worldview. I personally think it's quite reasonable to exclude pre-birth "deaths" from life expectancy, or event infant deaths sometimes, depending on what you are trying to measure.
In any case I didn't know this number and it's quite relevant to the discussion of how much we got rid of natural selection.
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How would you know?
When you make an outrageous claim the burden of proof is on the claimant. Given that there isn't a real indication of anything to the contrary, it is reasonable to assume reality is still the way it always was and humans are too.
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We have, we just have much, much better conditions for food, hygiene, personnal safety and medicine.
But have worse hormonal health (pmc.ncbi.nlm.nih.gov/articles/PMC7063751/), and are less fit (pmc.ncbi.nlm.nih.gov/articles/PMC4033061/). The flynn effect also seems to decline in some parts of the world: www.sciencedirect.com/science/article/abs/pii/S0160289619301679
It just doesn't compensate the immense gains tech created.
Turns out it's ok to be weaker if you don't have to worry about dying of parasites, malnutrition, cold.
Which, you could conclude, means the individual is weaker, but the species is stronger.
We haven't created humans from scratch using genetic engineering yet, why would you think our current state has anything to do with the comment you are replying to?
I like the spirit of what you are saying but the smart part isn’t true at all. IQ peaked around the mid 1990s and as someone that lived back then that tracks.
https://www.sciencedirect.com/science/article/pii/S016028962...
Look at Fig. 3. The world seems to be experiencing a reverse Flynn effect.
The abstract quite literary cautions against the way you're interpreting the data. The relevant quote:
> Notably, these gains do not uniformly translate to a rise in underlying GMA, suggesting the presence of domain-specific improvements and test characteristic changes over time. Conversely, the observed decline is primarily due to decreases in word comprehension and numerical reasoning tests, also reflecting specific abilities not attributable to changes in the latent GMA factor. Our findings further challenge the validity of claims that changes in the general factor drive the Flynn effect and its reversal. Furthermore, they caution against using these scores for longitudinal studies without accounting for changes in test characteristics.
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IQ is not a unit, it's a z-score. Z-scores can only be compared within the same cohort against which they are computed and given the same test. Given that the cohorts and tests keep evolving over time, it makes no sense to track IQ across large time periods.
The reversal of the Flynn effect is more likely explained by other factors such as the explosion of social media, endless addictive entertainment, and all the attention manipulation that comes with it. Conception didn’t change that much at a large enough scale during this short time period to explain it.
You’re layering several hypotheticals on top of each other, which leads to progressively distant possibilities. Good on you for caring about humans though
I think this is decisively the wrong way to think about it. Yes, layering hypotheticals like that means that any one scenario is extremely unlikely to be the thing that gets you, but that doesn't mean the shape of the problem is wrong.
It's like arguing with someone who doesn't believe in using seat belts when driving. "Why should I put them on?" they say, and when you try to explain what might go wrong they won't listen to any explanation that isn't a hyper-concrete hypothetical. So finally you give in and say, "Well, when we get onto the highway, a truck might lose control and hit us", and their response is "I don't think that's very likely, it seems highly improbable that today we will be hit by a truck when getting on the highway".
I agree with OP that this seems like the kind of thing where the unknown unknowns are so great that the correct approach is serious caution, and that any demand to know exactly how or why it will go wrong, falls in the trap where every specific example is very unlikely to be the thing that goes wrong, but still in total there's like an 80% chance that it goes horribly wrong. I don't know if we have the terminology to talk about this kind of failure mode. "You shouldn't play God" maybe? At least you shouldn't ask for specific examples of how things could go wrong, if you're going to turn around and claim each one highly improbable.
"I don't know if we have the terminology to talk about this kind of failure mode."
We actually have and is called RISK.
RISK = Probability * Damage.
Applied to the seatbelt event we have a death level damage and a high probability of happening given recent studies, so using a simple belt could easily save you from deadly accidents.
Applied to any unrealistic scenario we have insane level damages but also an incredibly low probability (near 0) so RISK = ~0%
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"To play God" isn't just to do something spectacular which wasn't possible before. It's to use other people - to put yourself on a higher teleological level than other people, declaring their purpose (whatever it is) as fully subordinate to your purpose (whatever it is).
As if they were a tool you created. Obviously, if I carve a piece of wood into a spoon, it's I who get to say that what used to be a piece of wood now has a purpose of moving soup to mouths. The carved piece of wood now has a purpose, but it's wholly subordinate to my purpose (whatever it is).
You don't have to actually design people to play God - you can subordinate others to your purpose without doing that, that's what various God-kings in history did. But it certainly gives you a head start if you make them.
You can make something and don't subordinate it to your purpose. In our culture, we see children that way. We claim, basically, that we didn't deliberately design a child, we only obeyed our own natures without really having much choice in the matter, and thus we and our child is on the same teleological level.
This is not a cultural universal. In many cultures, parents (in particular fathers) would say basically "I made you, so you must do as I please, you have no reason for existing except for my purposes". It was a hard won battle for our culture to assert that children matter for their own sake and not just for their parent's.
Many things in this thread makes me want to say "Y'all MFs need Jesus". I won't say that, but I will say that you should stop and think about why it is that the Catholic church is so difficult about contraception, why Christians in general have historically made such a big deal of the difference "born of God" vs "Created by God" (arianism, etc.), and what that story of Abraham and Isaac was really about. Whether you agree or not, there's much about other people you will never understand if you don't think about teleological levels.
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The history of humanity, I say of hominids even, was defined by humans playing it unsafe - migrating, sailing, inventing bombs, you name it. We played god before even we invented gods, and reached this point in time. Should we say "this is best we can do, let's stop everything"? Nah, not likely.
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But many of the listed hypotheticals are not dependent (on top) on others, and since there are multiple that actually increases probability of an undesirable outcome.
But it reads to me like the thread parent's point is that there are many unknown risks which can exist? I also wonder about long term effects to the health of the genome from IVF and other forms of fertility treatment as infertility could be acting as some sort of protection mechanism of the genome. But I suppose such objections form a continuum which extends to treatment of all genetic diseases or diseases in general--all of which probably applies some evolutionary pressure towards more healthy individuals but which we as a society have to balance against wellbeing of individuals and their human rights.
This seems distantly impossible right now, but for this reason, I predict that any species that survives this kind of "great filter" effect of accidentally messing up their genome long term, will develop a strong taboo against fertility treatments and treatment of genetic diseases.
Like it seems horrible not to help the individual, when we have the technology to; but it's also horrible to hurt your species by selfishly propagating faulty genes. And this seems like the kind of problem cultural taboos are good at solving, and I don't really see any other mechanism by which a species can avoid this filter trap.
There is precedent for infertility being beneficial for a species in the animal kingdom. For example the vast majority of ants and bees are infertile. Yet the infertile ones still contribute meaningfully to society.
Humans could easily be successful with a similar model, and did so in the past before fertility treatments.
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By contrast, we could also end up with humans that are stronger, smarter, or are better adapted to a changing environment.
In routine IVF, parents select for the strongest embryo to implant. This cannot happen in the case of traditional embryo development, where the released egg meets the sperm.
The assumption that IVF could produce weaker humans is an assumption rooted in what? Sci fi?
no natural selection as a filter though
Natural reproduction already has a lot of randomness and failure built into it. It's not like egg/sperm selection is a perfect quality-control system. IVF has also been around for decades, and while it definitely needs monitoring, we haven't seen some obvious collapse in health from it
>I am worried about the long term impact of research involving human conception, IVF, etc.
You'd have a rather different opinion if you had to squeeze out a water melon out of your genitals.
Nobody HAS to do that. If people WANT to have children they should give them the best chances they can. If science proves IVF is the best, every parent must do it, if it's risk freedom has not been proved yet, no person that has other options available should do it. Chances are they would be ruining their children's life by expecting and comparing them to the best, so they can at least not give them handicap from birth. The world is now much more competetive and unfair to our children than it was in our time. My mother has told me countless times that childbirth is one of easier parts of motherhood.
Taking advice for raising children from the childless is like asking virgins for advice on sex.
Now that's a very high ratio of personal beliefs to character ratio. I'd be delighted to see some evidence behind your opinions.
What? IVF doesn’t mean that the human is gestated in a glass tube like some 80s sci-fi, the pregnancy and birth still have to occur, carried out by a human.
> What? IVF
>>, etc.
What?
> humans which aren't as strong, aren't as smart, aren't as well adapted to a changing environment, etc.
But can they pay and vote? If yes, that is good enough for the people calling the shots.
I think it’s important to remember that the process of selection acts directly on human traits. For example being exposed to high summer heat temperatures may eliminate some people who have unproductive sweat glands, or needing to run down your food may eliminate people who have a muscles that easily tire. Selection (largely) does not act on far removed traits like egg cell characteristics as a proxy of human traits like muscle performance because the genes that are used by egg cells are quite different than those used by muscle cells. So if you worry about some kind of human trait decline you should be much more worried that people have access to air conditioning and grocery stores.
> A computer genetic algorithm run for a billion generations doesn't lead to anything anywhere near the the complexity of a human.
What?... Our computers can't simulate anything similar to a real world. You're comparing apples to galaxies.
> meaningful loss of fitness
What makes you think we don't have "loss of fitness" already?
150 years ago child mortality was around 30% in the developed world, now it's less than 1%. A lot of kids with weak health survive now. I'm one of them - I got pneumonia when I was ~2 y.o. and probably would have died without antibiotics. Then I had something which required antibiotic treatment pretty much every year. My wife also had a pneumonia in early childhood. And so did my daughter...
Why do we need to talk about some mysterious problem in 10 generations when modern medicine removes a lot of fitness pressure by itself?
It's a very common misconception that "survival of the fittest" means something related to physical fitness or stamina. It does not, in fact it's almost tautological. It means only "survival of those most likely to survive."
Natural selection is still fully in operation, but the things being selected for may have changed. Whatever they are now, they are still being selected for. Those most likely to reproduce are those whose who reproduce the most, and whatever those characteristics are, they will be the ones that become more prevalent.
It's also very important to remember that this operates over hundreds of millennia. Human beings changing substantially will not occur within a period of time less than that. You'd need to look back into deep prehistory to find changes to humans attributable to natural selection. Changes to modern humans are all explicable through changes to nutrition and lifestyle, not through evolution.
Well, modern medicine + economy + social pressure resulted in RADICAL change in fitness function for human population. It's very, very different.
So it's quite likely that modern population is not fit according to old criteria.
> It's also very important to remember that this operates over hundreds of millennia.
That's not true at all. People can make new breeds of dogs and cats in just a few generations. You can literally SEE how a change of fitness function affects the phenotype.
> You'd need to look back into deep prehistory to find changes to humans attributable to natural selection.
There are many studies which describe genetic changes within latest 10,000 years or less. E.g. paper "1,000 ancient genomes uncover 10,000 years of natural selection in Europe": "We identified 25 genetic loci with rapid changes 21 in frequency during these periods". You can find many similar papers if you do a search
One of studies identified changes in loci associated with Y. pestis immunity during the Black Death (i.e. something like a century). Black Death mortality is similar in scale to early childhood mortality 150 years ago.
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“survival of the fittest” was actually coined by a political economist, Herbert Spencer, to explain how lassiez-faire economics produces better companies. Darwin didn’t extrapolate to that in his theories and the quote is often applied to explain how evolution works, but that may not be the case. We can say that evolution results in change but that there are no guarantees that those changes result in fitness of the organism. We can only say that sometimes they obviously do and in other cases we can make up “just-so” stories to explain stuff in terms of fitness.
As I understand it, that they've gone back to the point of making the ovary and the egg itself is going through Meiosis helps here, because it's got the randomness of picking genes between the pair of chromosomes in the source. So it's not just a clone; it's a little more natural than if they tried to produce the egg directly.
Very interesting...maybe this is another great filter preventing a species from becoming multi planetary or expanding beyond a type 0 civilization?
I would've thought that generic engineering was the biggest ticket to getting a civilization out of their home planet...
Reminds me of this: https://badspacecomics.com/in-the-flesh-copy
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Several of your claims are unsubstantiated. Sure, species co-evolve together, environment shapes evolution.
But why do you think evolution doesn’t explain existence of humans? What’s missing?
Also, as someone else has replied to you, we’re way past “natural” existence of humans. The vast majority of 8+ billions wouldn’t have survived in the past.
> but after 5-10 generations of a combination of artificial and natural conception you could end up with meaningful loss of fitness
Yes, if we end up in some corner-case dystopia where evolution and natural selection continue to be in charge of fitness. But evolution and natural selection bring much suffering to the unlucky. In other words, if you go to a hospital, you'll quickly learn there's far more human suffering caused by God and Nature than by the "cruelty of man". Though common sense is never assured victory, I look forward to a world where our children live healthier and longer lives due to us properly messing with God and Nature.
I'm far more worried about the long term impact of letting evolution exert its pressure on humankind unchecked.
That's a lot of words to act like a total tool towards people born from IVF and their parents.
>The effect will be small for each generation, but after 5-10 generations of a combination of artificial and natural conception
How do you know it? Sci-fi tropes are not a good argument.
https://www.smbc-wiki.com/index.php/Royalty
There is nothing such as riskless technology, but you can't escape some risk anyway.
Tech like this gives some people a chance to be born. If they aren't born, this may damage the rest of the world in subtle, very hard to predict way. The invisible graveyard of medicine, caused by risk aversion, is real. In the name of safety, you may miss out on the next Freddie Mercury or David Attenborough, or Jonas Salk or Paul Erdös.
Also, the 5-10 generations you mention is 150-300 years in current humans. It is very unlikely that biological science will stagnate on current level of knowledge and blindly repeat beginner mistakes from 2026 for 150-300 years.
For comparison - 150 years ago, germ theory was still a contested newcomer. 300 years ago, medicine still believed in Galen's humor theory.
>The reason is that genetics/evolution don't yet seem to fully explain how humans exist. A computer genetic algorithm run for a billion generations doesn't lead to anything anywhere near the the complexity of a human.
I didn't have "creationism" as the top answer to a HN post in 2026, yet here we are...
Have you read the next paragraph?
> I suspect there are as-yet undiscovered effects which shape the next generation. Whether that be DNA methylation, gut bacteria passing from mother to child, selection of the 'correct' egg or sperm out of millions, or something new and un-discovered etc.
I can't see where it mentions "creationism".
How is that creationism? Saying that we don't have a good answer is not the same as suggestion one particular hypothesis.
To me suggesting that sounds pretty anti-intellectual!
Anti-intellectuallism is everywhere, especially amongst the intellectuals. The latest bent of this is to ask if an AI wrote this, rather than engage with the substance of what's written.
AI writing is anti-intellectual. It demands the time of thousands of people to read when they could be reading something with actual meaning. You're demanding scholars to read comic books all day in case they have content worth engaging with (spoiler: they don't).
> The latest bent of this is to ask if an AI wrote this, rather than engage with the substance of what's written.
Just an half hour ago, TomasBM wrote in another thread [1] why people first want to filter out AI slop, which IMHO fits perfectly:
> Getting those verbose, AI-authored walls of text is very annoying, especially when you're expected to thoroughly review it. It's like a denial-of-service attack on the human mind.
To that, I'd add my personal take: I go to HN, Bluesky, Reddit or Twitter to engage in meaningful conversation with other people (ranked in inverse likelihood of coming across sloppypasta). If I wanted to talk to a robot, I'd prompt ChatGPT myself. When others use AI for more than translation, this violates this core assumption of how human communication, how society has worked for all of human history.
Unfortunately, and I've been on the receiving end of this myself, anything longer or more substantive than a tweet will immediately evoke the "is this AI" assumption, and it's gotten worse as ChatGPT et al managed to eliminate the usual "tells".
[1] https://news.ycombinator.com/item?id=48743798
I have noticed that lately certain topics on HN seem to be eliciting low quality comments like "genetics/evolution don't yet seem to fully explain how humans exist". That is a really ignorant and silly thing to say. Are we being flooded with AI generated comment slop or do topics involving genetics attract a less knowledgeable crowd?