> 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?

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.

How would you know?

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.

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.

I would've thought that generic engineering was the biggest ticket to getting a civilization out of their home planet...

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.

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?

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.