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?
It doesn't "lead to". Supporting a wrong conclusion even with a valid argument is as old as time. Fans of eugenics don't need an excuse to go down that path.
Our natural and artificial environments shape us for better or worse. We're bigger and more intelligent as a direct outcome of better nutrition. But we also have far more people with deadly allergies because we're so good at managing them now.
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.
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.
https://www.sciencedirect.com/science/article/pii/S016028962...
Look at Fig. 3. The world seems to be experiencing a reverse Flynn effect.
> 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.
> the observed decline is primarily due to decreases in word comprehension and numerical reasoning tests
What else would this be but intelligence? Imagine if your AI didn’t know what words mean and couldn’t do math and you still tried to make the assertion that it was just as intelligent.
Counterpoint: If I don't teach a kid to read and then ask them to do a test that has reading as a requirement, I can say two contradictory things:
1. This kid isn't intelligent. 2. I don't know what this kid's intelligence is; I gave them a test on something they weren't taught.
What you're describing is in line with 1. That's completely fair and definitely part of what I'd consider intelligence.
This paper is making a statement more in line with 2. I've seen similar conclusions elsewhere; the theories are things like "education is less and less aligned with what IQ tests measure."
In the context of fitness, I feel like 2 is more in line with what we'd be thinking about?
I could make the same claim of a bridge before it collapses, without realising the steel was weak, or had micro fractures.
Where's the proof? What an outlandish claim! Don't you see traffic flowing as normal?
Of course, we shouldn't drop all advancement due to worries. I do think we should study the results a bit more closely though.
Humanity does not deteriorate by default. Claiming it does so through some hand-wavy pseudo-evolutionary arguments is not a strong case, and requires at least some evidence to be taken serious. How about a (equally unfounded and just for the sake of argument) reverse claim: Humanity got more intelligent, because high child mortality favored physically strong children instead of mentally strong children.
They are flaws. Flaws which should never happen, separate from normal environmental degradation.
You may debate the point, but that is irrelevant, for I am referring to abnormal issues with bridges. Flaws in construction. Taking this parallel to humanity, or any evolved species, what "forges" a strong species is constantly being tempered by their environment.
Predation. Disease. Parasites. Even lack of proper nutrition. Environmental adversity, eg exposure to heat, wind, sun, etc. Reproductive errors. Reproduction issues. Etc and so forth. We've eliminated almost all of this, which means that standard methods of evolutionary pressure are almost all removed.
Species do deteriorate by default, if they remain static. Or additionally, if they allow genetic errors (which happens every generation, yes every) to seep into the gene pool without being winnowed back out by the stresses above.
These days, we save babies which are born early. Ones which have a dozen birth defects. Ones which have 100 other issues. Adults (before breeding age) with issues. Note that I am not saying we should not do these things! Only, that there is a price. A long term price.
Now... that being said, I think this is the best part of genetic engineering. It allows us to fix issues like this in the womb, and to get rid of these sorts of errors whilst still helping the current generation live, and have good lives.
But to pretend that evolutionary pressure doesn't exist, is weird. And everything we have which is an enhancement to our survival capabilities, is evolutionarily pressure based.
So back to the start? Those microfractures and weaknesses in steel are not noticeable when the bridge is deployed, as the steel's production is actually the problem. It's years later, with bridge inspections (if done! and they should be!) that these issues are discovered.
But much like global warming, or said steel, you don't want be be performing corrective action. And you can't see it before the issue becomes apparent. People didn't notice the Earth getting warmer when they were burning coal in year 1000 or some such.
We barely see the evidence of global warming now. And it's already too late to arrest some change.
Is that what you'd prefer for humanity? Wait until genetic defects are so rampant that it is "in your face" apparent?