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Comment by NhanH | Hacker News Reader

Human society provides nowhere enough pressure for evolution to have effect (for good reasons), and our humanity timeline is nowhere near lengthy enough so far either. So I don’t think we are heading anywhere in that regards

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Selective reproduction is evolutionary pressure; survival is mere prerequisite.

I agree but on the flip side it is interesting to consider what were the pressures and the timeline to bring us to where we are now.

Great ape brains are distinguished from monkey brains by their larger frontal and cerebellar lobes. The Neanderthals had bigger brains than us but smaller cerebella. And, most strikingly, modern humans have much bigger cerebella than “anatomically modern” Cro-Magnon humans of only 50,000 years ago (but relatively smaller cerebral hemispheres!)

How would you explain increasing average height in the US youth in the last 30 years? It can't be food availability, because 30 years ago people weren't hungry either

Absolutely food, or at most a hormonal change based on food. Possibly with s side-order of lack of a few of the childhood diseases that have been controlled with inoculations. 30 years is WAY too small a timeframe for human evolution. That works on the order of 50-100 generations, not a single generation.

Evolution doesn't happen quickly, but selection does. If something greatly changed how we select partners the past 100 years it could have an effect within a single generation generation. What could that be? Well, maybe feminism so women don't need to rely on a man to provide income, maybe socialist policies so nobody has to go hungry, and so on, plenty of reasons why some genes could be selected out of the gene pool that was previously fine there.

Lack of disease and disease treatment. Mostly Vaccines. I got sick like 2-3 times grand total growing up, and only once any more than mildly. My parents and their parents all got badly sick more than that growing up, and both have stories about being on deaths door, e.g. my dad got german measels at 17 and was bed ridden for a month; I didn’t get my last growrh spurt until I was 19.

Height stopped increasing around the mid-1970s and has been flat or falling since

https://ourworldindata.org/grapher/average-height-by-year-of...

https://www.dailymail.co.uk/health/article-12868421/american...

Worse for city kids:

https://www.scientificamerican.com/article/rural-children-no...

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