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I’ve heard human jaw muscles are becoming smaller and weaker as there’s less need to chew for prolonged periods of time.
by MichaelZuo 2y ago
I’ve heard human jaw muscles are becoming smaller and weaker as there’s less need to chew for prolonged periods of time.
- abyssin 2y agoBut is there an evolutionary pressure in this direction because of the decrease in need? That would be Lamarckian then. I wonder if certain traits need evolutionary pressure to stay stable, and otherwise degenerate in some specific direction.
- jkrems 2y agoMany (most?) traits require energy to develop and maintain. A stronger muscle will need more energy so there's always pressure to reduce it. That pressure may just be countered by pressures in other directions.
- Y_Y 2y agoSomething something opportunity cost? If you can allocate your next bit of energy and protein to something with better bag-for-buck than a jaw muscle then that should be an evolutionary advantage.
- actionfromafar 2y agoWhat is better bang for buck? Pretty small buck too.
- Y_Y 2y agoMore expected (over ensemble of specimens) evolutionary "fitness" per unit of whatever you need to expend to make a jaw muscle a bit stronger. The buck is small because we're doing optimization calculus.
- Ekaros 2y agoOne thing to consider is that some things might not be genetic, but environmental. I think jaw muscles are one such thing and short-sightedness might be other. First caused by food we eat and the other by less natural light and less time spend outside in childhood. I think there might be more of these effects.