702

submitted 2 months ago by fossilesque@mander.xyz to c/science_memes@mander.xyz

106 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[-] Catoblepas@lemmy.blahaj.zone 32 points 2 months ago

Re: why didn’t horses evolve better leg healing, if you’re a proto horse and injure your leg you’re probably not living to heal it, because you can no longer run. So there is no evolutionary pressure to spread those genes through the population, even if a horse did randomly get born with genes that let it heal its legs better than other horses, because no selection mechanism would exist.

[-] merc@sh.itjust.works 6 points 2 months ago

There are certainly some injuries that are survivable, and that would let a horse survive long enough to heal, if they were a creature that could heal. I assume it's that leg healing reduces their speed or endurance, or requires that they consume more calories. They put all their points into "get away from predator" and zero points into "deal with injuries". I guess as long as the average female horse has more than 2 young that survive, that's enough.

So, probably there were mutant horses that could heal a bit better, but maybe they required a bit too much food, or they were a bit slower than the other horses.

[-] Catoblepas@lemmy.blahaj.zone 9 points 2 months ago

I assume it's that leg healing reduces their speed or endurance

Basically this, part of how they get their speed (legs being mostly tendon and cartilage) is what makes healing so difficult. Both tendons and cartilage have far less blood supply compared to muscle or skin, which heal much more quickly. So if a horse developed legs with more tissue and muscle (and thus an increased blood supply, improving healing), they would have been slower than their skinnier legged cousins and had no competitive advantage.