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.
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.
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.
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.
Why heal? If they are slowed by their injury they can’t keep up when the herd flees, and a predator will eat them
Healing won’t increase chances of survival
I think most of their problems are because they are optimised for speed over everything else
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.
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.
Maybe these are the ones that heal better.