So I started a response and it kinda spiralled.
And I don't want to post this on social media as I'm sure some asshole will try and use this to argue for eugenic type bill shit.
But Ii typed alot so I'm positing it here because there's some ideas in here that I want to play with again in the future:
(For context the question was if creatures that live shorter lives evolve faster than others)
Yes because evolution only happens at the moments of new generations.
So we as humans can see so many generations of fruit flies in our 80 or so years of life, where we're likely only able to witness 3 or 4 generations of our own species. The fact that mutations have to randomly happen in a generation, and that mutation has to be non-detrimental to the survival of the newborn. And then the mutation has to also not be detrimental for the chance of that individual reproducing itself. And then for actual evolutionary steps, the environment has to trigger a situation where that mutation actually assists the individual in surviving and reproducing.
We're never going to see evolutionary change in slower life forms like ourselves or horses or even dogs or cats. Like it only takes a year or so for a dog to reach reproduction age, and we've been able to create breads by selective breading. But we're still looking at dogs.
This can show environmental selection. But we can't trigger random mutations in each generation. So we don't encounter the evolutionary steps.
Smaller dogs that have the environmental advantage that people find them fashionable and feed and house them. They are well adapted to the environment.
But they are still dogs. If humans were snapped out of existence, for the most part the onset that survived after a few generations would probably trend back to the larger size that has a better advantage in the wilderness. Maybe one would develop a mutation that gave it a new advantage. And so a new species would branch off.
Even with fruit flies that reproduce every 24 hours, and us manipulating and controlling every aspect of their environment haven't shown any major jumps yet in our tests.
We see adaption. But again mutations are quite rare, and when they happen they are often disadvantageous. As they are born into environments that their parents generation were well suited to.
Like it doesn't happen in huge steps, but imagine if a baby was born the same year as you, but had mutated fully working gills.
This wouldn't have helped them as they went to the same school as you and sat next to you in every class. Like even if your school had a pool or is near an ocean they could turn it into an advantage in some ways, but ultimately we live in an environment where visual appearance is of utmost importance, so even if he could turn that evolution into a good job, his odds of reproduction would be almost nil. So even a macro mutation that would give advantages, would be a failed mutation, as it happens at a time where the environment leads it to fail.
Mutation happens typically when 2 of the molecules in the DNA sting get flipped. Most of the changes happen in areas of the DNA that don't play a role in our bodies actual development, and when it does happen to that area it's usually bad. Cancers are in part caused by the part of the DNA that tells the cell to stop reproducing is damaged and the cells continue creating tumors. And kill the host.
Or we can look at Downs syndrome.
It's a relatively common mutation where we have an extra set of the 18th chromosomes (I think that's where it happens, it was years since I was learning about that)
On the whole it's not a detrimental mutation. As people born that way can live full healthy lives.
( I just realized I don't know if they often pass on the extra chromosome set to their children)
Assuming they had a 1 in 4 chance of passing it on, they could represent a likely branch for the human evolutionary path.
But where I live it was common practice to sterilize these people ( as horrible as that sounds, the law wasn't changed until the early 70's). So again the environmental conditions were detrimental to the change being passed on.
I want to be clear, Downs Syndrome in no way makes a person "not human". I'm saying that it's a genetic mutation that has the opportunity to lead to a branch in the evolutionary tree.
It's a hanger that doesn't threaten survival, and maybe possible on to their offspring ,(again I dont know that part but seems likely).
What would be required for them to start a new branch, would be for a change to our environment that would give them a comparative advantage. If obtaining food became harder for a few generations and it turned out that those people were able to better deal with that it could lead to them becoming its own community and survival in their own different way from the others.
Carrying a different genetic makeup would leave the group with its own opportunities for further mutations and its own adaptations to stem from it.
after a few hundred generations, if we lived in separate environments and communities, we would be considered different animals.
Evolution doesn't have a goal. Its only a process of describing how changes and reproduction can lead to large changes.
Successful adoration and mutation are successful if they lead to the survival of the creatures carrying those genes.
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