>>14209732>doesn't that mean that all offspring that inherit this mutation would need to take in the foreign cellsThey are there from the start, when a cell divides some of the mitochondria go into both new cells. It's stuff like this why we know it works like this, mitochondria have their own genes independent from the host cell and you can track their evolution separately from the host cells. There doesn't even need to be any particular mechanism for dividing them, there's hundreds or thousands of them floating around inside cells, basically equally distributed in the cellular fluid so some will always go into the new cells and since they are essentially their own thing when they see a cell is underpopulated they multiply independently to fill the roster up, handy little buggers.
And yes they are beneficial to the offspring too.
>>14209822>immune systemIt can't really fight anything that's inside the cells and of course the same way your immune system has evolved not to fight your own cells (most of the time anyways) it has evolved to recognize organelles as friends. They belong into your body just as much as the rest of the cell does as far as immune system is concerned.
>"exist" and not somehow cause some sort of... damage... or negative side effectMitochondria have coevolved with cells since basically the beginning of life (which is why they are present in not only animals but plants and fungi as well, they are from the time when all these things were the same. They preexist immune systems as well. Even though are separate they are essentially just a part of the cell at this point. It's like asking why do windshields fit the front hole of your car, they are a separate part but the design has been hammered by evolution long enough that they are essentially inseparable.
>I suppose the negative side effects would be naturally selected against...Exactly
>>14209829Yes, the cell doesn't make mitochondria. Likely results in the cell death quite quickly.
