Re: Eternal lifespan, bacteria and natural selection
I've been pondering if it is possible that there could be bacteria with eternal - or at least very long - lifespans. If this trait is favored for by natural selection they should very probably exist. So the question is: Does natural selection favor this trait? On one hand a longer lifespan gives the organism more time to spawn. On the other hand it would probably be more complex and therefore more demanding on its environment. It would also die just the same when living conditions change. This being said organisms often seem to carry more capable functionality than they need and maybe the machinery needed for longevity isn't that taxing.
We have only very recently begun to look at what species of bacteria there actually are. As much strange functionality as is contained in some organisms anyway. Isn't it possible that there are species of bacteria with extremely good error correcting capabilities and internal clock-resets which would allow them to live for a very long time?
Or is there some obvious reason why extremely long lifespans go against natural selection?
It all depends on what you mean by 'eternal' or long life. Sure, a species that could stand extreme cold by making itself dormant could live a very long time until more favorable climates exist.
But, continued active existence doesn't sound very feasible due to, as you stated, the biological entity becoming to much of a tax on it's environment.
However, a species that can reset it's own genetic clock once it reaches an evolutionary stand still does sound like it could continue existence.