Adaptation is provable, easily... put a toxin into a colony of bacteria in an amount that will kill about half of the bacteria. The ones that live then reproduce and if you reintroduce the same amount of toxin to the new generation of bacteria a much smaller percentage will die. Infact a larger amount of the toxin could be introduced and if the process is repeated the bacteria could be made completely resistant to the toxin. That is adaptation, not evolution as one of my friends who does not believe in evolution made very clear.

Say we had that same set of origional bacteria though and instead of letting the bacteria most resistant to the toxin survive, we allow the bacteria that we arbitrarily decide remind us most of an alligator survive. We then let them multiply and pick the ones from the next generation that look most like an alligator survive and kill the rest. If we repeat this process enough times will we get an alligator?? Or say if we did it for a human instead of an alligator? Would that count as evolution? The bacteria are placed in an environment where it is ideal to be like an alligator and they've evolved over many generations to be like that. Just as in nature it was ideal in some environments to be like an alligator and evolution may have allowed non-alligator-like creatures to die while the more alligator like were able to survive.

I'm not asking anyone to believe, but is this at least possible? If we put some bacteria on another planet do you believe it could happen there with enough time?

Hahaha! The bacteria that "reminds us most of an alligator"? Oh, and who's going to wait 3 billion years to see if it works? Plus, the bacteria we have today aren't the same as the ones that existed 3 billion years ago. Meaning our complex, evolved bacteria we have now probably wouldn't even have the capability of someday becoming what we know as an alligator. Another creature of sorts? Quite possibly. An alligator? Eh...no.

quote:Originally posted by T-BagBikerStar

That is adaptation, not evolution as one of my friends who does not believe in evolution made very clear.

Your friend does not know what he's talking about and no belief is necessary when it comes to evolution. It is a fact.

eventually they would evolve to actually eat the toxin.

Not really.

If the toxin is a completely inefficient source of energy and there are other sources available, they won't.

Humans will never evolve to eat lead no matter how great a source we find, it's just not possible.

Bacteria eat sulfur (and iron i think?) deep below the suface, humans could probably (in one hell of a bad situation) evolve to injest sulfur/iron. Doubt if you would reconise them as human tho

As for bacteria eating toxins, many of them do. I would source it but i've just walked a long distance, so do it yourself

This isn't a very religious thread...

It would be evolution, but by artificial selection rather than natural. And it probably wouldn’t become an alligator as we know it, just something that resembles it. Perhaps. Maybe. You’d have to provide the exact conditions to encourage these single celled creatures to change in the way you want for millions of years to get anything that even half resembles an alligator from them.

I personally wouldn't want to be sitting in front of a Petri dish that long.



As for bacteria and the toxins, it’s a slightly different situation. The bacteria that do carry a resistance to it will survive and create more bacteria with the resistance, while others die, just like other creatures.

But bacteria can do something else as well. They have these little rings of DNA called plasmids that they can actually transfer to one another. Toxin resistance is likely to be coded for there, so it gets transferred into the population that way as well.

I thought people might want to know that.

Natural selection is such a complex process, there is no way you can recreate it artificially to get an existing species. The pressures applied are much more than adding some toxin. Your friend is basically ignorant and asks the impossible. You might as well as him to pray on it to prove God.

quote:Originally posted by elfstone:

Natural selection is such a complex process, there is no way you can recreate it artificially to get an existing species. The pressures applied are much more than adding some toxin. Your friend is basically ignorant and asks the impossible. You might as well as him to pray on it to prove God.



Practically, we couldn't recreate a species. Hypothetically, if we had a basic enough organism, we should be able to select the conditions to make it evolve into whatever we choose.