37 replies to this topic

[Rod]

When bacteria mutates to resist antibiotics, is this witnessed evolution?

[Modulous]

When bacteria mutates to resist antibiotics, is this witnessed evolution?

It is witnessed that a resistance that didn't exist, has come to exist. Thus the organism has evolved. I believe we can see what genes have mutated to cause this resistance, so we no that it was caused my random mutations of DNA, and the bacteria that aren't resistant are now dead so there is your selection.

[92g]

t is witnessed that a resistance that didn't exist, has come to exist. Thus the organism has evolved. I believe we can see what genes have mutated to cause this resistance, so we no that it was caused my random mutations of DNA, and the bacteria that aren't resistant are now dead so there is your selection.

Thus demonstrating that all known cases of mutation and natural selection do not result in turning a bacteria with a certain set of characteristic into something other than a bacteria with a different set of characteristics.

Terry

[Modulous]

Thus demonstrating that all known cases of mutation and natural selection do not result in turning a bacteria with a certain set of characteristic into something other than a bacteria with a different set of characteristics.

Terry

Is that what that demonstrates? I thought it demonstrated something else entirely. I thought it demonstrated that a bacteria's genome can mutate and generate resistances to antibiotics. I didn't realize it was an experiment to show every single known case of mutation and natural selection.

[92g]

Well,

You can make of it what you wish,...., I was just heading off the equivocation at the pass......

Terry

[Modulous]

Well,

You can make of it what you wish,...., I was just heading off the equivocation at the pass...... :D

Terry

I have absolutely no idea what on earth you are talking about. It was asked whether or not bacteria developing antiobiotic resistance was an example of evolution being observed. I said yes it was. You jump in and say that that demonstrates that bacteria have never been observed to evolve into anything other than bacteria with different characterisics. It clearly doesn't demonstrate that at all.

I see no equivocation on the horizon here, are you just trying to start an argument?

[92g]

You jump in and say that that demonstrates that bacteria have never been observed to evolve into anything other than bacteria with different characterisics. It clearly doesn't demonstrate that at all.

I see no equivocation on the horizon here, are you just trying to start an argument?

No, I'm not trying to start an argument.

I have absolutely no idea what on earth you are talking about. It was asked whether or not bacteria developing antiobiotic resistance was an example of evolution being observed. I said yes it was.

In your post here, you say that bacteria developing antibiotic resistance is an example of evolution being observed.

The general theme of the debate that goes on here is whether or not there is evidence of microbes-to-man evolution, see the Forum Rules, not whether a given species changes over time, even the creationist model requires this to explain what we see today.

Given that, I think its necessary to always be clear of what we talk about when we say "evolution", and what "mutation and natural selection" actually demonstrate.

Chareterstic changes in bacteria form one form of bacteria to another do not demonstrate microbes-to-man evolution, and I think its important to keep that in mind.

Terry

[Modulous]

It was never suggested that this was 'macro' evolution. If all you wanted to say was that, then that is fair enough. Its just that you said that the example of 'micro' evolution put forward demonstrates that 'macro' evolution has never been witnessed. Clearly the logic doesn't follow. Now we are clear, all you wanted to say was that bacteria developing antibacterial resistance in a labarotory is not an example of abiogenesis followed by several billion years of evolution. Agreed.

[ret]

It is witnessed that a resistance that didn't exist, has come to exist. Thus the organism has evolved. I believe we can see what genes have mutated to cause this resistance, so we no that it was caused my random mutations of DNA, and the bacteria that aren't resistant are now dead so there is your selection.

Finally, something I actually know about! Actually, the mutation here is information loss, not information gain. It makes the ribosome less specific, and degrades the general performance of the bacterium. It is a case of microevolution, but it would not lead to macroevolution.

Other such cases include: DDT-resistant insects, polar bears' resistance to cold, increased yield of grains and vegetables, and dairy cattle with increased production. All of these situations cause a loss, not a gain, of information, but have been used as examples for macroevolution.

[chance]

Finally, something I actually know about! Actually, the mutation here is information loss, not information gain. It makes the ribosome less specific, and degrades the general performance of the bacterium. It is a case of microevolution, but it would not lead to macroevolution.

Other such cases include: DDT-resistant insects, polar bears' resistance to cold, increased yield of grains and vegetables, and dairy cattle with increased production. All of these situations cause a loss, not a gain, of information, but have been used as examples for macroevolution.

If the DNA of a microbe without resistance could be described as – ABCDE,
then, after mutation as - ABCXDE or ABXDE, how can this a loss? It’s just different.

[Modulous]

Finally, something I actually know about! Actually, the mutation here is information loss, not information gain. It makes the ribosome less specific, and degrades the general performance of the bacterium. It is a case of microevolution, but it would not lead to macroevolution.

How is it an information loss when a bacteria population gains a resistance it didn't previously have? No resistance existed prior to the event, resistance existed afterwards.

[92g]

How is it an information loss when a bacteria population gains a resistance it didn't previously have?  No resistance existed prior to the event, resistance existed afterwards.

Information and traits are not the same thing. If a resistance is gained due to a loss of ability to do something, e.g. the ability to intake the antibiotic into the cell, then new trait is gained with the loss of functionality. That loss would probably make it less viable in a normal environment, but more viable in the pressence of the antibiotics.

Also, a loss of information can cause bacterial antibiotic resistance, e.g. penicillin resistance in Staphylococcus can be due to a mutation causing a regulatory gene's loss of control of production of penicillinase (an enzyme which destroys penicillin). The resulting overproduction of penicillinase increases resistance to penicillin. But in the wild (away from artificial environments swamped with penicillin), the Staphylococcus would be less 'fit' because it wastes resources producing heaps of unnecessary protein.

Another common cause of antibiotic resistance is mutational defects which hinder the bacterium's ability to transport substances through its cell membrane. Such a defect means that the antibiotic is less readily absorbed, so it is less likely to kill the bacterium. But in the wild, it would be unable to compete with bacteria with properly working cell membrane pumps which take up nutrients into the cell.

Antibiotic Resistance

Terry

[Modulous]

Information and traits are not the same thing.  If a resistance is gained due to a loss of ability to do something, e.g. the ability to intake the antibiotic into the cell, then  new trait is gained with the loss of functionality.  That loss would probably make it less viable in a normal environment, but more viable in the pressence of the antibiotics.
Antibiotic Resistance
Terry

Yes - it is possible that sometimes the overall fitness might go considerably down, but it is not always the case. this study is titled The isoleucyl-tRNA synthetase mutation V588F conferring mupirocin resistance in glycopeptide-intermediate Staphylococcus aureus is not associated with a significant fitness burden.

[92g]

Yes - it is possible that sometimes the overall fitness might go considerably down, but it is not always the case.

Perphaps not, but horizontal changes, or slight downward changes are not examples of upward changes, and that is part of what macro-evolution needs. The other being the generation of information that can produce new physical functionality, e.g. the information on where and how to construct a leg when there was none before.

Terry

[Modulous]

Perphaps not, but horizontal changes, or slight downward changes are not examples of upward changes, and that is part of what macro-evolution needs.  The other being the generation of information that can produce new physical functionality, e.g. the information on where and how to construct a leg when there was none before.

Terry

Upward changes? I was under the impression that there was no direction in evolution...things just change and survive.

[RockerforChrist14]

Well, I don't know much on this subject at all, but this is what I'm thinking.

"Upward changes? I was under the impression that there was no direction in evolution...things just change and survive. "

Yeah, you're absolutely right. Amoeba to human=upward change. I wonder what the chances of that happening would be even if macroevolution were possible.

[Modulous]

Well, I don't know much on this subject at all, but this is what I'm thinking.

"Upward changes? I was under the impression that there was no direction in evolution...things just change and survive. "

Yeah, you're absolutely right. Amoeba to human=upward change. I wonder what the chances of that happening would be even if macroevolution were possible.

So humans are 'above' amoebas? Are dogs 'above' cats? Bats 'above' kangaroos?

[92g]

Upward changes?  I was under the impression that there was no direction in evolution...things just change and survive.

What do you mean by "change" and "evolution", please be specific.

Terry

[Modulous]

What do you mean by "change" and "evolution", please be specific.

Terry

I thought change is a fairly non-ambigious word. Evolution is another word for it.