Intersting article but I’m unsure exactly what is its value.
Demonstrates that evolutionary theory is able to predict the future forms of antibiotic resistance.
I can predict that many bacteria will soon develop resistance to fourth generation fluoroquinilones. And I didn’t even have to waste any grant money.
But that’s not good enough. Evolutionary theory did that in the 1940s. What the new research is doing, is predicting the form that resistance will take so that we can take steps to deal with it.
Now these questions are sincere … How do a bacterial colonies know how to do all its nice mutagenesis to arrive at just the right steps to produce what is necessary to stop a new agent that is killing it off ?
OK, I’ll accept that you don’t know. Bacterial colonies know nothing at all. All that happens is that any mutations that make it more resistant to a specific antibiotic in the culture, will preferentially allow the bacteria having it, to increase, while the others are removed. And each generation, the most resistant are removed, so resistance procedes by steps, mutation by mutation.
How does it keep moving in the right direction when an ineffective preliminary mutation may have no value.and it is being systematically killed off by the antibiotic?
Any mutation that has no value is neither favored nor removed. But it is true that an additional mutation may make that one quite favorable. Evolution has limits, which is why you don’t see squirrels with another set of limbs for wings. It would be useful, but there seems to be no way to deal with the useless intermediate stages.
It appears (and I am saying simply that it appears) that the bacteria, in this instance, needed someone to guide it to develop resistance?
Nope. All natural. God knew what He was doing.
Why do bacteria seem to suddenly develop resistance?
Mutation or transfer of plasmids.
If a bacterial colony has been mutating for thousands of years should one expect that these same mutations giving rise to resistance have ocurred in the past themselves thousands of times but were just of no value and faded away?
Yes. A rather clever test showed this to be the case. Would you like to learn about it?
Coming and going on a regular basis? (Perhaps if the bacteria have been around long enough could they already have had mutations which would have given them resistance to every antibiotic that will ever exist, and perhaps a few are just hanging around in the background while their more numerous comrades are fighting the present battle?)
Problem is, without a use, the metabolic cost of antibiotic resistance is harmful. So they tend to die out, unless the antibiotic is present. Remember, fitness counts only in terms of environment.
Are their any instances of bacteria changing into a new species(ie. staphylococcus aureus becoming staphylbacillus aureus)
Yes, although bacteria being asexual makes it hard to actually draw the line. Bacteriologists don’t worry that much about it. For example, there are forms of E. coli that differ from other forms of E. coli by much more than humans differ from chimps. They get designations.
What does evolution theory inform that will actually change a physicians prescribing recommendations? What specific protocols for antibiotic use are derived solely from evolution theory that could not have been derived without it?
See here:
tinyurl.com/2svrgf
Is it necessary to presume something such as a mutation to be truly random.
No. If God were, for example, faking it and inserting them in to look random, evolution would work the same way.
Back in the good old days of windows 3.1 i made a game for my daughters and at the end of the game a random reward would occur. It appeared to be random but it really wasn’t because it all depended on the what was put into the program.
A sufficiently educated person could infer this from sampling the output and the (name removed by moderator)ut. However, mutations do seem to be random in the sense that a roll of dice is random.