Saturday, June 23, 2007
Is antibiotic resistance evidence for Darwinian evolution?
Here's a short video where the IDiots discuss antibiotic resistance in bacteria. This is part of the new attack on evolution. It's the main point of Michael Behe's new book, The Edge of Evolution. The idea is that random mutation and natural selection can only break things but they can't make new structures.
I suspect that very few people can scientifically refute the arguments in this video. It can be done, but it's going to take a bit of effort.
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23 comments :
Hmm, when you are phrasing it as "scientifically" refuting it, it will imply a biologist making an argument from known science or new research.
However, if I may make a small attempt, I don't hear much of anything that hasn't been presented many times before. Evolution has a magical barrier against unspecified characteristics that would make a new species, bacterias are supposed to make well defined species in some unspecified species conception (to use Wilkins terminology), and evolving resistance is somehow a special situation and incurs a special fitness cost when compared to the original situation.
The one claim that is specific is Minnich's on compensatory mutations that doesn't recover the original fitness and somehow 'locks in' organisms. But that is yet another magical barrier, where the allowed time is unspecified and Minnich description of "recovery" is not detailed. How can we tell without references?
For a counter example while waiting for Minnich's references, whales didn't get 'locked in' for land living by their residual anterior limbs, but recovered well the original swimming capabilities among us fishes.
Nonsense. Resistant strains of bateria occur naturally and prosper well enough, despite any such "impossibilities of the decreased fitness". So pay attention to the logic that leads to a patently false conclusion.
This is just "fitness thinking", a bad alley to go down, yet not an uncommon practice in darwinian biology.
Quite simply, evolution does not follow any progressist unbreakable law of perpetual and uninterrupted increase of fitness, as if all there was to evolution were "survival of the fittests"
Is it too hard to imagine how the new strain grows in the new environment, rather than being wiped out by simply remaining in the old environment competing with the ancestral bacteria?
Competition is NOT an important part of this process. This is more of a grid-like elimination according to innate differences when exposed to a potentially lethal environments.
I agree evolution is certainly less darwinian than some would like it (including ID-creationists). What I cannot freaking understand is how anyone in his right mind can infer from any of this that common descent is false, that there is no tree of life. It just blows my mind.
Oh, and of course on Minnich, there is the effect of selective sweep on the original genome. To compare selection without considering variability, which is what we hear suggested here, is #@?! stupid. [I'm trying to work on your PG-13 rating.]
Alipio,
I agree that Minnich is basically comparing apples and pears. But he does seem to describe selection in the laboratory ('compensatory mutations'), so that needed to be dealt with as well.
As usual, a creationist can mess things up so it takes quite a while to straighten everything out.
These arguments are easily refuted. But the problem is first defining, and listing precisely, what the arguments are.
scientifically refuting it doesn't seem too hard to me..
put species in different environments and different mutations will be selected for or against... put them back into their old environment, and they'll likely evolve back to how they were before (or similarly) because every adaptation has a cost that goes along with it (using up energy, etc.) and it's probably not worth the cost of evolving a resistance to a certain drug if the drug isn't even there!!
I'm a first year bio student and it seems pretty simple to me... or am I missing something?
What about nylonase? Not an example of resistance, but increased fitness nonetheless. Something new and useful was made.
You are right to say that this is a matter of logic and not one of science. I would add that it is also a matter of language.
The first logical fallacy is the implication that "since we didn't see it, it didn't happen". In reality it could have happened and we missed it. To validate his claim, he would have to show evidence that all of the strains of bacteria in the known universe have *not* mutated sufficiently enough to be considered a new species in the last 150 years. Further, he would have to define very precisely the single point at which one mutation caused the organism to be different enough to fit our definition for a new species. Once he has done that, he would have to face the underlying claim that if evolution doesn't produce new species within 3 human generations, it must be false. But maybe he has a shorter time frame to work with - maybe he thinks the world is only a few thousand years old...
The second false claim (if a mutated organism is less fit for it's original environment, it represents a backwards motion in evolution) exploits our perspective as larger beings that live longer. We see cells going from one dish to another and then "back" to the first when really this is a linear, forward moving sequence of events. From the bacteria's point of view, they were in one environment, then it changed, then they were in a new environment. That the new environment was identical to the original has no bearing on the direction of the change - two forward motions.
Lowered fitness respect to an environment you are not inhabiting is meaningless. In peniciland, there is no one to compete with the immune bacteria . A niche that otherwise would not exist.
Changes in environmental conditions can lead to lower reproductive rates in evolution. There is no law against it, as long as they are still alive and reproducing.
What about "compensatory" mutations? They may increase fitness but again, the occurence or non occurrence of the mutation is what is crucial. Elimination of the ancestral form (competition) is a possible consequence, but not a prerequisite. As I said before, competition exists, but it is not an important part of the process. More of a side-effect.
Summarizing: Measuring fitness provides a description, a "fotograph" but it does not allow us to predict the path that will be taken by evolution, since fitness may decrease or increase.
THink about this. How did bacteria evolve the capacity to become latent spores under adverse conditions? My guess is, not precisely through increasing reproductive rates.
-Alipio
I would say it's relatively easy to refute the arguments made in the video. The key lies in the changing of environments: fitness can only be defined in terms of a specific environment. Take a fish out of the water, it'll die; take a frog out, it lives on just fine. Does this mean a fish is somehow less fit than a frog? Of course not. It only means a fish is less fit for life on land than a frog is.
The same rule applies to bacteria. When you expose them to penicillin, you're changing their environment. When you remove the penicillin, you're changing their environment. Every change has to be adapted to. And yes, most of the adaptations will be Rube-Goldberg-type contraptions -- clumsy, inefficient, easily broken by another change in the environment, and easily outcompeted by a strain that was never subjected to as many conflicting selective influences.
So yeah, of course resistant bacteria will show as less fit than the parent strain in the original environment. But in the environment they evolved for -- one that includes penicillin -- they're more fit, not less fit.
And if anyone tries to argue that penicillin is an artificial addition, just show them a similar situation from natural history: anaerobic vs. aerobic bacteria.
"anterior limbs" - posterior limbs. Serves me right for trying to use fancy words. :-)
Hmm - According to the film, bacteria selected for antibiotic resistance don't recover the level of 'fitness' re the original environment that their unmutated cousins have. So it's characteristic of mutation plus selection that ancestral defects don't entirely disappear in subsequent generations.
Can someone please remind me for what purpose the human appendix was designed?
Evolution, is it a science? The agruement continues. But it doesn't have to...
Many people, when they can't provide evidence for their theory, adopt the strategy of falsehood. Such is the case with many of those who have fallen victim to the propaganda of renowned evolutionists.
If evolutionists want to end the arguments all they have to do is, get their brilliant heads together and assemble a 'simple' living cell. This should be possible, since they certainly have a very great amount of knowledge about what is inside the 'simple' cell.
After all, shouldn't all the combined Intelligence of all the worlds scientist be able the do what chance encounters with random chemicals, without a set of instructions, accomplished about 4 billion years ago,according to the evolutionists, having no intelligence at all available to help them along in their quest to become a living entity. Surely then the evolutionists scientists today should be able to make us a 'simple' cell.
If it weren't so pitiful it would be humorous, that intelligent people have swallowed the evolution mythology.
Beyond doubt, the main reason people believe in evolution is that sources they admire, say it is so. It would pay for these people to do a thorough examination of all the evidence CONTRARY to evolution that is readily available: Try answersingenesis.org. The evolutionists should honestly examine the SUPPOSED evidence 'FOR' evolution for THEMSELVES.
Build us a cell, from scratch, with the required raw material, that is with NO cell material, just the 'raw' stuff, and the argument is over. But if the scientists are unsuccessful, perhaps they should try Mother Earth's recipe, you know, the one they claim worked the first time about 4 billion years ago, so they say. All they need to do is to gather all the chemicals that we know are essential for life, pour them into a large clay pot and stir vigorously for a few billion years, and Walla, LIFE!
Oh, you don't believe the 'original' Mother Earth recipe will work? You are NOT alone, Neither do I, and MILLIONS of others!
"anterior limbs" - posterior limbs. Serves me right for trying to use fancy words."
And yes - I usually get confused by "ante meridiem" and "post meridiem" too. What is wrong with "pre" and "post"? (Or a 24 h clock.) Stupid latin! ;-)
"The agruement continues."
There is no 'agrueing' in scientific circles.
But why do I have the feeling that you mean discussion among anti-science groups?
Perhaps because you confuse the origin of life question with biological science describing existing life.
Or perhaps it is the anti-scientific idea that evidence against one theory is evidence for another. That this isn't so is so basic it is even a fallacy, the fallacy of false choice.
You're IT :)
http://tinyurl.com/2snj2w
I have Seen the Light: "fitness" is environment-specific. But what, Dr. Wells, constitutes a bacterial "species"?
To see this kind of thing--selection-mediated bacterial evolution in the lab--done right, point the google to Richard Lenski of Michigan State Univ.
anonymous has already pasted his "claypot" model of the origin of life elsewhere...%&$ing spammer.
...and he/she/it still hasn't figured out how to spell "voila"...
"Walla" is half a town in Washington
Ah, a spammer. had I but known.
"and Walla"
What do you know, I missed that. Must be because I tend to scan creationists comments, they are so repetitive and usually boring...
In french that would be "et violà", without any uppercase. You know what happens to foreigners that mistreats the noble french language? Me neither, which is why it is so scary, but the rumor is that it involves dark alleys and butterfly knifes...
Oops, I think my previous comment flew away before I have finished...sorry!
Anyways, since it is well known (and published) that in bacteria there are genetic exchange (NOT like in eukaryotes) - this story does not prove a thing! Definitely not Darwinism. A cell changed (mutated/gained a plasmid) to survive an environmental pressure, and obviously that mutation/change will serve as a disadvantage compared to the wild type. (I am yet to hear about the mutation that benefits the organism on the long run. Evolutionists, here is your chance to prove yourselves!)
Sorry Alipio, resistant type of bacteria do not occur very often in nature, otherwise we would not be able to use antibiotics very well (see GE bacteria in pharmacy or antibiotic supplement for farm animals...they still work!). But don't be hung up on that "fitness" stuff, it is a slippery slope.
And for Jud: your appendix is there to help fight stomach infections (mostly occuring in childhood), like your tonsils are there to help with throat infections.
Has Minnich published a paper on the subject? If so is there a link?
Where can I get more info?
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