Evolution in action.

[RoadRunner79]

Ever heard about the microbes that live exclusively on nylon?

I am familiar with the nylonase enzyme, although I have not heard, that they lost abilities to absorb materials they where previously capable of (excluseively sustains itslef on nylon). There is some controversy about as to the how and why. Some think that a previously existing enzyme was partially capable of breaking down nylon, but not as efficient as the current form.

Then there is directed mutagenesis and some people make money, by doing similar things on purpose. Perhaps it is not random and unguided after all.

[Tiberius]

although I have not heard, that they lost abilities to absorb materials they where previously capable of (excluseively sustains itslef on nylon).

That's not how evolution works though. You don't have to lose an ability in order to gain one.

[RoadRunner79]

Convinced of what exactly?    All the video shows, is that some bacteria survived and multiplied (it doesn't tell us anything about why or how).

Well, given that the bacteria didn't grow beyond the initial boundary, before rapidly spreading, does seem to suggest that they underwent some sort of change don't you think? Unless you think that there is another reason why the bacteria didn't grow on the antibiotic at first, but then suddenly were able to?

Also, I don't think that this is all that controversial.  Bacteria have been resistant to antibiotics for millions of years.
http://www.ncbi.nlm.nih.gov/pubmed/22509370

Again, the video shows they weren't resistant to this particular antibiotic. If they were, they would not have stopped or even slowed down when they reached the agar that was in contact with it. The antibiotic prevented the bacteria from growing past it, until one of the bacteria developed a mutation which gave it resistance.

Perhaps it would be more apparent in real time, but I didn't see them stop much at all. What I seen could possibly be explained as a bottleneck, where most of the bacteria where not able to survive in the antibiotic, but some where. Once they got through, then they where able to spread in the new medium and start reproduction again. Even a short stop at the changeover could be easily explained in this way. Personally, I didn't see any mutant bacteria ninja turtles in the video (perhaps I missed it). I think you are making an assumption here.

I would be interested in seeing multiple tests ran either side by side, or in succession, started from a very small culture (reduced genetic diversity). It would be interesting to compare the results time wise. I would think, that if the expansion into the antibiotic was the result of some unguided mutation, then the results would be greatly dis-similar. if it was fairly repeatable (which from my knowledge, I am guessing this is), I think that you would be able to reproduce fairly consistent results with reason and given the occasional anomaly.

[BrianSoddingBoru4]

Is no one here but me abso-fucking-lutely terrified by this video?

Boru

Addendum (back on topic): Creationists wouldn't accept evolution if you showed them an 11-day time lapse of a fish growing feet.

[Gawdzilla Sama]

Creationists are beginning to realize they're irrelevant. About fifty years late, but finally.

[Cyberman]

Natural selection, in ironic fact.

[vorlon13]

I've enjoyed watching the ID/creationist arguments evolve over the years.


One might think God would have imbued them with the 'ultimate' argument/rationale in the first go round back during the Scopes trial.

[bennyboy]

You want "proof" of evolution.
Well here ya go.


http://scienceblogs.com/pharyngula/2016/...ent-845647

Good one.

[Tiberius]

Perhaps it would be more apparent in real time, but I didn't see them stop much at all.

Watch the video again from 0:49 until 0:53. Remember, this is a timelapse across 11 days, so 4 seconds in the video is several hours in real life. The bacteria were reproducing quickly before and after that point in the video. There's a clear moment (when they reach the antibiotic) when they just don't reproduce in that direction, until a mutation occurs (at 0:53).

What I seen could possibly be explained as a bottleneck, where most of the bacteria where not able to survive in the antibiotic, but some where. Once they got through, then they where able to spread in the new medium and start reproduction again.

I think you're missing the point. The bacteria are all the same species at the beginning (the same strain) and none of the original strain were able to survive in the antibiotic. Bacteria reproduce by splitting themselves in half, making an almost identical copy of themselves, so unless these resistant bacteria were introduced externally somehow (which is certainly a possibility that I suspect they looked into / controlled for), they must have come from the original strain after several generations.

If the original strain was not resistant to the antibiotic, and some of the strain's descendants are, that means they evolved the ability to resist the antibiotic at some stage, through a mutation.

[RoadRunner79]

Perhaps it would be more apparent in real time, but I didn't see them stop much at all.

Watch the video again from 0:49 until 0:53. Remember, this is a timelapse across 11 days, so 4 seconds in the video is several hours in real life. The bacteria were reproducing quickly before and after that point in the video. There's a clear moment (when they reach the antibiotic) when they just don't reproduce in that direction, until a mutation occurs (at 0:53).

I was watching compared to the normal rate of expansion.... I still think that this could be explained as a bottleneck, and that some bacteria where at least partially resistant before... more study would be required.

What I seen could possibly be explained as a bottleneck, where most of the bacteria where not able to survive in the antibiotic, but some where.  Once they got through, then they where able to spread in the new medium and start reproduction again.

I think you're missing the point. The bacteria are all the same species at the beginning (the same strain) and none of the original strain were able to survive in the antibiotic. Bacteria reproduce by splitting themselves in half, making an almost identical copy of themselves, so unless these resistant bacteria were introduced externally somehow (which is certainly a possibility that I suspect they looked into / controlled for), they must have come from the original strain after several generations.

If the original strain was not resistant to the antibiotic, and some of the strain's descendants are, that means they evolved the ability to resist the antibiotic at some stage, through a mutation.
[/quote]

I understand that they are all the same species (a form of E. Coli) I believe. My point was to minimize the initial genetic diversification within the starting group. Bacteria are highly adaptable, and the changes are more pronounced under stress. I'm not saying that it definitely isn't evolution (change over time). But I think that there are other possibilities.

While I would like more trials, I did re-watch the video; and there are two samples here on either side. If you watch, while the left side falls behind a little, and there is a definitive spot in the middle which struggles near the end, they for the most part keep up with each other. I would predict, that this would be repeatable, as to the point I made previously.