Great Video of Bacterial Resistance Evolution

This is a very cool experiment/ demonstration. I just had a couple of comments on what I have seen. I have seen some try to dismiss this as intelligent design, essentially; because the experiment was designed by humans. This appears to me, to be a rather weak argument, and I think it should be avoided. Because an experiment was designed by humans in my high school chemistry class, doesn't mean that the chemistry observed is the result of intelligent design. The only way, that I can see where this may be applied, is that a particularly strong selection barrier was used and the selection in reality, would not be so complete. The second comment, is that when I watch the video, I notice that the progression of bacteria through the barrier hardly stops. There is a bottleneck, where those that are incapable of surviving in the antibiotic mediums no longer progress; but especially in the time lapse of the recording, they can hardly be seen to slow down. Third, I notice a similarity in timing, between the progressions of the two sides of the plate. Further, within each group, there are multiple lines that are able to progress into the stronger antibiotic shortly after the first. While I would suggest further testing, from what I have seen here, I believe that this would be a fairly repeatable experiment. Someone may be able to correct me; but, if it is relatively consistent and repeatable, then unguided or random mutations could be ruled out. What I gathered in the video, is that either some of the bacteria where previously resistant to the antibiotic, or that the resistance is well within the natural variability of the organism. bjMurray

gpuccio, Thank you. Dionisio

Dionisio: As far as I know, there is no case of observed or demonstrated complex molecular emergence by neo darwinian mechanisms, exactly as there is no case in general of new original complex functional information arising in non design systems. Regarding the finches, I am not sure of what is known today about the molecular mechanisms of the adaptation (I read something, but I can't remember), so I cannot really comment. The molecular complexity of a variation is the key point. Adaptation oh human populations to high altitudes is a complex subject. However, as far as I can understand, the best known genetic trait associated to that adaptation is a single nucleotide polymorphism in EPAS1, a TF involved in response to hypoxia, and a 3.4-kb deletion downstream the same gene. Interesting, but again these are very simple variations. Probably, another example of microevolution favored by NS. gpuccio

gpuccio: As usual, some of my questions might fall into the 'dumb' category, but I want to be ready to respond any questions related to my part of a project I'm currently working on (and struggling with). And believe me, many of the questions I have to answer are very difficult for me. The software part of the project is much easier than the associated biology research, because MSFT, Xamarin, Unity3D programming tools are relatively well documented. Only time and concentration are required. But biology concepts are extremely complex and documentation is not easily accessible. Sometimes it's everywhere and sometimes it's nowhere. Looking back my years in engineering software development seem easy bow. :) Thank you. Dionisio

gpuccio: Regarding the last three questions I posted @4 (in reference to this current johnnyb's OP):

How does this compare to the famous case of the Galapagos finches changing their beak size under different conditions? How does this compare to the case where humans adapt to highest or lower altitudes through changes in the amount of red blood cells? Are there any relations between those scenarios?

Can we say the above scenarios don't relate exactly to the bacteria case, because the latter involves more complex phenotype changes than the former? IOW, can changes in bird feather coloration, beak shape/size, in response to environmental changes, be compared to changes in RBC count at different altitudes or to bacteria resistance changes? Are there any general conceptual similarities worth pointing at? What are the major conceptual differences between those scenarios? Dionisio

gpuccio:

Macroevolution would be the observed or demonstrated emergence of a new complex molecule, like penicillinase, through definite neo darwinian mechanisms.

@1 you referred to pre-existing complex molecules that can be transferred by means of HGT mechanisms and you provided a link to a related paper. However, as far as you know, are there published cases of observed or demonstrated complex molecular emergence, like your example of penicillinase ? I could search it online, but if you can suggest some paper(s) that you have reviewed, it would same me time. Thank you. Dionisio

gpuccio:

Macroevolution would be the observed or demonstrated emergence of a new complex molecule, like penicillinase, through definite neo darwinian mechanisms.

Thank you for the explanation. When you say 'emergence of a new complex molecule' are you referring to a concept similar to what Professor Denis Noble said in the following quote?

I also agree that the concept of a nonlinear attractor is a useful tool for thinking about the teleological character of living systems. What do we mean by “teleology” if not the tendency of a system to move towards the function that serves its interests in the organism as a whole, i.e., to have a goal? As I will argue later in this Dialogue, that does not require us to believe that there was a creator that designed the cardiac pacemaker. The term “final cause” has unfortunately created the impression that there is some ultimate goal in the universe from which all other forms of teleology derive. By contrast it is sufficient in my view to see teleological behavior as emergent during evolution.

Denis Noble Interview @ TBS blog http://www.thebestschools.org/dialogues/evolution-denis-noble-interview/ [emphasis mine] Dionisio

Dionisio: This is definitely microevolution. Macroevolution would be the observed or demonstrated emergence of a new complex molecule, like penicillinase, through definite neo darwinian mechanisms. gpuccio

"Michael Behe: Mega-Plate Antibiotic Resistance Video - Evidence for Evolution?" - podcast http://www.discovery.org/multimedia/audio/2016/09/michael-behe-mega-plate-antibiotic-resistance-video-evidence-for-evolution/ bornagain77

johnnyb and gpuccio: Very interesting article and comment respectively. The article subtitle is:

"The MEGA-plate allows scientists to watch bacteria adapting to antibiotics before their eyes."

http://www.theatlantic.com/science/archive/2016/09/stunning-videos-of-evolution-in-action/499136/ Are there adaptation mechanisms associated with this? Does the term "micro-evolution" relate to this type of case? In the case of bacteria, what kind of process would qualify as "macro-evolution"? How does this compare to the famous case of the Galapagos finches changing their beak size under different conditions? How does this compare to the case where humans adapt to highest or lower altitudes through changes in the amount of red blood cells? Are there any relations between those scenarios? Dionisio

OT: New video upload

Pre-Cambrian Rabbits plus Natural Selection Falsified by Population Genetics - video https://youtu.be/zlGwjUJLgAE

bornagain77

Great to see this in action. It should be clear that every new antibiotic boundary induces cell cycle arrest and mutations cannot be induced. Resting cells do not duplicate their DNA and cannot mutate unless an active mechanism takes over. This is what we observe here: the action of insertion sequences (Frontloaded evolution). Peer

johhnyb: It seems that one of the antibiotics used was trimethoprim. Just as an example, you can find a discussion about resistance to trimethoprim here: http://cid.oxfordjournals.org/content/32/11/1608.full Many simple individual mutational events can cause resistance to antibiotics, usually modifying the target protein which is affected by the antibiotic itself. Transferable antibiotic resistance by plasmids or transposons is all another story: in that case, pre-existing complex molecules can be transferred by means of HGT mechanisms. See here: http://amrls.cvm.msu.edu/microbiology/molecular-basis-for-antimicrobial-resistance/acquired-resistance/acquisition-of-antimicrobial-resistance-via-horizontal-gene-transfer gpuccio