Is Evolution Science?

crashfrog responds to

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Science is OBSERVABLE. Evolution isn't!

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Sure it is. Rrhain has an experiment you can do in your own biology lab (I love when he says that)

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Ooh...then perhaps I should say it more often. Though, that runs the risk of it becoming a stock phrase and thus losing its effectiveness. Drat these difficult decisions!

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where bacteria evolve resistance to disease, and then the disease evolves new ways to atack the bacteria. You can watch it happen and observe evolution.

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And the best thing, it doesn't cost a lot of money.Take a single E. coli bacterium of the wild, K-type. This type of bacteria is susceptible to a type of virus called T4 phage. So you take this single bacterium and let it reproduce to form a lawn. Then, infect the lawn with T4 phage.What should we expect to happen?That's right, plaques of dead bacteria start to form. The phage is infecting them and, since they are susceptible to T4 phage, they start to die.But we also see some colonies within the plaques merrily living without a care in the world, surrounded by live, active phage.How can this be? Remember, all the bacteria are descended from a single ancestor whom we knew to be susceptible.That's right...the bacteria evolved. In fact, they are now called K4-type because they are resistant to T4 phage.But wait. Let's continue. Take one of the K4 bacteria and again, let it reproduce to form a lawn. Now, infect the lawn with T4 phage.What should we expect to happen?That's right: Absolutely nothing. These bacteria are resistant to T4 phage and thus, the phage should have no way to establish itself.But what do we actually see? Instead, we see plaques starting to form again. How can this be? Remember, all the bacteria are descended from a single ancestor that was resistant to T4 phage. So how could any of them be dying?We now have to figure out which one evolved. A little thought will show that it has to be the phage that evolved, not the bacteria. See, if a bacterium experienced a reversion mutation such that it would be susceptible to T4 phage, it would immediately be infected and killed, leaving it surrounded by K4 bacteria which would immediately take over the space just vacated. In short, K-type bacteria could never take hold.Instead, it necessarily must be the phage that evolved. And, in fact, we call these phage T4h because they have experienced a "host" shift.So there you go. Evolution right before your eyes. And it doesn't take that long to do. Many high schools do this experiment.------------------
Rrhain
WWJD? JWRTFM!

prophecyexclaimed responds to me:[description of the E. coli/T4 experiment deleted for space]

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This isn't evolution this is call immunities.

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Nope. Can't be. If it were immunity, then it would be something that all the bacteria could do since they are all descended from a single ancestor, remember? (Hmmm...perhaps I shouldn't have deleted the description of the experiment.)What you are claiming is that there was some hidden or dormant or masked ability within the bacteria to fend off the phage. But if that were true, then the entire lawn should behave the same way. If one is immune, then all are immune because they all come from the same singular source.

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Ever hear of the Native Americans? If not listen to this: When the Europeans came to America they brought disease that they were already immuned to from being around it and being infected with it and dying from it.

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Yeah...they were completely wiped out.

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Ever hear of vaccinations? Same concept. Don't give me that, I know the difference between gaining immunities from disease and Evolution!

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Who vaccinated the bacteria? I know it wasn't in the description. Damn...I need to describe it again, don't I?You take a single bacterium. You do know what that means, right? Just one. Only one. You then let that single bacterium reproduce until it forms a lawn. You then infect the lawn with phage.Now, if there was immunity to this phage, then they should all survive. But since the exact opposite is true, we determine that the problem is that there is no immunity.If any one of these bacteria is immune, then they're all immune because they're all genetically descended from a single ancestor.So where on earth did they get this immunity from? If one can do it, then they all can do it. Why did only a few bacteria survive? Why not the whole lawn?

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For the bacteria starting to die again, the answer is this: they weren't strong enough, their immunities gave in. Not Evolution!

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You obviously didn't read my post. Here it is again: The same thing applies even if we think it's an immune response: We started with a single ancestor that was immune to T4 phage. It reproduced to form a lawn. Any bacterium that had lost that immunity (how? They're all descended from a single ancestor that was immune) is surrounded by bacteria that still have it. So let it die...it merely makes room for the immune bacteria to reproduce and fill in.Thus, we would never, ever see any plaques: All the bacteria that "weren't strong enough" would die and be replaced by those that were.But that isn't what we see. Instead, we get to watch the lawn die.------------------
Rrhain
WWJD? JWRTFM!