Friday, November 04, 2005

 
Evolution and Bird Flu

Let me cut to the quick. People are using "evolution" to mean microevolution and macroevolution. An example of microevolution does not establish macroevolution. No one has a problem with microevolution.
The origin of the Avian Flu is indeed an example of evolution. However, as many of us learned in school, evolution can simply mean change over time. Scientists suspect that this new "Avian Flu" strain of the flu virus arose because two flu viruses (probably one previously in humans, and another in birds), swapped genetic material in a process known as "reassortment."

This reassortment thus happened when there was a coinfection of two viruses in the same cell, and then the resulting viruses that came out were a mixture of the genes in two different viruses. This process is analagous to horizontal gene transfer, which has been identified in bacteria as a way for spreading antibiotic resistance. This link provides an excellent graphical illustration.

So our fight to combat the Avian Flu is undoubtedly a fight against evolution. The question is, has there been a net increase in genetic information through this "evolution"? The Avian Flu is essentially the swapping of genes--but its genes probably came from other pre-existing viruses.

One new twist on the Avian Flu is that it can infect organs other than the lungs and cause damage to greater parts of our bodies. This more widespread attack has caused some fatalities. The fact that the Avian Flu can activate this protein in other places probably has something to do with its new configuration of genes. But we're really not dealing with anything new.

Viruses are always mutating to avoid detection by our immune system by becoming something that current antibodies can't recognize. Thus, many viruses survive by having extremely high mutation rates. However, viruses only mutate at a certain rate or they will mutate themselves into oblivion.

Thus, there are limits to the amount that viruses can mutate. When they breach this limit they will experience "error catastrophe." Even virus populations which don't breach this limit can experience permanent fixation of deleterious mutations. Indeed, some scientists are trying to create vaccines for HIV by targeting viruses in the very sites where they can't mutate. The limits are wider than what our immune system can handle at any given time and often when we are sick, it is because a virus has mutated into something our immune system cannot immediately target. But still, even the evolution of viruses has limits. Some researchers have called this the "mutation limit."

The reason that the Avian Flu is succeding thus far is because when the two previously-existing viruses swapped some genetic material and created Avian Flu strains, its current configuration is different enough from microbes our immune systems can already target that many people are unable to fight off the virus.

But it's evolution within limits, and it's evolution that generally uses pre-existing genetic material. After all, the current strains of the Avian flu are nothing more than viruses, which are descended from nothing more than a line of billions upon billions of generations of viruses, which, as far as we can tell, have always been viruses, and aren't becoming anything other than more viruses.

Comments:
This is a weak argument. You are accepting part of the theory and rejecting the other, strictly based on when it suits your needs. The mechanisms described in both "microevolution" and "macroevolution" are the same. This distinction that you make is one of convenience. Basically, what you are saying is that you accept every part of evolution except for the one that says a species can evolve into another, more complicated species.

The fundamental problem here is this: you are not arguing science with science. At the heart of your argument is an issue of religion (i.e. faith). By the very definition, faith is something that can only be logically argued up to a point. You can only have so much evidence one way or another. At some point, you have to make that leap that turns a belief into faith rather than just a strong opinion.

You accept that evolution happens because you have to. There is clear evidence that you are not disputing (what you are calling "microevolution"). Yet you arbitrarily draw a line and say that the rest is not true. Now, here is this evidence to suggest that the rest may very well be true. Yet yo provide no counter evidence to suggest anything else to be the truth. You are trying to argue religion on science's turf. You can't win that battle any more than a scientist could come into a church and debunk religion.

Hwang
 
I should also point out that it is not just a matter of two pre-existing genes. Genes can mutate and if that mutation provides a function benefitial to an organisms surroundings, it can--and sometimes does--thrive.

Hwang
 
Viruses becoming viruses is not shocking. Nor does it dispute anything I would hold. So I see no need to provide counter-evidence. Counter-evidence against a straw man? Why would I do that?

What I'm saying is that the mechanism that undergirds macroevolution, mutation, can't do everything you want to claim about it. What your comments, and the comments of many others to be fair to you, show is a faulty assumption about those who oppose some or all of atheistic evolution. We understand that mutations and changes occur. But viruses are becoming viruses. And the main question would be if mutations produce any net gain of information in a system. These apparently don't.

This line is not arbitrary. Just because we accept the mechanism doesn't mean we have to accept everything you want that mechanism to accomplish. That's the whole point of concepts like irreducible complexity. There are things in nature which are so complex and inter-dependant that mutation over time cannot explain their existance.

But we can always rely on the Darwin of the gaps. I know that looks like a city grid inside the human cell or an outboard motor on a boat. But there could possibly be a way that could have evolved.

That's just faith in materialism.
 
Post a Comment

<< Home

This page is powered by Blogger. Isn't yours?