How do genetic engineers rely upon evolution when they produce human insulin in vats?

Let's try a thought experiment. You're a fan of chocolate cake and across the street are two restaurants which serve chocolate cake. So you go into the first restaurant and order a piece and eat it and it tastes good. Then you go into the second restaurant and order a piece and eat it and it tastes EXACTLY the same as the other one. You get two pieces to go from the two restaurants and take them home and analyze them, and you can't tell them apart.

Here's what you don't know: the cook in the first restaurant only speaks Russian and the cookbook he used to make the cake is written in Russian. The cook in the second restaurant only speaks Hindi, and the cookbook he used was written in Hindi. But they were both translations of the same cookbook, and in fact both cooks were using the same recipe. Also, both restaurants get their supplies from the same supplier. So the cakes came out the same way. They are completely indistinguishable.

The importance here is to differentiate between information (the recipe), material (flour and chocolate) and encoding (the language in which the recipe is written) and to understand that the encoding has nothing whatever to do with the others.

When you eat a piece of cake, the recipe for the cake is important, but the language in which the recipe is written is not important. The information is important, but the encoding is not important, as long as the cook understands the encoding and can thus derive the information from the stored representation.

On the other hand, you can certainly tell the difference between chocolate cake and angel-food cake. In that case, the actual recipes themselves are different. And the resulting cakes would be different if their recipes were written in the same language, or if they were written in different languages. The recipes (the information) matter, but the languages (the encoding) don't.

The "recipe" for a human being is the genetic information held in our 23 pairs of chromosomes. It's written as a sequence of codons, and for each entry there are four choices which are usually referred to as A, C, G, and T (the first letters of the four chemicals which are used). A human is made of proteins, and the genetic code describes how to make about a hundred thousand of them. Each of those proteins is a chain, sometimes short and sometimes long, made up of amino acids, of which there are 20. So the trick is to figure out how to convert sequences of DNA into proteins -- how to bake a human from the recipe stored in the chromosomes. It ain't easy.

The way you make a protein is by taking the DNA entries in threes. (Actually, the DNA gets converted into RNA first, but...) Because there are four choices for each of the three positions, the total number of combinations is 64, and there's a chart which shows how each of those 64 translates into a specific amino acid -- with three exceptions. Three of the entries are "stop", and what that means is "this is the end of this protein; stop adding amino acids and start using it." So the chart has to make it possible to access all 20 amino acids, and it has to be able to encode a "stop". But there's no particular rhyme or reason to the way that they're assigned to the chart; it's totally arbitrary. The recipe for a cake can be written in Russian or Urdu or any of a hundred other languages, and equally, there are a large number of "languages" in which the recipe for a human could be written representing different ways that this chart could be laid out. In fact, the number of possible "languages" is truly gargantuan. And any of them could be used, and as long as the "recipe" (the descriptions of those hundred thousand proteins) were translated to match the language of that chart, the result would be the same, and you'd still bake a human.

There are 64 entries and 21 essential values which must appear in that chart. The total number of possible ways in which the encoding could take place is 21 factorial multiplied by 43 to the 21st power.

21 factorial guarantees that every one of the essential values appears at least once. The other 43 entries each can contain any of the 21 values, which means 43 to the 21st power possible combinations to fill the chart out.

That's a REALLY BIG NUMBER.

But the one thing which is necessary is that every member of a particular species use the same chart, because otherwise they wouldn't be able to breed. I got half my genes from my dad and half from my mom, and they better be encoded the same way, or my body isn't going to know how to understand them.

It is, however, NOT necessary for members of DIFFERENT species to use the same chart. This is critical. The encoding is arbitrary; as long as it's used consistently within a single species. There is nothing special about the particular chart that humans use; nothing to prefer it to any of the other charts which are possible. All that's important is that every human use the same one.

In fact, by simple observation of a living organism and how it relates to its environment, there is no way to tell what encoding chart it uses. Actually, that's not quite true. There is one and only one way to actually tell that two different species use the same chart, though even here you cannot tell what chart it is. If a virus has the ability to move from one species to another, then it means both species use the same chart, because it means that they both interpret the genetic information in the virus the same way. We can prove that swine, geese and humans all use the same chart because all of us get influenza and the disease can move between us. But if you have two species which cannot trade viruses, there's no way to tell if they use the same chart. There are no viruses known which infect both Sequoias and humans. So there's no way of proving that we use the same chart as redwood trees.

However, the chart can be determined for any given species by laboratory analysis.

So here's where we reach the central point: [i][u]EVERY KNOWN SPECIES USES EXACTLY THE SAME CHART.[/i][/u]

This precise chart is used by bacteria, by fungi, by animals, by plants, by the slime on the bottom of the ocean, by EVERYTHING living. No exception has ever been found. There's nothing particularly special about that particular chart except for the fact that it's the one that everything uses. Any of the other 21!*4321 possible charts could have been used instead, except that none of them were. Evolution DEMANDS this because evolution predicts that ultimately everything alive started from a single original living cell. Evolutionary theory basically says that the initial creation of life was a low probability event, but that once it happened it spread very rapidly. Therefore, there was no opportunity for it to happen twice. Because of that, everything uses the same chart.

And it happens to be the case that this is so fundamental that any mutation in this area must have overwhelming effect on the organism, so overwhelming that the chance that it would be alive is essentially zero. Remember those hundred thousand proteins which make up a human? Changing one of these 64 entries would alter perhaps 5,000 or 10,000 of those in random ways; the chance of surviving this is so low that we can forget about it. All it takes is one critical protein being changed enough so that it can't carry out its function, and we have a stillborn baby. And the same thing is true for other organisms. So this encoding is mutation-proof. Any organism suffering a mutation in this area would simply die instantly because too many critical proteins would be built incorrectly.

But Creationism doesn't require a single chart for all species. A single chart is not contradictory to the theory (because in fact NOTHING is contradictory to creationism, it happens to be unfalsifiable) but it's also not required. In a creationist scenario, there's no reason why the recipe for a lion couldn't be written in Swahili and the recipe for a Zebra be written in Zulu, which is to say that the recipe for a lion would use one chart and the recipe for a zebra use an entirely different and unrelated one. It is completely plausible under a Creationist scenario for every species to have its own chart. From external observation of the organisms and the way they live, it would be impossible to tell the difference between this case and the one where all of them are using the same chart (except for the behavior of viruses, as explained above). The lion could still eat the zebra and find it delicious, and no-one would ever know.

But in fact, they all use the same chart, and this fact is an essential part of evolutionary theory. And that brings us to our genetic engineers who are using evolutionary theory to get useful things done. The example I gave was the production of huge amounts of human insulin.

Genetic engineers have located the place in the human genetic library where the recipe for insulin is located and have extracted it out. They then produced what's called a plasmid, a ring of genetic material which includes the recipe for insulin plus a few other critical things like activation sequences. This plasmid was then injected into an E. Coli, which has by now reproduced and had billions of offspring all of which carry that same plasmid. What that plasmid does is program those particular E. Coli so that in addition to doing all the normal things that they do to stay alive and reproduce, they also produce a lot of human insulin along the way. Grow a big vat full of these things, then process it and extract out the human insulin, and you have a valuable and life-saving commercial drug. It has changed the lives of diabetics worldwide, because before this the only source of insulin was through processing of pancreases of pigs and cattle gotten from slaughterhouses, and while those forms of insulin are very similar to human insulin, they aren't identical and they don't work quite the same way, and in some cases some human diabetics had allergic problems.. Human insulin is simply better since it is exactly the form we really need, and has pretty much become the standard form used to treat diabetes.

The reason that genetic engineers can use E. Coli to reproduce human insulin is because E. Coli interprets DNA exactly the same way that a human does. Suppose that E. Coli had a different chart. In that case, while that genetic sequence could be inserted into the E. Coli, the E. Coli would interpret it entirely differently and produce something else entirely -- probably something completely useless, but whatever it was, it wouldn't be insulin.

But E. Coli does use the same chart as humans, so E. Coli understands the recipe exactly the same way that a human does, and therefore the E. Coli does make human insulin from the recipe, just as the genetic engineers expect it to.

The recipe for every single living organism is written in exactly the same language. This is an essential prediction of evolution. If this were not true, eventually the genetic engineers would notice because one of their experiments in genetic modification would fail because the DNA sequence they've programmed will be interpreted wrong.

But that's never happened. Evolutionary theory predicts that everything alive uses the same chart. Genetic engineers are using that prediction to do their work -- [i]and they're getting the right answer[/i]. Every time they do so, they're testing Evolution and proving that it is true.

If anyone ever finds an organism here on earth whose encoding chart is completely different than the one we know now, and as I mentioned there's an astronomically large number of possible encoding charts, someone's going to have a lot of explaining to do. (At the very least it probably represents an independent creation of life from the one we all know of now, though it may not mean that evolution didn't happen thereafter. But there will certainly be a lot of fundamental reappraisal of evolutionary theory.) If someone found a whole series of organisms and every one of them had a different chart, then overall Evolutionary theory as an explanation of the origin of life would be toast and we'd be back to square one. (Which is why creationists who claim that evolution is unfalsifiable are lying.)

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The recipe for every single living organism is written in exactly the same language. [red]This is an essential prediction of evolution.[/red] If this were not true, eventually the genetic engineers would notice because one of their experiments in genetic modification would fail because the DNA sequence they've programmed will be interpreted wrong.

But that's never happened. [red]Evolutionary theory predicts that everything alive uses the same chart.[/red] Genetic engineers are using that prediction to do their work -- [i]and they're getting the right answer[/i]. Every time they do so, they're testing Evolution and proving that it is true.

The recipe for every single living organism is written in exactly the same language.

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I would like to know how he is going to explain how the first cell of any living thing knew which switch to flip in order to form its hand, antler, horn, etc.....

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[Wicked Witch of West's Marching Guards mode]

Ho-ME-O B-O- X
Ho-ME-O B-O- X

[/Wicked Witch of West's Marching Guards mode]

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Come now, where are all of the scientist on this board that have an answer for such a simpleton as I?

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No, no all wrong.

My GOD "skitzophrenia" personally told me how he created the universe and it is NOTHING like anything you said. Since my GOD told ME personally everyone else is wrong and only "I" am right.

Also becasue everyone else is wrong, you guys are all going to eternal damnation town and only "I" and a chosen few are going to be saved.

PS, if you even try and argue with me you will only PROVE that you are possessed by "assholy" Lord of the Underground and are trying to undermine my faith. And for that you will also be damned.

Have a nice day. [:)]

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I just gave you the answer.

Homeobox.

It's a global gene regulation system based on the influences of cellular position in the developing early embryo.

The exact location of each cell VERY early in embryo development dictates which set of homeobox genes will be activated and that homeobox gene then regulates which sets of genes will then be "switched on" during embryo development for making an eyeball or a leg or a liver out of those cells.

The "switching on" of those homeobox genes are partly what triggers terminal differentiation or "the point of no return" for cells destined to be come skin, liver, bone or nerve cells.

By switching the position of as-of-yet undifferentiated embryonic cells in a fly for example, one can force a leg to develop out of the top of the fly's head where an antenna should be.

[%|]

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Then what determined the switches in [b]the[/b] first cell?

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I don't know.

I didn't design it. [:)]


And that's what I tell my students. [;)]

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That's where we part then, because I do, and I will continue to state it. [b]GOD[/b]

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Actually "we" don't part there.

I just don't bring up God in "science" class.



But dat don't mean I done don't buhlieve in God tho! [brick]

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I do! Science was made by him.

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To each his own.

But when I'm describing how to run a gel or how to bake a cake I don't include "God allowed the ions to flow" or "God allowed the cake to rise". It just "happens" by nature following nature's (God's) laws.

If you're explaining how to change a flat tire, do you say that "God turns the lugnuts" or do you simply describe the basic mechanism behind [i]changing the flat tire[/i] and leave theology out of it?

I view "science" like that. Very mechanistic. And that's the way God made it, IMO.



No flame taken [;)]

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Come now, you took that wrong on porpus. When explaining where the atoms that make up everything came from, I clearly state that it was God that made them.

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Yep. The "Big Bang" is a lot like the story of creation in Genesis. I'll have to dig up that old side-by-side comparison. Science supports a lot of the basics of the creation account it seems.

But I gotta go do some REMing now.  

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You need a new god!

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Been waiting for this all night.

There is only ONE Skitzophrenia. [:D]

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Entertaining read. But a bit flawed in a couple  areas. I highlighted one.

Evolutionary theory doesn't really "predict" that all living things use the same DNA. The theory is DERIVED from that observation (and others) using inductive reasoning.

The general principle of evolution was created by examining the regular pattern in specific cases, not the other way around.

It's almost a circular (and hence, trivial) statement to say that the specific cases we observe regarding DNA support the general principle of evolution which was BASED in part on those specific observations.

I do however like the example of stop codons and how they're so well conserved in nearly all living organisms - well beyond mere chance. I'll have to use that as an example next time I lecture on "evolution".


And BTW...

It's not EXACTLY the same language for all living organisms. There are quite a few big differences between eukaryotic and prokaryotic DNA structure and gene expression.

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So this encoding is mutation-proof. Any organism suffering a mutation in this area would simply die instantly because too many critical proteins would be built incorrectly.