The Gene for Abstract Thought

Originally posted by Astrocyte
Care to clarify? If the numbers of genes are more or less the same - and the genes in question are the same,

Let's start by making your question less fussy and remove the "more or less the same" and replace it with "same", and the genes being the same. Then we'd have two "copies" of the same creature. Say, a human, or a sheep.

If we the human gene-pool instead, we normally have tiny differences between each other. These errors are, as you probably already know, due to both the errors in DNA-replication as well as us breeding and creating a mix of genes. The end result is genes from two parents + some individual mutations. This is a fact shown to us by DNA-analysis. Nothing particularly strange there.

how can two utterly different species arise from this same informational pool?

The above should already answer it, but our early human history showed what happens when we live in our own groups. Africans, Europeans, Indians (both kinds), Asians.. We can see slight physical differences in appearance, just from the fact that we lived in groups and got a specific gene-pools within them that gave us physical traits.
Still, we humans are very similar as our genes differ extremely little that it in most cases makes no difference at all in the job of being a human.

There is a reason why we name something to be a new kind of species only after many many many years, and it is that this process is so extremely slow.

However,
look at what we've done, if we focus the effort:




We shrunk, changed color, made it fluffy (and hairier all over), we removed the nose, and maybe removed a claw or two (I have no idea), changed the tail, in very few years compared to what it would take for nature to do the same.
And that was just done by breeding.

That's the thing. Species do not "split" spontaneously, they evolve. We're the ones who put labels on organic matter, the organic matter isn't aware of it being a specific type of species. If you have wings or live under the water doesn't matter to anyone else than us.

I don't see how someone can be so closed minded to the fact that genes are either a) far too complex for our finite minds to comprehend

Am I close-minded because I want us to learn all we can about DNA? Aren't you the one trying to ignore the fact that we have discovered the blueprints to organic life, and that we, in theory, know how to grow any species in a lab, and are fighting partly with mere practicalities and the moral dilemma? That we already can construct our own species by using this very thing?

or b) there may be some some non-physical source which "informs" DNA, which causes the corpus of genes to interact in such a way to produce a fin instead of a hand.

No, because we can see in the DNA wether or not the creature has a fin or not. DNA without a fin doesn't grow a fin. All fin-bearing creatures have an active fin-gene, (side-note: except those who have a part on their body that merely looks like a fin to us with untrained eyes).

reply to post by Nevertheless


Appreciate the reply. I'll try to tone down the fussiness.

There is a reason why we name something to be a new kind of species only after many many many years, and it is that this process is so extremely slow.

Sorry. You still haven't explained how the same genes create species wide divergences.

I wont pretend to be a genealogist. I have read a few books on the subject and many other books on biology and the brain (I study neuroscience) so I'd imagine myself to be somewhere between an ignorant laymen who knows nothing and someone who spends their days and nights immersed in understanding how genes work.

Basically, I know the gist of how genes are passed on. I understand how complicated the interactions within species can become - how, for instance, monozygotic twins usually have a 40-60% chance of both inheriting a "gay gene" (or more likely a set of genes). But WHAT causes one twin to inherit the gene while the other one doesn't is unknown. Why? Because in all likelihood, genes work as a package. It's said that any cell nucleus contains the DNA for the whole bodies structure. This is an inference - it's not understood HOW it happens, it's just known to indeed be the case.

In short, there seem to be insurmountable difficulties and complexities in establishing species wide divergences. How a mouse and a human can share almost the exact same gene pool. Within this gene pool, only some genes are "master genes" doing all the work of getting the body plan rolling. So in fact, it is a relatively small number of genes that makes a mouse a mouse and a human a human. But between a mouse and a human - macroscopically speaking - is a massive world of difference.

We shrunk, changed color, made it fluffy (and hairier all over), we removed the nose, and maybe removed a claw or two (I have no idea), changed the tail, in very few years compared to what it would take for nature to do the same. And that was just done by breeding.

The Soviets successfully turned a fox into a dog after a few generations of selective breeding. I'm not denying this. I know species evolve to conditions in the environment. I'm merely saying "how"? Current genetic theory seems vague in explaining how a few genes can create such massive macroscopic differences between species

That's the thing. Species do not "split" spontaneously, they evolve. We're the ones who put labels on organic matter, the organic matter isn't aware of it being a specific type of species. If you have wings or live under the water doesn't matter to anyone else than us.

.

Yes, I've read Origin of the Species. This doesn't explain the problem of how a few genes can create a horse, elephant and a fly.

What I said before is merely a repetition of what many scientists actually advise: don't turn theory into dogma. Keplers idea were replaced by Copernicus, who was replaced by Newtons, who was supplanted by Einstein. This doesn't mean Kepler, Copernicus, and Newton were wrong, but rather, that they had an incomplete picture. Who would have thought the world was as complicated as current quantum physicists postulate? This is what I'm saying: there might be another layer to DNA and genes that can't be located "within" a genes physical structure.

And nevermind the added difficulty of inconsistency between fields. Current genetic theory is in line with traditional Newtonian physics. Yet, Newtonian physics has been superseded by Quantum mechanics as a more correct understanding of physical reality. Shouldn't we be preparing for a time where the source of the information for genes is found in the ether - in the same place where "atoms" and "quarks" live? Obviously, at our current point in this scientific odyssey, it would be premature to explore this question. Yet, it stands to reason that the information which guides genes is somewhere 'out there' in the same non-material sense as electrons, protons and neutrons.

I suspect the relationship between genes and the information which guides its activity is similar to the Semitic Alphabets. The genes which contain the information for the organic structure of an organism are the consonant sounds formed by the organs of the mouth. Whereas the "information" which guides it would be like the vowel points beneath letters. Vowels are elusive creations of the breath. It doesn't ricochet off the palate, labia, etc, but rather, works "within" consonants the way information works within genes.

Am I close-minded because I want us to learn all we can about DNA? Aren't you the one trying to ignore the fact that we have discovered the blueprints to organic life, and that we, in theory, know how to grow any species in a lab, and are fighting partly with mere practicalities and the moral dilemma?

That's an overstatement. There's also a serious dearth of knowledge. Consider for example that we don't know WHAT long term consequences there would be to genetically modifying organisms. Already, there are plenty of scientists who believe GMO fruits, vegetables and grains may create disease. Who are we to believe we can one up nature? Doesn't nature follow the principle of homeostasis? And isn't changing the genetic structure of an apple a perturbation of that balance? Take for example the fact that variety promotes ecological stability. When we grow the same types of apples, wheat etc, we actually threaten our food supply when a blight attacks a particular variety of food. We didn't know that. Now that we do, we've begun to take precautionary measures against that.

Don't get me wrong. I am genuinely excited about the possibilities of gene therapy. But I'm also cautious enough to wonder: what sort of consequences could there be? People aren't guinea pigs. I know to a scientist (and I consider myself scientifically inclined) the libertarian idea of human dignity can make you a bit squeamish. You'd like to think in terms of probability: if a few people die (which will obviously happen) for the sake of advancing our medicine, more people will eventually be saved. That may be true, but it doesn't feel right. It strikes one of eugenics.

Originally posted by Astrocyte
Sorry. You still haven't explained how the same genes create species wide divergences.

I think we both did in our posts where we stated that we are even able to modify a species drastically by selective breeding. We can choose one, two, three or a million different targets and breed towards those goals.

Clearly, making a bird out of a dog is a ridiculous thought, considering that such a split occurred in a very very early stage of life on this planet, where "simpler" organisms weren't already as divergent as mammals, birds and reptiles. Surely you can play with the thought of a simple lump of cells being able to evolve in quite a lot of different ways depending on the requirements to survive? Something prone to plenty of water has different requirements to that of a bunch that are getting exposed to more dry environments (which in order can then benefit those to whom rain is sufficient.. and those that can get some movement going on on ground, as swimming doesn't help).

Surely you can see the split occurring of beneficial mutations of a single species, where "beneficial" is completely dependent on the surrounding of that subgroup, causing a species becoming several different?

I wont pretend to be a genealogist.

Neither will I.

Basically, I know the gist of how genes are passed on. I understand how complicated the interactions within species can become - how, for instance, monozygotic twins usually have a 40-60% chance of both inheriting a "gay gene" (or more likely a set of genes). But WHAT causes one twin to inherit the gene while the other one doesn't is unknown. Why? Because in all likelihood, genes work as a package. It's said that any cell nucleus contains the DNA for the whole bodies structure. This is an inference - it's not understood HOW it happens, it's just known to indeed be the case.

We have the same problem with quantum mechanics, it doesn't mean that we have any reason to overthrow it. Science is beautiful that way, that what we see happens, happens. We know it's the DNA regardless of how exactly the selection occurs.

How a mouse and a human can share almost the exact same gene pool.

Because we originate from the same thing.
I suspect that the problem you may be having is your definition that we share "almost the exact same gene pool, and compare it to something humanly relevant, as a product consisting of the same components and therefore being almost the exact same product. Evidently, organic life shares a lot of the same genes because we're all from the same thing. Evidently, the "few" genes are what differs. Evidently, we can take DNA, and DNA only and create that life, if we get all the practicalities out of the way. That is just how it is.
Maybe I have never seen this almost the exact same the way you do because when dealing with software, it's everyday business to create extremely different things from the same building blocks. All that they share is a simple set of blocks and rules.

Within this gene pool, only some genes are "master genes" doing all the work of getting the body plan rolling. So in fact, it is a relatively small number of genes that makes a mouse a mouse and a human a human. But between a mouse and a human - macroscopically speaking - is a massive world of difference.

Yes, fascinating, isn't it?
Try the extremely simple old simulation "game of life" (which you've probably seen many many times) and realize the fact that even with a very simple set of rules, something can grow "out of nothing" without any intelligence at all.
For additional fun, google after interesting models to start with, and be amazed.

I only want you to think about that to realize that you do not necessarily need a lot of information to "explain" to nature how to build something. It does it due to the laws of physics and a specifict starting condition. The DNA.

I'm running out of characters and time, so I won't be able to answer to the rest. But peeking forward, I just want to say that I'm not saying that we already know everything, and plenty of what we know about the DNA will be cleared out and guesses will be corrected. What I just want you to understand is that it is not that strange that "so little" information can do so much. Freakin' amazing it is, but it is not strange. There is no reason to doubt that because we can see that that is the case. We still have a long way to go until we can make a "game of life" program that takes in DNA and shows what comes out of it.

And also, yes, I don't think we should be playing "gods" either. I can see the problems as well as you do.

Basically, if it was the food source or the solar radiation or anything else natural on Earth that caused the first mutations for abstract thought, why aren't there any OTHER terrestrial creatures that come close?

Human civilizations, after all, didn't develop until very late.