It's a known fact that cloned DNA is often (but not always) weaker and ages faster.
This is a murky statement. DNA is digital, and therefor capable of being perfectly copied without noise (not to say noise does not sometimes creep in, but in theory it can be perfect). The faster aging and increased number of defects in a clone is not a product of the cloning, but of the natural wear of entropy in the organism, whose somatic (non-reproductive) cell was then used to supply the genome for the clone.
This is mainly a worry in reproductive cloning, where that cell gives rise to the whole new organism. In cloning to produce stem cells, a larger population of cells can be created and culled to leave only the healthiest possibilities for use in regenerative therapy.
I hate picking nits, but what the heck. I frequently see "it doesn't use a nanomachine so it isn't nanotech" statements, here on slashdot and elsewhere. I think this is due to people thinking inside a box constructed years ago about what nanotech is. Is it biotech if it doesn't involve a living cell? What about if its a virus, or a modified protein? The Diamond Age isn't going to show up tomorrow. First there will be custom catalysts, chemistry-on-a-chip, a host of new materials, etc. I think it will be a good while before we actually build something that qualifies as a machine, but in the mean time there will be plenty of things worthy of the name nanotech.
I'm impressed that ION even managed to become something you could write a specific description about. A friend of mine who worked on ION for a while initially described it as "sales tracking software, already in version 4.0, without customers, and not ready for release." It morphed endlessly as different peoples' egos got hold of it. A recent VP said of it "All I can say is this: we will sell it, people will buy it, and it will be called ION."
Actually, its effects are worse than the taste. If you consume salt water, osmotic pressure sucks water out of your body to balance the salinity inside and outside. If you consume distilled water (distilled deionized water more precisely) your cells have to dump salt to raise the salinity outside cells to prevent osmotic pressure from causing them to swell and burst. You need both salt and water in the proper amounts, so losing either is bad, natch.
I wouldn't say there *has* to be >1 species. One species that gets energy photosynthetically and can recycle its own dead would also work. Dead cells would spill their contents which could then be directly absorbed or gradually be degraded by non-biological processes (seasonal temperature changes, photobreakdown, etc) into something less complex that can be.
Imagine a scenario where at the end of the martian spring these organisms throw off tough, highly resistant spores. Summer arrives, killing the adult organisms. The rest of the year's worth of abuse degrades them somewhat. Then, next spring the spores germinate and consume the previous generation before themselves producing spores.
I think there will be more than one species, however. It might just be a variety of species all trying to use the same strategy, or there could be room for several niches in what looks like a very simple ecology from way over here. I think the reason you don't see the number of species debated by scientists is that that would be jumping the gun somewhat. Just proving there is one species is a task not yet accomplished. Imagine you were a martian focusing your telescope on Earth. You can't say much about its life except that there is a lot of monospectral green (chlorophyll) down there. Debating how many kinds of green critters live there, until you can get a closer look, is best left to your martian science fiction writers.
So if the laws of physics can change over time, perhaps we're just in a small window in which they allow things like the chemical reactions necessary for life.
"But you can't go faster than the speed of light."
"Of course not, that's why scientists raised the speed of light back in 2260."
--Futurama
A couple of clarifications. There is a gene for AIF that produces a protein AIF. So you could purify the protein and inject it if you wanted, but like any drug it would be subject to diffusion throughout the body and eventual breakdown. Only by inserting the gene can you ensure a constant supply (though I'm not sure you'd want to).
Secondly, we can insert genes, but not the way we'd like to. I work in a lab where one of our major projects is finding a way to insert a liver enzyme into tumor cells. This would in effect turn the tumor into a tiny liver, so it will metabolize chemotheraputic drugs locally, killing it instead of your liver. The system works great...except we have no good way to deliver the gene to only cancer cells.
You can't just inject naked DNA into the body. Yes, it will be taken up, but most of it will be broken down. Secondly, if the DNA is just a basic plasmid, its copy number and segregation between the new halves of a dividing cell won't work well, and the cell is likely to destroy or silence the DNA. If you use something like a retrovirus, which actually inserts the DNA into the host genome (as HIV does), you have no control over where it will insert. This could end up damaging existing genes, or the body might just target and silence the gene, treating it like an inept virus.
There is another method, tweaking the natural repair system to make small changes in an existing gene. Its a really neat method, but its got a ways to go until its really usable, especially in an organism as opposed to cells in a dish.
So its possible but very difficult. Don't expect it to be commonplace this decade. To continue your analogy, we haven't got scapels yet, just sledgehammers.
Just to clarify a point, we didn't actually evolve from bacteria, we and bacteria both evolved from a common ancestor which produced both the prokayotic and eukaryotic domains.
Well, I did the Google search and I can't say I found much, though like you I haven't got time to read through 20 pages of hits. And I'm fairly sure that appearance on the Internet is not a good sign of truthfulness.
What exactly do you claim has been refuted, the occurance of organisms changing over time or random chance/selection as the driving force for change? The first is IMNSHO rock solid, we have plenty of evidence in the form of fossils, genetic homology, etc.
The second is more interesting to debate. Experiments have shown that a plate of bacteria can evolve antibiotic resistance faster than the rate of random mutation/selection should allow. Does this disprove evolution? Not any more than the observation of the first quantum phenomena disproved classical physics. Its these kinds of things that tell you that your theory is not wrong, just incomplete. With my study in this field, I've begun to get a feeling that life has "evolved to take advantage of evolution", so to speak. There are a number of events that show organisms playing an active role in the reorganization of their genomes, the most obvious being sexual exchange of genetic information, but also recombination between chromosomes in the formation of sperm and eggs. This is likely to be just the tip of the iceberg.
Anyway, I've tried avoiding telling you where to stick it, strong as the urge might be, but please read some more sites on that Google search. www.talkorigins.org/origins/faqs-evolution.html was a good one that caught my eye. We are smart enough to decode the genome, and we do fairly well at casting off old theories. The fact that we haven't cast off evolution should hopefully tell you it warrants further examination.
Actually, the number-of-genes calculation has been getting increasingly refined. Early rough guesses had it around 100k. This got revised down to 60k and we just let that stand pending actual sequencing of the genome. Now that that's been done, 60k turned out to be more like 32k once we ran the sequence through a computer to look for tell-tale signs of genes. Its not just statistical at this point, and I doubt there will be any further major revision of the number.
On the complexity side, each of these genes on average can produce at least 2 different versions of its protein through alternative splicing, so the protein complexity remains up around 60k. And each of these proteins can have more than one function, and each function can be combined with the activity of more than one other protein...
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This is a murky statement. DNA is digital, and therefor capable of being perfectly copied without noise (not to say noise does not sometimes creep in, but in theory it can be perfect). The faster aging and increased number of defects in a clone is not a product of the cloning, but of the natural wear of entropy in the organism, whose somatic (non-reproductive) cell was then used to supply the genome for the clone.
This is mainly a worry in reproductive cloning, where that cell gives rise to the whole new organism. In cloning to produce stem cells, a larger population of cells can be created and culled to leave only the healthiest possibilities for use in regenerative therapy.
I hate picking nits, but what the heck. I frequently see "it doesn't use a nanomachine so it isn't nanotech" statements, here on slashdot and elsewhere. I think this is due to people thinking inside a box constructed years ago about what nanotech is. Is it biotech if it doesn't involve a living cell? What about if its a virus, or a modified protein? The Diamond Age isn't going to show up tomorrow. First there will be custom catalysts, chemistry-on-a-chip, a host of new materials, etc. I think it will be a good while before we actually build something that qualifies as a machine, but in the mean time there will be plenty of things worthy of the name nanotech.
I'm impressed that ION even managed to become something you could write a specific description about. A friend of mine who worked on ION for a while initially described it as "sales tracking software, already in version 4.0, without customers, and not ready for release." It morphed endlessly as different peoples' egos got hold of it. A recent VP said of it "All I can say is this: we will sell it, people will buy it, and it will be called ION."
Just my factoid for the day.
Imagine a scenario where at the end of the martian spring these organisms throw off tough, highly resistant spores. Summer arrives, killing the adult organisms. The rest of the year's worth of abuse degrades them somewhat. Then, next spring the spores germinate and consume the previous generation before themselves producing spores.
I think there will be more than one species, however. It might just be a variety of species all trying to use the same strategy, or there could be room for several niches in what looks like a very simple ecology from way over here. I think the reason you don't see the number of species debated by scientists is that that would be jumping the gun somewhat. Just proving there is one species is a task not yet accomplished. Imagine you were a martian focusing your telescope on Earth. You can't say much about its life except that there is a lot of monospectral green (chlorophyll) down there. Debating how many kinds of green critters live there, until you can get a closer look, is best left to your martian science fiction writers.
"But you can't go faster than the speed of light."
"Of course not, that's why scientists raised the speed of light back in 2260." --Futurama
Secondly, we can insert genes, but not the way we'd like to. I work in a lab where one of our major projects is finding a way to insert a liver enzyme into tumor cells. This would in effect turn the tumor into a tiny liver, so it will metabolize chemotheraputic drugs locally, killing it instead of your liver. The system works great...except we have no good way to deliver the gene to only cancer cells.
You can't just inject naked DNA into the body. Yes, it will be taken up, but most of it will be broken down. Secondly, if the DNA is just a basic plasmid, its copy number and segregation between the new halves of a dividing cell won't work well, and the cell is likely to destroy or silence the DNA. If you use something like a retrovirus, which actually inserts the DNA into the host genome (as HIV does), you have no control over where it will insert. This could end up damaging existing genes, or the body might just target and silence the gene, treating it like an inept virus.
There is another method, tweaking the natural repair system to make small changes in an existing gene. Its a really neat method, but its got a ways to go until its really usable, especially in an organism as opposed to cells in a dish.
So its possible but very difficult. Don't expect it to be commonplace this decade. To continue your analogy, we haven't got scapels yet, just sledgehammers.
Just to clarify a point, we didn't actually evolve from bacteria, we and bacteria both evolved from a common ancestor which produced both the prokayotic and eukaryotic domains.
Well, I did the Google search and I can't say I found much, though like you I haven't got time to read through 20 pages of hits. And I'm fairly sure that appearance on the Internet is not a good sign of truthfulness. What exactly do you claim has been refuted, the occurance of organisms changing over time or random chance/selection as the driving force for change? The first is IMNSHO rock solid, we have plenty of evidence in the form of fossils, genetic homology, etc. The second is more interesting to debate. Experiments have shown that a plate of bacteria can evolve antibiotic resistance faster than the rate of random mutation/selection should allow. Does this disprove evolution? Not any more than the observation of the first quantum phenomena disproved classical physics. Its these kinds of things that tell you that your theory is not wrong, just incomplete. With my study in this field, I've begun to get a feeling that life has "evolved to take advantage of evolution", so to speak. There are a number of events that show organisms playing an active role in the reorganization of their genomes, the most obvious being sexual exchange of genetic information, but also recombination between chromosomes in the formation of sperm and eggs. This is likely to be just the tip of the iceberg. Anyway, I've tried avoiding telling you where to stick it, strong as the urge might be, but please read some more sites on that Google search. www.talkorigins.org/origins/faqs-evolution.html was a good one that caught my eye. We are smart enough to decode the genome, and we do fairly well at casting off old theories. The fact that we haven't cast off evolution should hopefully tell you it warrants further examination.
Actually, the number-of-genes calculation has been getting increasingly refined. Early rough guesses had it around 100k. This got revised down to 60k and we just let that stand pending actual sequencing of the genome. Now that that's been done, 60k turned out to be more like 32k once we ran the sequence through a computer to look for tell-tale signs of genes. Its not just statistical at this point, and I doubt there will be any further major revision of the number.
On the complexity side, each of these genes on average can produce at least 2 different versions of its protein through alternative splicing, so the protein complexity remains up around 60k. And each of these proteins can have more than one function, and each function can be combined with the activity of more than one other protein...