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(Discover)   20 things you didn't know about DNA, but were too afraid to ask without getting labeled an ubergeek   (discovermagazine.com) divider line 37
    More: Interesting, DNA, venom  
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7851 clicks; posted to Geek » on 26 Jun 2011 at 9:30 AM (4 years ago)   |  Favorite    |   share:  Share on Twitter share via Email Share on Facebook   more»



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2011-06-26 09:10:31 AM  
21 Most DNA sequences are poly-functional and so must also be poly-constrained. This means that DNA sequences have meaning on several different levels (poly-functional) and each level of meaning limits possible future change (poly-constrained). For example, imagine a sentence which has a very specific message in its normal form but with an equally coherent message when read backwards. Now let's suppose that it also has a third message when reading every other letter, and a forth message when a simple encryption program is used to translate it. Such a message would be poly-functional and poly-constrained. We know that misspellings in a normal sentence will not normally improve the message, but at least this would be possible. However, a poly-constrained message is fascinating, in that it cannot be improved. It can only degenerate. Any misspellings which might possible improve the normal sentence from will be disruptive to the other levels of information... Trifonov (1989) has shown that probably all DNA sequences in the genome encrypt multiple codes (up to 12). ~ John Sanford
 
2011-06-26 09:22:02 AM  
16 Guess who's in your DNA? At least 8 percent of the human genome originated in viruses, whose genetic code was integrated with ours over roughly 40 million years of primate evolution.

Would have thought it would be more than that and from the Pre-Cambrian, not the Eocene?
 
2011-06-26 09:39:00 AM  
Bevets: 21

K.
 
2011-06-26 09:40:12 AM  
21. Their cover of 'Tom's Diner' was more popular than the original.
 
2011-06-26 09:57:51 AM  
Some of those "20 Things" were just the author pressing the carriage return at the wrong time while creating a new paragraph on a previous item.


14 Bad news if you're a mouse: Scientists at Osaka University recently developed mice that are especially susceptible to DNA copying errors, seeking to increase the rate of mutations and see what new traits appear.
15 The results so far include short-legged mice, mice with fewer toes than normal, and mice that chirp like songbirds.
 
2011-06-26 10:18:09 AM  
DNA is shiat. RNA is where the party is at. While DNA sits in its little nuclear envelope, all smug and protected, RNA is out in the cell, getting transcribed and making protein. It also makes up a part of ribosomes, so while DNA is just in farking mitochondria, making some ATP, RNA is making protein. Protein has the word Pro- in it, so it is much better than ATP.
 
2011-06-26 10:22:22 AM  
#1 Knew that, I think thanks to Skeptics Guide to the Universe

#4 Wrong. Not the blurb, but the scientists involved. The whole arsenic replacing phosphorus doesn't work because the freaking arsenic is the wrong size.

#18 WASH YOUR HANDS. Especially after you spank it.
 
2011-06-26 10:25:09 AM  

Bevets: 21 Most DNA sequences are poly-functional and so must also be poly-constrained. This means that DNA sequences have meaning on several different levels (poly-functional) and each level of meaning limits possible future change (poly-constrained). For example, imagine a sentence which has a very specific message in its normal form but with an equally coherent message when read backwards. Now let's suppose that it also has a third message when reading every other letter, and a forth message when a simple encryption program is used to translate it. Such a message would be poly-functional and poly-constrained. We know that misspellings in a normal sentence will not normally improve the message, but at least this would be possible. However, a poly-constrained message is fascinating, in that it cannot be improved. It can only degenerate. Any misspellings which might possible improve the normal sentence from will be disruptive to the other levels of information... Trifonov (1989) has shown that probably all DNA sequences in the genome encrypt multiple codes (up to 12). ~ John Sanford


So which is a higher number: the number of possible universes according to string theory, or the number of permutations/combinations possible in DNA?
 
2011-06-26 11:04:35 AM  
I have a hard time believing that each of our bodies has created anything that could stretch out to 10 billion miles. That's a lot of construction.
 
2011-06-26 11:07:54 AM  
Actually Watson and Crick didn't even do that.

List fails with out Rosalind Franklin.

http://en.wikipedia.org/wiki/Rosalind_Franklin (new window)
 
2011-06-26 11:08:10 AM  
All that stuff about Watson and Crick and no mention of Rosalind Franklin? That lady still can't get any respect.
 
2011-06-26 11:09:08 AM  
At least two errors in TFA: 6 Most of that DNA resides not in the cell nuclei, which control heredity, but in our mitochondria, the organelles (units within cells) that generate metabolic energy.

Even with hundreds of mitochondria per cell, nuclear DNA dwarfs the quantity of mtDNA.

8 Aside from bacteria, the smallest genome belongs to the intestinal parasite Encephalitozoon intestinalis, with a trifling 2.3 billion base pairs

Million, not billion.
 
2011-06-26 11:13:37 AM  
Makh props.
 
2011-06-26 11:30:51 AM  
I prefer TNA, thanks
 
2011-06-26 12:41:43 PM  
Knew most of those already. Pretty sure number 6 is utterly incorrect.

Also, FAIL for listing E. intestinalis as smallest genome. I know it said "aside from bacteria" but that's like saying "aside from Chinese citizens, China is the least densely populated nation on earth!" Also, if you are going to nitpick (and I am!) it's still wrong, because Archaea aren't true bacteria and their genomes are still smaller.

/microbiologist
 
2011-06-26 01:07:29 PM  

Bevets: [BS quotes]


fark off, shiathead.
 
2011-06-26 01:32:12 PM  
#1's no surprise. Crick and Watson discovered the structure of DNA.

Sorry, Franklin fans, she was barking up the wrong tree when that happened.
 
2011-06-26 01:37:20 PM  
the 8% of genome = viruses part is wrong ... should read 80%.
 
2011-06-26 01:52:37 PM  

Bevets: 21 Most DNA sequences are poly-functional and so must also be poly-constrained. This means that DNA sequences have meaning on several different levels (poly-functional) and each level of meaning limits possible future change (poly-constrained). For example, imagine a sentence which has a very specific message in its normal form but with an equally coherent message when read backwards. Now let's suppose that it also has a third message when reading every other letter, and a forth message when a simple encryption program is used to translate it. Such a message would be poly-functional and poly-constrained. We know that misspellings in a normal sentence will not normally improve the message, but at least this would be possible. However, a poly-constrained message is fascinating, in that it cannot be improved. It can only degenerate. Any misspellings which might possible improve the normal sentence from will be disruptive to the other levels of information... Trifonov (1989) has shown that probably all DNA sequences in the genome encrypt multiple codes (up to 12). ~ John Sanford


No.
 
2011-06-26 02:27:37 PM  

Bevets: We know that misspellings in a normal sentence will not normally improve the message, but at least this would be possible. However, a poly-constrained message is fascinating, in that it cannot be improved. It can only degenerate.


DNA isn't a "message." It has no meaning, therefore "improvement" doesn't make sense. Is having dark-colored wings an "improvement" over having light-colored wings? Or is it a degeneration?
 
2011-06-26 02:39:49 PM  

jack21221: Bevets: We know that misspellings in a normal sentence will not normally improve the message, but at least this would be possible. However, a poly-constrained message is fascinating, in that it cannot be improved. It can only degenerate.

DNA isn't a "message." It has no meaning, therefore "improvement" doesn't make sense. Is having dark-colored wings an "improvement" over having light-colored wings? Or is it a degeneration?


I guess only some kind of selection process would determine if a change was an improvement. Naturally, it may take some time but in the end any "errors" would eventually be the only type left and would be continue on.
 
2011-06-26 02:51:33 PM  

zcat: #1's no surprise. Crick and Watson discovered the structure of DNA.

Sorry, Franklin fans, she was barking up the wrong tree when that happened.


Do you know why Rosalind Franklin didn't get the credit for her material?

Because there's no cure for cancer.

/Oh wait, that's a Bill Hicks Joke.
 
2011-06-26 03:13:18 PM  

jack21221: Bevets: We know that misspellings in a normal sentence will not normally improve the message, but at least this would be possible. However, a poly-constrained message is fascinating, in that it cannot be improved. It can only degenerate.

DNA isn't a "message." It has no meaning, therefore "improvement" doesn't make sense. Is having dark-colored wings an "improvement" over having light-colored wings? Or is it a degeneration?


Actually, DNA is a message, and it does have meaning. The meaning is the phenotype- the traits an organism has. Mutations are noise in the channel. Most of the time, as one would expect, those mutations add nothing of interest or value to the message. In fact, we've evolved all sorts of error checking mechanisms to avoid mutations.

Fortunately, mutation is not the sole introducer of variation into the genome. Drift, recombination, and the most important one- differential survival.

In any case, that last one is the important because it is the only function that determines the "quality" of the message. If the message replicates successfully, it is "good". If it fails, it is bad n

Tl;dr version: Bevets is still wrong.
 
2011-06-26 04:40:06 PM  
Beware the cops getting your DNA.... As due to budget cuts, when they test crime scene DNA, they only want DNA test results down to 30 people, instead of down to one person. And people have already been jailed for not having a good alibi, due to incompetent police work.
 
2011-06-26 04:52:03 PM  
FTFA 12 Telomeres, sequences of DNA at the tips of chromosomes, get shorter every time a cell divides; when they get too short, the cell dies. Some scientists are trying to extend life by extending the telomere.

Cell devision leads to a loss of 35 base pairs, except the enzyme telomerase ensures that cell devision includes the telomeres. Telomerase activity is high in rapidly multiplying cells such as bone marrow and cancer. As well telomerase activity is essential for single celled eukaroytic organisms, or else their species would cease to exist. Many human cells are found in tissues that are fully developed and need to be sustained longer through life. Thus, both the rate of cell devision and telomerase activity is low.
 
2011-06-26 05:55:54 PM  
OK, the guy goes into telomerase in 13, thus adding to this forum's complaint that successively numbered points should be included in the same paragraph. There is still DNA loss following cell division despite normal telomerase activity, so the link of telomere degradation to aging is still in area of early biological research and many other factors linked to aging are known as well.
 
2011-06-26 06:59:41 PM  

t3knomanser:
Fortunately, mutation is not the sole introducer of variation into the genome. Drift, recombination, and the most important one- differential survival.


There's horizontal gene transfer, too, which is increasingly being regarded as more important than first considered.
 
2011-06-26 07:45:40 PM  
And the whole NASA-paper on the arsenic-bacterium-thingy was a fluke...

/and don't get trolled by Bevets
 
2011-06-26 07:45:50 PM  

Samwise Gamgee: There's horizontal gene transfer, too, which is increasingly being regarded as more important than first considered.


True. I should make sure to call that out on my list. It sort of falls under recombination, if you tilt your head and squint. For genetic purposes, we really should consider horizontal transfer and vertical transfer as special cases of recombination.
 
2011-06-26 09:11:11 PM  

Makh: zcat: #1's no surprise. Crick and Watson discovered the structure of DNA.

Sorry, Franklin fans, she was barking up the wrong tree when that happened.

Do you know why Rosalind Franklin didn't get the credit for her material?

Because there's no cure for cancer.

/Oh wait, that's a Bill Hicks Joke.


True, she did collect the data, and pointed out that they're inside out triple helix was way off (one which Linus Pauling eventually settled on) and had no physical basis in reality. But it really was Crick's vision of interpreting the data and using the chemical knowledge from Watson to correctly get the structure. It really was a tragic case, she should have gotten the Nobel, if she were still alive, instead of Maurice Wilkins. We do know that she was instrumental in getting the structure and collecting the data, a fact that Crick acknowledged but Watson did not, and that without her skill it would have taken much, much longer to get it. The chief handicap she had was her meticulousness, which helped in her work but failed her in the interpretation of it, she felt that the structure would only be determined with a complete chemical solution from her data, while Crick was content with building models that, while underdetermined, could be used to test different hypotheses out against the data. Its a similar approach to what Pauling pioneered and it worked.
 
2011-06-26 09:13:07 PM  

Markus D: And the whole NASA-paper on the arsenic-bacterium-thingy was a fluke...

/and don't get trolled by Bevets


Actually, I'm having a hard time understanding what he (she?) is going on about.
 
2011-06-26 09:20:47 PM  

Bevets: 21 Most DNA sequences are poly-functional and so must also be poly-constrained. This means that DNA sequences have meaning on several different levels (poly-functional) and each level of meaning limits possible future change (poly-constrained). For example, imagine a sentence which has a very specific message in its normal form but with an equally coherent message when read backwards. Now let's suppose that it also has a third message when reading every other letter, and a forth message when a simple encryption program is used to translate it. Such a message would be poly-functional and poly-constrained. We know that misspellings in a normal sentence will not normally improve the message, but at least this would be possible. However, a poly-constrained message is fascinating, in that it cannot be improved. It can only degenerate. Any misspellings which might possible improve the normal sentence from will be disruptive to the other levels of information... Trifonov (1989) has shown that probably all DNA sequences in the genome encrypt multiple codes (up to 12). ~ John Sanford


struct:

Actually, I'm having a hard time understanding what he (she?) is going on about.

S A T O R
A R E P O
T E N E T
O P E R A
R O T A S

Like puns, palindromes, and other word puzzles, DNA contains poly-functional letters, words, and phrases. Such sequences can only arise by very careful design. Once they are created, they cannot be "mutated" to make them better. An excellent example is the painstakingly crafted poly-functional Latin phase shown above. This ancient word puzzle (dating back to 79 AD) has a translation something like, "THE SOWER NAMED AREPO HOLDS THE WORKING OF THE WHEELS." It reads the same, four different ways: left to right, up to down, and starting at the lower right, down to up, right to left. Any single letter change in this system destroys all four messages simultaneously (all four of which happen to be the same in this example). Similarly, a simple sentence palindrome would be: ABLE WAS I ERE I SAW ELBA, which reads the same forward or backwards. Any letter change destroys both messages. A simple example of a poly-functional word would be LIVE, which backwards is EVIL. To change LIVE to HIVE might be desirable, but it turns EVIL which has meaning, to EVIH, which is meaningless. So this dual-meaning word, like the other examples above, is poly-constrained, precisely because it is poly-functional. ~ John Sanford
 
2011-06-26 09:25:05 PM  
Fun: http://www.dnai.org/ (new window)
 
2011-06-26 09:58:10 PM  
First off Bevets genetic life predated written language as well as puns, palindromes, and other word puzzles.

Secondly the human genome includes variable genes sequences used create nearly infinite immune receptors and antibody formations needed to bind with the vast quantity of bacterial antigens one may encounter. Human immune cells are purposely mutating parts of its own genetic DNA code everyday inside our bodies to produce the most highly specific antibodies/receptors needed to kill off our bacterial and viral enemies. These immune genes do not function at all unless they self mutate their own genetic code by splicing out unwanted code using "RAG" proteins and other self mutation mechanics.

Beyond that mutations and variability occur generation to generation resulting in more viable and often more complex organisms through the natural selection phenomenon. It's been happening for billions of years.
 
2011-06-26 10:26:30 PM  
Bevets:

Like puns, palindromes, and other word puzzles, DNA contains poly-functional letters, words, and phrases.

Pinnacle Point:

First off Bevets genetic life predated written language as well as puns, palindromes, and other word puzzles.

It was an analogy. Not a chronological account.

Secondly the human genome includes variable genes sequences used create nearly infinite immune receptors and antibody formations needed to bind with the vast quantity of bacterial antigens one may encounter. Human immune cells are purposely mutating parts of its own genetic DNA code everyday inside our bodies to produce the most highly specific antibodies/receptors needed to kill off our bacterial and viral enemies. These immune genes do not function at all unless they self mutate their own genetic code by splicing out unwanted code using "RAG" proteins and other self mutation mechanics.

Sounds complicated

Beyond that mutations and variability occur generation to generation resulting in more viable and often more complex organisms through the natural selection phenomenon. It's been happening for billions of years.

Alert Richard Dawkins
 
2011-06-26 10:30:56 PM  
www.snorgtees.com
 
2011-06-28 12:08:29 AM  

t3knomanser: Actually, DNA is a message, and it does have meaning. The meaning is the phenotype


That's a stretch of the definition of "meaning" if you ask me. DNA is a molecule and it has a function, I'd say. Bevets was using a completely different definition of "meaning" and "message" than you were.
 
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