Genetic damage

[bugmenot]

Do humans lose genetic information as time goes on?

Everyone knows that when something is copied like data on a PC the data always loses some of it's identity. For example. If I make copies of an audio CD over and over but not using the original every time and using the last copy made to make another copy the data always gets worse in quality. It's the same process as human reproduction. Does that apply to DNA? If not how is DNA preserved in human generations?

 

If what I think is true what will be the first thing that will suffer as a result of DNA damage?

Will it be the reproductive system? Will humans lose the ability to reproduce in the near future because of DNA damage?

 

What other factors can cause DNA damage other than radiation and DNA copies if true?

 

I think that DNA from any living thing gets lost as time goes on and it gets worse in quality as time goes on. The most vurnerable system in all of living things is the reproductive system and I also believe that DNA damage will lead to extinction. Am I correct?

[alxian]

as per your example the loss of quality is non existant to negligable when dealing with digital information

 

you only lose quality if you use compression. making dupes of a cd to a cd is not the same as duping a vhs cassette.

 

(though the longer you use a duped cd the more it ages and ripens, eventually you'll lose quality but nothing noticeable if you are using quality blanks)

 

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as for genetic damage [in humans]

 

ultraviolet radiation

 

toxins, smoking, drugs, alcohol?

 

inbreeding

 

there are many ways to corrupt our genome

 

viruses can be blamed for some damage (and some beneficial mutations too)

 

disease

 

heavy doses or prolonged exposure to ionized particles, such as ozone created from sparks or lightning.. it causes cancer, i'm not sure about communicable genetic damage.

 

our dna is flawed before trying to breed it, breeding it may make the bad dna ressessive but if there is no healthy dominant trait the bad dna is expressed.

 

very little is being done to clean it our genome.

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if this is the same with dna. degredation with each new human of woman born?

 

its not that black and white, our dna is engineered to fix itself, bad dna becomes recessive and good dna, the beneficial mutations (the more a mutant breeds the more the trait is spread around the more dominant it becomes).

 

so imo, no, degredation doesn't really happen the way it would in the cassette duping example, but neither does dna copy bit for bit. mainly because it isn't being copied. that would be cloning (which if memory serves dna does degrade with each serial clone). but adding two different stocks together to form one unique person benefits greatly from more dominant dna and the ability to ignore recessive traits.

--

digital dna... could there be a way to make dna as stable as the binary bits of a computer?

 

four bits on their own seems to be a stable enough system but during the splicing and merging of the parental and maternal code the unique offspring sometimes have anomalies. would making dna binary solve this problem? what about efficiency? if our genome was purged of junk chains would the reduced and purified strings in binary formation be more or less efficient than keeping the old gatc system?

 

OTOH what about using more than only a pair of nucliecs base pairs, why not have 3 pairs and make our genome even more efficient (once cleaned up). are Purine and Pyrimidine compatible enough to form a third base pair? (or a terciary base pair of adenine and uracil) a base pair that could be used as a backup in case anomolies crop up. the third pair can read off changes.. like a federally mandated universal base pair, an unmodifyable dataset of everything "human".

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if anything would noticeable suffer from expression of recessive traits or other forms of damaged dna then it would be the brain, the skin, hair, things you can see.

 

basic systems like digestion, reproduction can be affected but you can live a normal life and hide such defects more easily that splotchy skin or slurred speech.

[bugmenot]

Thx for that. Great explanation.

[EWright]

as per your example the loss of quality is non existant to negligable when dealing with digital information

 

you only lose quality if you use compression. making dupes of a cd to a cd is not the same as duping a vhs cassette.

 

(though the longer you use a duped cd the more it ages and ripens, eventually you'll lose quality but nothing noticeable if you are using quality blanks)

 

----

as for genetic damage [in humans]

 

ultraviolet radiation

 

toxins, smoking, drugs, alcohol?

 

inbreeding

 

there are many ways to corrupt our genome

 

viruses can be blamed for some damage (and some beneficial mutations too)

 

disease

 

heavy doses or prolonged exposure to ionized particles, such as ozone created from sparks or lightning.. it causes cancer, i'm not sure about communicable genetic damage.

 

our dna is flawed before trying to breed it, breeding it may make the bad dna ressessive but if there is no healthy dominant trait the bad dna is expressed.

 

very little is being done to clean it our genome.

----

if this is the same with dna. degredation with each new human of woman born?

 

its not that black and white, our dna is engineered to fix itself, bad dna becomes recessive and good dna, the beneficial mutations (the more a mutant breeds the more the trait is spread around the more dominant it becomes).

 

so imo, no, degredation doesn't really happen the way it would in the cassette duping example, but neither does dna copy bit for bit. mainly because it isn't being copied. that would be cloning (which if memory serves dna does degrade with each serial clone). but adding two different stocks together to form one unique person benefits greatly from more dominant dna and the ability to ignore recessive traits.

--

digital dna... could there be a way to make dna as stable as the binary bits of a computer?

 

four bits on their own seems to be a stable enough system but during the splicing and merging of the parental and maternal code the unique offspring sometimes have anomalies. would making dna binary solve this problem? what about efficiency? if our genome was purged of junk chains would the reduced and purified strings in binary formation be more or less efficient than keeping the old gatc system?

 

OTOH what about using more than only a pair of nucliecs base pairs, why not have 3 pairs and make our genome even more efficient (once cleaned up). are Purine and Pyrimidine compatible enough to form a third base pair? (or a terciary base pair of adenine and uracil) a base pair that could be used as a backup in case anomolies crop up. the third pair can read off changes.. like a federally mandated universal base pair, an unmodifyable dataset of everything "human".

----

if anything would noticeable suffer from expression of recessive traits or other forms of damaged dna then it would be the brain, the skin, hair, things you can see.

 

basic systems like digestion, reproduction can be affected but you can live a normal life and hide such defects more easily that splotchy skin or slurred speech.

 

"Terciary base pair" ... I'm trying to picture this one :)

 

There is a difference between a 'loss of genetic information' and 'genetic damage', as well as a systemic loss of such information in an individual that is not passed on to its offspring, and that which is... and yet another set of conditions gives rise to changes in genetic information that is passed on in regards to an entire species (this one is an ongoing process, usually resulting for 'adaptive' reasons and thus the betterment of the species = evolution).

 

The difference in a loss of genetic information and genetic damage in an individual is this: The cells in your body are always rejuvenating themseves... or rather, they divide and form new cells to replace old ones that die (ie, old skin cells slough off and new ones replace them). This happens through a process called mitosis, at difference rates throughout your body, depending on how actively dividing the cells are (ie, skin cells will divide more rapidly than bone cells). When this happens, the 26 pairs of chromosomes (which equals 46 chromosomes total) line up at the center of the cell like football players at the line of scrimage, and then divide in opposite directions and the cell membrane closes in, in between them and the cell divides into two (Each of the chromosomes has produced an identical counterpart prior to dividing so you end up with 23 pair of chromosomes after the seperation... so for a moment you actually have 46pr of chromosomes).

 

Now, in before these chromosomes line up to divide, they may be damaged in ways that can or can not be passed on to the daughter cells (damged by processes such as ionizing radiation). In either case, genetic damage has occurred... but in most cases it is of no negative consequence. Without getting too drawn out, if the change is passed on to the daughter cell it has become a mutation.... other types of damage creates a portion of a chromosome that can not be passed on (ie, the chormatid is spliced and the ends attach to itself like a ring, rather than to 'viable' portions of itself or another) and that information in lost. BUT... this only pertains to that particular cell.. .and in the cases where the information was passed, to any future generations of that cell. The reason this is of no consequence to this person's (or other organism's) offspring, is that these cells (those undergoing mitosis as opposed to meiosis) are not germ cells (sperm or egg). Thus, the changes are not passed on. Cellular damage, however, can lead to cancer in the individual. This can also not be passed on of course, and (depending on the age of the effected person and whether they've had children) can lessen the chances of some persons reproducing offspring (ie, the individual dies from its disease or is rendered incapable of reproducing due to reprecussions from his or her treatment).

 

Now, these same mutations can occur in germ cells (sperm or egg) and can be passed on as well. (That is why, when you get an x-ray taken, they shield your gonads... in addition to the fact that too much radiation can lead to steralization). This does not mean that there was necesarrily a loss of information (though there can be), but that there is a change/mutation. Some of these can adversely affect the offspring, but if the offspring is adversely effected, it lessens its chance of reproducing, and thus lessess the chance of it affecting the larger population due to safeguards set in place by God, called natural selection (scientifically speaking).

[bugmenot]

Some of these can adversely affect the offspring, but if the offspring is adversely effected, it lessens its chance of reproducing, and thus lessess the chance of it affecting the larger population due to safeguards set in place by God, called natural selection (scientifically speaking).

That's the problem these days. Natural selection no longer happens. Everybody gets to reproduce and have offspring. The weak out number the strong. In the past the sick and the weak died off thus bettering the species by allowing only the strong to reproduce and pass on stronger traits.

Does natural selection still apply to humans? I think it does not.

[Turtle]

That's the problem these days. Natural selection no longer happens. Everybody gets to reproduce and have offspring. The weak out number the strong. In the past the sick and the weak died off thus bettering the species by allowing only the strong to reproduce and pass on stronger traits.

___I think the archeological evidence clearly shows the sick & weak were cared for by their groups/tribes in the ancient past. :) Skeletons showing crippling injuries & surgeries long healed before death aren't uncommon. We are a "better" species precisely because we care for our sick & feeble. It is natural, & we select it. :)

[EWright]

That's the problem these days. Natural selection no longer happens. Everybody gets to reproduce and have offspring. The weak out number the strong. In the past the sick and the weak died off thus bettering the species by allowing only the strong to reproduce and pass on stronger traits.

Does natural selection still apply to humans? I think it does not.

 

Those with the most significant biological defects are less likely to breed, thus natural selection still exists. I would say that natural selection in humans is undergoing a course that will be primarily based on a combination of intellect and physical attributes. The course of this type of selection may be slowed, however, by the fact that intellectuals *tend* to produce fewer offspring. However, these offspring are presumably, in most cases, better cared for. But there's still a lot of stupid, ignorant and unattractive people with nothing better to do than to make a bunch of babies. But hopefully it just means it will take longer to naturally weed out them out of the gene pool.

[Turtle]

___..."most significant" & "less likely" express far too general a situation to scientifically substantate a conclusion.

___We humans still don't understand our own nature, so conclusions on what is valuable for later selection have no strong basis in fact. No end of great intellects were "ugly", bad-tempered, or ill-kempt. The principle of emergence, by its very definition, is reason enough not to judge the value of a human being.

___I do think natural selection is at work, but the direction it is taking is an emergent property & therefore unknowable until it is expressed.

[EWright]

___..."most significant" & "less likely" express far too general a situation to scientifically substantate a conclusion.

___We humans still don't understand our own nature, so conclusions on what is valuable for later selection have no strong basis in fact. No end of great intellects were "ugly", bad-tempered, or ill-kempt. The principle of emergence, by its very definition, is reason enough not to judge the value of a human being.

___I do think natural selection is at work, but the direction it is taking is an emergent property & therefore unknowable until it is expressed.

 

Very likely true. My point was certainly speculative, but I still like it :)

[Biochemist]

Do humans lose genetic information as time goes on?....

We certainyl do lose genetic information. Most (and perhaps all) mutations are essentially genetic information losses. The presumption that speciation occurs via sequential mutaion is broadal held, but it is only a presumption. There is no example that credibly demonstrates a mutation resulting in increased information load.

 

The general case is that most species lose genetic information over time.

[alxian]

wouldn't the fact the animals get bigger and smarter point to mutations that are not only beneficial but that add genetic information thus splitting off a new species?

 

sure you can say the pure stcok may degenerate into new species but that a little counterproductive.

 

you might as well say god seeded the planet with a billion odd spieces of animals and over billenia they died out and degenerated into the species we know now.

 

we know for a fact that more animals have died out than new species evolved over recorded history.

 

i womder what would happen if proof made it to the public that that was the case, animals in all forms have always existed but they have been dying off.

[Biochemist]

wouldn't the fact the animals get bigger and smarter point to mutations that are not only beneficial but that add genetic information thus splitting off a new species?..

No one has demonstrated that mutation is causal to speciation. The fact that species exist does not indicate any specific mechanism is causal. Speciation via mutation is an assumption. There is very little evidence to support it.

 

The fossil record itself (since it does not show gradual introduction of increasingly complex phjyla) argues strongly against speciation through a mutative mechanism. There is other counter evidence as well.

[EWright]

No one has demonstrated that mutation is causal to speciation. The fact that species exist does not indicate any specific mechanism is causal. Speciation via mutation is an assumption. There is very little evidence to support it.

 

The fossil record itself (since it does not show gradual introduction of increasingly complex phjyla) argues strongly against speciation through a mutative mechanism. There is other counter evidence as well.

 

Should you not clarify for him then, what *is* the presumed cause, if mutation is not?

[Biochemist]

Should you not clarify for him then, what *is* the presumed cause, if mutation is not?

Not if we don't know. We are not obligated to have an answer to every question. The fact that we have uncovered a body of evidence that calls into question a broadly held assumption is good. We are not required to have an alternative hypothesis to reject an extant one.

[alxian]

in that case the garden of eden lost theory [all living animals have always lived until they died, sans god], ID [by god or other higher power], evolution [via mutation] are all possible explanations.

 

 

what is clear is that living animals can deal with all the mentioned causes of genetic damage and manage to keep there stock fresh enough to procreate.

 

in my fiction i start out by introducing a UV star that mucks up the genetic stock of a newborn planet, live on that planet over time evolves adaptions to the UV and even learn to metabolize the UV to generate far more power than under an older dwarf star.

 

if we are to continue living on this planet we'll have to design life to take better advantage of the energy system available. its not like evolution is going to step in and magically fix or jackassery (killing off countless animal and planet species), we might as well do it ourselves. bind and gag all the god fearing folk and toss them in a closet if necessary.

[Biochemist]

...if we are to continue living on this planet we'll have to design life to take better advantage of the energy system available....

Design life? We are a significant distance form that objective. Further, it is presumptious to suggest we could significantly alter our biological energy usage or souce energy at all.

[grhyink]

Re: Genetic damage

 

Read the book "Mutants, on Genetic variety and the Human Body" by Armand Marie Leroi