Is our DNA pool degrading ?

[MandrakeRoot]

When looking to some stats, there are an ever increasing number of children with allergies or other illnesses. Since we are sort of trying to cheat evolution in using technology to keep people alive that would have otherwise died or help a couple having difficulty to have children to have children etc...

So my question/debate issue is : Does our DNA degrade ?

with this i mean that, will our population contain an ever increasing number of individuals with illnesses (including allergies etc...), that could ultimately (or not) lead to the destruction of the species ?

I know this is a pretty wild statement, and i am not convinced it is true, i find it just remarkable that the number of children with allergies/illnesses has increased a lot, making me think of some genetic defauts (maybe) ?

So what do you guys/girls think of it ?

 

Mandrake

[Sayonara]

Consider the possibility that there are an increased number of diagnosed cases because diagnosis and detection technologies are becoming more sophisticated and more widespread.

[MandrakeRoot]

Yes true, but even taking that into account, the number of children suffering from allergies increases. But that is not the most important, the debate i wanted to iniaet is about the following :

 

Will our technologic influence (keeping people that are sick alive, and thus allowing (some) to reproduce whereas they never could have, where we always to live in "natural" circumstances) ultimately degrade the DNA pool ?

 

Mandrake

[admiral_ju00]

No, not at all. It might put a dent in a small and geographically/culturally isolated gene pool, but not of the entire species.

[Sayonara]

What do you mean by "degrade the gene pool"?

 

I would dispute that increased susceptibility to allergies is evidence of anything other than forced selection with increased domestic hygeine as the root cause.

 

I don't see how keeping people alive who would otherwise have died can have a significant effect on our population, even in cumulative terms. People in general just aren't that promiscuous, except in some third world countries where both the birth rate and infant mortality rates are way higher than in the West (and therefore don't count, because your "artificially kept alive" candidates aren't.)

[MandrakeRoot]

With degrading the gene pool i meant that an increasing number of "flawed genes" is present,i.e., genes with genetic defauts.

 

There are families, where the parents have serious health problems, the children the same plus more etc..., so that is what initialised this debate (though like i said i am not convinced either, it is a debate , an hypothesis that needs testing, disproving etc....)

 

The idea is the following : Someone that has an heriditary kidney problem for instance, (would have died in the 3 world countries and hence not reproduced), but we keep him alive by technology, kidney transplant whatever, so he can reproduce and hence passes over the genes of this hereditary kidney failure. So in "natural" circumstances these genes would have disappeared from the pool , whereas in the technologic circumstances they are allowed to stay in it !

(if the couple has even more children then 2, then maybe they will even be more frequent ?)

 

Mandrake

[admiral_ju00]

Natural Selection has, is and will always be here. Taking into the account that say for the past 3 thousand years, the average lifespan of h.sapiens peaked at 20's and it was a marvel when someone lived to 30's, it will not change.

 

Also, when you're talking about genes, be sure to consider or include the following factors: dominant alleles, co-dominant alleles and resecive alleles.

Just because the parent or even parents have some 'undesirable alleles or genes', it does in no way guarantee that they will be passed on to their offspring.

 

In Evolution, Natural selection will deal with the 'problematic' genes before in many cases they can have an effect on the total gene pool.

Taking things like a life threatening genetic disorder, and in particularly a disorder that occurs at a very early stage in the life of the organism, will be dealt with by natural selection. After a certain age, you could say that the forces of natural selection may weaken on an organism thereby it may life well beyond it usefulness.

 

For an example of the 1st one, take the one(I don't remember the name of this condition, someone help me out pls if you know it), There are mechanisms in the brain that keep fatty cells from forming, but if one is born with a genetic defect in this system, then fat cells start to accumulate in the brain and eventually leads to the death of the child by the age of 7. The very reason this condition is RARE is because of Natural Selection. This child has not yet had a chance to reproduce and possibly pass the mutation. Issues like that are fairly simply to eliminate from the total gene pool. That's why potential parents can have their DNA checked for such problems and make a decision of taking the chance or simply choose not to have any kids.

 

For the 2nd example, take someone with Alzheimer's decease. This problem occurs relatively late in one's life. This organism(person) HAS had a chance to reproduce and pass the genetic information. This is a problem as Natural Selection's affect on this is severely limited and it will not be selected against, as far as the evolution is concerned.

 

Taking something like asthma, allergy or other non-life threatening decease before the organism is capable of reproduction is irrelevant to the natural selection. Organ donation is a relatively new phenomenon and when compared to the total history of h.sapiens is also irrelevant and should not be used as a metric in the evolutionary forces.

 

(if the couple has even more children then 2, then maybe they will even be more frequent ?)

 

No. The genes will be in the circulation, but they won't make any significant impact.

 

If you haven't (yet) been introduced to the square, then try and play with this, as it gets fascinating really quick. Keep in mind, that for each offspring, you got to start fresh.

 

http://www.borg.com/~lubehawk/psquare.htm

[Sayonara]

Bear in mind there is a difference between "genetic defects" and "unfavourable genetic makeup".

 

Also that keeping someone alive despite their condition does not mean they can or will reproduce.

[MandrakeRoot]

I disagree that asthma is non relevant to natural selection. In the time where h. sapiens was a hunter/gatherer, clearly someone with asthma would have had a disadvantage. I know there is a difference between having having "undesirable genes" and them actually being active, but having them could allow you to pass them on to your children that might have these genes active (i.e., show signs of the disease or whatever).

 

I think most people will take the chance, even if they know their children might be sick. I even know some people that knew their child would be seriously handicapped (drown syndrom + other physical complications) and didnt choose an abortion !

It is clearly true that natural selection is something that has effect after many years, but can also go rather suddenly. A famous example is this butterfly species (white) in england of which normally only a few specimens are black and would have been selected against, (since they were to easy to remark) but due to industrial revolution and pollution it was the black specimens that became predominant.

 

Maybe the correct formulation of the issue is : Can we cheat natural selection by use of technology ? (on the long run).

 

Mandrake

[admiral_ju00]

I disagree that asthma is non relevant to natural selection. In the time where h. sapiens was a hunter/gatherer, clearly someone with asthma would have had a disadvantage.

 

And they would have been dealt with by the selection. Those that had the more severe form of it, would have certainly not lasted very long as opposed to others.

 

I think most people will take the chance, even if they know their children might be sick. I even know some people that knew their child would be seriously handicapped (drown syndrom + other physical complications) and didnt choose an abortion !

 

That is true, many do not abort even when they know that their child will not be normal. While people with down syndrome, may maintain a good and healthy lives, they are useless when it comes to evolution as they are sterile.

 

It is clearly true that natural selection is something that has effect after many years

 

Or very quick. Many chromosomal aberrations result is self abortions. So most deleterious or problematic mutations in major biological functions of an organism never reach the fetus stage.

 

A famous example is this butterfly species (white) in england of which normally only a few specimens are black and would have been selected against, (since they were to easy to remark) but due to industrial revolution and pollution it was the black specimens that became predominant.

 

Oh yes, the infamous butterfly effect. Know all about it. The problem with this is that it affected the population of the species rather drastically because it changed major keys in their environment. There are many other similar examples of such works in progress. One that I like myself is the affect of pesticides on a population of pests. Same thing, basically.

 

Unless something happens that affects the 'human' ecology global-wide, such as should something happen to all the phytoplankton, we may discover that there are some individuals that are able to use say Methane or Carbon Dioxide just as well all of use Oxygen. Who knows. Until that happens, things most likely will remain as they are, since h.sapiens have dominated the entire world ecology with our technology.

 

Maybe the correct formulation of the issue is : Can we cheat natural selection by use of technology ? (on the long run).

 

No, but perhaps we can delay the inevitable.

[MandrakeRoot]

Yeah i agree with you, cheating on natural selection is not possible in the long run.

 

But i surely don't agree on the point where you say humans dominate ecology with the technology, destroy would be more likely (a slow autodestruction maybe ??).

 

Mandrake

[admiral_ju00]

But i surely don't agree on the point where you say humans dominate ecology with the technology' date=' destroy would be more likely (a slow autodestruction maybe ??).

 

Mandrake[/quote']

 

That is just a byproduct of it. One that has not entered the concerns of many and probably won't 'till it's too late to fix anything.

 

However, we did conquer the ecology with technology. Be it with a nice and shiny submarine that takes to places deep underwater where no other land animal can venture, or with a very thick & warm jacket with a pair of boots and a portable heater in Antarctica. How about the spacesuit for the astronauts/cosmonauts and the shuttle to get them there?

[Sayonara]

That's not conquering ecology, it's conquering physiology.

[MandrakeRoot]

conquaring ecology would be "nice and warm jacket on the antartic with a loaded shotgun to kill everything that moves !"

[Sayonara]

Yeah ok.

[Aardvark]

I suppose the ultimate victory against ecology would be when the last man turns the shotgun on himself.

[Arg]

I suppose the ultimate victory against ecology would be when the last man turns the shotgun on himself.

That would be fairly ultimate, yes.

 

On the bright side, given time and a loosening of the "moral" deathgrip which threatens to be the end of us all, we will be able to manipulate our genes for any traits we so desire. We will succeed in artificial selection where we are failing in natural selection, and damn the consequences!

[MandrakeRoot]

I think that the so called genetic manipulation you are suggestion will be this shotgun turned upon ourselves !

I dont think that it is possible to create some sort of superhuman by genetic manipulation without any indesirable consequences (on the long term, maybe originally neglected).

 

Mandrake

[SurfSciGuy]

When looking to some stats' date=' there are an ever increasing number of children with allergies or other illnesses. Since we are sort of trying to cheat evolution in using technology to keep people alive that would have otherwise died or help a couple having difficulty to have children to have children etc...

So my question/debate issue is : Does our DNA degrade ?

with this i mean that, will our population contain an ever increasing number of individuals with illnesses (including allergies etc...), that could ultimately (or not) lead to the destruction of the species ?

I know this is a pretty wild statement, and i am not convinced it is true, i find it just remarkable that the number of children with allergies/illnesses has increased a lot, making me think of some genetic defauts (maybe) ?

So what do you guys/girls think of it ?

 

Mandrake[/quote']

 

Sorry I'm a bit late on this one. I would say that increased allergies in children is more to do with our chemical environment than genetics. We are exposed to vastly more chemicals in our environment than previous generations and some of these chemicals cause allergenic sensitisation. Take asthma for instance - there are significant increases in asthma cases in inner-city areas with heavy traffic as compared with areas with low traffic density (such as the country-side). Basically it's our pollution and waste that is making us ill, not poor genes.

 

Here are some refs:

 

C.H. van Niererk et al., "Prevalence of Asthma: A Community Study of Urban and Rural Xhosa," Clinical Allergy, Vol. 9 (1979), pp. 319-24, cited in Anthony Newman-Taylor, "Environmental Determinants of Asthma,"Lancet, Vol. 345 (February 4, 1995), p. 296.

 

Kevin B. Weiss, Peter J. Gergen, and Ellen F. Crain, "Inner-City Asthma: The Epidemiology of an Emerging U.S. Public Health Concern,"Chest, Vol. 101, No. 6, Supplement (June 1992), p. 362S.

 

Hillel S. Koren and Mark J. Utell, "Asthma and the Environment,"Environmental Health Perspectives, Vol. 105, No. 5 (May 1997), p. 534.

 

Hillel S. Koren, "Associations between Criteria Air Pollutants and Asthma," Environmental Health Perspectives, Vol. 103, Supplement 6 (1995), p. 238.

 

David V. Bates, "Observations on Asthma,"Environmental Health Perspectives, Vol. 103, Supplement 6 (1995), p. 245.

 

Rebecca Bascom, "Environmental Factors and Respiratory Hypersensitivity: The Americas,"Toxicology Letters, Vol. 86 (1996), pp. 122-124.

 

David V. Bates, "The Effects of Air Pollution on Children,"Environmental Health Perspectives, Vol. 103, Supplement 6 (1995), p. 50.

[Arg]

I think that the so called genetic manipulation you are suggestion will be this shotgun turned upon ourselves !

I dont think that it is possible to create some sort of superhuman by genetic manipulation without any indesirable consequences (on the long term' date=' maybe originally neglected).

 

Mandrake[/quote']

With enough time and will, almost anything is possible. I also think that in your case, turning a shot gun on yourself might not be such a bad idea.

[MandrakeRoot]

I also think that in your case, turning a shot gun on yourself might not be such a bad idea.

 

what is that supposed to mean ? Anyway i dont care.

 

I remind you that the car was originally seen as something that could help to reduce city pollution (i.e., horse shit !)

Nobody ever imagined at that time that someday millions and millions of cars would be used every day creating tons of pollution. Thinking that you can perfectly manipulate genes without any side effects is rather arrogant and arrogance is surely not something science needs !

 

Mandrake

[budullewraagh]

i would say that humans are becoming more fragile people. it is known that exposure to bacteria and virii make people much more resistent too illness.