Defeating Evolution: How Unnatural Factors Weaken Adaptation

[horseguards]

Life forms adapt, and thereby strengthen, by countering detrimental influences.

Given that man is increasingly less dependent on his (natural) body defence mechanisms, and more reliant on (unnatural) man-made solutions (pharmaceuticals), is it the logical conclusion that the biological defences are weakened? It may be argued that by eradicating a particular disease its defence would not be needed, however, once that defence is gone it may not be revived.

Dependence on non-evolutionary factors undermines the ability to adapt in an evolutionary context. But perhaps the alternative is thousands of deaths for the sake of evolution.

 

[Evo]

Life forms adapt, and thereby strengthen, by countering detrimental influences.

Given that man is increasingly less dependent on his (natural) body defence mechanisms, and more reliant on (unnatural) man-made solutions (pharmaceuticals), is it the logical conclusion that the biological defences are weakened? It may be argued that by eradicating a particular disease its defence would not be needed, however, once that defence is gone it may not be revived.

Dependence on non-evolutionary factors undermines the ability to adapt in an evolutionary context. But perhaps the alternative is thousands of deaths for the sake of evolution.

I would suggest that you do some research on what evolution is, you seem to have some misconceptions.

 

[Pythagorean]

sure, horseguards. One example is antibiotics. We manufacture antibiotics and take them, and lots of people don't complete their antibiotic program. The result is that in the next 100,000 years, people that don't develop defenses won't die because they relied on antibiotics and thus, will spread their "inferior" genes (while the the bacteria get stronger, adapting to the antibiotics).

But evolution an adaptation will still happen in the same way, it's just that they face a different set of environmental pressures due to society (society takes some away, but adds others).

 

[Ryan_m_b]

Life forms adapt, and thereby strengthen, by countering detrimental influences.

Or they go extinct, like the vast majority of species.

Given that man is increasingly less dependent on his (natural) body defence mechanisms, and more reliant on (unnatural) man-made solutions (pharmaceuticals), is it the logical conclusion that the biological defences are weakened?

Are you talking about the individual or the population? Using antibiotics won't necessarily mean that the body's immune system won't adapt to the pathogen for future infections.

It may be argued that by eradicating a particular disease its defence would not be needed, however, once that defence is gone it may not be revived.

And...?

Dependence on non-evolutionary factors undermines the ability to adapt in an evolutionary context. But perhaps the alternative is thousands of deaths for the sake of evolution.

Not thousands: millions upon millions with no guarantee that immunity will ever be gained. Pathogens evolve also so if an organism (humans) evolves resistance to a pathogen it puts a selective pressure on that pathogen adapt. There are legitimate concerns from over reliance on medicine (see antibiotic resistant bacteria and the hygiene hypothesis) but making the species as a whole weaker is not one of them. Billions of healthy living humans is more worthwhile than thousands that have slightly more resistant immune systems.

 

[horseguards]

Evo,

Being a non-scientist, especially an evolutionary biologist, without doubt I have many misconceptions. Hence, my post to a biology forum.

I was not making statements; the clues are the question mark and the term, "It may be argued..."

I'm thankful you are not my doctor.

Pythagorean,

Thank you for the helpful reply.

“people that don't develop defenses won't die because they relied on antibiotics and thus, will spread their "inferior" genes”. Isn’t medicine (antibiotics) a proxy for a (lack of) natural defence? And if the antibiotics provide a cure then why should an “inferior” gene develop?

Ryan,

“Or they go extinct...” I think that’s inferred by the sentence.

“Using antibiotics...” This is the point of my post; man seems to be sidestepping evolution by substituting his natural defence mechanisms for man-made medical solutions. Would man still exist if he depended solely on the evolutionary process?

“There are legitimate concerns... resistant immune systems.” Do you think I’m advocating eugenics?

 

[Evo]

“Using antibiotics...” This is the point of my post; man seems to be sidestepping evolution by substituting his natural defence mechanisms for man-made medical solutions. Would man still exist if he depended solely on the evolutionary process?

“There are legitimate concerns... resistant immune systems.” Do you think I’m advocating eugenics?

I'm not criticizing you, I'm trying to help you. Of course, people seldom want to be told that they need to learn the basics first. Like it or not, you do not understand how evolution works, and until you get at least a basic understanding, you are going to continue to misunderstand what you are being told.

No, we are NOT sidestepping evolution.

For people with little or no understanding of evolution, I love this little video. Hopefully this will help you understand how natural selection works, which is an important first step in understanding more complex information.



https://www.youtube.com/watch?v=GcjgWov7mTM

 

[Ryan_m_b]

“Or they go extinct...” I think that’s inferred by the sentence.

When you want to quote a post please use the quote button at the bottom right of their post. I felt it worth mentioning because a species either adapts or goes extinct (not getting into long term stability here for simplicity). So whilst one might say "is medicine side-stepping evolution" you could also ask "is medicine side-stepping extinction".

“Using antibiotics...” This is the point of my post; man seems to be sidestepping evolution by substituting his natural defence mechanisms for man-made medical solutions. Would man still exist if he depended solely on the evolutionary process?

Note that humans are still evolving and will continue to do so for a myriad of reasons. Not developing resistance to one specific pathogen due to use of medicines is not significant. For instance widespread antimalarial treatments might diminish the prevalence of sickle cell trait but that doesn't effect the immunity of humanity as a whole.

“There are legitimate concerns... resistant immune systems.” Do you think I’m advocating eugenics?

No, are you?

 

[horseguards]

Evo,

"do some research" is so ambiguous as to be of no value whatsoever.

If you are unwilling to address my points beyond a brushoff then don't: leave it to others.

To avoid embarrassing myself, perhaps you could suggest what level of understanding is a pre-condition to submitting questions?

Thank you for the video link. I am familiar with Khan - his selflessness should be a model for all.

 

[horseguards]

Ryan,

Thank you for the reply. You have certainly provided food for thought.

 

[atyy]

Thank you for the video link. I am familiar with Khan - his selflessness should be a model for all.

Be careful with the Khan video. It is oversimplified. Evolution is not natural selection. Natural selection is only one of the mechanisms of evolution. Another mechanism is genetic drift.
http://www.blackwellpublishing.com/ridley/a-z/Genetic_drift.asp

 

[Ryan_m_b]

We have an introduction to evolution that you might be interested in. It also has links to other good resources.
https://www.physicsforums.com/showthread.php?t=543950

 

[Evo]

Be careful with the Khan video. It is oversimplified. Evolution is not natural selection. Natural selection is only one of the mechanisms of evolution. Another mechanism is genetic drift.
http://www.blackwellpublishing.com/ridley/a-z/Genetic_drift.asp

Yes, it's very basic, you can't put everything into one short beginner video meant to hold one's attention. They have more videos that get into more specifics. But for someone with little or no basic knowledge, it's an entertaining, non-threatening way to open the door. It avoids scientific jargon that can stop a person new to the concept from shutting down. Many times sceintists use what they think are very basic terms when speaking with a new learner and completely lose them.

 

[Cantstandit]

Life forms adapt, and thereby strengthen, by countering detrimental influences.

Given that man is increasingly less dependent on his (natural) body defence mechanisms, and more reliant on (unnatural) man-made solutions (pharmaceuticals), is it the logical conclusion that the biological defences are weakened? It may be argued that by eradicating a particular disease its defence would not be needed, however, once that defence is gone it may not be revived.

Dependence on non-evolutionary factors undermines the ability to adapt in an evolutionary context. But perhaps the alternative is thousands of deaths for the sake of evolution.

Ok, I'm not a biologist, but here's my take on it.
I don't think you can actually infer evolution in any direction from such an insignificant period of time. We use pharmaceuticals for maybe 200 years? That's nothing in evolutionary terms, and the phenomenon itself will be (I think) very short indeed. Consider two cases:
1) If we continue to rely on man-made solutions: We are not using the same drugs as 20 years ago, and in 20 years we will be using different drugs still. If they significantly cripple our immune system, isn't it possible that future generations of drugs will take that into account?
2) If we stop relying on man-made solutions: Our civilization could be gone quite soon. Say in 300 years from now we are back in the caves, will this 500 year long period (during which we influenced our immunity) make any difference on evolutionary time-scale?

In any case, I think our invention of medicine is not significant to influence evolution in any way, because whatever happens we will not be using the same methods for an extended period of time.

 

[Ophiolite]

Given that man is increasingly less dependent on his (natural) body defence mechanisms, and more reliant on (unnatural) man-made solutions (pharmaceuticals), is it the logical conclusion that the biological defences are weakened?

Biological defences, by which I take it you mean the immune system, have a range of characteristics. Some of these characteristics will be very important in one environment, but not in another. Medical intervention has changed the environment in which many of us live and thus has changed which chracteristics of the immune system, or the body in general, are to be considered fit or unfit.

So, the biological defences may have been weakened, but only in relation to a specific range of environments. Investing energy in maintaining some aspect of the immune system when that is now addressed by external means is a disadvantage to the organism. The organism is then less fit than one which has abandoned that feature.

Dependence on non-evolutionary factors undermines the ability to adapt in an evolutionary context.

I don't know what you mean by non-evolutionary factors. If something undermines the ability to adapt then it is assuredly an evolutionary factor.

 

[MathAmateur]

You can’t defeat evolution any more than you can defeat gravity or electro-magnetic forces. Sure you can make it work for you by selective breeding, just like you can make electro-magnetics work for you with radios and computers. But in these cases you haven’t defeated evolution or electro-magnetics, just used them. If we remove the selective force of disease, something else will select for or against certain genes in a population whether it be carelessness with cars or drugs or the ability to make money (it has been shown that the rich have more children).

 

[Ryan_m_b]

something else will select for or against certain genes in a population whether it be carelessness with cars or drugs or the ability to make money (it has been shown that the rich have more children).

That's assuming that those things have a genetic component which mostly they wont. Also I'm not sure where you're getting the figure that the rich have more children. In the developed world the demographic transition has meant that the average number of children per couple has dropped to around two whereas in the developing world it is much higher.

 

[Pythagorean]

The Population Pyramid for different stages of society: