In order for the basic evolutionary process to work, there must be a feedback mechanism which increases the probability that people with desireable genetic traits can sucessfully procreate. If this mechanism breaks down, then natural selection is circumvented and undesirable genetic traits continue to thrive in the gene pool, thus halting the evolutionary change agent.

Modern medicine enables the survival of people who would have in past eras died of various causes. For example, someone with natural eyesite as bad as mine living in early human society probably wouldn't have survived because they would have been unable to function absent glasses or contacts. Unable to hunt, see predators, etc. However, in the modern world I have many options for correcting this genetic problem and my chance of procreating and passing this genetic malady on to my children is high.

1. By enabling people with certain physical traits to survice and thrive, who in a less civilized society might die prematurely, is modern medicine short-circuiting the evoluationary mechanism?

2. Assuming this is happening, is this a negative trend? That is, if medicine can prevent said maladies from being life threatening, is there any danger in preventing evolution from eliminating them?

Interesting topic.

1. By enabling people with certain physical traits to survive and thrive, who in a less civilized society might die prematurely, is modern medicine short-circuiting the evolutionary mechanism?
2. Assuming this is happening, is this a negative trend? That is, if medicine can prevent said maladies from being life threatening, is there any danger in preventing evolution from eliminating them?
My immediate answer to the first question would be no. The "faulty" properties of some humans, which they pass on to their offspring, would indeed in earlier times have been a factor in their survival, but since modern medicine also will enable this offspring to survive, one could argue, that these faulty properties no longer matter in an evolutionary context, simply because they have been corrected (even though its an artificial correction).

Other "faulty" properties, which modern medicine is not able to correct, still have a significant impact on who lives and who dies. If a pandemic of an untreatable ebolalike virus breaks out, then probably millions of people will die, and ultimately only those who can the resist the virus will survive, and in the future almost everybody will be practically immune to the disease - this was what happened with the Spanish disease and the black plague. So the evolutionary mechanism will still work in the areas where it is essential for the survival of human kind. Nobody hopes for evolutionary steps of this kind though.

I don't think there is any immediate danger in this. The only scenario I could foresee, where it would be a bad thing, is if in the future access to modern medicine is severely limited, so that diseases easily treatable now run rampant to such a degree, that the deathtoll is higher than it would have been, had we let the evolutionary process advance at it's natural pace. However I don't think we ethically could stop doing what we are doing? Are we just going to let people suffer and die with the purpose of hardening our resistance to diseases and biotoxins... I think not.

1. By enabling people with certain physical traits to survice and thrive, who in a less civilized society might die prematurely, is modern medicine short-circuiting the evoluationary mechanism?
You must also take into account the sheer scale of the evolutionary process in regards to time. Also remember that in the case of humanity a large part of our continued survival has also been a result of our ingenuity and the ability to think rationally and in a linear fashion and then reference in observations and adapt our thinking--we can plan ahead. Our ingenuity has allowwed us to adapt to every known condition on this planet except under water. The use of tools and methods of dealing with the local climates also allowed certain physical attributes to develop that met needs of the body to survive the conditions.

2. Assuming this is happening, is this a negative trend? That is, if medicine can prevent said maladies from being life threatening, is there any danger in preventing evolution from eliminating them?
I would argue the answer is NO.
We are able to create our own environments now--anywhere. Our growing ability to modify our genetics will change the evolutionary process--but it seems to me that nature has a funny way of humbling us. We may think we have it beat or can completely control it and then--there always seems to be a wildcard factor.
really who knows? we're getting a better understanding of how evolution has functioned--enough so that its detractors best defense now it the weakness of intelligent design. The scientific version of a 3 card monty parlor trick. We still however have a ways to go to completely understand it all.

1. By enabling people with certain physical traits to survice and thrive, who in a less civilized society might die prematurely, is modern medicine short-circuiting the evoluationary mechanism?

No, its because of evolution that the organism homo sapien is able to do such. Genotype to phenotype to many other aspects of biology one could study under the umbrella term evolution is far from in perfect understanding. Simply a cow can only be a cow, barring the passing of time and countless mutations to its genetic code it might be extinct or something else. The same is true for homo sapiens, we are what we are and do such according to what we are. We don’t have wings, so we have to make air planes… Of course this did not just come about overnight, the air plane that is. Of course you could maybe splice a fly and a human, it could make a good movie and maybe help the field of animal behavior I mean psychology make progress.

2. Assuming this is happening, is this a negative trend? That is, if medicine can prevent said maladies from being life threatening, is there any danger in preventing evolution from eliminating them?

Well, we don’t live alone in the wild without any form of technology either, is that something of a negative trend, maybe we should go live hunter gather type lifestyles and see how the world comes to express overall in regards to cultures of homo sapiens lol.

No, simply because if we fix them, it will not kill the person, and eventually we will come to be able to fix things on a genetic level, which means in the long term a negative trend that could be produced currently via offspring will be able to be countered.

Science seeks to end mortality, its nothing new, and eventually it will be able to do such, for now its only science fiction, like rockets were way back in the day.

1. By enabling people with certain physical traits to survive and thrive, who in a less civilized society might die prematurely, is modern medicine short-circuiting the evolutionary mechanism? Slow down, maybe but not short-circuit. The human race isn't in perfect equilibrium so evolution is taking place on some level. There may be a large gene pool and a low morality rate but we're definitely going somewhere.

2. Assuming this is happening, is this a negative trend? That is, if medicine can prevent said maladies from being life threatening, is there any danger in preventing evolution from eliminating them? The alternative is eugenics and it's immoral so it isn't any of our concern.

Some have argued though that there is a new evolution, cultural and technological evolution. This cultural evolution isn't slowing down at all, it's actually speeding up exponentially. We invented fire 800,000 years ago, agriculture 10,000 years ago, Iron 4,000 years ago, Steel 150 years ago, transistors 60 years ago, the integrated circuit 45 years ago, personal computers 30 years ago, etc. Today it almost feels like technology is advancing so fast the average person can see it change before their eyes. 1000 years ago people lived almost exactly like their parents did, but kids today couldn't imagine living without computers, DVD's or cellphones. Humans today don't need to wait for their offspring to have better genes. Adaptation is something we are all doing constantly through the choices we make and the way we live. Hungry? If you were alive 30,000 years ago you'd have to wait 20,000 for agriculture to be invented. Today you can hop in your car and drive down to the Burger King. Culture is a dynamic thing and can be much more powerful than genetics sometimes.

1. By enabling people with certain physical traits to survice and thrive, who in a less civilized society might die prematurely, is modern medicine short-circuiting the evoluationary mechanism?

First of all, it's important to mention here that evolution does not appear to be a continuous process - species can stay more or less the same for millions of years (e.g. the horseshoe crab).

Our species emerged as a discrete human type perhaps 100,000 years ago, and from what we've managed to deduced from fossil remains, we haven't changed biologically in any significant way since then.

Rancid Uncle is right to suggest that our pace of evolution has been mostly technological and cultural since then - up to a point we have insulated ourselves from evolution.

This is not necessarily a bad thing - much of Richard Dawkins work follows the narrative that we have the ability to free ourselves from the tyranny of our genes. We don't HAVE to kill, rape, cheat, steal, or exploit others to succeed, all of which are the natural result of bowing to the demands of our selfish genes. We have a choice.

And by having a very large gene pool, where even apparently disadvantageous genes can survive to be passed on to a new generation, we may be protecting ourselves from the next big disease. Who's to say that, when some nightmare scenario occurs and a virus as lethal as HIV or even Ebola can be spread as easily as influenza or the common cold, the only people who could survive might be those with cystic fibrosis or sickle cell anaemia or heamochromatosis or any number of other genetic conditions that might be fatal themselves without modern medicine.

2. Assuming this is happening, is this a negative trend? That is, if medicine can prevent said maladies from being life threatening, is there any danger in preventing evolution from eliminating them?

No.

But let's not get too complacent. Outside the first world, we haven't removed the liife threatening potential of said maladies anyway. With the notable exception of smallpox, we've put the economic cost of eliminating some diseases at higher priority than then human cost of living, and dying, from them (most notably malaria).

And we've been so ill-disciplined in the use of anti-biotics - pumping our food animals full of them as growth promoters, for example - that in the foreseeable future, genetic diseases might be a fond memory, since we'll all be dying of tuberculosis, scarlet fever & syphillis long before we get the lluxury of succumbing to any particular genetic timebomb.

And inside the first world - or at least inside the sections of it for whom we deign to fund decent quality healthcare - birth rates are way down anyway, and the chemical cocktail we blithely pump into the air and water supply seem to be increasing the incidence of some conditions, as well as decreasing fertility and further depressing birth rates.

Any genetic advantages the wider gene pool gives our species' can gain through medical and techonological advances will be wasted if we only permit their use on a tiny, rich proportion of the global population. By, for example, only allowing rich people to afford them, and structuring the global economy in such a way that only a tiny proportion of the global population is that rich.

1. By enabling people with certain physical traits to surface and thrive, who in a less civilized society might die prematurely, is modern medicine short-circuiting the evolutionary mechanism?

I think that modern medicine does, to a certain extent, enable certain conditions to be more widespread simply because they are not as deadly as they were in years past.

Think of diabetes. 100 years ago, type I (juvenile) diabetes was deadly. Until the discovery of insulin in 1922, a diabetic could only be expected to last a few years. Today, in developed countries, diabetics are expected to live decades after diagnosis. Modern medicine has removed the death sentence from the disease.

What has this caused, in evolutionary terms? Of course there are many more diabetics around. In the US alone, there are an estimated 2 million people living with type I diabetes. These people can live healthy, relatively normal lives--as long as they have access to insulin and blood testing supplies. Should some catastrophe strike, many diabetics will be again at high risk due to the lack of medical supplies.

But medicine, like other innovations such as fire and weapons, are simply tools that have been developed by man over the centuries to help him conquer his environment. The use of technology is indeed an evolutionary advantage that man has, although it is not a genetic one. It is pseudo-hereditary, however, since it is passed on from generation to generation.

2. Assuming this is happening, is this a negative trend? That is, if medicine can prevent said maladies from being life threatening, is there any danger in preventing evolution from eliminating them?

Disease is very rarely entirely eliminated by evolution. What you have is a resistance. In my example, diabetics never lived long, historically, but the disease has been known for over 3000 years and has not gone away. Of course, it is more prevalent now, which can be seen as a negative. However, it is only negative if we lose our ability to treat these diseases. If that happens, evolution will again kick in .

By enabling people with certain physical traits to survice and thrive, who in a less civilized society might die prematurely, is modern medicine short-circuiting the evoluationary mechanism?
I have two responses to this:
1) That ship has sailed. Reproduction depends on two things -- the ability to reproduce, and the willingness to reproduce. Ever since beings such as us started reproducing for reasons other than the purely physical drive to do so (i.e., love & familial responsibility), evolution has been short-circuited. That modern medicine saved those individuals who would have died before reproducing (or cause genetically infertile members to become fertile [no pun intended]) is largely self-fulfilling. That is, if modern medicine can sustain such individuals, then evolution is irrelevant. There is also the issue of the detritus of modern life causing some of the diseases we are currently trying to solve -- like the rise in certain digestive cancers, Rye's syndrome, oil allergies, tobacco-related bodily destruction, etc.
2) Who decides what "certain physical traits" are? Vive la difference!

Assuming this is happening, is this a negative trend? That is, if medicine can prevent said maladies from being life threatening, is there any danger in preventing evolution from eliminating them?
That's really a moral question. Eugenics, and all that. But look at it this way, there is a danger of the opposite. We first must assume that genetic diversity is a good thing -- we can state this because survival of a species depends on the ability of a few individuals being able to withstand whatever nature decides to throw at us. HIV immunity for certain individuals, for example. By allowing evolution to determine which genetic lines get saved and which get discarded, we run the risk of eliminating those lines that might have immunity to certain other diseases by coincidence. By maximizing variability -- by artifically extending the lives of certain genetic lines -- we are actually increasing the odds for survival of the species.

Regarding the second question: several people have mentioned Eugenics and I'm not sure how we got off on that subject. I was just asking if there is a danger to humanity in using medicine to prevent diseases that might otherwise be cured by evolution.

I wasn't suggesting we stop treating people so that they would die and thus improve the gene pool! I was just asking if in so doing we are adopting some evolutionary risk. Risk that we obviously choose to accept. My question was intended to provoke responses regarding if there was said risk and if so how severe it is.

Furthermore, Eugenics is an active philosophy. Killing or otherwise preventing people of a certain genetic background from procreating. Disease killing off a group of people without natural immunity isn't Eugenics. Even letting people die, immoral as that would be on humanitarian grounds, wouldn't necessarily be Eugenics.