Is ID non-scientific because it has relgious implications?

[Himantolophus]

Indeed. But "pinnacle of evolution" is a rather loaded phrase, I think. It may seem a little presumptuous to assume that we are the best that 3.8 billion years of evolution has to offer. I think it is fair to say that we are just as evolved as bacteria (they have, in fact, been evolving far longer than we have). But it is also fair to say we are more complex (however this metric is measured) than many other organisms. And I think it is further fair to say that if we turned the clock back a few billion years and let it all happen again that there is no reason to expect two big brained primates ought to be the ones having this discussion.

I don't mean to take away from the other creatures on the planet as there are plenty of them that can challenge humans for the "best of" award. I'd have to say the deep-sea anglerfishes are pretty darn cool. But since we (hominids) were the last major group of organisms to evolve, that would make us the "most" evolved lifeform.
Who knows who or what may be having this conversation in 3 billion years AFTER humans are gone. I'd put my money on some type of highly evolved cephalopod.

I think that this, too, may be another another claim that needs qualification. On what basis do you think we are above natural selection? In what way is evolution not working itself out in the AIDS epidemic? How about the thousands of people who die each year in the US from influenza? Or the millions who die of starvation and diseases such as dysentery, malaria, yellow fever, Dengue fever, pneumonia, tuberculosis and various and sundry viruses causing encephalitis? And what of those who contract but do not succumb to these diseases?

Well of course humans are not above every single disease on the planet mainly because they have not been cured yet and new strains are continuously evolving to beat our vaccines. AIDS, malaria, influenza, yellow fever and the like are mostly problems in the third world where people live closer to nature and have poor health care systems (and many are illiterate and uneducated). But if you look at the average European or American, we do not live by the rules of natural selection. We overharvest the land to a point where we have to import our food, manipulate our food to make it bigger and "better", build shelters to house us out of the elements, and have vaccines to prevent us from dying of disease. We also keep people alive that shouldn't really be alive (both diseased and disabled) and practice lifestyles that wouldn't benefit wild animals. We also do not have tooth and nail competition for territory and mates.

A better way to phrase this is to compare how many MORE Americans would die if we had none of the things we have above. Imagine how much smaller the population of the US and the world would be if we didn't have all of these artificial advantages?For these reasons I believe Americans and other first world countries are above natural selection. Those in the third world are also above it, but to a lesser extent.

[Himantolophus]

not to say that we'd be above catastrophic events of "selection" like asteroid impacts, volcanic outbreaks, and pandemics... I'm saying currently we're a step above it.

[ARWallace]

But since we (hominids) were the last major group of organisms to evolve, that would make us the "most" evolved lifeform.

On what basis do you think we were the last major "group" to evolve? And what do you mean by "group"?

new strains are continuously evolving to beat our vaccines.

Is there any reason to expect this will cease being the case? Otherwise, it sounds an awful lot like evolution to me.

AIDS, malaria, influenza, yellow fever and the like are mostly problems in the third world where people live closer to nature and have poor health care systems (and many are illiterate and uneducated).

On the one hand you seem to be making the case that evolution is occurring and favoring those, who by virtue of luck or by intent, have access to sanitation and health care. On the other hand, it's worth noting that evolution is operating on those who are afflicted with these diseases who lack access to health care - some surviving by virtue of their genetic predisposition. On the other hand, AIDS afflicts people in developed nations every bit as much as developing ones. And influenza kills 36 000 people a year in the United States, excellence in health care notwithstanding. And a global flu pandemic - like the 1918 one that killed 30-50 million people worldwide - is long overdue according to many doctors and scientists. And that pandemic seemed to primarily affect the young and otherwise healthy as opposed to old and weak. Curious. West Nile virus and Lyme disease are emerging diseases here in the US, and there seems to be little we can do to eradicate them. And what of those people who die from cancer because they have inherited mutations in their proto-oncogenes and tumor suppressor genes?

Humans have become smaller and their brain size has decreased over the last 10 000 years. I would take it to mean they have evolved, in some sense. And what if we extend the life expectancy of humans such that they could have dozens of children - all of whom have access to wealth, are healthier and more fecund than their parents. Is this not evolution? And would you agree that selection may favor more intelligent people who are better able to accumulate wealth, support a family and ensure their survival? These are rhetorical questions, to be sure, but worth kicking around a little.

We also keep people alive that shouldn't really be alive (both diseased and disabled) and practice lifestyles that wouldn't benefit wild animals.

And the make up of our gene pool is affected accordingly. Sounds like a textbook definition of evolution to me.

Don't get me wrong. I am not arguing that humans are not able to manipulate their environment in ways that reduces their risk of death by disease or starvation. I am humbly suggesting that to consider (a) humans the zenith of biological evolution and (b) not subject to selective pressures - ability to reduce their risk notwithstanding - is a somewhat limiting and even dangerous perspective when taken literally. But that's just me.

[zoegirl]

Braces....

Mate choice...

If we consider that much of the orthodontia out there has artificially manipulated the mate choice selection of humans (I know I'm over simplifying...bear with me) then certainly we have circumvented selection here.

If we consider that people may be attracted to and marry others and if we may presume that this attraction can be influenced by their smiles and looks and where this attraction might otherwise not be there without that orthodontia, then we are allowing genes to be passed onto the next generation that would normally (possibly) not be in the next generation.

Ceasarean sections.....if you consider that many of these babies and women would die because of the size of the babies or whether these babies fit through the pelvic brim of the woman, then we have also circumvented selection. We are keeping these babies and women alive where otherwise they would be selected against.

So certainly we govern what genes are selected for.....ceratinly NOT because we are doing so deliberatley for the selection but rather from morality.

But there can be no doubt that these do change the genes that would otherwise be passed on to the next generation.

(btw, certainly no advocating ceasing the above procedures, just pointing out that these procedures change the gene frequencies of the next generation from what they would normally be)

[ARWallace]

btw, certainly no advocating ceasing the above procedures, just pointing out that these procedures change the gene frequencies of the next generation from what they would normally be

But this is my point exactly! Changes in alleles frequencies over time is evolution! The landscape of alleles in the gene pool would be decidedly different if we were to stop doing c-sections, allowing disabled and diseased individuals to survive long enough to reproduce and putting braces on anything with a full set of chompers - but the fact remains, human populations are evolving. Just in different ways than they were when we stood upright, threw on a loincloth and tossed a rock at a woolly mammoth.

And there is real and compelling evidence to suggest that we are manipulating our environment and behaving in ways that is influencing the ways that diseases affect us as well as the library of diseases that do affect us. To suggest that because we have deciphered a genome or stamped out smallpox (possibly) makes us beyond the reproach of natural or sexual selection would be an extremely limiting (and in my opinion) myopic view of our place in nature.

[zoegirl]

To suggest that because we have deciphered a genome or stamped out smallpox (possibly) makes us beyond the reproach of natural or sexual selection would be an extremely limiting (and in my opinion) myopic view of our place in nature.

No, there is no doubt that we are still under diseases and selective pressures. I have never disagreed to changing gene frequencies. But you had argued that we weren't above selection, but is these instances WE have dictated what genes out still passed down....now you can argue that this is artificial selection, but there is no doubt that we HAVE changed the gene frequencies in ways that would NOT be dictated by natural selection.

I think this was a major point of Himantolophus's posts.

[frankbaginski]

ARWalace,

I am surprised you used the malaria parasite to support natural selection in the human population. You said:

"I think that this, too, may be another another claim that needs qualification. On what basis do you think we are above natural selection? In what way is evolution not working itself out in the AIDS epidemic? How about the thousands of people who die each year in the US from influenza? Or the millions who die of starvation and diseases such as dysentery, malaria, yellow fever, Dengue fever, pneumonia, tuberculosis and various and sundry viruses causing encephalitis? And what of those who contract but do not succumb to these diseases? And do you think it is a coincidence that the distribution map showing the areas where malaria is endemic mirrors the distribution map of sickle cell disease quite closely - a disease that, in its heterozygous form affords some resistance to the malaria parasite? Paul Ewald has argued fairly convincingly that not only are humans subject to evolution, but that current human practices and behaviors affect both our predisposition to contracting contagious diseases as well as the degree of their pathogenicity."

I agree with you that the sickle cell desease (a molecular defect) in its heterozygous form (acquired from only one parent) does offer some resistance to Malaria. This is because only part of the blood in these people show the trait. That resistance comes from the malaria having a hard time attaching to the defective cell. But the down side is that if both parents have the desease then 25% of their children die a terrible and early death. Also the spleen destroys the defective red blood cells more than normal cells which leads to life long anemia. The down side of this defect makes it impossible to spread across the human population. The only reason the defect is concentrated in some parts of the world is because that area has the parasite in high concentrations. And the only reason the defect is there is due to the death of people who don't have the defect. Since the desease is only effective in the heterozygous state then this is not an example of natural selection at work. And if the desease were to spread to the entire population then 25% of all children born would die an early and painful death. In fact if the population did not have a genetic mix and every one born had the defect the human race would go extinct because the offspring would not live long enough to have children. If this is natural selection at work then you can have it.

[zoegirl]

But the down side is that if both parents have the desease then 25% of their children die a terrible and early death. Also the spleen destroys the defective red blood cells more than normal cells which leads to life long anemia. The down side of this defect makes it impossible to spread across the human population. The only reason the defect is concentrated in some parts of the world is because that area has the parasite in high concentrations. And the only reason the defect is there is due to the death of people who don't have the defect. Since the desease is only effective in the heterozygous state then this is not an example of natural selection at work. And if the desease were to spread to the entire population then 25% of all children born would die an early and painful death. In fact if the population did not have a genetic mix and every one born had the defect the human race would go extinct because the offspring would not live long enough to have children. If this is natural selection at work then you can have it.

NO, respectfully, sickle cell anemia IS an example of selectoin. Those that are heterozygous survive better than either the homozygous dominant or homozygous condition. The very definition means that in those areas (environmental pressure) with malaria, that environmental condition means that those heterozygous for the condition are selected for.

Your very description DESCRIBES the conditions for selection. Those people are more fit in that environment. They survive better. The next generation has a higher frequency of heterozygotes and this represents microevolution.

[ARWallace]

I am surprised you used the malaria parasite to support natural selection in the human population.

Well, I used it because it actually is a very elegant example of natural selection working in human populations.

This is because only part of the blood in these people show the trait.

Well, technically all blood cells carry the defective hemoglobin. But only half of the hemoglobin in any red blood cell is of the mutant variety, and they are therefore less likely to form the polymers that cause the cells to sickle.

That resistance comes from the malaria having a hard time attaching to the defective cell.

Sort of. The red blood cells (all of them) tend to sickle when the malaria parasite tries to infect them preventing infection.

But the down side is that if both parents have the desease then 25% of their children die a terrible and early death.

25%, on average, will have sickle cell anemia. And while I agree there are a whole host of health issues for those that have it, the median life expectancy is 42 for males and 48 for females. (ref)

The down side of this defect makes it impossible to spread across the human population.

In what way? Are there any human populations that don't have sickle cell disease?

The only reason the defect is concentrated in some parts of the world is because that area has the parasite in high concentrations.

Precisely, Frank. This is exactly what evolution is - an allele exists in higher frequency in some populations because there is a survival benefit in those populations. We just happen to know, in this case, what the survival benefit is. And if you remove the selective agent (i.e. the parasite or mosquitoes carrying it) then we have every reason to expect that the frequency of the sickle cell allele would decrease and become similar to that found in populations where malaria was not endemic (such as eastern Europe). If this is not evolution - by anyone's standard (YEC or die hard evolutionist) than I don't know what is.

And the only reason the defect is there is due to the death of people who don't have the defect.

I am not sure I follow. The disease persists because (a) there is insufficient selective pressure to eliminate it in any population, (b) carriers of the disease suffer virtually no ill effects unless they are in oxygen deprived conditions and (c) because in areas where malaria is endemic, being a carrier has survival benefits over both those with the disease and those without.

Since the desease is only effective in the heterozygous state then this is not an example of natural selection at work.

I am not sure I follow the logic behind this conclusion.

And if the desease were to spread to the entire population then 25% of all children born would die an early and painful death.

What makes you think that the allele is not present in other populations? 50 000 Americans have sickle cell anemia (ref) making it one of the most common genetic diseases in America. Furthermore, the percentage of children born with sickle cell anemia would not be 25% - it would depend on the frequency of the allele in the population and the probability of two carriers or people with the disease (or some combination thereof) producing offspring. And finally, since the median age of people dying of sickle cell is in the 40's, their children wouldn't be dying as children. In fact they would be living more than long enough to pass on their genes to the next generation.

In fact if the population did not have a genetic mix and every one born had the defect the human race would go extinct because the offspring would not live long enough to have children.

Then how come there are so many people in Africa - where the frequency of the deleterious allele may be 10% who are still managing to thrive?

I think, Frank, that this is actually a pretty clear example of evolution at work. In fact, it has been described as an example of selection favoring one genotype over another - heterozygote advantage.

[Himantolophus]

Is there any reason to expect this will cease being the case? Otherwise, it sounds an awful lot like evolution to me.

ARWallace: I'm not arguing against you here. I consider myself an evolutionist as well, although more of a theistic evolutionist as far as the origin of the Big Bang.

I completely agree that humans are subject to selection in some forms, but we are above natural selection in alot of things as well. If you threw the average American into the jungle with no tools and no vaccines, he/she would suddenly be in the same position as our ancestors 100,000 years ago. A situation like that would subject us to the same selective forces as say an elephant, bird, or insect. The fact that Americans live the way they do today puts them a step above everything else. That is NOT to say that we are immune from disease or natural disasters, but it means that we are able to remove many of the selective forces that our ancestors had to deal with.

As far as pathogens/vaccines and the distributions of various diseases, I'd say it was more of an artificial selection since the distributions of many (NOT ALL) diseases is directly correlated with factors like education, population density, economic development, and even habitat. All of these factors we create ourselves. So the survival of humans can be attributed to the vulnerbility of population as created by man.
Of course the pathogens will evolve themselves since those with a resistance to a vaccine will be selected over those that are killed by it. That is why we will never eradicate disease. Humans lag behind in the co-evolution of the host/pathogen system. The evolution of the pathogen is driven by true natural selection.

[frankbaginski]

ARwalace,

I thought the lifespan for someone with the desease was shorter. So my comment about the earths population of humans going to zero obviously does not apply.

Let me ask you, when do you think that malaria came onto the earth and when do you think sickle cell came on the earth? Do you think we are seeing a balance of the defect in the populations right now? Should we encourage people with the desease to have more children and those without the desease to refrain from having children? If this is a true benefit why is it called a desease? If this is a benefit why are we spending so much money trying to find a nanobot to destroy the parasite, when we could just adjust our breeding habits? If this is a benefit then why do we try and keep the parasite out of the United States? If natural selection and benefits go hand in hand should we form a group to determine which forms of DNA should continue and which ones do not? If you do not agree with human intervention at the conscience level to interfere with natural selection then why do we make drugs to kill bacteria? If we allow some people to live who otherwise would have died from natural causes are we causing the gene pool to become weak?

Once you place sickle cell as a benefit of natural selection then should we consider other deseases a benefit because they kill off old people thus saving more resources for the young? Should we scan all children born for acceptable defects and discard the ones we don't like?

To me a benefit would be a mutation which would lead to us being immune to malaria, and no desease that comes along for the ride. I have a hard time with sickle cell being called a benefit if you haven't guessed that already.

[ARWallace]

Frank:

Let me ask you, when do you think that malaria came onto the earth and when do you think sickle cell came on the earth?

I have no idea. I'm sure I could see what the "experts" think vis-a-vis phylogenetic reconstruction of the group to which the malaria-causing Plasmodium belongs and their subsequent estimates. As for sickle cell - well, as long as you have a gene for hemoglobin it stands to reason you could get mutant forms. so it sort of depends on how long the hemoglobin gene has been around.

Do you think we are seeing a balance of the defect in the populations right now?

I'm not sure what you mean by "balance". In North American populations, I would guess the frequency of the allele is fairly stable by evolutionary standards, and it tends to vary mostly by genetic drift. I guess I am not sure what you're asking.

Should we encourage people with the desease to have more children and those without the desease to refrain from having children?

It's my opinion that we have no right to discourage anyone from having children.

If this is a true benefit why is it called a desease?

Sickle cell anemia is a disease. The carrier form - not so much. And it is the carrier form and not the sickle cell anemic form that confers a benefit. A particularly intriguing disease is cystic fibrosis. CF is autosomal recessive, so carriers have no ill effects. Yet it is found in relatively high frequencies - and some have argued that the carrier form may confer some resistance to tuberculosis. For 300 years, tuberculosis was responsible for 20% of all deaths in Europe. So we may be seeing a leagacy in today's populations - higher incidences of the CF gene because those that carried it in the 1700's were less prone to die of tuberculosis. Yet another example of human evolution.

If this is a benefit why are we spending so much money trying to find a nanobot to destroy the parasite, when we could just adjust our breeding habits?

This is a bit of an odd question to me. This sounds a little like the reasoning of some of the founders of the eugenics movement in the US who - for reasons they felt noble - sought to restrict breeding in humans considered mentally deficient - often through forced sterilization. I think restricting the right to have children may violate our civil liberties - some rather core ones, I think. Life and liberty, and maybe even the pursuit of happiness.

If this is a benefit then why do we try and keep the parasite out of the United States?

Because we have enough diseases to contend with? If malaria was introduced into the US, the frequency of the SC gene would likely increase. That's the way evolution works. Of course it would likely result in a huge number of deaths while it sorted itself out, and most of these deaths would be seen in Caucasians (unlike African Americans and people of middle Eastern descent who carry the allele in higher frequencies because of their origins). So it would seem a high price to pay just to get an allele to increase in a population to confer greater resistance.

If natural selection and benefits go hand in hand should we form a group to determine which forms of DNA should continue and which ones do not?

Well, no. This is not a position I support. This is, again, sounding ominously like eugenics - an inherently evil doctrine.

If you do not agree with human intervention at the conscience level to interfere with natural selection then why do we make drugs to kill bacteria?

I never said I opposed human intervention to improve quality of life or to save lives. But I would argue that human misuse of antibiotics is creating a whole host of problems that we're eventually going to have to face. But this doesn't mean I am against antibiotics.

If we allow some people to live who otherwise would have died from natural causes are we causing the gene pool to become weak?

That's a good question. I don't know.

To me a benefit would be a mutation which would lead to us being immune to malaria, and no desease that comes along for the ride.

Well, that's a tall order to fill. See my cystic fibrosis example. But this does not change the fact that evolution has driven a change in the frequency of the sickle cell allele in areas where it benefits the carriers. And to be clear, I have never said having sickle cell disease is a benefit. But I would claim that risks of being infected with (and dying from) malaria outweigh the risks of having children with SC anemia in certain areas on Earth. Whether you like sickle cell being called a benefit is rather inconsequential in the question of whether it can be...because it is, in some cases.

[ARWallace]

I'm not arguing against you here. I consider myself an evolutionist as well, although more of a theistic evolutionist as far as the origin of the Big Bang.

Well, I have been rather mute, to date, on my theological and (and to a lesser extent) scientific opinions. And I am not trying to argue - merely seek a little clarification. It is my opinion that human populations are evolving - in many ways, in fact - but that I do not disagree that we are unique among species in our ability to manipulate our environment in ways that (usually) positively effect our chance of survival and reproduction. But this is not true in all populations, all the time. I further contend that to assume we are insulated from the effects of natural selection because of our ingenuity may be a rather nearsighted perspective to adopt. And I think we're a razor sharp edge away from finding out just how true this can be - had it not been for some good luck and timely clinical intervention, SARS might have lived up to its reputation, and we'd be looking at a pandemic that mirrored that of 1918. But beyond that, human populations do change, albeit in small and subtle ways which, in the strictest sense, is microevolution. I won't put a finer point than that on it.

Second, I remain somewhat more conservative about our place in nature. We are a frail and not very resilient species compared to many. And if you believe we are the products of evolution, I would remind you that despite our profound impact on the planet, that we've only been here a nanosecond in the history of the Earth. We are not, by this reasoning, the paragon of evolution in action - we are merely a clever and somewhat talented group among all extant taxa that are also products of evolution, at this moment in time. This doesn't mean we aren't unique or special in god's eye, if you have such theistic leanings. Only that I tend to be a bit circumspect in my views of our place in nature. I used to live near Seattle, and every year a handful of hikers would perish on Mt. Ranier. This mountain is visible from Seattle, and these hikers were usually equipped with the best and most expensive equipment and survival gear that REI had to offer. And usually they would only be missing a few days before they were found dead. So if 21st century mountaineers, in the peak of their physical fitness, equipped with the best that technology had to offer could die within clear view of a major American city (with cell phones in hand), I contend that the human species may not be the masters of nature we might think we are.

[frankbaginski]

ARWalace,

It is my understanding that natural selection requires a benefit to go along with a change to the species or else the change does not grow in the host population. So calling sickle cell an example of natural selection is by inference calling it a benefit. A defect is suppose to decrease in the host populations where a benefit grows in the population. If I am wrong in my interpretation of theory then let me know.

So you have no problem with man's interference with the natural order. Then we can make drugs and try and prolong life even though it may affect the gene pool in unnatural ways. So we should prevent suffering where we can. How about genetic engineered foods, should we continue to make changes to our foods to make some plants more resistant to pest and desease. Should we try and increase the vitamin content of our produce? If man made a nanobot that destroyed all malaria parasites would you oppose the release of this device because it would make a natural organism extinct? Should Congress step in because the release of the nanobot would cause a lifeform to go extinct, could the endangered species act be used to save the malaria parasite?

I bring up these issues not to be flippant but to point out that how you view nature tends to form the answers to these questions. I think of nature as made for man and we can do what we want so it benefits us. So us interfering with nature has no meaning to me because it was given to us. Making drugs to kill parasites and desease is an extension of our control over the earth. However, we were created in God's image so we are not to interfere with our design. I see no grey area what so ever. If you believe in evolution and we came from a lower species then when did we get to God's image? And since we are still changing according to evolution does that mean we are no longer in God's image? I have read on this site that man will be replaced by some other species in the future. Isn't this the natural outcome of evolution and does it imply that nature will win over God's image over time? I think that what we see as mechanisms to explain evolution are just devices to maintain the species we have. I see the world as 8000 years old and everything is simple and everything makes sense. I know you have a vast amount of knowledge in understanding the details of life science. But life has little to do with atoms, molecules or nanobots.

Because of my beliefs I take offense when someone says that a defect in a human gene is a benefit. Now I do not know if God had anything to do with the defect but I allow for the possibility. But to give nature the power to change human flesh outside of God's will I do not accept and never will. For if God protects His name I have a hard time seeing Him not protecting His image.

Oh, I can't access the documents on the PNAS site. Is there another source for this information?

[zoegirl]

ARWalace,

It is my understanding that natural selection requires a benefit to go along with a change to the species or else the change does not grow in the host population. So calling sickle cell an example of natural selection is by inference calling it a benefit. A defect is suppose to decrease in the host populations where a benefit grows in the population. If I am wrong in my interpretation of theory then let me know.

Selection requires that the characteristic in question merely be a benefit/advantage to those in the population in that particular area. FOr those living in malaria dense areas, the sickle cell gene IS an advantage, insofar as heterozygotes go. The heterozygotes survive preferentially over either homozygous condition. In areas withou malaria, the homozygous genotype for the normal hemoglobin survives preferentially. Selection operates within the environmental pressures. The homozygous sickle cell genotype IS a disadvantage in those area without malaria.

Because of my beliefs I take offense when someone says that a defect in a human gene is a benefit. Now I do not know if God had anything to do with the defect but I allow for the possibility. But to give nature the power to change human flesh outside of God's will I do not accept and never will. For if God protects His name I have a hard time seeing Him not protecting His image.

I think this reveals a lack of trust in God. Could not God have created this variation in the gene in order to ENDURE , even in the midst of this parasite, we would have the flexibility to survive? Can this change in gene frequency not be a reflection of God's planning and design? Why does this example somehow "give nature the power"?

I don't think, in examining gene frequency changes, that we are somehow undermining God's will. Nor does this example require that Christians give up some element of God's sovereignty or power or will. There are PLENTY of examples of simple gene frequency changes that reflect genetic flexibility within a population.