The SIV virus is too different from HIV for this story to be credible.

And you're basing that statement on what evidence?

We're human, therefore curious, and need to know the sources of things. Other than that curiosity, though, did the authors of the study say what other benefits this finding could bring?

SO, EXPLAIN WHY AIDS SPREAD FASTER IN THE GAY COMMUNITY!!!

Reply to John Bleau:

Your statement is very general. It would make a good topic sentence, but you offer no details to support your main idea.

Are you a virologist?

Viri, particularly RNA based retroviri like HIV, mutate easily and rapidly. There are two major types of HIV and each of those now has now evolved several subtypes.

Again, are you a virologist? Can you point out the differences in the RNA sequencing and demonstrate why evolutionary mutation cannot possibly account for the minor genomic differences?

Epistomology is the field of philosophy concerned with the question, "How do you know?" Throughout our history, humans have come up with a number of ways of "knowing", the most perverse of which are "authority" and "revelation."

The only credible epistomology is the hypothetico-deductive model of scientific investigation, commonly known as the scientific method. Science is about testing hypotheses.

For too long people have made blanket statements such as, "The world is flat," "People who suffer infirmity do so because God is punishing them for their transgression (Pat Robertson re. Ariel Sharon)."

Psychics are not allowed to testify in court that they had visions of a defendant perpetrating a crime. EVIDENCE is required. Allegations cannot even be brought to court without supporting EVIDENCE.

So if you want to make general statements in the field of science, you have absolutely no credibility unless you bring with them the EVIDENCE.

Re similarity or not of SIV and HIV-1.

This is what makes the Science paper so striking.

Hahn and her colleagues looked at complete genetic sequences of SIV in the Cameroonian chimpanzees and compared them to HIV-1.

The sequences were closely correlated only in the chimpanzees of southeastern Cameroon and not in SIV strains found elsewhere.

Guillermo, ask yourself this: if more people had cared about what was happening to gay men in the U.S. in the 1980s, would so many millions of men, women and children have died in Africa in the 1990s and early part of this century?

This is something that Franklin Graham and I spoke about when I interviewed him for the current issue of TIME. He counted himself among the Christians who couldn't see beyond the gay issue in the 1980s to the larger implications of the AIDS epidemic.

I didn't include that in my story because he has said it elsewhere but perhaps I should have repeated it.

To the Epistimologist, Tom H.

How do you "know" the hypothetico-deductive model of scientific investigation is the only credible way of "knowing"??

What if your methods are slanted? Are you, can you still be credible. What if there is another way of knowing? What if it doesn't fit into your method?

Sure, EVIDENCE will get you convicted, but so will a slanted jury, great lawyer, or biased judge. Maybe not everything fits into your box...

If the chimp virus is a composite of two other viruses, could HIV also be composed of two viruses then? If so, couldn't researchers find a way of separating those viruses and thus destroying HIV?

GUILLERMO, AIDS was easily able to spread through the gay community for several reasons, unprotected anal sex probably the most significant of all of them. Gay men are infected at a significantly higher rate then gay women, specifically due to the chief form of intercourse they engage in.

When you multiply the risks of unprotected sex in general with the additional tears in the anus, of which the virus can easily get into, coupled with societies ignorance of the "gay issue" you have a recipe for disaster.

That is why AIDS spread so fast through the gay community.

This is very interesting, but somehow, at least in this country, HIV/AIDS have been largly confined first to gay men, then to IV drug users. Somehow, later, to African-American women of childbearing age. The virus that was to spread to the so-called general population didn't. I cannot understand how a virus can be discriminatory.

I think there is not enough evidence about Orgin of HIV in this article.

Maybe it's necessary for more information for common people who don't have knowledge about HIV.

Fascinating viewpoints one and all, however, I think we can all find common ground in the fact that we are lucky we don't have to hunt viral chimpanzees for food...we just have to make sure that we get the right food at the drive-thru! Man, I hate driving away with the wrong order;-)

Further critique of the Scientific Method:

Tyler, keeping in mind that we're talking about Science here (not Law), two key components of the hypothetico-deductive model missing in this dialogue (which also do not exist in other "knowledge" models) are Peer Review and Repetitive Methodology.

Peer Review ensures objectivity in Science: at least 3 senior scientists (usually not known to the researcher) examine the research hypotheses and supporting evidence offered. In addition, the researcher's Methodology must be repeatable.

More than anything, these constructs ensure the validity of the work offered for publication, act as a strong filter against various biases, and place a high standard on any knowledge 'gained'.

If you've never run the gauntlet of pre-publication peer review (in any discipline - not just Science), I encourage you to give it a go. The experience usually leaves a lasting impression on the sheer complexity of conducting careful research and a vast appreciation for just how truly difficult some answers are to obtain.

So, while Science is often an easy target when debating contentious issues within society, we would do well to remember this same model has produced stunning results, for instance, in eradicating certain diseases, revealing genetic structure, and putting a man on the moon.

Such accomplishments did not happen merely because someone "wished" them into existence.

No system or model is perfect, and scepticism is healthy. If anyone knows of a better process to ensure quantitative results, please enlighten this forum.

Enquiring minds want to know.

To Tyler:

One knows by testing, repeatedly and rigorously, to see whether the hypothesis is correct.

You raise an outstanding point with your question about slanted methods. Results are published in peer review journals and independently verified by others. In fact, a good scientist will do everything possible to disprove a hypothesis and accept it only after failing to do so.

No other ways of knowing, even pure induction, are verifiable. Other epistomological systems are, in essence, systems of belief, taken on faith.

Court, obviously, is not the same as a laboratory. The point was that the legal system allows (between opening and closing statements) empirical evidence, not belief, heresay, conjecture, etc. The original discussion was about SIV evolving into HIV. I am using court as an analogy, not an equivocation.

Speaking in absolutisms can be a dangerous thing. In physics, theorists speak in terms of "models" more than absolutisms. A century ago, physicists thought that there was nothing more to be learned. Quantum mechanics and relativity turned that notion on its head. The Newtonian model of understanding was not overthrown, but was shown to be incomplete in what was truly a revolution in thought.

So can anything be known with absolute certainty? Probably not. The scientific method, however, is the ONLY epistomological system which truly attempts to demonstrate its truth with rigorous testing.

Scott: nice touch.

I'd also like to point out that just because the AIDS virus first jumped from chimps to humans in Cameroon that doesn't explain how it triggered a pandemic.

Probably such jumps from the animal to the human world happen all the time--witness the small clusters we have seen with avian flu.

Usually these clusters die out. We still don't know why that wasn't the case with HIV.

I am interested to see the discussion turning around why it seems particular sects of society (in the USA) are infected with HIV/AIDSs.

It is an interesting epidemic in that it is very social. What i mean is that, because it can only be transferred in certain ways, by sexual contact and/or transference of blood, one usually contracts the virus from someone they know.

Whatever be the cause, humans tend to associate with those similar to them. Homosexuals socialize with other homosexuals. The impoverished usually socialize within their socioeconomic strata. Intravenous drug users socialize with other intravenous drug users. Therefore, there wasn't much room for the disease to spread.

Perhaps I am incorrect. But, consider that the reported statistics are just that: reported cases. Middle and upper class Americans in the past have been quick to hide social "blemishes," and since most Americans are egocentric and consider those with HIV/AIDS to be inferior to themselves, how many cases exist hidden from society and statistics?

In many Sub-Saharan African countries, the statistics are devastating: in some cases, the majority of the population lives with and dies from HIV or AIDS. Perhaps we should stop focusing on who is infected and start looking even closer at what we can do to help.

In response to the clearly inflammatory question about the relationship of HIV/AIDS to the gay community:

While a virus might be "prejudiced" by a genetic succeptibility, they generally aren't selective based on moral lines. However, people are.

Prejudice can effect how quickly people are willing to admit having a "gay disease." Prejudice can also effect the way in which media responds to an unknown epidemic, in for example, the era of Reagan's conservative presidency.

While AIDS seemed to the public eye to spread exclusively through the gay population, there were thousands of deaths from "liver cancer" or "pneumonia" or another euphemism during this era.

Fact is: we now know how the disease seems to spread. We are (reluctantly) educated to practice sex with barrier methods. We know that anyone, of any class can get it. We are overwhelmingly sympathetic to children who get the disease through transfusions.

And still...our cultural prejudice is leading us to be relatively unsympathetic to gay men, Africans, poor people, single mothers, or other "undesirables" who die from it too.

In summary: Guillermo, YOU are the reason AIDS spread through the gay population faster and earlier. A gay man who feared YOUR hate didn't talk about his sexual practices in time to help understand the spread of the disease; A woman wasn't educated because a restrictive society feared frank discussion about sex; a straight, white, christian man died of AIDS but it was reported as lung cancer by a family who didn't want people to think he was gay.

The disease brought fear, and exposed our stereotypes and hatred. 25 years later, we're able to see that it isn't a biblical plague, but we're also still trying to point a finger of judgement. Another of the sadnesses of this disease.

Hi !

Great article. I havent listened to the soundbite yet, however reading the article doesnt convince me about the causality.

Why should I not think that the chimps got the virus after biting the humans (i.e. it was the humans who had it first, probably got it from somewhere and the chimps then got it from humans). Afterall the similarity of genes argument works both ways. And 25 years is a long time for the virus to mutate in any which form that virus wants.

Would I be too wrong if I ventured that this is a possibility too ? and if so how do you refute it ?

Thanks, Nik.

1) The original Science article has a lot of good supporting material. It's not available on the web for free but you can find a copy in any good library.

2) Viruses usually cause more severe illness in the new species, not the originating species. So, for example, Ebola virus is suspected to originate in fruit bats in between causing devastating outbreaks in people.

3) Are you thinking maybe of time flowing backwards? :) Following the genetic analysis, you'd have to explain how the virus went from humans to chimps and then split into two to infect two different monkey species.

RE: Scientific Method Discussion

Demetrius, Tyler’s apparent aversion to the hypothetico-deductive model brings to light something I see all too commonly…that is someone bringing me problem without also bringing ideas for a solution. Further, some see the model as being a rigid academic process that does not allow for creativity or diversity of thought. Nothing could be further from the truth. To every systemic problem there is a pattern and every pattern has its own unique set of variables. Thus, each effort should end up as unique as the problem being studied. If it does not, if it lacks spirit and a passion for the truth it will not yield results worthy of those counting on them.

Now, we need to bring this back to the problem at hand. It is clear to me that this was more than a boilerplate study. It is also clear that this is the type of study we need to arm ourselves against the evolution of viruses. Composite & designer viruses pose an even greater risk to humanity due to their adaptability in transmission. The process of decompiling the sequential path of their metamorphosis is a logical path to a retrovirus.

Finally, to nik sarpotd, I find your hypothesis suspect in that it does not follow natural order. It is like asking if the mule created the horse and the donkey.

Michael Koy asked:

If the chimp virus is a composite of two other viruses, could HIV also be composed of two viruses then? If so, couldn't researchers find a way of separating those viruses and thus destroying HIV?

I'm not sure what your reasoning is here. The article says, "the investigators have traced the origin of HIV to a simian virus that is itself a composite of two other viruses."

It does not mean that the composite is a set of independent and separable components. They are merged at the molecular genetic level. It's like saying a fertilized egg is a composite of a female egg and male sperm. You wouldn't propose that they could be separated, would you?

Why does Africa have to stand accused of everything bad? I see the report as biased with no scientific truth to it.

This is really a great discussion, but the key here is that the virus doesn't appear to be a single virus in origin. It appears rather that the chimps were a petri dish of sorts that mutated two viruses from another species into SIV which then got into humans as HIV. So the real gem here is what were the two originating viri? Examining the two legacy viri might reveal a clue on vulnerabilities in the virus.

When you boil it down, we really *don't* understand how the DNA and RNA works. We understand some of it's effects, but not the why. When we understand the why we will be faced with the challenge of using it responsibly to manage diseases and not each other. To put it more bluntly, if we understood why, we would understand how to change the genetic code of the virus to disable, debilitate, or destroy the virus.

Mankind has not traditionally done the right thing when presented with powerful knowledge. Even now there are rumors that the drug companies don't want to cure HIV but to actually make it chronic so they can improve their profitability.

This is in response to C.G:

Perhaps the reason that HIV triggered a pandemic is because HIV takes much longer to kill its host than the avian flu or other communicable diseases. This gives the host plenty of time to spread it to others.

I was surprised to hear that the virus was estimated to have made the jump back in the thirties. I always thought that it happened in the eighties especially since I seem to recall reports of a gay male flight attendant who was given responsibility for bringing it into the larger population.

Re Robert Cran's comment "why Africa?"

From a purely biological point of view, you'd expect a lot of diseases to originate in Africa because that is where humans originated. It's where we have lived the longest as a species and therefore it's the place that germs, viruses and parasites have had the most practice at infecting us.

But, of course, Africa is not the only place for diseases to originate. Many researchers believe syphilis, for example, began in the Americas--interesting parallel there on how it spread to the world via sailors and other travellers. Others think syphillis began in the Mediterranean, where it was mistaken for leprosy.

In any event, we don't have the substantial genetic evidence to draw a definitive conclusion for syphillis--the way we do for HIV-1.

From a larger, sociological perspective, I take your point that Africa is still often portrayed as a "benighted continent full of woe." My hope is that with the greater expansion of the Internet and personal contacts, we can move beyond stereotypes and report both the good and the bad from the countries of Africa and around the world.

To J. Mieles on the origin of the HIV pandemic in the 1930s.

The 1930s dateline fits both the genetic evidence and the historical evidence. Huge mines needing thousands of workers had been set up in the 1920s in Congo. Many of the men were far from home for the first time and turned to prostitutes for sex. Soon, there was an unprecedented movement of people from rural to urban areas in search of work.

Blood samples stored from the 1950s show retrospectively that the first known case of HIV infection occurred in 1959 in Kinshasa, just before independence, which led to fighting and yet more travel.

I read an article in Newsweek a number of years ago, in which they claimed the origin was from the use of Monkey blood to culture the Polio vaccine.
Has this been discounted?

Yes, any link between the polio vaccine developed at the Wistar Institute and the AIDS virus has been discounted by tests done by three independent labs.

Here's the relevant information from an article that appeared in the research journal in Nature in the September 14, 2000 issue.

". . . Tests on samples of [a polio vaccine used in Africa in the 1950s], in storage for over 40 years, have shown no trace of HIV or its primate antecedent SIV.

The tests were conducted at three different laboratories in the United States, Germany and France). . .

According to the eagerly awaited results, which were revealed at a two-day meeting on the origins of AIDS held at the Royal Society in London, none of the laboratories found any trace of HIV or SIV in their samples.

In addition, studies of mitochondrial DNA from the samples failed to provide any evidence to support allegations that the polio vaccine had been prepared using chimpanzee tissue — known to be the source of the HIV virus. In each case, the material used to produce the polio virus for the vaccine was shown to be of monkey origin. . ."