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Prions Evolve Despite Having No DNA

kdawson posted more than 4 years ago | from the wipe-that-foam-off-your-mouth dept.

Medicine 214

An anonymous reader writes "Scientists from the Scripps Research Institute have shown for the first time that 'lifeless' organic substances with no genetic material — prions similar to those believed responsible for Mad Cow disease and similar, rare conditions in humans — are capable of evolving just like higher forms of life. The discovery could reshape the definition of life and have revolutionary impacts on how certain diseases are treated."

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214 comments

Where (0, Funny)

Anonymous Coward | more than 4 years ago | (#30713566)

Where's your God now?

Let's get the flame war started? (0)

reiisi (1211052) | more than 4 years ago | (#30713600)

Less than a minute?

Oh! There's a dandelion growing in the cracks in the pavement.
QED There is no God!

Shrug.

Re:Where (3, Funny)

Anonymous Coward | more than 4 years ago | (#30713644)

im in ur prions
redesigning them

-- God

genetic material (3, Insightful)

Anonymous Coward | more than 4 years ago | (#30713580)

Genetic material and DNA aren't really synonymous, are they? Alien life that appeared independently of that on Earth would likely have "genetic material" that served a similar purpose to DNA, but wasn't DNA.

Prions are proteins that, like viruses, replicate via a host cell. All the high-level principles of evolution by natural selection apply; it's just the low-level mechanisms that are quite different.

Re:genetic material (5, Interesting)

The End Of Days (1243248) | more than 4 years ago | (#30714484)

Putting the perils of terming new knowledge "obvious" aside, it does seem obvious that evolutionary mechanisms would have to be preexisting for life to have indeed evolved. Since the most generic definitions of life I've seen boil down to providing some form of localized reverse entropy, evolution of the materials of that reverse entropy should be able to happen before the condition itself is actually achieved.

To draw an utterly meaningless comparison, you can certainly have a power supply without a computer, but good luck doing any computing without the power supply. If that makes sense. I should probably cut my breakfast rum down to under 5 shots.

Re:genetic material (3, Interesting)

trum4n (982031) | more than 4 years ago | (#30715060)

People over think evolution way to much. Sure, there are a lot of things going on, but simply put: If you suck at your job, you die. If your good at your job, you make babies. That is evolution in a nutshell. There is a slight deviation in every copy of this protein, and the ones that are better at their job reproduce. Ones that arn't so great at it, have trouble reproducing, or just die off.

Why would that be likely? (2, Informative)

gbutler69 (910166) | more than 4 years ago | (#30714498)

Possible maybe, but likely? There is probably a reason that DNA (and RNA) are DNA and RNA and not something else. It's the same reason by complex chemicals/life chemicals are mostly constructed around Carbon. Carbon has lots of free valences, which allow it to act like a universal lego-block. Other elements, just don't have as much flexibility. It's why it's entirely unlikely that you will ever see something that can be classified as life that isn't carbon-based. Other elements just can't be as flexible as Carbon.

Evolution for creationists. (4, Funny)

X-Power (1009277) | more than 4 years ago | (#30713584)

Re:Evolution for creationists. (2, Insightful)

Macka (9388) | more than 4 years ago | (#30713886)

Shame I don't have any mod points right now. That comic strip is quite funny and more on topic than off.

Re:Evolution for creationists. (0, Troll)

ilguido (1704434) | more than 4 years ago | (#30714212)

Selection != evolution ...

Re:Evolution for creationists. (0)

Anonymous Coward | more than 4 years ago | (#30714312)

Perhaps you'd like to elaborate?

Re:Evolution for creationists. (-1, Offtopic)

phoenix321 (734987) | more than 4 years ago | (#30714392)

If only individuals of a species that exhibit a certain trait ("fur color", "eye color", "drug resistance") survive and have offspring, will their descendants not share that certain trait, just like most puppies have the same fur as their parents, like most babies with blonde curly hair have parents that also had blonde curly hair?

There is a population of moths that exhibit a random mixture of black and white pigments, most individuals look like this:
http://upload.wikimedia.org/wikipedia/commons/6/6c/Biston.betularia.7200.jpg [wikimedia.org]

Some individuals of this Peppered Moth have an all black or all white coat, so we have three types of moths: random color, all black, all white.

Some weather or climates heavily select on certain coat colors, because white moths stand out like a sore thumb in 1900's coal-covered forests in England and black moths have a snowball's chance in Hell in light forests and snow covered terrain. Random colored moths blend in best in most environments and while they are more visible in either extreme environmental condition, their chances of survival are fair enough.

Imagine we would spray paint the entire forest black with coal dust, for centuries, just like it was in England, we just need to assume we never run out of coal to do that. Imagine the moths are not really bothered by the coal dust and their overall food sources and their predators conditions remain stable. Now all random and white colored moths are always eaten first by birds, for centuries, selected heavily, that is.

Now imagine we have another species of moth, a blindingly yellow type, say the http://en.wikipedia.org/wiki/Common_Brimstone [wikipedia.org].

Both species are exposed to the same environment of a pitch-black coal dusted forest. Both have identical predators and food sources.

The Peppered Moth survives in their black-coated variant, while the Common Brimstone, presenting a yellow eat-me sign to all the birds in the area will be swiftly eradicated.

Have the moths adapted to their environment? Has selective pressure brought one species to extinction? Will random and white colored Peppered Moths reappear if the heavily coal-dusted forest clears up after 50 years? Would they also reappear if the forest remained black for 500 or 5000 or 5 million years?

Re:Evolution for creationists. (1)

sco08y (615665) | more than 4 years ago | (#30715038)

Wow, just because creationists are wrong doesn't mean you have to be so blatant about suppressing them.

They happen to be right on this point: proof of natural selection is not proof of evolution as a whole. The Doonesbury comic got that wrong.

The creationists are a little more clever than (3, Insightful)

NotSoHeavyD3 (1400425) | more than 4 years ago | (#30714432)

that but not by much. Basically they'll say little changes like that (they call it micro-evolution) can happen but nope, no big ones into other species. (But anybody that's taken Bio 102 and seen how impossible it is to come up with a definitive answer to what is one species is and what is another knows that differential is horse-shit.) Guess they needed that so they could have an excuse why it was ok to take newer antibiotics and such. (You know, so they could allow the evolution that's so obvious you have to be pretty much insane to say it doesn't happen.)

Re:The creationists are a little more clever than (4, Funny)

Anonymous Coward | more than 4 years ago | (#30714540)

"I believe in micro-evolution but not macro-evolution"

"I believe in centimetres, but not metres"

Re:The creationists are a little more clever than (1)

sco08y (615665) | more than 4 years ago | (#30715066)

"I believe in micro-evolution but not macro-evolution"

"I believe in centimetres, but not metres"

More like, "So you claim I'm standing in my "house," and that it's 20 meters high. Well, if I squint I can see a centimeter of housey-stuff here, and a centimeter of housey-stuff there, and I do in fact live here, but there's no evidence of this large structure you call a "house"!"

But I can kinda understand them (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#30715000)

(Note here: I haven't taken as much as highschool biology classes. If I say something that is completely off here, I'd appreciatete someone correcting me)

What they are saying is that "Yeah... You could originally have had just a pair of birds and they evolved to different species... But it doesn't make sense for a squirrel to gain wings through natural selection". And in fact, they are correct there. A trait can develop further over numerous generations but in order to introduce a completely new trait, natural selection just doesn't cut it. There needs to be a mutation. And the mutation needs to not hamper reproduction (this is a big problem: Animals often shun anything different). In fact it needs to be so beneficial that the new traits will slowly spread and then evolve further.

To my understanding, even scientists are puzzled about those phases. (I chose my squirrel -> bird examples because as a bird-enthusiast I've seen a few documents about development of wings. Also the news featured on /. a while ago) What creationists are saying "We just don't believe that can happen. There just isn't much proof about that.". The normal, non-fundamentalist christians (Many protestant churches at least, though I think that even Vatican has accept evolution now) just say "Yeah, that can happen but how do we know that god doesn't influence that phase? Yeah, there isn't scientific evidence of such - and can't be - but I choose to believe so anyways."

While I am personally atheist, neither of those really seems that horrible way to think. Or even that idiotic... The problem with creationists really isn't their lack of faith in evolution. It is what they choose to believe as more credible alternative.

This might revive the age-old debate... (0, Funny)

Anonymous Coward | more than 4 years ago | (#30713592)

Are Rebublicans technically life-forms?

Re:This might revive the age-old debate... (3, Funny)

Anonymous Coward | more than 4 years ago | (#30713836)

a failing one, a subspecies teanominus partius has evolved and is slowly choking out the main species. its sad beacuse teanominus partius cannot survive without the host species. We are watching evolution at work here people.

Re:This might revive the age-old debate... (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#30714406)

Are Rebublicans technically life-forms?

How'd those housing starts go in November? Oh, down 19%?

How are the continuing job loses going? Oh, another 200,000 jobs lost?

How's that withdrawal from Iraq going?

Nice to see our DHS Secretary telling us all how well the system worked when a jihadi got on a plane with a bomb.

I hear Gitmo is going to be closed any decade now.

And just wait until you see the asshattery unleashed when Khalid Sheikh Mohammad et al are tried in a standard criminal court.

Think you can come up with a health care "reform" that relies even more on bribery and political payoffs and pisses even more people off?

Nice to see we have a Democratic Senate Majority Leader who thinks it's great that the President is "light-skinned and doesn't speak with a Negro dialect".

No fucking wonder Senator Harry Reid (D-Nev) is polling about 30 points behind his probably election opponent.

How about forcing people to buy health insurance even if they don't want it? Where are all the libertarians-of-convenience who got so up in arms over the freedoms lost when a relatively small number of phone calls to known Al Qaeda related phones where intercepted without warrants? Where are all those JACKASSES when Democrats propose laws that would literally unconstitutionally under penalty of jail time force millions of people into private contracts that they don't want and cost thousands of dollars a year?

Democrats. TOO DUMB TO KNOW THEY'RE DUMB

Evolution is the good news ... wait, bad news? (5, Insightful)

Gopal.V (532678) | more than 4 years ago | (#30713598)

Natural selection doesn't pre-suppose DNA. Anything which multiplies to produce copies of itself, which can degrade/mutate between generations can evolve just in exactly the same way. Selection pressures work exactly the same. So does the chain reaction effect of multiplication of the survivors, resulting in major shifts in characteristics of a population.

But the actual story is the bad news part of it. That using anti-prion medication probably won't work all the time as it would just breed a drug-resistant breed of prions by preference.

Definitely bad news. We can forget about having the "saviour" take a bath in the daily oatmeal for our protection :)

Re:Evolution is the good news ... wait, bad news? (2, Informative)

CxDoo (918501) | more than 4 years ago | (#30713876)

And iterative improvement based on external definition of 'improvement' (in other words, selection) doesn't presuppose either 'natural' or 'self'.
Cars evolve. Societies evolve. And so on.
Life is defined by metabolism & self replication, not evolution.

Re:Evolution is the good news ... wait, bad news? (1)

SlothDead (1251206) | more than 4 years ago | (#30714186)

Sure, but that's the pop culture definition of "evolve".
In the context of biology its basically an abbrevation for "improves from generation to generation because of reproduction, variation and unintended selection".
If you create harder to swat mosquitos by only swatting the ones in your room that you actually CAN swat its evolution in the biological sense, since the mosquitos are adapting to the swatter (as opposed to you intending to breed better mosquitos).
If a car manufacturer takes the bestselling cars from last year and varies them a bit he is doing this to make them sell better. That's not evolution in the biological sense, at best you could call it "car breeding". ;)

Re:Evolution is the good news ... wait, bad news? (2, Insightful)

CxDoo (918501) | more than 4 years ago | (#30714730)

You're right. However, whether prions evolve or not has no influence on their classification as (non-a)live matter.

Re:Evolution is the good news ... wait, bad news? (1)

Yvanhoe (564877) | more than 4 years ago | (#30714022)

Definitely bad news. We can forget about having the "saviour" take a bath in the daily oatmeal for our protection :)

Once again, it seems the only way to get rid of a disease is by aiming at its total eradication and extinction like has been done for smallpox and like is almost done for polio.

Re:Evolution is the good news ... wait, bad news? (-1, Troll)

phoenix321 (734987) | more than 4 years ago | (#30714398)

I wonder if that would work on other pests we currently are at war with.

Nah, we just protect our homeland against terrorism, that is sufficient.

Re:Evolution is the good news ... wait, bad news? (1)

WalksOnDirt (704461) | more than 4 years ago | (#30714868)

"...total eradication and extinction..."

I doubt that would work with prions. They're simple enough they probably pop up spontaneously from time to time.

Re:Evolution is the good news ... wait, bad news? (5, Insightful)

famebait (450028) | more than 4 years ago | (#30714142)

using anti-prion medication probably won't work all the time as it would just breed a drug-resistant breed of prions

Not necesarily. Unlike the changes available for lifeforms with their own DNA, there is probably a finite number of ways a given human protein can degrade into a replicating prion configuration. Most proteins probaly have no capacity for becoming prions. For others, the body is perfectly capable of dealing with them.

The capacity to become a prion is already built into the structure of the host protein in question, not aquired through exposure. So while this evolution is probably real and possibly a stumbling block for therapies, it remains confined to the space of potential configurations already inherent in our proteome, of which only a very small subset will cause trouble as prions.

Re:Evolution is the good news ... wait, bad news? (0)

dimeglio (456244) | more than 4 years ago | (#30714202)

The current shape of our entire universe is in fact a result of evolution by natural selection. Do you see any anti-matter out there? Hence the superiority of matter.

Not Surprised. (5, Insightful)

nog_lorp (896553) | more than 4 years ago | (#30713602)

It's time we recognized that the interesting things about "life" are all just products of the fact that all kinds of systems can convey self-replicating entities of some sort, and they tend to be interesting and undergo evolutionary processes and etc. Whether they are non-biological DNA bundles, cellular organisms, oddly folded proteins, crystalized clay, etc.

So where are the nefarious / useful engineered prions at?

Re:Not Surprised. (1)

Shikaku (1129753) | more than 4 years ago | (#30713656)

I don't think fire is a lifeform even though it is self replicating, can die, moves and grows on its own, and reacts to outside forces (and may attempt to consume it).

Re:Not Surprised. (3, Informative)

MichaelSmith (789609) | more than 4 years ago | (#30713682)

Fire has a symbiotic relationship with some plants in Australia. The plants help start fire. The fire kills the plants competitors, including other plants and humans.

Re:Not Surprised. (3, Interesting)

tragedy (27079) | more than 4 years ago | (#30713736)

Interesting thought on that. I remember an old episode of _Sliders_ where they ended up on a world in the midst of a big fire, and accidentally brought some living (and intelligent) fire with them to the next universe. I got into a discussion (funny, I can't remember who it was with anymore) about what things would be necessary to actually have living fire. In other words, what additional things would fire need to have to be considered living and how could it be achieved in nature. We covered a lot of ground, and the conclusion we sort of got to is that, in a sense, we, and all other aerobic life at least are already a form of living fire. That's what cellular respiration is all about. It was an interesting discussion and, in the end, a lot of it depends on points of view. That of course is the problem. You don't think fire is alive because you know that fire isn't alive and if someone comes along and tells you that fire is now included in the scientific definition of things that are alive, you'll disagree, just like lots of people are still pretty upset that Pluto isn't a planet anymore. If you examine what is and isn't alive in enough detail, the boundary gets fuzzy enough that it becomes harder to know where to draw the line rather than easier.

Re:Not Surprised. (2, Insightful)

digitig (1056110) | more than 4 years ago | (#30713882)

That's what cellular respiration is all about. It was an interesting discussion and, in the end, a lot of it depends on points of view. That of course is the problem. You don't think fire is alive because you know that fire isn't alive and if someone comes along and tells you that fire is now included in the scientific definition of things that are alive, you'll disagree, just like lots of people are still pretty upset that Pluto isn't a planet anymore. If you examine what is and isn't alive in enough detail, the boundary gets fuzzy enough that it becomes harder to know where to draw the line rather than easier.

Yes, and that's where I think the summary gets it wrong. It talks about the definition of life, as if there's only one (probably the one that the author learned in grade school -- "respiration, reproduction etc.". As James Lovelock points out, "If we ask a group of scientists 'What is life?' they will answer from the restricted viewpoint of their own scientific disciplines. A physicist will say that life is a peculiar state of matter that reduces its internal entropy in a flux of free energy, and is characterised by an intricate capacity for self-organisation. ... A neo-Darwinist biologist will define a living organism as one able to reproduce and to correct the errors of reproduction by natural selection among its progeny To a biochemist, a living organism is one that takes in free energy as sunlight, or chemical potential energy, such as food and oxygen, and uses the energy to grow according to the instructions coded in its genes." (Quoted in Mary Midgley, Science and Poetry) Prions were probably already classified as life by the physicists, but the biologists hadn't bothered to ask them.

Re:Not Surprised. (2, Insightful)

phoenix321 (734987) | more than 4 years ago | (#30714410)

We already have intelligent living fire.

Did you consume hydrocarbons today? What about carbohydrates? (Stuff with hydrogen and carbon in it, at least)

Did you inhale oxygen and exhale carbon dioxide? Did you somehow got rid of dihydrogenmonoxide or did the / a / one of the girl(s) block the bathroom the entire morning? :) - and did you emit heat while doing so?

Re:Not Surprised. (1)

osgeek (239988) | more than 4 years ago | (#30714500)

Interesting example, but I don't think that fire reproduces in a cycle where any instructions (genetic material) are ever created and used.

A fire is more like one simple entity that grows until it consumes all available food and then dies of starvation.

The alternative is to consider that combustion is a process that all life forms use. It has evolved into you.

Re:Not Surprised. (1, Interesting)

chrb (1083577) | more than 4 years ago | (#30713688)

It's time we recognized that the interesting things about "life" are all just products of the fact that all kinds of systems can convey self-replicating entities of some sort, and they tend to be interesting and undergo evolutionary processes and etc. Whether they are non-biological DNA bundles, cellular organisms, oddly folded proteins, crystalized clay, etc.

It goes further than that - almost everything that is built is a product of evolution. Bicycles, planes, cars, the computer, have all been subject to the process of evolution. The fact that they can't self-replicate does not mean that the evolutionary process isn't present. No life can replicate without the necessary supporting environmental conditions, and if one of those prerequisite environmental conditions happens to be the presence of humans and amounts of refined steel and other materials, how is this any different to a bacteria requiring sugars and oxygen?

Re:Not Surprised. (1)

siloko (1133863) | more than 4 years ago | (#30713728)

You make an interesting point but I believe there is a difference - and it has something to do with intrinsic functionality. There is nothing intrinsic to a bicycle, for example, which necessitates evolution given supporting environmental conditions. This appears fundamentally different to non-artifacts which have some intrinsic nature enabling them to take advantage of environmental factors without a so-called 'external' guiding hand, be it human or divine ;) I actually think the inter-dependence of all things, be they living or inanimate, is so chaotic delineating specific causal factors for observable traits will prove almost impossible in the long run . . .

Re:Not Surprised. (0)

GreekLawyer (1542713) | more than 4 years ago | (#30713770)

A huge paradigm shift is taking place lately with the realisation by humanity that "life" is not only organic - in fact organic life is simply an efficient thermodynamic machine and acts in exactly the same as inorganic "life" An excellent example is that plasma crystals exhibit the same properties as organic life http://www.iop.org/EJ/article/1367-2630/9/8/263/njp7_8_263.html [iop.org] Given that 99% of the universe is probably plasma as plasmas are by far the most common phase of matter in the universe, both by mass and by volume and all the stars are made of plasma, and even the space between the stars is filled with a plasma, albeit a very sparse one (http://en.wikipedia.org/wiki/Plasma_(physics)), it is most probable that organic life is simply very small part and specific type of thermodynamic machine. Nonetheless all Universe appears to be following the 2nd law of thermodynamics and humanity and organic life is simply a local iteration/mutation in the universe's attempt to obey the law, perhaps not even the most efficient one. This is the reason why we have Fermi's paradox, as we are looking to find life that is a mirror of us, whereas the universe is full of very intelligent inorganic life which even performs computations more complex than humanity at present - can you seriously stare at the remnants of Tycho's supernova with a clear mind and not think that the supernova is alive in an exotic way ? http://en.wikipedia.org/wiki/File:Main_tycho_remnant_full.jpg [wikipedia.org] For the above reason perhaps the most efficient thermodynamic machines in the universe are not organically driven but inorganically driven like black holes which are the maximum entropy objects in the universe. In fact, is very possible, given the nature of humanity to create efficiencies in energy creation which however do not cover its needs but on the other hand create more needs for more consumption of energy, consistent with the 2nd law (http://www.theglobeandmail.com/blogs/jeff-rubins-smaller-world/why-energy-efficiency-means-higher-consumption/article1419515/), it is very possible that the logical progression of this trend is the creation of a black hole by humanity as the singular point of maximum entropy creation (could it be the CERN one?) In fact, the black holes in the universe may be "life" such as ours which may have "awakened" earlier than us and reached their "purpose" (see thermodynamic conclusion/limit) at an earlier time. Good stuff! Ntemis

Surprise This (0)

Anonymous Coward | more than 4 years ago | (#30714038)

For what it's worth, everything can "evolve" - ranging from a speck of cosmic dust all the way to a galaxy - depending on how something is measured determines life by the definition of that measure. We and everything else are all part of that same continuum - more precisely, where do we draw the line at not drawing a line?

Surprising? (0)

headkase (533448) | more than 4 years ago | (#30713612)

Evolution can be loosely defined as "change over time." Everything in our Universe is evolved under this definition, the key is time. The constants of our Universe provide the selection pressure and the matter provides the instance.

Re:Surprising? (5, Insightful)

ZorbaTHut (126196) | more than 4 years ago | (#30713650)

It's a little more complicated than that. There's basically three properties that are both necessary and sufficient for evolution to take place.

* Some sort of fitness function
* Reproduction, largely based on the properties of the "parent"
* Imperfect reproduction, so that variation can be introduced

Once you've got those three items, you have the potential for evolution.

That said, it should be pretty obvious that basically any frequently-duplicated structure in the physical world, whether it be made out of DNA, protein, or metal and gears, is going to have all three of those items - the third just thanks to the physical world being imperfect. Note that it's not required that it be capable of duplicating itself - if all machines were built by copying older machines, we'd get to see "machine evolution" as people tended to copy the ones that worked better and throw away the ones that didn't.

Of course it's also worth pointing out that none of these requires that the item exist in a physical sense - you can meaningfully talk about memetic evolution, societal evolution, language evolution, joke and humor evolution, so forth ad nauseum.

Re:Surprising? (1)

chico_the_chihuahua (925601) | more than 4 years ago | (#30713758)

Evolution is an emergent property of a system - I'd be careful to distinguish how you would build a model to describe the system that can evolve (as you have here), and what actually happens in empirical settings.

It could be argued that Darwin only 'discovered' evolution in the Galapagos Islands, as the classical theory of natural selection is particularly pronounced in the flora and fauna there, and why other pioneers such as Mendel didn't make the same intellectual leap (especially since he was actually examining the very mechanisms of genetic evolution).

Re:Surprising? (4, Insightful)

sevennus (1702060) | more than 4 years ago | (#30713776)

This is misleading, and upon second reading, it is some overly-philosophical hand-waving.

Yes, prions do not reproduce through the conventional genetic mechanisms. From my understanding, they encourage, through some direct protein-protein interaction, other polypeptides to fold incorrectly.

Think of it this way. HIV and other genetic disorders propagate through normal reproductive means. Like, if a person with an extraordinary innate musical ability has a child, that child will probably possess a natural ability for music.

However, if a talented musician adopts a child and then teaches him how to read music and how to play instruments, he will probably grow up to be equally talented.

Prions are similar to the latter case. They are encouraging other proteins, who don't in themselves possess any malicious function, the fold in such a way to attack the host.

This isn't reproduction. The "parent" prions are not in anyway responsible for the actual formation of the "child" prions. They are just responsible for causing them to become malicious, making them more role-model proteins than actual parents.

Re:Surprising? (3, Interesting)

chico_the_chihuahua (925601) | more than 4 years ago | (#30714166)

I agree - it is important to get away from the concept of evolution as being life-based, and recognise that evolution is an emergent property of a system.

For the prion example, the key is to remember that incorrectly folded proteins accumulate and cause the prion disease - the proteins themselves are not the disease, but the accumulation is. If one folding configuration is more likely to cause other proteins to fold incorrectly, then it is natural to assume that this configuration will become eventually dominant, until a more effective configuration arises. Also, the accumulation of protein causes a feedback loop, increasing the likelihood of further malign folding. Presumably, the folding is sometimes imperfect, so this is the source of the all important mutations causing variety. Without the accumulation, I would presume that the configuration of folding has a benign effect.

So, folding configurations that increase the rate of malign folds or increase the rate of accumulation would be more successful in this feedback loop. Does this really justify the tag 'evolutionary'? It just seems that the natural progression of the disease causes what appears to be a natural selection process, but it's not clear at what point we should distinguish between a feedback loop and an evolutionary process, if indeed they are actually one and the same thing...

HIV and other genetic disorders? (1)

gbutler69 (910166) | more than 4 years ago | (#30714598)

That's like saying, "Oranges and other dimwits!"

Seriously, you do realize that HIV is a virus, NOT a genetic disorder?

Re:Surprising? (1)

ByteSlicer (735276) | more than 4 years ago | (#30713850)

if all machines were built by copying older machines, we'd get to see "machine evolution" as people tended to copy the ones that worked better and throw away the ones that didn't.

You say this like it is hypothetical, but look around. This has been going on for quite a while. Just compare the earliest airplane with an F18.

Re:Surprising? (1)

wisty (1335733) | more than 4 years ago | (#30713998)

So machines (a new life-form) have evolved in a symbiotic relationship with humans? Perhaps Ford Prefect was correct when he took cars to be the dominant species.

Re:Surprising? (1)

odourpreventer (898853) | more than 4 years ago | (#30714110)

if all machines were built by copying older machines, we'd get to see "machine evolution"

No, that would actually be a variation of intelligent design.

Regardless, it seems to me people here are confusing the everyday use of the word evolution with the actual theory.

TIme to rewrite the science books (-1, Flamebait)

Anonymous Coward | more than 4 years ago | (#30713626)

... the definition of life is going to have to change.

But mine will still be the same. :)

evolution is not about dna (1, Informative)

Anonymous Coward | more than 4 years ago | (#30713630)

Don't get me wrong, dna has some neat copying-related properties... but evolution is not about dna. The idea came along long before the physical basis of human heredity was understood, and it is a far more general principle. To get evolution via natural selection, all you really need is:
1. Variation
2. ... that is heritable ( prions, dna, epigenetic markers, and cultural practices all have this to some extent or another)
3. and something that ensures differential survival (as simple as limited resources).

These aren't very hard criteria to fulfill. The sticking point is really the heritability bit, but once prions work out the "how to propagate more of me" problem, evolution comes along for the ride.

I don't see a need to get spiritual about it (3, Interesting)

Trepidity (597) | more than 4 years ago | (#30713648)

Even from a purely materialist perspective, it seems reasonable to ponder a class of materials that replicate themselves. How exactly they do so might be more or less complex but the basic idea that it's possible to configure matter in a way that it replicates itself doesn't seem that absurd. And there's no particular reason it has to be DNA --- there are even purely mechanical possibilities [wikipedia.org].

Re:I don't see a need to get spiritual about it (0)

Anonymous Coward | more than 4 years ago | (#30714048)

Being spiritual is irrelevant to this. Neither does a prion evolving depend on spiritual belief nor does it diminish the validity of spiritual belief. The fact that we are surprised that it does so without DNA has more to do with our narrow scope of nature, and from a spiritual sense, our scope of god too. DNA is material. Its just stuff. That other stuff can do similar tricks should be expected, not shocking.

From a public health standpoint I'm not sure why this is bad news. It isn't like prions just started evolving. It seems new and scary because we just found out they could do so. But it stands to reason they've been doing it for eons. Our newfound fear is just another product of our narrow, human-centric focus.

Rocks Too (0)

Anonymous Coward | more than 4 years ago | (#30713660)

I don't think this discovery will mean anything about the definition of life. Rocks evolve too [nationalpost.com].

Re:Rocks Too (4, Insightful)

glwtta (532858) | more than 4 years ago | (#30713690)

Rocks evolve too.

Hasn't this bullshit "claim" been dredged up enough already? It's just a bit of really weak sensationalism from an attention-whoring geologist.

He himself doesn't even believe this nonsense, and does say, towards the end of that article that obviously "being changed by your environment" has nothing to do with "evolution", but hey, why not get some free publicity?

Re:Rocks Too (5, Insightful)

Hurricane78 (562437) | more than 4 years ago | (#30714346)

But you’re no better. You insult the other side, and bring no arguments to the table. You’re obviously right... to us... but to them, you now just made it worse, making them protect themselves from your pointless attacks even more.

This time, I’ll do it for you:
The difference is, that Rocks have no fitness function. Which is the difference between undirected change and directed evolution.

But the next time, if you wanna act superior, bring an argument. Like a common basis, and proper logic on top of it.

Re:Rocks Too (0)

Anonymous Coward | more than 4 years ago | (#30714864)

Rocks have fitness functions!

Those that look nice get picked up by humans and taken away from the orgy porgy of rock reproduction.

Hence, rocks have evolved to not look nice.

They don't reproduce outside of their natural habitats, like in Fort Knox. But if you want more gold, where do you go to dig? Out amongst the rocks!

QED

Understanding evolution (0)

Anonymous Coward | more than 4 years ago | (#30713664)

Evolution is not a capability of living beings, living things, inorganic things or whatever.

Evolution is the result of passing time, environment pressure and changes.

It's not the subject who evolves, it's the differences from 'starting' subject and 'surviving' subject what is called evolution.

Natural Selection? (0)

Anonymous Coward | more than 4 years ago | (#30713676)

Is this just another form of evolution or does it impact the very core of genetic evolution? I wonder how Richard Dawkins will react to this having based his life on the study and preachings of Charles Darwin's Natural Selection and genetic mutation/evolution. How does this affect those theories, is the evolutionary process as closely intertwined with DNA as first thought?

Okay, lets get redefining then... (1)

Ceriel Nosforit (682174) | more than 4 years ago | (#30713686)

If I glanced correctly at this [scientificamerican.com] article, which does ramble on, prions are rogue proteins which aren't just detrimental to the organism, but cause other proteins to mutate as well. It wasn't clear to me if they do this by altering the genetic code or the neighbouring proteins directly.

The host organism may apparently have DNA of such nature that a random mutation reliably triggers the disease symptoms. This indicates to me that the code molecules exist in a higher energetic state and them getting upset makes them fall to a predictable lower energetic state which happens to produce malignant proteins.

This doesn't seem to be about wether or not prions are alive, but if disease is living. I think that instead of giving life a broader sense, we need to split the concept up to be more specific. I would be comfortable calling things that have neurons and therefre possess intelligence "living", and everything else "biomass". That way a tree isn't alive, but it is capable of becoming dead biomass. A person in a coma isn't alive, but enters the category of biomass.

Of course more useful definitons are possible. This is just something to tickle your creativity.

Re:Okay, lets get redefining then... (1)

MPAB (1074440) | more than 4 years ago | (#30713840)

The theory is that prions are not neccessarily mutated but "misfolded" proteins, and they can provoke the same misfolding in neighbouring twin proteins by chemical bridging much like what happens when enzimes do their stuff. The misfolded proteins cannot be digested and precipitate, causing neuronal death. Because each prion turns many proteins like it into prions, their effect grows exponentially.

Re:Okay, lets get redefining then... (2, Interesting)

famebait (450028) | more than 4 years ago | (#30714198)

And it is not surprising that many seem to require unnatural diets to occur (feeding meat to herbivores, forcing cannibalism where this is not found in nature, etc). For whatever prions might occur under normal circumstances, evolution has probably equipped us to stop the chain reaction, or deal with the products. Ones that can only spread under circumstances not found in nature OTOH, are "new" to the body and some of them may therefore accumulate in dangerous amounts.

Re:Okay, lets get redefining then... (1)

MPAB (1074440) | more than 4 years ago | (#30714872)

For most of us, "unnatural" really means "disgusting to me". There's nothing natural or unnatural. As long as something occurs within nature and following its rules, it's natural. The "natural" thing is some kind of 'argumentum ad verecundiam' fallacy.

Evolution doesn't equip any being at all. It just works if the non-equipped are killed before breeding or if the equipped are better breeders.

Scrapie or CJD are normally ocurring and normally fatal. In the case of CJD, the mean age is around 65 y/o: long after the average human has had its offspring. What's more: an age that most humans from longer than a century ago didn't reach.

We have no means to stop the reaction or deal with the products. And even if some of us had them: unless the disease did strike before 30 y/o, evolution wouldn't give a **** about it.

You are right in that cows eating corpses of sheep doesn't occur under normal circumstances. We know it can happen among primates, though (Kuru). Still, there could always be a way for prions to appear in cows (as they appeared in sheep and in humans). Bestiality, promiscuity, homosexuality and prostitution have been blamed for the spread of AIDS, but those that feel constricted by conservative sexual practices put most of the blame on direct blood contact such as hunting, transfusions, surgery and wounds.

Where does Death Begin? (5, Interesting)

dorpus (636554) | more than 4 years ago | (#30713702)

Not really related, but it is entirely possible for humans to be "alive" in a physical sense even after they are brain dead. As long as they are hooked up to respirators etc., they can be kept alive indefinitely. To date, no human being is ever known to have regained consciousness after brain death.

The _big_ catch here is that most physicians are not properly trained to test for brain death. Most physicians will just see a flat line on an EKG and declare the patient brain dead. I used to work at an organ transplant center, where there were technicians that went through a formal checklist to make sure the patient really is brain dead. It was not uncommon to find patients who did not meet the strict criteria. In the most dramatic example, a 3-yo boy was supposedly brain dead, and he was in the operating room, ready to have his organs removed. The technicians discovered that his pupils did respond to light, so they rushed him out of the OR. On the way back to his room, the boy opened his eyes and smiled. But then he went back into a coma and died 5 days later.

Needless to say, the boy's parents were furious.

Re:Where does Death Begin? (4, Informative)

MPAB (1074440) | more than 4 years ago | (#30713824)

Here are the criteria for brain death. An in the case of children, they must be consistent with repeatedly flat EEGs throughout 48 or 72 hours depending on the place. Also, barbiturate and BZD intoxication must be ruled out.

        * Unresponsiveness
                    o The patient is completely unresponsive to external visual, auditory, and tactile stimuli and is incapable of communication in any manner.

        * Absence of cerebral and brain stem function
                    o Pupillary responses are absent, and eye movements cannot be elicited by the vestibulo-ocular reflex or by irrigating the ears with cold water.
                    o The corneal and gag reflex are absent, and there is no facial or tongue movement.
                    o The limbs are flaccid, and there is no movement, although primitive withdrawal movements in response to local painful stimuli, mediated at a spinal cord level, can occur.
                    o Apnea Test: An apnea test should be performed to ascertain that no respirations occur at a PCO2 level of at least 60 mmHg. The patient oxygenation should be maintained with giving 100% oxygen by a cannula inserted into endotracheal tube as the PCO2 rises. The inability to develop respiration is consistent with medullary failure.
        * Nature of coma must be know
                    o Known structural disease or irreversible systemic metabolic cause that can explain the clinical picture.
        * Some causes must be ruled out
                    o Body temperature must be above 32 C to rule out hypothermia
                    o No chance of drug intoxication or neuromuscular blockade
                    o Patient is not in shock
        * Persistence of brain dysfunction
                    o Six hours with a confirmatory isoelectric EEG or electrocerebral silence, performed according to the technical standards of the American Electroencephalographic Society
                    o Twelve hours without a confirmatory EEG
                    o Twenty-four hours for anoxic brain injury without a confirmatory isoeletric EEG

        * Confirmatory tests (are not necessary to diagnose brain death)
                    o EEG with no physiologic brain activity
                    o No cerebral circulation present on angiographic examination( is the principal legal sign in many European countries)
                    o Brain stem-evoked responses with absent function in vital brain stem structures

Re:Where does Death Begin? (0, Redundant)

sevennus (1702060) | more than 4 years ago | (#30713852)

You claim that most *physicians* are not properly trained to test for brain death, and then you back it up with an anecdote about *technicians* that weren't able to properly identify real brain death.

The difference between a technician and a physician? 6-12 years of top-level education and experience. Don't confuse the two.

Logic FTL... (0)

Anonymous Coward | more than 4 years ago | (#30713910)

I didn't know technicians could declare death.

Re:Where does Death Begin? (1)

Hurricane78 (562437) | more than 4 years ago | (#30714320)

The huge failure here is, to have this pointless urge, to draw a line between life and death. There is none. It’s a gradient!
Just like there is no separation between intelligent and dumb. Or between alive and dead when you ask if something is a life form.
The wish to draw a line is purely a human artifact.

But if you start to ask: How much alive is something? Or: how much of a life form is something? How intelligent is it?
Then you start get answers that are useful and make sense.
Now all you have to do, is stop thinking in absolutes, and only think of relative answers.
“Less alive than us. Less of a life form and less intelligent too. But more alive, more of a life form and more intelligent, than a stone or a carbohydrate.”

Re:Where does Death Begin? (1)

Hognoxious (631665) | more than 4 years ago | (#30714374)

As long as they are hooked up to respirators etc., they can be kept alive indefinitely.

Indefinitely? Brain death stops the normal aging process, even at the cellular level? Telomeres cease to get shorter with each division?

This could have awesome implications for long distance spaceflight, as an alternative to hibernation or crygenics.

Evolution: (0)

Anonymous Coward | more than 4 years ago | (#30713740)

Just a theory, you guys!

Lol, not really. I had to do that.

The idea isn't surprising (1)

Dunbal (464142) | more than 4 years ago | (#30713760)

After all there's nothing "magical" about DNA. Any self replicating molecule should theoretically be capable of evolution if the replication process is less than perfect.

Re:The idea isn't surprising (1)

slim (1652) | more than 4 years ago | (#30713914)

After all there's nothing "magical" about DNA.

Except that it's a "better" replicator. DNA must have evolved from something. Given a few hundred million years, these prions might evolve into something similar to DNA.

Re:The idea isn't surprising (1)

famebait (450028) | more than 4 years ago | (#30714158)

Prions do not self replicate. They can merely spread their degenrate configuration to other preexisting molecules of the same kind. And this is only a problem when the degenerate version is highly stable and the body doesn't know how to deal with it.

Randomly Mutating Post (1, Insightful)

mindbrane (1548037) | more than 4 years ago | (#30713786)

it's late, i'm over tired and maybe i should have cooked that last brain i ate. anyway i did a reread of Darwin's TOOS and then binged on a buncha evolutionary theory and evo-devo stuff, this over the last 3 years. 1st off evolution theory, at least the mainstream stuff presupposes a genotype (dna) translated into a phenotype like me typing this. so the question should arise as to whether prions have a genotype source that has a transcription mechanism. old school Darwinianism as penned by Darwin drifted toward acquired characteristics a la Lamarck because Darwin didn't have any working knowledge of genetics even tho Mendel had sent him a draft of his work. somewhere over 95% of all species have gone extinct and after all the reading and questions i came away seeing life as a random walk of living crud crusting eons of dead crud. no winners no losers no game no gameplan just stuff that hasn't died yet on top of stuff that has; being slow cooked by a middle aged average sun.

Re:Randomly Mutating Post (0)

Anonymous Coward | more than 4 years ago | (#30714106)

Well, if that doesn't give hope for the future, I don't know what will!

Re:Randomly Mutating Post (2, Insightful)

mindbrane (1548037) | more than 4 years ago | (#30714274)

Oddly i see it very much the opposite. It's because we know our state and can act to leave the world a better place for those who come after us, and, because we can act humanely and compassionately from choice that we can be more than our nature has endowed us to be. I like the idea of pissing in the abyss while wondering who's gonna win the playoffs, but that's just me.

Re:Randomly Mutating Post (1)

Alrescha (50745) | more than 4 years ago | (#30714936)

"it's late, i'm over tired and maybe i should have cooked that last brain i ate"

Cooking won't help. Prions aren't alive*, cooking them won't kill them.

* depending on your definition of life, of course.

A.

Obligatory (0)

Anonymous Coward | more than 4 years ago | (#30713808)

*insert joke about prion overlords here*

Explains my Boss (0)

Anonymous Coward | more than 4 years ago | (#30713918)

This explains how someone with a rock for a brain could evolve. His is a prion version of V.

I'm skeptical (2, Insightful)

BlueCoder (223005) | more than 4 years ago | (#30713956)

I'm not quite sure I would call it evolution. I can easily imagine that many prions replicate not only themselves but variations as well and those variations will produce variations of different proportions and so on and so forth. So just because you subjected a prion to an adverse environment for a particular copy of a prion only means that form will be less populous.

It feels to me that this is less evolution and something more akin to chemical computation. Although ironically it does in some ways remind me of the poorly labeled Conway's game of life.

Matter. (2, Insightful)

Tibia1 (1615959) | more than 4 years ago | (#30714014)

Any matter has one mission and one mission only: to find greater order. If matter without DNA or any prior form of order couldn't achieve more order, then life would not exist. Things want to be able to interact with their environment more efficiently, and must evolve to do so.

Re:Matter. (2, Informative)

magsol (1406749) | more than 4 years ago | (#30714390)

Actually, according to the Gibbs free energy equation, it is in fact the opposite: matter's mission to attain a lower energy level, which equates to an increasing amount of disorder in the system. Finding a "greater order", on the other hand, requires an input of energy to the system.

Evolution is a large-scale byproduct of adapting to the changing environment in such a way that is energetically favorable for the organism.

We need DNA? (0)

Anonymous Coward | more than 4 years ago | (#30714104)

I thought at some point, the definition become

"Non-random survival of randomly mutating replicators"

How is this not a surprise then?

Do Life and Evolution always go together? (3, Insightful)

giladpn (1657217) | more than 4 years ago | (#30714128)

As posts above testify, the word "evolution" is used more and more in contexts that have nothing to do with life.

For example people talk a lot about the evolution of ideas, societies, and so on... Quite possibly, the philosopher Wilson is one of the popularizers of this approach.

Anyway, this also leads to a different point - Evolution by itself is not a proof of the existence of Life. For example, Ideas or Societies are not living organisms, yet they do evolve.

So the fact that prions evolve does not mean they are alive! One can fairly say that they are just a chemical (a protein) that can reproduce itself, evolve, and do damage.

In Science, Mathematics and Philosophy, it is very common to take "edge cases" in order to better understand the limits of an idea. Prions give us a good example of something that can reproduce and evolve, yet its a chemical not a living organism.

So what is "Life" ? Perhaps we should require the ability to perceive - awareness of ones surroundings - in order to define true life? In that case Bacteria aren't alive either, which is fine by me.

Jellyfish and Lizards do qualify as alive. More generally, you would need some sort of functioning nervous system (however primitive) to be "alive". Brain-dead people would possibly not be "alive" by this definition.

Re:Do Life and Evolution always go together? (2, Interesting)

Anonymous Coward | more than 4 years ago | (#30714384)

"So what is "Life" ? Perhaps we should require the ability to perceive - awareness of ones surroundings - in order to define true life? In that case Bacteria aren't alive either, which is fine by me. "

Wow, that is simply the most pathetic attempt at creating a human-centric definition of life Ive seen... and Im a biologist, so Ive seen plenty of strange ideas.

There is not a single form of life that that is completely isolated from its environment. Animals, plants, fungi, bacteria, viruses, prions (I tend to include these last two in my working definition of life, but that is my opinion based on my studies and research) ALL depend on specific environmental inputs in some way in order to exist. The line you try to draw between presence and absence of a nervous system might look fine at a first glance, but most of the elements necessary to build a nervous system are already present in many single-celled creatures, so there is no huge qualitative leap in environmental perception.

And I love the way you think bacteria can be simply dismissed with a wave of the hand just because theyre non-thinking and seemingly primitive. Guess what? MOST of the life on Earth is bacteria... Scratch that, theres one fact thats even better to make you think a bit about life: a human body is composed of TEN non-animal (bacteria, "protozoa", fungi...) cells for every one "truly living" human cell. So, were just made up of 1 part living stuff and the other 10 parts are non-living crap?

Indeed (1)

dandart (1274360) | more than 4 years ago | (#30714190)

All evolution is is random mutations, and the ones best suiting to survival ... surviving. Or in this case, continuing to exist. Dust particles in space can be said to evolve, the ones closest together might one day form a star. There's nothing new here, if weird organic matter happens to be more resistant to anything trying to destroy it, then we might define it as evolving.

The best universal definition of life: (1)

Hurricane78 (562437) | more than 4 years ago | (#30714286)

A (bio)mass, fighting for resources.

(If you raise the point, that that would include remote-controlled robots: Well yes, we control them, like limbs. And we live.)

mo3 0p (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#30714368)

demise. You don't unpleasant mod points and The fruitless

Redefinition of life as we know it... (1)

HigH5 (1242290) | more than 4 years ago | (#30714402)

The same thing is happening to biology what already happened to Newtonian physics with relativity theory.

I have a question. (1)

telomerewhythere (1493937) | more than 4 years ago | (#30714482)

From the Article:

The researchers began to see new prion-infected cells after leaving the swa-sensitive prion in the drug for 22 cell divisions, which took about 22 days. In other petri dishes, drug resistant strains did not emerge until the cells had doubled over 50 times, or for 50 days. From these results, Weissmann's team approximated that one swa-resistant prion will emerge for every one million new prions that are formed.

Does that mean that all individual prions in all petri dishes were successful in spreading?

Prions scare the living brain out of me.

I thought it said "PRISONS" have no DNA... (1)

HouseOfMisterE (659953) | more than 4 years ago | (#30714818)

...and I then remembered the year I spent on a Federal work release program and the nasty bathrooms in the facility housing. Those bathrooms had plenty of DNA.

Change Evolve (1)

Gothmolly (148874) | more than 4 years ago | (#30715068)

Just because some prions are different than others, and those differences cause them to last longer, linger around longer, etc does not mean that they are evolving. It's not as if the prion wakes up one day and says "I'm going to change". The suckier prions just don't make the cut. There's a difference.

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