Multicellular Life Evolves In Months, In a Lab 285
ananyo writes "The origin of multicellular life, one of the most important developments in Earth's history, could have occurred with surprising speed, U.S. researchers have shown. In the lab, a single-celled yeast (Saccharomyces cerevisiae) took less than 60 days to evolve into many-celled clusters that behaved as individuals. The clusters even developed a primitive division of labor, with some cells dying so that others could grow and reproduce. Multicellular life has evolved independently at least 25 times, but these transitions are so ancient that they have been hard to study. The researchers wanted to see if they could evolve multicellularity in a single-celled organism, using gravity as the selective pressure. In a tube of liquid, clusters of yeast cells settle at the bottom more quickly than single cells. By culturing only the cells that sank, they selected for those that stick together. After many rounds of selection over 60 days, the yeast had evolved into 'snowflakes' comprising dozens of cells."
Not so sure about this. (Score:5, Informative)
Re:Not so sure about this. (Score:5, Informative)
Also mentioned in tfa. The scientist says that he plans to do an experiment with organisms without multicellular ancestors.
Yes - sounds like "grant time" (Score:5, Insightful)
I suspect it's not "evolution" at all, but subtly bad science (i.e. a scientist gunning for more grant money). DNA can express in many ways given varying environmental conditions, without the mutations that characterize true evolution -- and artificially forcing genetic drift by selecting for the bottom-clumpers is certainly VERY DIFFERENT from having gravity serve as the "selection pressure."
It's well known DNA can express in many different ways without true evolution. We've come a long way from the theory of Lamarckian evolutionary theory (evolution of acquired characteristics). One is example: exons, which can express differently across generations based on environmental conditions-- without actual change to the DNA.
I'm thinking this great discovery will get pounded upon by other biologists pretty quickly -- and put in its proper place as an interesting science experiment that really does not advance the field much if at all. INTERESTING evolution would be a group of mutations that lead to a multicellular outcome. That's NOT what these guys 1) demonstrated happened (multicellular DNA base-pair-causing mutations) or 2) proved was the actual genetic cause at the molecular-biology level.
so dna mutation over generation is not enough for (Score:2, Troll)
you.
http://www.newscientist.com/article/dn14094-bacteria-make-major-evolutionary-shift-in-the-lab.html [newscientist.com]
and you need bacteria not only to evolve in dna, but also develop into a multicellular organism. in your lifetime.
please.
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This is quite informative. The simplistic experiment in the TFA seems to be just that: simplistic. IOW - bad science.
Re:Yes - sounds like "grant time" (Score:5, Informative)
The summary is true, but ultimately misleading.
This is evolution, and it did happen in months. What it doesn't account for is getting the clumping gene in the first place, and that the likelihood of getting selection pressures as extreme as the ones in the lab is fairly low.
They've proven that yeast has the capacity to evolve in this way given the right selection pressures, which is interesting. With additional research they may be able to prove that many other single celled life forms have the same capacity, from which we may extrapolate that the gene responsible for this behavior either occurred very early or is a relatively minor mutation.
The "more quickly than we believed" part is probably bogus. They applied extreme selection pressures to this particular colony of yeast and so they got an extreme time scale result the same would happen in any species if you extrapolated for the length of a given generation. You could do the same thing to humans for some arbitrary characteristic.
Re:Yes - sounds like "grant time" (Score:5, Informative)
IIRC from the times when I used yeast in my PhD research, wild type (that means: not mutated) S. cerevisiae clumps in advanced stationary phase (end of growth curve, nutritional deprivation). Such circumstances happen more often that not in the real life of S. cerevisae: just imagine that in nature it cannot walk to the nearest grapevine and say 'hey lets do some sugar fermentation here'... no it depends on being able to survive in times of drought. ne way it does that is through forming spores, another way of temporarily surviving could be this kind of 'clumping'. So, the 'clumping gene' is already there, it is just expressed in certain circumstances, circumstances easily simulated in a lab situation.
In my mind the argument would revolve around self-organisation versus (old, dormant) organisational information still present in the S. cerevisae genome. I'm bummed I cannot access the original article at the PNAS site, else I could comment on that in a bit more detail.
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Yeah, it's not like you get large vessels full of water, yeast, and things that yeast likes to eat anywhere else [google.com]
Brewers were distinguishing between top and bottom yeasts before God got his driving license; certain styles of beer work better with one type than the other.
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Brewers were distinguishing between top and bottom yeasts before God got his driving license; certain styles of beer work better with one type than the other.
Just to complete that thought, ales are top fermenting beers, lagers are bottom fermenting. I suppose there is some relation to aerobic and anaerobic fermentation there.
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ales are top fermenting beers, lagers are bottom fermenting
Sometimes I get the impression that was an afterthought created for no other reason than to find a difference between the two of them.
I suppose there is some relation to aerobic and anaerobic fermentation there.
Books could and probably have been written on the subject. I might be interested in reading the Cliff Notes version of one or two of them.
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Also, ale fermentation, because of the warmer temperatures, are typically more vigorous. The yeast are able to eat the sugar more quickly. I guess it's possible that it is this vigorous fermentation that is t
Re:Yes - sounds like "grant time" (Score:4, Informative)
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Just to complete that thought, ales are top fermenting beers, lagers are bottom fermenting. I suppose there is some relation to aerobic and anaerobic fermentation there.
There is no relationship between top/bottom and aerobic/anaerobic whatsoever. Fermentation is anaerobic, period. The difference between lager and ale is the strain of yeast used, and the temperature at which fermentation occurs. Saying that a beer is fermenting "on the bottom" or "on the top" just indicates that somebody has never actually
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Yes and no. Look at it again and you will see this is a more extreme version.
This isn't just about top or bottom fermenting. Certainly, top fermenters are being culled here but, so are many bottoms. This isn't just "does it fall" but "how fast does it fall".
Imagine this.... mix up some wort (yes, I am a brewer too). Pitch your yeast... wait 12 hours, then take the bottom yeast. Rinse and repeat.
So now, you have a real selective pressure. Before...all yeast that could live or made it to the bottom would live
Re:Yes - sounds like "grant time" (Score:5, Insightful)
I suspect it's not "evolution" at all, but subtly bad science (i.e. a scientist gunning for more grant money). DNA can express in many ways given varying environmental conditions, without the mutations that characterize true evolution -- and artificially forcing genetic drift by selecting for the bottom-clumpers is certainly VERY DIFFERENT from having gravity serve as the "selection pressure."
It's well known DNA can express in many different ways without true evolution. We've come a long way from the theory of Lamarckian evolutionary theory (evolution of acquired characteristics). One is example: exons, which can express differently across generations based on environmental conditions-- without actual change to the DNA.
I'm thinking this great discovery will get pounded upon by other biologists pretty quickly -- and put in its proper place as an interesting science experiment that really does not advance the field much if at all. INTERESTING evolution would be a group of mutations that lead to a multicellular outcome. That's NOT what these guys 1) demonstrated happened (multicellular DNA base-pair-causing mutations) or 2) proved was the actual genetic cause at the molecular-biology level.
IAAMBP (I am a molecular biophysicist) and I actually just finished discussing this article at work before seeing it on /. The parent post is an odd mix of insightful comments and flamebait so I'll respond to the former. BTW the actual research article itself is free for everyone to read, thanks to the authors shelling out an extra 1K$ to allow public access. I'll link it below:
http://www.pnas.org/content/early/2012/01/10/1115323109.full.pdf+html [pnas.org]
If you would prefer having to pay 10-30$ for the privilege of reading what your tax dollars already paid for instead of this commie "open access" stuff, please call your congressman and tell him/her to support HR bill 3699.
To contextualize this work: the path that led from single-celled eukaryotes to multicellular organisms is one of those $64,000 questions in evolutionary biology, that weird crossover from outright competition to coordinated teamwork. The advantages of being multicellular really pay off for big, complex organisms, but why on earth would it have been advantageous for a small group of a few dozen cells? This paper does not answer the question by any stretch, but it does provide a few interesting, unexpected clues. Most groups asking this question focus on Volvocine algae, which evolved multicellularity so recently such that you can compare them side by side with their nearly identical single-celled cousins in the very same pond. But these are not the most convenient organisms to work with; they have a very complicated life cycle, and have a monster-sized genome for their diminutive size (~140 million bases) and doing genetics on such beasties is still quite difficult and tedious.
Yeast, on the other hand, are really easy to work with and are actually pretty boring in most respects; ~12 million base pairs which have all been sequenced many times over. You can actually custom order them with any gene you want deleted just to see what happens, it's that well characterized. So the observation that artificially selecting for clusters in boring yeast leads to weird snowflake-shape colonies with something that resembles "programmed cell death" in higher organisms is completely unexpected an novel. "Programmed cell death" literally means that the colony has found a way to promote what's good for the colony over what's good for the individual, even though these are only 60 days removed from being a pretty ordinary yeast.
Is this how it happened billions of years ago? Probably not, this is just boring yeast after all, and I can't think of a scenario where sinking to the bottom is a life-or-death advantage. In the case of the algae, it would in fact be suicidal to sink beyond where the
Re:Yes - sounds like "grant time" (Score:5, Interesting)
I'm betting they chose yeast because now they can get the interesting ones sequenced for a few thousand each, which is completely feasible even with a very modest grant compared to what it would cost for algae (or anything that isn't yeast or e. coli really).
Just skimmed through the paper and was almost surprised to see they haven't done the sequencing (yet?) - identifying the presumed mutations would have made this study much more interesting. A 12 Mb genome doesn't need much NGS capacity! Until then, I don't think we can rule out epigenetic inheritance, which has previously been demonstrated in yeast.
Re:Yes - sounds like "grant time" (Score:5, Interesting)
First. Thank you for a very interesting post which provides insight that is still understandable by those of us who are not molecular biophysicists. This is not always easy to do.
I may now be able to provide some insight into Slashdot's science discussions, which you may or may not have discovered yet....
A good scientist (which I'm sure you are) will read new research with an open mind combined with healthy scepticism. He/she won't automatically discard papers due to confirmation bias, and they won't shout "CORRELATION DOES NOT EQUAL CAUSATION" every single time they read reporting of a paper which suggests some correlation, because they realise that demonstrating correlation is often a necessary first step towards establishing causation and as such it is still novel and useful to publish papers that suggests correlation.
Slashdot, however, is home to some brilliant scientists who are completely drowned out by the masses of cynical, semi-clever "know-it-alls" who love to demonstrate their cleverness by shooting down any new research, often without bothering to read it first. They will shout "bad science" at the top of their lungs as a knee-jerk reaction to any perceived short coming, even if this short coming is just a limitation in scope of a paper or simply just ignorance on their own part. If the paper doesn't fully answer every possible question, it is worthless.
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Occam's razor is useful for determining the most likely answer, not for establishing fact. I don't think you were asserting it as a fact, but it can be read it that way.
(Tired of Occam being used as proof in arguments)
Re:Yes - sounds like "grant time" (Score:5, Informative)
Bzzt. Please review the difference between mass and density and the relationship between density and buoyancy.
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The relevant fact here is how terminal velocity relates to volume.
Re:Not so sure about this. (Score:5, Informative)
This was on RichardDawkins.net back in June, and in the version of the article linked there, there were these telling paragraphs:
Sceptics, however, point out that many yeast strains naturally form colonies, and that their ancestors were multicellular tens or hundreds of millions of years ago. As a result, they may have retained some evolved mechanisms for cell adhesion and programmed cell death, effectively stacking the deck in favour of Ratcliff's experiment.
"I bet that yeast, having once been multicellular, never lost it completely," says Neil Blackstone, an evolutionary biologist at Northern Illinois University in DeKalb. "I don't think if you took something that had never been multicellular you would get it so quickly."
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It will definitely take longer - how long is anyone's guess. Nevertheless it'd be an interesting experiment.
Now a variation. Evolution involves random mutations: most don't do much if anything, others are lethal, and some will give a small advantage and giving those individuals an edge. These random mutations, mostly DNA copying errors, are thought to be caused by a.o. radiation. We are constantly bombarded by a low dose of cosmic radiation, and I would expect that is a major source of such errors. An impac
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Well cosmic radiation, at least the part that makes it through the atmosphere and which is powerful enough to do tamper with molecules, is gamma radiation.
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Glad this got the mod up.
It may not be re-emergence behavior, but even so, the other factor is - yeast are eukaryotic cells, which took a long time develop. If this example were done with prokaryotic cells, it might be more interesting from the perspective of an evolutionary biologist, given that is what life started with.
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Re:Not so sure about this. (Score:5, Funny)
This. I'd mod informative if I could.
Slashdot moderation simply hasn't evolved to the point where you can.
Re:Not so sure about this. (Score:4, Funny)
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Re:Not so sure about this. (Score:4, Funny)
Apparently the group has become self aware!
Nuke from orbit. It's the only way to be sure!
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Apparently the group has become self aware!
Nuke from orbit. It's the only way to be sure!
Once again I feel I have to point out. THAT DIDN'T WORK! So it is not a way to be sure.
Re:Not so sure about this. (Score:4, Interesting)
Slashdot moderation simply hasn't evolved to the point where you can.
Good joke, but you've actually hit on a fundamental flaw with Slashdot's moderation system.
Once in a while, I have mod points. I dig really deep, and look really hard, for those comments that are truly insightful and informative. But I get punished for trying to do a really good job: many of my mod points expire before I can use them.
I've always wondered what the justification is for Slashdot mod points to have an arbitrary and artificial expiration date. Here's to hoping that, some day, the moderation system will evolve!
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Re:Not so sure about this. (Score:4, Funny)
Here's the actual article (Score:5, Informative)
And PNAS has it listed as open access, which means you should be able to download the full text regardless of your subscriber (or non-subscriber) status. Just click the Full Text link.
I've always wondered... (Score:5, Insightful)
Do the mechanisms which originally created life still occur? Or is "The Genesis Event" so rare that it was a one-time occurrence billions of years ago?
Genesis (Score:5, Funny)
God still holds the copyright for the original genesis event. It should have entered the public domain, but the copyright just keeps getting extended, and extended for billions of years. God keeps raking in the royalties and has no incentive to create new works, which is why you haven't heard anything from him lately.
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Re:I've always wondered... (Score:5, Informative)
Re:I've always wondered... (Score:5, Interesting)
Now a related question -- is there any evidence (for or against) that life originated more than once on earth? Is the prevailing theory that a single reproducing organism came into being, from which all others were derived, or is it more likely that multiple instances of life happened over the course of time, and they all happen to take the same form? If this is the case, then it lends credence to life existing elsewhere in the universe, with much similarity to what we know. However, if it is unlikely for more than one independent instance of life to be similar, then we should be observing various non-related life types here on earth (i.e., some carbon based, some silicon based, etc).
Re:I've always wondered... (Score:5, Informative)
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Re:I've always wondered... (Score:4, Interesting)
Re:I've always wondered... (Score:4, Insightful)
More likely, it occurred once, and the first species ate the primordial soup until conditions (mainly nutrient density, I expect) dropped below the level that allowed abiogenesis to repeat. All that is required is that the expected time between abiogenesis events is longer than the time for first life to reproduce and spread throughout the world (or at least that part where the event could reoccur), and you have just one life event per planet (at least for most planets - statistically at least a few times the events must occur too frequently for only one type to dominate).
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This has indeed been pondered! We're pretty sure that all life that presently exists all comes from one root, however.
That doesn't surprise me in the least. There are so many similarities between various life forms it almost has to have a single root. With that I'm thinking of e.g. DNA: all life forms use the same four aminoacids and the same basic mechanisms for handling DNA, with minor variations like viruses that use RNA iirc. It's been a while since I had my biology lessons.
Also the basic structure of cells is pretty much the same throughout all life forms. All cells have their mitochondria, their core, etc., often usi
Re:I've always wondered... (Score:5, Insightful)
1. The nucleus and mitochondria only appear in more complex organisms (eukaryotes.) Simpler ones (prokaryotes: bacteria and archaeons) are just bags with DNA in them. Mitochondria and chloroplasts (and their less well-known cousins, chromoplasts and amyloplasts) actually started out as different kinds of bacteria and just got absorbed into a cell one day. They even have their own DNA, ribosomes, and reproductive cycle.
2. No two species have exactly the same proteins, but their sequences are similar enough that we can infer homology (relatedness) over great distances; often billions of years of separation. That being said, there are some species so isolated and so remote (because all of their relatives have died off) that we have trouble proving homology for—but these species still do more or less the same functions with similarly-shaped proteins.
3. The arsenic-using extremophile was more like arsenic-tolerant. Normally, organisms die when they take up arsenic because it replaces phosphorus with a heavier nucleus that has different binding affinities. However, the organism those researchers discovered was capable of replacing at least some of its phosphorus with arsenic without dying. But yeah, your point is correct!
4. It's widely believed now (in an idea called the RNA World hypothesis) that DNA and proteins were invented later. The original "life" was probably a self-replicating RNA molecule. RNA can perform both catalytic functions (like proteins) and information storage functions (like DNA), it's just not as good at them. It still performs many of these functions in the modern cell as well—almost the entire ribosome (the protein making machine) is made out of RNA, and there's a large class of so-called "ribozymes" that can cut and modify other molecules.
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The more you learn about it, the more complex life becomes!
Mitochondria and chloroplasts (and their less well-known cousins, chromoplasts and amyloplasts) actually started out as different kinds of bacteria and just got absorbed into a cell one day. They even have their own DNA, ribosomes, and reproductive cycle.
I am familiar with mitochondria having their own set of DNA, but that's pretty much how far my knowledge in the subject goes. And that this DNA is not shared through sexual reproduction: in case of human reproduction the mitochondrial DNA is exclusively the mother's, as sperm cells don't have any. But I've never heard about them having their own reproduction cycle etc - it seems like we could call mitochondria a separate life form, living in symbios
Re:I've always wondered... (Score:5, Informative)
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I'm sure those intelligent design people will use this to support their theory, it's surely easier than to explain fossils etc in a young-earth theory: how can such a complex design come into being without a highly intelligent designer creating it?
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Glad to welcome you to /., in case no one has before. I may be behind times. :-)
I have been here a while, and just now noticed you.(knowledgeable and informative comments...I love it, I'm drawn in, I'm curious....)
Not to mention the most generous offer:
I am a biologist. Ask me questions in my journal. I'll give car/computer analogies if possible!
Car/computer analogies? :-).
Natural hit here. Just remember Libraries of Congress conversions, and Hogsheads per hectacre metrics for the/us Luddites
Even with my minor degree in biochem, your comments are news to me....off to read up!
This is what keeps me com
Re:I've always wondered... (Score:5, Interesting)
This has indeed been pondered! We're pretty sure that all life that presently exists all comes from one root, however. If there ever were alternative life-starting events, they didn't survive. The reason for this is that all extant organisms share a number of completely arbitrary decisions called chirality [wikipedia.org] (if you know any physics, that's left-handed vs. right-handed molecular symmetry.) Chirality is completely random in the chemical reactions that produce amino acids and nucleotides, but absolutely fixed, in the same way, in every living organism we've studied. A number of environmental tests have been conducted specifically to look for organisms of contrary chirality, but we haven't found anything yet.
There are two points here. As for the single root of life, I saw Carl Woese give a talk on this - see timely PNAS perspective here if you have institutional access: http://www.pnas.org/content/early/2012/01/13/1120749109.short?rss=1 [pnas.org]
(he's a giant in evolutionary biology and the one who proved archaea were a separate lineage using ribosomal RNA sequences, thus redefining our understanding of microbiology, so I'm inclined to give large weight to his views)
His view was that some events almost certainly happened to one unique organism, you can do the backwards projection on the endosymbiosis of mitochondria and a very distinct genetic profile emerges from multiple, independent lines of evidence. But when you try and project all the way back to the LUCA (last universal common ancestor of all three kingdoms) the uncertainty becomes so large and some of the contradictions so severe that it is in fact best explained by groups of highly similar (but not identical) universal ancestors over a window of time, not just literally one unique genome at a specific point in time. So he thinks that the "base" of the tree of life ends up being more like a collection of small shrubbery or bushes instead of a singular point of origin. Carrying that thought a bit further, if there were indeed multiple bushes of life at the start it seems probable there were also other bushes that completely vanished without a trace (no fossil record possible).
As for the universal chirality, that speaks to the origin of self-replicating macromolecules that would have preceeded the last universal common ancestor by quite a spell, so we can only speculate what happened based on our knowledge of organic chemistry. NASA funds some rather creative chemists to think about this question to help define what life might be like elsewhere, and last time I saw one of them speak they seemed to be of the opinion that it was probably just a random chance that gave us one hand and not the other and that there were pools of similar chemical species being selectively concentrated by some sort of clay catalyst. But that means it could have occurred multiple times and only one pool resulted in a proto-cell, or multiple proto-cells arose and the rest died off, or maybe all steps really did only happen once, there's absolutely no projection or record to build upon except geological models of what the earth might have been like then.
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This has indeed been pondered! We're pretty sure that all life that presently exists all comes from one root, however. If there ever were alternative life-starting events, they didn't survive. The reason for this is that all extant organisms share a number of completely arbitrary decisions called chirality [wikipedia.org] (if you know any physics, that's left-handed vs. right-handed molecular symmetry.) Chirality is completely random in the chemical reactions that produce amino acids and nucleotides, but absolutely fixed, in the same way, in every living organism we've studied. A number of environmental tests have been conducted specifically to look for organisms of contrary chirality, but we haven't found anything yet.
Fascinating. However, is it possible that the alternative life didn't survive because they were different? I mean, if there was already a fairly large base of life out there that shared this chirality, couldn't it be an evolutionary advantage to be part of this? Would a different set of decisions make it difficult/impossible to join in with the chemical processes that supports the established type of life?
You can probably tell I don't know that much about this!
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My wild, completely uninformed guess is that life originated multiple times, and each subsequent new instance got immediately eaten by the (by then more evolved) first one.
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And perhaps with the universe occasionally hurling a massive rock at the earth, destroying much of the more evolved life on it in an epochal extinction event [wikipedia.org], allowing life to evolve in yet another direction. The impact point [wikipedia.org] may have had some of the attributes of the ancient earth.
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The question at that point becomes: What do you call life and where is the boundary between non-life or proto-life and "real" life?
Just like you can never observe a speciation event because it is such a slow process and when you look very closely it becomes fuzzy and you have to ask what exactly is a species. Life is always a river and not a thread.
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A species is a living thing that creates more of itself. If it mates, any other being that can mate with it to produce the same offspring is the same species. When evolution drifts them apart far enough so they cannot do that, then a new species has formed.
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That's a big question! We currently believe that the circumstances that created life were pretty harsh in some respects and extremely mild in others.
No, wrong! Everyone knows Gil Gerard went back in time and ejaculated into the primordial ooze [wikia.com]. Why do people make things so complicated?
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Even if it was to happen, the world is a very different place now. A self-replicating bit of RNA or some other precursor is made of things that "real" life wants to eat. Not really any possibility you can evolve from a replicator to something capable of defending itself from advanced life fast enough to avoid the replicator being eaten.
So, it could be happening all the time, but you're just not going to get a whole new form of life out of it, without some privacy and a chance to evolve.
Re:I've always wondered... (Score:5, Interesting)
In all probability new life (unrelated to current life) cannot evolve on Earth because current life either prevents the required conditions (eating the food before it gets concentrated enough for extremely primitive life to make use of it) or out competing the new life as soon as it arises.
If somehow the Earth were cleansed of all life but otherwise left unaffected, there is no great reason to believe it couldn't re-evolve life. However, as we don't understand the origin of life, there is a possibility that necessary conditions are no longer available - e.g. early life relies critically on the presence of a radioactive nucleotide with half-life of a few hundred million years, present in the early Earth but now decayed.
We find evidence of life in pretty much the oldest rocks on Earth which could contain evidence of life. So in the only instance we can study, life arose about as soon as it possibly could have. This suggests (but does not prove) that given the right conditions, evolution of life is an easy step, rather than one which requires a once-in-a-trillion-years fluke occurance.
However, unicellular life was around for some 2.5 to 3 billion years before multicellular life arose (or at least, multicellular life which left fossil evidence.) This suggests that the step from unicellular to multicellular is hard. Or so I've argued, until this result turned up...
So, we have this result, and the fact that multicellularity has arisen multiple times, and although only in Eukaryotes, it has arisen in very distantly related Eukaryotes (plants vs the fungi/animal clade) suggesting that multicellularity is fairly easy to evolve. So why did it take so long? Perhaps it required a certain level of atmospheric oxygen before multicellular life was viable (plot [wikipedia.org].)
(I have only tangential professional connection to these topics, so these are merely semi-educated ramblings.)
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Just the presence of oxygen will prevent whatever happened from occurring today. You can't have primeval soup on Earth today. However, I wonder if we shouldn't push the Urey experiment further. I always liked it and it was a big revelation when I read about it for the first time as a kid.
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If no plants are photosynthesizing, will all the oxygen eventually go away? Is there enough reducing material sitting around to use it all up?
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The dead plants and animals would start to rot, with bacteria consuming the oxygen.
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Huh. That got me thinking quite a bit! Wikipedia shows it's a questions that's been pondered since the father of gradual change himself, Darwin:
He though that self replicating structures could happen, but that... "at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed."
And on that subject, "No new notable research or theory on the subject appeared until 1924, when Alexander Oparin reasoned that atmospheric oxygen prevent
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The mechanisms and conditions still exist - to an extent. There are abundant chemical precursors around, energy from the sun or chemosynthesis. But there are a couple of important differences between now and when life first arose from the organic soup of aeons ago. The biggest difference I can think of: life already exists, which puts any new, nascent for
Better Beer? (Score:2)
Given the yeast they evolved, "Saccharomyces cerevisiae", does this mean we get better, or more intelligent beer?
Red
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Yay, intelligent beer design!
That's why I prefer unfiltered wheat beer. The smart yeast collects at the bottom, you shake it up and pour it into your glass. Then you drink it and it goes straight to your brain, improving your intelligence. That's my hypothesis anyway.
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OMG; are you saying that Budweiser is people?!
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If my Latin doesn't fail me it means "sugar fungus from beer."
Oh and that fuzzy reading comes with age. You get lazy, don't look closely and in 99.999% of the cases you still read the correct word. Or maybe it's just the brain got *that* good at pattern recognition.
Relation to yeast (Score:5, Funny)
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Flocculation (Score:3, Informative)
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According the paper (linked in several other comments, and is much more fascinating than the article), the clumps were not the result of flocculation.
I am looking forward to seeing future experiments with other type of single celled organisms.
Not that impressive (Score:2)
Actually I thought Eukaryotes were the big jump (Score:5, Informative)
Not to diminish the importance of multi-cellularity (and of this discovery) but wasn't the development of Eukaryotes (cells with Nuclei and other differentiated organelles) the big step needed for complex life? I mean with chloroplasts you get plants and mitochondria (or mitoklorines for you Star Wars fans) you get animals.
With multi-cellularity and prokaryotes you get strombolites (algal mats).
That said, it shows that evolution can happen quite quickly and can overcome some serious obstacles in a short amount of time in a very limited scope (a laboratory workbench). When multiplied by geologic ages and oceans of room is it any wonder that life has evolved in so many fascinating ways?
Re:Actually I thought Eukaryotes were the big jump (Score:5, Informative)
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Yeah, that's what you think. One tiny little change and we could end up with just a planet in an evolutionary dead-end filled with anoxic bacteria and politicians!
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That's an insult to the anoxic bacteria!
Division of labor? (Score:2)
Already common knowledge among brewers (Score:4, Insightful)
I brew (and judge) beer... different strains of brewers yeast already have widely varying behaviors with regards to how they settle out. Yeast with "low flocculation" tend to remain in suspension for weeks, consuming more of the sugars (drier, more alcoholic beer); yeast with "high flocculation" tend to clump together and settle after a few days, leaving more residual sugar (sweeter/heavier beer). This is widely known already in the brewing community. These strains have evolved over the years to suit the preferences and procedures of individual breweries. So all these guys have really done is to repeat in a controlled environment the same selective breeding that brewers have been doing (whether they understood it or not) for centuries.
Take a look here [wyeastlab.com]; if you click through to each individual strain of yeast, you'll see that there's a spec for flocculation (tendency to clump) and attenuation (tendency to consume sugars); there's a pretty good (though not perfect) inverse correlation between the two.
The only thing really novel here is the claim that these yeast clumps somehow represent a first step towards multi-cellular life. Interesting, but -- while I'm not dismissing it out-of-hand -- I'm definitely taking it with a pinch of salt.
Cart before the horse? (Score:2)
The origin of multicellular life, one of the most important developments in Earth's history, could have occurred with surprising speed, U.S. researchers have shown.
The origin of multicellular life comes from unicellular life, which would be one of the most important developments in Earth's history. When they can create that in the lab, then let's talk.
Outside intervention? (Score:2)
From the article, they had to intervene and select the yeast cells that were cooperating with what they were trying to do. Unless they are proposing outside intervention by a deity or alien race, it seems that the process they used isn't representative of what would have occurred in nature.
Huh? (Score:2)
Life evolved... (Score:3)
From life. I'm not surprised.
Life evolves. Dead things don't. And dead things don't evolve into life.
Wake me up if that changes.
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Actually, the opposite of what you say is true. That's the whole point of using the word "selection" in the phrase "natural selection". Anything that helps the organism survive and reproduce better in its environment is a selective pressure. So if you postulate that there exists somewhere on the planet where multi-cellularism is a selective force, then this experiment replicates those conditions.
Re:Yeasty "evolution" (Score:5, Insightful)
Think of it this way: a random walk will get to every possible location eventually. If you push it in a certain direction, it'll simply get there sooner. But if it doesn't get there when you do, then there's no chance it'll ever get there on its own. Unless they tampered with the genes of the yeast in question, these results are completely legitimate.
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Once again, great successes hailed while ignoring the elephant in the room: the researchers cheated by selecting out certain ones (those that sank to the bottom.) in TRUE life-by-incremental-changes, every event is random, including which cells are selected out of the tube to prosper.
False.
The purpose of this "selection" was simply to simulate a larger environment. If this occurred in a big place relative to the size of the yeast, let's call this imaginary place the ocean, it is highly likely the yeast wouldn't be contained to a test tube. It would disperse on its own. Selecting certain ones and continuing to examine them is the same as zooming in and following the large ones in the ocean you'd like to examine. The centrifuge is not meant for culling, selective breeding or to "intellige
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Except he didn't plan the form, look or workings of the organism, which means he didn't actually design.
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He designed it to the same extent that some people design software. But that probably says more about the coders than him...
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If there was an 'intelligent designer' then why are the sewer outflows in the middle of the play ground.
Because for some people sewer outflows ARE a playground, especially when the playground is under the effects of a red tide.
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It's still a pretty bad decision for *most* people.
And also: could this designer please fix my lung-design so the exhaust is on the bottom where it used to be when we were in the prototype phase (codename "monkey")?
My eyes could use an upgrade as well. And while I applaud the decision to incorporate a spare kidney, I would have preferred a heart and liver that is split in two smaller, separate entities as well. We could have one lung with a heart and a liver on each side, drastically reducing the chance of
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If you do eat it make sure it is the deactivated (dead) kind from the supermarket or health shop or it will start to grow in you.
It it does, do I get any super mutant abilities?
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If you consider farting to be a special power, then yes.
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If you do eat it make sure it is the deactivated (dead) kind from the supermarket or health shop or it will start to grow in you.
It it does, do I get any super mutant abilities?
If you take it in the proper manner (suspended in 12 ounces of beer) it gets you drunk.
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That's not the problem. The problem is that moderators gave him +5 Informative and are now modding down the accused, even for legitimate posts.
Even the legitimate posts? We'll have to be more careful and not mod the legitimate posts down. Sorry, sometimes it's hard to tell.
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On the upside, you are so busy posting about the moderation system that you aren't posting your usual anti-google drivel. I call that a win.
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I think if anyone left Digg to come to Slashdot, the next stage would be suicide, not going back to Digg.