Flaws in proteins responsible for complex life, a study shows. - Polidicks

[quote]Tiny structural errors in proteins may have been responsible for changes that sparked complex life, researchers say. A comparison of proteins across 36 modern species suggests that protein flaws called "dehydrons" may have made proteins less stable in water. This would have made them more adhesive and more likely to end up working together, building up complex function. The Nature study adds weight to the idea that natural selection is not the only means by which complexity rises. Natural selection is a theory with no equal in terms of its power to explain how organisms and populations survive through the ages; random mutations that are helpful to an organism are maintained while harmful ones are bred out. But the study provides evidence that the "adaptive" nature of the changes it wreaks may not be the only way that complexity grew. Single-celled life gave rise to more complex organisms, and with them came ever-more complicated networks of gene and protein interactions. Michael Lynch, an evolutionary theorist at Indiana University, teamed up with Ariel Fernandez of the University of Chicago, both in the US, to look specifically at protein structure. They considered 106 proteins shared among 36 modern-day organisms of widely varying complexity, from single-celled protozoa up to humans. The pair were studying "dehydrons" - regions of proteins that make them more unstable in watery environments. These dehydrons - first discovered by Dr Fernandez - make the proteins more sticky in water, thereby raising the probability that they will adhere to other such proteins. The analysis showed that organisms with smaller populations - such as humans - had accumulated more of these defects than simpler organisms with vastly higher population numbers. The suggestion is that it is the acquisition of these defects, with sticky proteins more likely to work together in ever-more complex protein-protein interactions, that nudged cellular complexity upward. "We've tried to bridge the gap between protein structure and evolution and believe we've uncovered evidence that proteins develop mild defects in organisms with smaller population sizes, over the great divide from bacteria to unicellular eukaryotes to invertebrates up to us vertebrates," said Professor Lynch. These slight defects may decrease protein function even as they increase protein cooperation. The authors suggest then that other adaptations occur that "undo" the deleterious effects of the sticky proteins. For example, the protein haemoglobin that carries oxygen in our blood, is made of four identical subunits, each with a range of dehydron flaws; simpler organisms have globin molecules that accomplish the same job with just one subunit. But the overlap of the four subunits actually masks the flaws in each one. The authors stress that they are not arguing against natural selection as a process; they say rather that it can be aided by "non-adaptive" mechanisms. "There's been this general feeling that complexity is a good thing and evolves for complexity's sake - that it's adaptive," Professor Lynch told BBC News. "We've opened up the idea that the roots of complexity don't have to reside in purely adaptational arguments. "It's opening up a new evolutionary pathway that didn't exist before." 'A mess' Ford Doolittle of Dalhousie University agrees that this mechanism, separate from Darwin's vision of natural selection, is an important consideration. "Darwinists are a little bit like the pre-Darwinists before them, who would have marveled at the perfection of God's creation," he told BBC News. "We tend to marvel at the Darwinian perfection of organisms now, saying 'this must have been highly selected for, it's a tuned and sophisticated machine'. "In fact, it's a mess - there's so much unnecessary complexity." While he called the Nature study "important and interesting", he disagrees with the mechanism that allows organisms to recover from the protein flaws. He has long argued for a "presuppression" mechanism, in which some organisms may have a way to overcome the limited functionality of the slightly damaged proteins, and those that do survive best. "He's putting the cart before the horse," Professor Doolittle said of Professor Lynch's idea that subsequent mutations solve the problems raised by the protein changes. "But we both agree that much of complexity does not have an adaptive explanation."[/quote] [url=http://www.bbc.co.uk/news/science-environment-13445951]BBC Source[/url] Well, so basically we exist because nature fucked up. :v:

So that means we will never be perfect and we are all failures? Damn life, you so negative

so the chances of it happening again are quite slim, well better get comfortable here

[QUOTE=johan_sm;29927432]So that means we will never be perfect and we are all failures? Damn life, you so negative[/QUOTE] life is accidental

[QUOTE=angelangel;29927501]life is accidental[/QUOTE] Damn angelangel you so negative.

So looks like proteins can turn children into pro-teens. Seems legit.

[quote]"We tend to marvel at the Darwinian perfection of organisms now, saying 'this must have been highly selected for, it's a tuned and sophisticated machine'. "In fact, it's a mess - there's so much unnecessary complexity."[/quote] yeah. i thought this was kind of fucking obvious as we have vestigial organs and shit, it would only make sense that there's also a mess at a more molecular/structural level. [editline]19th May 2011[/editline] but i guess now they found evidence of it, which i suppose is a good thing.

[QUOTE=Kendra;29927393]The Nature study adds weight to the idea that natural selection is not the only means by which complexity rises.[/QUOTE] Natural Selection isn't how complexity rises, it's how more effective organisms become more common. It has nothing to do directly with complexity, unless that complexity aids the organism. There is some terrible misunderstanding of how evolution works in this report. [editline]19th May 2011[/editline] [quote]"We've opened up the idea that the roots of complexity don't have to reside in purely adaptational arguments.[/quote]I don't understand what he's meaning here. Nothing in evolution is purposeful - things that, on average, do worse are pruned. If a randomly acquired complexity makes something better off, it does better. If it doesn't (say in the case of the most abundant life on Earth, prokaryotes), then the complexity will be selected against. It could also be neutral, and persist in a population until it becomes useful, or detrimental.

[QUOTE=Kybalt;29927971]yeah. i thought this was kind of fucking obvious as we have vestigial organs and shit, it would only make sense that there's also a mess at a more molecular/structural level. [editline]19th May 2011[/editline] but i guess now they found evidence of it, which i suppose is a good thing.[/QUOTE] [media]http://www.youtube.com/watch?v=0cH2bkZfHw4[/media] Evolution get's sloppy.

[QUOTE=Satane;29929305]Ok, now think what will happen if we keep letting gays and retards live [sp](not trying to insult anyone, just a thought that came up when I saw everyone talking about evolution)[/sp][/QUOTE] well if we keep letting retards live there'd be more posts like yours

I always wanted to be a fuck up

[QUOTE=Kendra;29927393]Well, so basically we exist because nature fucked up. :v:[/QUOTE] Nature is fucking beautiful. If you think our world is one big fucking abomination, then so be it. It's miraculous. But humans.. or human life, that's fucked up. But it's also a lot more than just that. It's miraculous too!

[QUOTE=Satane;29929305]Ok, now think what will happen if we keep letting gays and retards live [sp](not trying to insult anyone, just a thought that came up when I saw everyone talking about evolution)[/sp][/QUOTE] Well, nothing.

[QUOTE=Satane;29929305]Ok, now think what will happen if we keep letting gays and retards live [sp](not trying to insult anyone, just a thought that came up when I saw everyone talking about evolution)[/sp][/QUOTE] So you mean people like you? Yeah then we will slowly get more and more stupid, so go kill yourself.

I'm reading this while drinking a protein shake. Sweet.

Ha So if god's creations really were perfect they wouldn't exist This is obviously Odin's doing [editline]19th May 2011[/editline] All hail Odin

[QUOTE=Satane;29931600]At least try to argument your shit you ignorant fucks.[/QUOTE] that was a joke don't get me wrong, you're in no possible way correct in believing that homosexuals and retards are going to ruin civilization

[QUOTE=Satane;29929305]Ok, now think what will happen if we keep letting gays and retards live [sp](not trying to insult anyone, just a thought that came up when I saw everyone talking about evolution)[/sp][/QUOTE] Then we're not bigots.

Even at a molecular level we always knew things were pretty messy. This doesn't change much. What about rubisco? That's a shitty enzyme that's responsible for most organic matter even though it's really inefficient. And how there are only 22 amino acids but 64 codons for them in RNA (Yes I get why there are 64, but you still have to admit, it's not that clean of a system) Also all the other little mess-ups like mitochondria and plastids entering cells on accident and viruses being created by mistake. Actually the entire realm of viruses is extremely messy, because we aren't sure whether to classify them as alive or dead. That doesn't fit into the spectrum of life very neatly.

So...there was a lot of fuck ups.

[QUOTE=johan_sm;29927432]So that means we will never be perfect and we are all failures? Damn life, you so negative[/QUOTE] Every mutation is caused by a flaw. So flaws aren't always a bad thing. Some thing inspiring if you ask me.

Hey garry, you were an accident.... So am I.

[QUOTE=Zeke129;29930953]Ha So if god's creations really were perfect they wouldn't exist This is obviously Odin's doing [editline]19th May 2011[/editline] All hail Odin[/QUOTE] why WHY why the fuck do people need to start this shit for some funny ratings

[QUOTE=Satane;29931600]At least try to argument your shit you ignorant fucks.[/QUOTE] Why the outburst? Detective P is right. Nothing would happen. My conclusion is pure common sense. Gays can't reproduce effectively, if you believe there's a "faulty gay gene" somewhere. Retarded people and the mentally challenged seldom get children since they can't handle the responsibility. [editline]20th May 2011[/editline] Scratch that last part. Forgot about Jersey Shore.

So we may be an accident because earth made itself silly. My theory of "We don't know what life is" happens to be somewhat true. Just because we are fuck ups and our breed happening again would be extremely rare does not mean that other beings can't exist.

Basically what the op is saying is that a mutation happened. But this happens all the time in nature and is the cause of evolution so I dont see why everyones saying we are flaws now.

[QUOTE=imasillypiggy;29936778]Basically what the op is saying is that a mutation happened. But this happens all the time in nature and is the cause of evolution so I dont see why everyones saying we are flaws now.[/QUOTE] We don't know how common this mutation is though. Or if we even should be considered flaws.

I don't understand what they mean from protein flaws. Flawed compared to what? Is this just saying that chance mutations in the gene could have resulted in a slightly different protein being synthesised that ended up working better than the original?

[QUOTE=Jabberwocky;29941244]I don't understand what they mean from protein flaws. Flawed compared to what? Is this just saying that chance mutations in the gene could have resulted in a slightly different protein being synthesised that ended up working better than the original?[/QUOTE] [quote]A comparison of proteins across 36 modern species suggests that protein flaws called "dehydrons" may have made proteins less stable in water. This would have made them more adhesive and more likely to end up working together, building up complex function.[/quote]

I think I sort of understand now (after wiki-ing what a dehydron was). But now I just have more questions like how did they form? How was a beneficial change retained by the genetic code?