Tópico: A New Physics Theory of Life

[_tiago]

Fonte: https://www.simonsfoundation.org/quanta/20140122-a-new-physics-theory-of-life/

Why does life exist?

Popular hypotheses credit a primordial soup, a bolt of lightning and a colossal stroke of luck. But if a provocative new theory is correct, luck may have little to do with it. Instead, according to the physicist proposing the idea, the origin and subsequent evolution of life follow from the fundamental laws of nature and “should be as unsurprising as rocks rolling downhill.”

From the standpoint of physics, there is one essential difference between living things and inanimate clumps of carbon atoms: The former tend to be much better at capturing energy from their environment and dissipating that energy as heat. Jeremy England, a 31-year-old assistant professor at the Massachusetts Institute of Technology, has derived a mathematical formula that he believes explains this capacity. The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life.
Plagiomnium affine

Kristian Peters

Cells from the moss Plagiomnium affine with visible chloroplasts, organelles that conduct photosynthesis by capturing sunlight.

“You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant,” England said.

England’s theory is meant to underlie, rather than replace, Darwin’s theory of evolution by natural selection, which provides a powerful description of life at the level of genes and populations. “I am certainly not saying that Darwinian ideas are wrong,” he explained. “On the contrary, I am just saying that from the perspective of the physics, you might call Darwinian evolution a special case of a more general phenomenon.”

His idea, detailed in a recent paper and further elaborated in a talk he is delivering at universities around the world, has sparked controversy among his colleagues, who see it as either tenuous or a potential breakthrough, or both.

England has taken “a very brave and very important step,” said Alexander Grosberg, a professor of physics at New York University who has followed England’s work since its early stages. The “big hope” is that he has identified the underlying physical principle driving the origin and evolution of life, Grosberg said.

“Jeremy is just about the brightest young scientist I ever came across,” said Attila Szabo, a biophysicist in the Laboratory of Chemical Physics at the National Institutes of Health who corresponded with England about his theory after meeting him at a conference. “I was struck by the originality of the ideas.”

Others, such as Eugene Shakhnovich, a professor of chemistry, chemical biology and biophysics at Harvard University, are not convinced. “Jeremy’s ideas are interesting and potentially promising, but at this point are extremely speculative, especially as applied to life phenomena,” Shakhnovich said.

England’s theoretical results are generally considered valid. It is his interpretation — that his formula represents the driving force behind a class of phenomena in nature that includes life — that remains unproven. But already, there are ideas about how to test that interpretation in the lab.

“He’s trying something radically different,” said Mara Prentiss, a professor of physics at Harvard who is contemplating such an experiment after learning about England’s work. “As an organizing lens, I think he has a fabulous idea. Right or wrong, it’s going to be very much worth the investigation.”
A computer simulation by Jeremy England and colleagues shows a system of particles confined inside a viscous fluid in which the turquoise particles are driven by an oscillating force. Over time (from top to bottom), the force triggers the formation of more bonds among the particles.

Courtesy of Jeremy England

A computer simulation by Jeremy England and colleagues shows a system of particles confined inside a viscous fluid in which the turquoise particles are driven by an oscillating force. Over time (from top to bottom), the force triggers the formation of more bonds among the particles.

At the heart of England’s idea is the second law of thermodynamics, also known as the law of increasing entropy or the “arrow of time.” Hot things cool down, gas diffuses through air, eggs scramble but never spontaneously unscramble; in short, energy tends to disperse or spread out as time progresses. Entropy is a measure of this tendency, quantifying how dispersed the energy is among the particles in a system, and how diffuse those particles are throughout space. It increases as a simple matter of probability: There are more ways for energy to be spread out than for it to be concentrated. Thus, as particles in a system move around and interact, they will, through sheer chance, tend to adopt configurations in which the energy is spread out. Eventually, the system arrives at a state of maximum entropy called “thermodynamic equilibrium,” in which energy is uniformly distributed. A cup of coffee and the room it sits in become the same temperature, for example. As long as the cup and the room are left alone, this process is irreversible. The coffee never spontaneously heats up again because the odds are overwhelmingly stacked against so much of the room’s energy randomly concentrating in its atoms.

Although entropy must increase over time in an isolated or “closed” system, an “open” system can keep its entropy low — that is, divide energy unevenly among its atoms — by greatly increasing the entropy of its surroundings. In his influential 1944 monograph “What Is Life?” the eminent quantum physicist Erwin Schrödinger argued that this is what living things must do. A plant, for example, absorbs extremely energetic sunlight, uses it to build sugars, and ejects infrared light, a much less concentrated form of energy. The overall entropy of the universe increases during photosynthesis as the sunlight dissipates, even as the plant prevents itself from decaying by maintaining an orderly internal structure.

Life does not violate the second law of thermodynamics, but until recently, physicists were unable to use thermodynamics to explain why it should arise in the first place. In Schrödinger’s day, they could solve the equations of thermodynamics only for closed systems in equilibrium. In the 1960s, the Belgian physicist Ilya Prigogine made progress on predicting the behavior of open systems weakly driven by external energy sources (for which he won the 1977 Nobel Prize in chemistry). But the behavior of systems that are far from equilibrium, which are connected to the outside environment and strongly driven by external sources of energy, could not be predicted.

This situation changed in the late 1990s, due primarily to the work of Chris Jarzynski, now at the University of Maryland, and Gavin Crooks, now at Lawrence Berkeley National Laboratory. Jarzynski and Crooks showed that the entropy produced by a thermodynamic process, such as the cooling of a cup of coffee, corresponds to a simple ratio: the probability that the atoms will undergo that process divided by their probability of undergoing the reverse process (that is, spontaneously interacting in such a way that the coffee warms up). As entropy production increases, so does this ratio: A system’s behavior becomes more and more “irreversible.” The simple yet rigorous formula could in principle be applied to any thermodynamic process, no matter how fast or far from equilibrium. “Our understanding of far-from-equilibrium statistical mechanics greatly improved,” Grosberg said. England, who is trained in both biochemistry and physics, started his own lab at MIT two years ago and decided to apply the new knowledge of statistical physics to biology.

Using Jarzynski and Crooks’ formulation, he derived a generalization of the second law of thermodynamics that holds for systems of particles with certain characteristics: The systems are strongly driven by an external energy source such as an electromagnetic wave, and they can dump heat into a surrounding bath. This class of systems includes all living things. England then determined how such systems tend to evolve over time as they increase their irreversibility. “We can show very simply from the formula that the more likely evolutionary outcomes are going to be the ones that absorbed and dissipated more energy from the environment’s external drives on the way to getting there,” he said. The finding makes intuitive sense: Particles tend to dissipate more energy when they resonate with a driving force, or move in the direction it is pushing them, and they are more likely to move in that direction than any other at any given moment.

“This means clumps of atoms surrounded by a bath at some temperature, like the atmosphere or the ocean, should tend over time to arrange themselves to resonate better and better with the sources of mechanical, electromagnetic or chemical work in their environments,” England explained.
Self Replicating Microstructures

Courtesy of Michael Brenner/Proceedings of the National Academy of Sciences

Self-Replicating Sphere Clusters: According to new research at Harvard, coating the surfaces of microspheres can cause them to spontaneously assemble into a chosen structure, such as a polytetrahedron (red), which then triggers nearby spheres into forming an identical structure.

Self-replication (or reproduction, in biological terms), the process that drives the evolution of life on Earth, is one such mechanism by which a system might dissipate an increasing amount of energy over time. As England put it, “A great way of dissipating more is to make more copies of yourself.” In a September paper in the Journal of Chemical Physics, he reported the theoretical minimum amount of dissipation that can occur during the self-replication of RNA molecules and bacterial cells, and showed that it is very close to the actual amounts these systems dissipate when replicating. He also showed that RNA, the nucleic acid that many scientists believe served as the precursor to DNA-based life, is a particularly cheap building material. Once RNA arose, he argues, its “Darwinian takeover” was perhaps not surprising.

The chemistry of the primordial soup, random mutations, geography, catastrophic events and countless other factors have contributed to the fine details of Earth’s diverse flora and fauna. But according to England’s theory, the underlying principle driving the whole process is dissipation-driven adaptation of matter.

This principle would apply to inanimate matter as well. “It is very tempting to speculate about what phenomena in nature we can now fit under this big tent of dissipation-driven adaptive organization,” England said. “Many examples could just be right under our nose, but because we haven’t been looking for them we haven’t noticed them.”

Scientists have already observed self-replication in nonliving systems. According to new research led by Philip Marcus of the University of California, Berkeley, and reported in Physical Review Letters in August, vortices in turbulent fluids spontaneously replicate themselves by drawing energy from shear in the surrounding fluid. And in a paper appearing online this week in Proceedings of the National Academy of Sciences, Michael Brenner, a professor of applied mathematics and physics at Harvard, and his collaborators present theoretical models and simulations of microstructures that self-replicate. These clusters of specially coated microspheres dissipate energy by roping nearby spheres into forming identical clusters. “This connects very much to what Jeremy is saying,” Brenner said.

Besides self-replication, greater structural organization is another means by which strongly driven systems ramp up their ability to dissipate energy. A plant, for example, is much better at capturing and routing solar energy through itself than an unstructured heap of carbon atoms. Thus, England argues that under certain conditions, matter will spontaneously self-organize. This tendency could account for the internal order of living things and of many inanimate structures as well. “Snowflakes, sand dunes and turbulent vortices all have in common that they are strikingly patterned structures that emerge in many-particle systems driven by some dissipative process,” he said. Condensation, wind and viscous drag are the relevant processes in these particular cases.

“He is making me think that the distinction between living and nonliving matter is not sharp,” said Carl Franck, a biological physicist at Cornell University, in an email. “I’m particularly impressed by this notion when one considers systems as small as chemical circuits involving a few biomolecules.”
Snowflake

Wilson Bentley

If a new theory is correct, the same physics it identifies as responsible for the origin of living things could explain the formation of many other patterned structures in nature. Snowflakes, sand dunes and self-replicating vortices in the protoplanetary disk may all be examples of dissipation-driven adaptation.

England’s bold idea will likely face close scrutiny in the coming years. He is currently running computer simulations to test his theory that systems of particles adapt their structures to become better at dissipating energy. The next step will be to run experiments on living systems.

Prentiss, who runs an experimental biophysics lab at Harvard, says England’s theory could be tested by comparing cells with different mutations and looking for a correlation between the amount of energy the cells dissipate and their replication rates. “One has to be careful because any mutation might do many things,” she said. “But if one kept doing many of these experiments on different systems and if [dissipation and replication success] are indeed correlated, that would suggest this is the correct organizing principle.”

Brenner said he hopes to connect England’s theory to his own microsphere constructions and determine whether the theory correctly predicts which self-replication and self-assembly processes can occur — “a fundamental question in science,” he said.

Having an overarching principle of life and evolution would give researchers a broader perspective on the emergence of structure and function in living things, many of the researchers said. “Natural selection doesn’t explain certain characteristics,” said Ard Louis, a biophysicist at Oxford University, in an email. These characteristics include a heritable change to gene expression called methylation, increases in complexity in the absence of natural selection, and certain molecular changes Louis has recently studied.

If England’s approach stands up to more testing, it could further liberate biologists from seeking a Darwinian explanation for every adaptation and allow them to think more generally in terms of dissipation-driven organization. They might find, for example, that “the reason that an organism shows characteristic X rather than Y may not be because X is more fit than Y, but because physical constraints make it easier for X to evolve than for Y to evolve,” Louis said.

“People often get stuck in thinking about individual problems,” Prentiss said.  Whether or not England’s ideas turn out to be exactly right, she said, “thinking more broadly is where many scientific breakthroughs are made.”

[Buckaroo Banzai]

Por essa reportagem, parece apenas empolgação exagerada com algo que não deve ter muita utilidade em prever qualquer coisa de evolução ou mesmo origem da vida.

Colocam a coisa como, "é uma tendência natural do influxo de energia sobre certos tipos de matéria", você pergunta, "ok, então por que calha de aparentemente só haver vida na Terra? Ela recebeu mais energia ou o que", "er, bem... humm... é que... não é bem assim... a energia... er... agora tenho que ir..."

Se no entanto a idéia prever algo como que vão achar vidas nos outros planetas daqui, e isso for verificado, eu compro um chapéu de chocolate e como.

[AlienígenA]

Ou, pelo menos, vão achar vida noutros planetas com condições tais, por exemplo, água.

[Gigaview]

O cara é bom...

http://www.englandlab.com/curriculum-vitae.html

[Feliperj]

"England’s theory is meant to underlie, rather than replace, Darwin’s theory of evolution by natural selection, which provides a powerful description of life at the level of genes and populations. “I am certainly not saying that Darwinian ideas are wrong,” he explained. “On the contrary, I am just saying that from the perspective of the physics, you might call Darwinian evolution a special case of a more general phenomenon.”

Bom, acho que independentemente da teoria dele estar certa ou não, isto seja uma verdade!

[_tiago]

Li por cima, mas a perspectiva do cara é interessante. Basicamente, pelo pouco que entendi, a vida se criou pois organismos vivos dispersam melhor a energia do meio onde se encontram.

The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy.
(...)
At the heart of England’s idea is the second law of thermodynamics, also known as the law of increasing entropy or the “arrow of time.” Hot things cool down, gas diffuses through air, eggs scramble but never spontaneously unscramble; in short, energy tends to disperse or spread out as time progresses. Entropy is a measure of this tendency, quantifying how dispersed the energy is among the particles in a system, and how diffuse those particles are throughout space(...) As particles in a system move around and interact, they will, through sheer chance, tend to adopt configurations in which the energy is spread out. Eventually, the system arrives at a state of maximum entropy called “thermodynamic equilibrium,” in which energy is uniformly distributed.
(...)
Using Jarzynski and Crooks’ formulation, he derived a generalization of the second law of thermodynamics that holds for systems of particles with certain characteristics: The systems are strongly driven by an external energy source such as an electromagnetic wave, and they can dump heat into a surrounding bath. This class of systems includes all living things. England then determined how such systems tend to evolve over time as they increase their irreversibility. “We can show very simply from the formula that the more likely evolutionary outcomes are going to be the ones that absorbed and dissipated more energy from the environment’s external drives on the way to getting there,” he said. The finding makes intuitive sense: Particles tend to dissipate more energy when they resonate with a driving force, or move in the direction it is pushing them, and they are more likely to move in that direction than any other at any given moment.

“This means clumps of atoms surrounded by a bath at some temperature, like the atmosphere or the ocean, should tend over time to arrange themselves to resonate better and better with the sources of mechanical, electromagnetic or chemical work in their environments,” England explained.

Self-Replicating Sphere Clusters: According to new research at Harvard, coating the surfaces of microspheres can cause them to spontaneously assemble into a chosen structure, such as a polytetrahedron (red), which then triggers nearby spheres into forming an identical structure.

Self-replication (or reproduction, in biological terms), the process that drives the evolution of life on Earth, is one such mechanism by which a system might dissipate an increasing amount of energy over time. As England put it, “A great way of dissipating more is to make more copies of yourself.” In a September paper in the Journal of Chemical Physics, he reported the theoretical minimum amount of dissipation that can occur during the self-replication of RNA molecules and bacterial cells, and showed that it is very close to the actual amounts these systems dissipate when replicating. He also showed that RNA, the nucleic acid that many scientists believe served as the precursor to DNA-based life, is a particularly cheap building material. Once RNA arose, he argues, its “Darwinian takeover” was perhaps not surprising.

Fonte: a mesma!

[Buckaroo Banzai]

Maneira extremamente teleológica de colocar...

Eu tenho a impressão que não diz nada além de que "a origem da vida nada mais é do que o caminho de menor esforço", o que creio que não é exatamente novidade (a menos que a idéia de "pockets" de diminuição de entropia não se enquadre nisso, o que eu acho que não é o caso), ao mesmo tempo em que não parece sugerir qualquer pista adicional sobre como exatamente ocorreu, uma linha de pesquisa. A contribuição para evolução em si parece ainda mais ínfima, só um fraseamento termodinâmico de "aptidão".

[_tiago]

Maneira extremamente teleológica de colocar...

Sim, e daí? Inclusive no meu comentário consta um "basicamente". Não sei se entendi bem o que você quis dizer com isso.
Se você espera um comentário meu a respeito dessa proposta, não sei o que afirmar. É só uma perspectiva "da física" sobre como a vida pode ter surgido. A meu ver faz sentido e complementa a Teoria da Evolução, formando uma espécie de fundamento e uma razão para o porquê da vida ter surgido. Ainda que quando ele começa a falar que "a melhor forma de gastar energia é se reproduzindo" eu fique com a impressão de que é somente uma explicação diferente pra um mesmo fato, qual seja, a reprodução, e por isso pouco acrescente ao debate.
Se você está a comentar a ideia do fulano, que a ideia dele é extremamente teleológica, não entendi sua crítica.

[1] Eu tenho a impressão que não diz nada além de que "a origem da vida nada mais é do que o caminho de menor esforço", o que creio que não é exatamente novidade (a menos que a idéia de "pockets" de diminuição de entropia não se enquadre nisso, o que eu acho que não é o caso), [2] ao mesmo tempo em que não parece sugerir qualquer pista adicional sobre como exatamente ocorreu, uma linha de pesquisa. [3] A contribuição para evolução em si parece ainda mais ínfima, só um fraseamento termodinâmico de "aptidão".

[1] Não é novidade, e nem precisa ser, muito menos vejo a necessidade em ser, afinal é só uma forma de se entender um fenômeno (aliás, uma proposta!). Inclusive, a ideia nem é plenamente aceita. Tem muito ainda a correr por debaixo dos papers.
[2] Por que não? Talvez agora tenham um novo caminho a seguir sobre o surgimento da vida, ao invés do puro acaso na tal sopa primordial (a bem da verdade, li uma vez no Gene Egoísta algo sobre "moléculas buscando estabilidade"). Ele colocou conceitos nesse mesmo lugar, definindo os termos e a mecânica da coisa. A meu ver a coisa ficou bem explicada, razoável e, na minha visão de quem pouco entende sobre o surgimento da vida, cheia de "sentido". Ainda que dependa do acaso, ao menos a mecância da coisa ficou compreensiva. Saber os reflexos dessa ideia pro futuro, se terá ou não utilidade, dificil concluir algo a partir de um artigo de imprensa.
[3] Lendo seus dois posts fico com a impressão que vc tá fazendo, até agora, e em sua maior parte, mero juízo de valor, do tipo: "ideia boba do cara, termodinâmica em processos biológicos? pra quê, num precisa".

[Buckaroo Banzai]

O problema de uma explicação ou fraseamento teleológico é que acaba na verdade não sendo explicação alguma, mas só a afirmação de que as coisas acontecem "para" ocasionar suas conseqüências. E pode até acabar em raciocínios equivocados como "teoria de Gaia".


Não sei se dá para se caracterizar a visão "anterior" da origem da vida como "puro acaso", ou essa contribuição como reduzindo significativamente o papel do acaso.


O meu "juízo de valor" não é exatamente quanto a idéia, mas o "hype", exagero em torno, de algo que nem é na visão geral realmente novo -- se alguma vez foi proposto algo que realmente fosse diferente; eu suponho que qualquer idéia que tenha sido minimamente levada a sério nunca teria suposto uma "violação" da termodinâmica, mesmo que a abordagem não procurasse ver as coisas por esse "nível" de explicação, geralmente se preocupando mais com o que de fato teria ocorrido, e não em enfatizar não ter sido uma violação de qualquer lei física. Vitalismo acabou faz tempo.

Mathematical and Computer Modelling
Volume 19, Issues 6–8, March–April 1994, Pages 25–48

Life as a manifestation of the second law of thermodynamics ☆
E.D. Schneider∗
Hawkwood Institute P.O. Box 1017, Livingston, MT 59047, USA
J.J. Kay∗
Environment and Resource Studies, University of Waterloo Waterloo, Ontario, Canada, N2L 3G1
  Open Archive
Abstract
We examine the thermodynamic evolution of various evolving systems, from primitive physical systems to complex living systems, and conclude that they involve similar processes which are phenomenological manifestations of the second law of thermodynamics. We take the reformulated second law of thermodynamics of Hatsopoulos and Keenan and Kestin and extend it to nonequilibrium regions, where nonequilibrium is described in terms of gradients maintaining systems at some distance away from equilibrium.

The reformulated second law suggests that as systems are moved away from equilibrium they will take advantage of all available means to resist externally applied gradients. When highly ordered complex systems emerge, they develop and grow at the expense of increasing the disorder at higher levels in the system's hierarchy. We note that this behaviour appears universally in physical and chemical systems. We present a paradigm which provides for a thermodynamically consistent explanation of why there is life, including the origin of life, biological growth, the development of ecosystems, and patterns of biological evolution observed in the fossil record.

We illustrate the use of this paradigm through a discussion of ecosystem development. We argue that as ecosystems grow and develop, they should increase their total dissipation, develop more complex structures with more energy flow, increase their cycling activity, develop greater diversity and generate more hierarchical levels, all to abet energy degradation. Species which survive in ecosystems are those that funnel energy into their own production and reproduction and contribute to autocatalytic processes which increase the total dissipation of the ecosystem. In short, ecosystems develop in ways which systematically increase their ability to degrade the incoming solar energy. We believe that our thermodynamic paradigm makes it possible for the study of ecosystems to be developed from a descriptive science to predictive science founded on the most basic principle of physics.

Acho que as primeiras considerações mais explícitas/diretas são de Schrodinger, em "what is life", de 1940.

http://en.wikipedia.org/wiki/What_Is_Life%3F

[_tiago]

O problema de uma explicação ou fraseamento teleológico é que acaba na verdade não sendo explicação alguma, mas só a afirmação de que as coisas acontecem "para" ocasionar suas conseqüências. E pode até acabar em raciocínios equivocados como "teoria de Gaia".

Você me definiu teleologia, mas não as razões da sua impressão. A perspectiva apresentada não explica o surgimento da vida?

Não sei se dá para se caracterizar a visão "anterior" da origem da vida como "puro acaso", ou essa contribuição como reduzindo significativamente o papel do acaso.

Não sei se ela reduz, ela pretende explicar a mecânica da coisa.

O meu "juízo de valor" não é exatamente quanto a idéia, mas o "hype", exagero em torno, de algo que nem é na visão geral realmente novo -- se alguma vez foi proposto algo que realmente fosse diferente; eu suponho que qualquer idéia que tenha sido minimamente levada a sério nunca teria suposto uma "violação" da termodinâmica, mesmo que a abordagem não procurasse ver as coisas por esse "nível" de explicação, geralmente se preocupando mais com o que de fato teria ocorrido, e não em enfatizar não ter sido uma violação de qualquer lei física. Vitalismo acabou faz tempo.

A ideia não é nova, realmente, inclusive no texto eles mostram o desenvolvimento dela até a sacada do England, que ainda me é confusa, mas, ao que parece, seria explicada aqui:

Using Jarzynski and Crooks’ formulation, he derived a generalization of the second law of thermodynamics that holds for systems of particles with certain characteristics: The systems are strongly driven by an external energy source such as an electromagnetic wave, and they can dump heat into a surrounding bath. This class of systems includes all living things. England then determined how such systems tend to evolve over time as they increase their irreversibility. “We can show very simply from the formula that the more likely evolutionary outcomes are going to be the ones that absorbed and dissipated more energy from the environment’s external drives on the way to getting there,” he said. The finding makes intuitive sense: Particles tend to dissipate more energy when they resonate with a driving force, or move in the direction it is pushing them, and they are more likely to move in that direction than any other at any given moment.

Eu preciso ler e pensar, tem muita coisa pra eu entender ainda.

[EuSouOqueSou]

Muito interessante a nova teoria. Ademais, o artigo eh um bom exemplo para mostrar como a Ciencia funciona.

[Buckaroo Banzai]

Eu queria entender o que ela preveria de diferente de qualquer coisa que já se tivesse, em particular  das idéias desse outro paper de 20 anos atrás que postei.

[_tiago]

Talvez nada, Buck, da termodinâmica só sei que existe e dessa ideia, simplesmente gostei dela pois não a conhecia. Quer provar que a ideia é em nada original, porque sabe-se lá como essa certeza ou talvez percepção há de satisfazer algo em você, ótimo!

[EuSouOqueSou]

Tem outro detalhe. O artigo nao mostra, mas cita que ele desenvolveu uma formula matematica para prever esse fenomeno. Creio que isso eh o diferencial, o que da alguma originalidade e, mais importante, uma maneira de provar se estar certo ou nao.

Buck, se for fazer mimimi disso, deveria reclamar tbm de Newton que usou estudos de Copernico, Galileu e Kepler. E deveria reclamar tbm de Darwin usou estudos de cientistas de diversas areas, viajou pelo mundo e chegou a mesma conclusao que Wallace. Mas so Darwin eh lembrado, quanta injustica.

[Buckaroo Banzai]

É argumentavel que Darwin está fundamentalmente errado, mas um certo culto de personalidade acaba tornando dizer isso uma espécie de heresia. E para complicar, é pedir para ser mal interpretado/distorcido por criacionistas, uma vez que "darwinismo" virou sinônimo de "evolução". Sim, tem "hype" até aqui.



Ah, e não estou "reclamando" de se basear em conhecimento anterior. Só queria entender o que há de novo, uma vez que, tirando essa fórmula, não parece haver nenhuma "teoria nova" aí.

[_tiago]

E daí, Buck? Não por acaso isso é comentado no texto, que se trata da evolução de uma ideia, ainda que o título seja exagerado. E meu, isso é um artigo de divulgação, sei lá qual o título da tese do cara.

[Buckaroo Banzai]

"E daí"?

Daí "nada". Só não percebo o que haveria de novo aí, apesar da coisa estar sendo colocada como tal ("new physics theory of life"), e então fico com curiosidade sobre isso. Teria uma fórmula, OK, gostaria de saber o que exatamente ela preveria. Mesmo se não prever nada 100% novo ainda pode ser interessante (pela perspectiva/abordagem em um nível mais fundamental), o problema é que está bem vago o que seria.

Não quis magoar ninguém, me desculpem.






Provavelmente o artigo completo:

http://scitation.aip.org/content/aip/journal/jcp/139/12/10.1063/1.4818538

[Feliperj]

Ola Pessoal,

Uma coisa que não sei se é abordada neste texto; essa nova teoria, para ser mais "concreta" não deveria prever em que "faixa energética" determinados elementos irão evoluir para algo vivo? Claro que, em áreas do universo que já atingiram equilíbrio termodinamico (ou algo proximo a isso), ela deve prever a não evolução dos elementos para algo vivo (ela faz isso?); da mesma forma, deveria prever em que faixa isso seria esperável. Sabemos, observando a vida na terra que, talvez, a zona habitável seja maior do que originalmente pensávamos (extremófilos). Esta teoria deveria prever algo assim, não?

Abs
Felipe

[Buckaroo Banzai]

A impressão que eu tive de dar uma olhada rápida sobre o texto do artigo em si é que a coisa se resume (resumindo muito mesmo) a ter uma fórmula que verifica que a eficência da reprodução das bactérias analisadas é altíssima, e alguma coisa sobre uma vantagem de RNA sobre DNA como base para origem da vida; apesar de maior fragilidade, teria um custo menor, podendo se reproduzir mais numerosamente, e ser maior.

Não tem essas pretensões de dizer onde vai haver vida e tudo mais, sendo muito exagero toda essa coisa de "nova teoria para a origem da vida" e etc.

[_tiago]

Não quis magoar ninguém, me desculpem.

Terceira pessoa do plural foi ótimo!
E relaxa, vc não me magoou.

[AlienígenA]

Eu entendi, resumidamente, que sempre que o meio fornecer condições mínimas para a ocorrencia de vida, ela vai ocorrer, obedecendo as leis da termonidinamica - o que não me parece em princípio trazer implicações diretas para a teoria evolutiva, mas para certas interpretações feitas a partir dela.

[_tiago]

Eu fiquei mais pro: a segunda lei seria uma indutora de vida, visto que organismos complexos são mais eficientes na dispersão de energia, principalmente quando se reproduzem.

[AlienígenA]

Também, só que sob certas condições e/ou a partir de certas condições.

[_tiago]

Condicionantes ali é um sol e um ambiente muito "energético".

[Entropia]

Condicionantes ali é um sol e um ambiente muito "energético".

Só isso? Não depende das propriedades físicas e químicas dos elementos? Da estabilidade dos produtos complexos mais eficientes em dissipacão de energia? Pelo que o texto deu a entender, basta você ter uma amostra de  Quaisquer elementos, você bota ele sob certas condicões e eles vão "dar um jeito" de ser organizar, ignorando suas propriedades. Eu espero ter entendido errado.

EDIT: Fui trollado pela reportagem, ignore este post.