Is the planet "broken" and did that cause the evolution of predation?

Discussion in 'Biology & Genetics' started by Wexler, Jun 21, 2015.

  1. rpenner Fully Wired Staff Member

    Messages:
    4,833
    Stellar Interiors: Physical Principles, Structure, and Evolution gives the time on the Main Sequence as roughly \(T_{\textrm{Main Sequence}} \propto \frac{M}{L} \). It makes sense, because if you burn up a percentage of your nuclear fuel big enough to matter, you can't maintain your original structure and fall off the Main Sequence.

    Evolution of Stars and Stellar Populations (2005) gives
    \(L \propto \left\{ \begin{array}{ccl} M^{2.6} & \quad & 0.2 M_{\odot} < M < 0.5 M_{\odot} \\ M^{4.5} & \quad & 0.5 M_{\odot} < M < 2 M_{\odot} \\ M^{3.6} & \quad & 2 M_{\odot} < M < 20 M_{\odot} \\ M & \quad & 20 M_{\odot} < M \end{array} \right. \)

    Expressed another way:
    \(\frac{L}{L_{\odot}} \approx \left\{ \begin{array}{ccl}\frac{56}{209} \left( \frac{M}{M_{\odot}} \right)^{2.6} & \quad & 0.2 M_{\odot} < M < 0.5 M_{\odot} \\ \left( \frac{M}{M_{\odot}} \right)^{4.5} & \quad & 0.5 M_{\odot} < M < 2 M_{\odot} \\ \frac{209}{112} \left( \frac{M}{M_{\odot}} \right)^{3.6} & \quad & 2 M_{\odot} < M < 20 M_{\odot} \\ 4504 \left( \frac{M}{M_{\odot}} \right) & \quad & 20 M_{\odot} < M \end{array} \right.\)

    So
    \(T_{\textrm{Main Sequence}} \approx \left\{ \begin{array}{rcl} (37 \, \textrm{Ga}) \left( \frac{M}{M_{\odot}} \right)^{-1.6} & \quad & 0.2 M_{\odot} < M < 0.5 M_{\odot} \\ (10 \, \textrm{Ga}) \left( \frac{M}{M_{\odot}} \right)^{-3.5} & \quad & 0.5 M_{\odot} < M < 2 M_{\odot} \\ (5.4 \, \textrm{Ga}) \left( \frac{M}{M_{\odot}} \right)^{-2.6} & \quad & 2 M_{\odot} < M < 20 M_{\odot} \\ 2.2 \, \textrm{Ma} & \quad & 20 M_{\odot} < M \end{array} \right.\)

    Thus, stars more massive than about \(6.06 \, M_{\odot}\) are expected to spend less than 50 million years on the main sequence.

    \(\begin{array}{c|c} \frac{M}{M_{\odot}} & \frac{ T_{\textrm{Main Sequence}} }{ 1 \, \textrm{Ga} } \\ \hline \\ 0.2 & 490 \\ 0.4 & 110 \\ 0.6 & 60. \\ 0.8 & 22 \\ 1.0 & 10. \\ 1.5 & 2.4 \\ 2.0 & 0.88 \\ 4.0 & 0.15 \\ 6.0 & 0.051 \\ 9.0 & 0.018 \\ 14 & 0.0057 \\ 20 & 0.0022 \end{array} \)

    Big, bright stars are short-lived. [Insert gratuitous reference to Hollywood celebrities here.]
     
    Last edited: Jul 2, 2015
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Wexler Gadfly Registered Senior Member

    Messages:
    114
    Iron core leaking into the early ocean = possible impact in the formation of the primordial cell.

    @ 5:00 (1)...there could be 1bn earth like planets orbiting sun-like stars in this galaxy...microbial life can live in incredibly harsh and diverse environments...there could be life on those planets...easy for life to emerge...

    @ 30:00 (1) ...self assembling molecules...various materials...into nucleotides...

    @ 28:00 (2) ...Darwinian selection: competition between protocells...based on a transition to the absorption of phospolibids...absorption of neighboring fatty acid vesicle...he uses "eating" colloquially.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Wexler Gadfly Registered Senior Member

    Messages:
    114
    So we have a potential 1Bn earth like planets in this galaxy alone...each one with a potentially vastly different core than Earth...

    "A major factor controlling the evolution of a planet is how its ingredients melt. These ingredients include silica, "the main constituent of rock," said lead study author Marius Millot, a physicist at Lawrence Livermore National Laboratory in Livermore, California.

    Melting is arguably the most important process that determines how the interiors of planets evolve. For instance, melting determines whether or not the innards of a rocky planet such as Earth separate into a crust, mantle and core. In addition, the magnetic fields of planets result from the churning of electrically conductive fluids such as molten iron. Magnetic fields could help protect the atmospheres of planets from getting stripped away by winds of particles from their host stars, and therefore may prove vital to theevolution of life.

    The extreme pressures found inside planets can greatly modify the melting temperatures and other properties of their constituent materials.

    "Pressure squeezes atoms together, modifying their properties in ways that can be quite hard to predict," Millot said.

    The innards of super-Earths and giant planets experience much higher pressure than Earth's because they have more mass squeezing inward. However, it was uncertain what effects such conditions might have on the properties of the interiors of these planets, since it is very difficult to generate such extraordinarily high pressures on Earth."


    We have the general understanding that not all planets evolve the same way, and we know that cores can be modified by size of the planet.




     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. exchemist Valued Senior Member

    Messages:
    6,637
    Well yes, but I see do not see what any of this has to do with your contention that terrestrial organisms only eat other organisms because something on Earth is "broken" (whatever "broken" means in this context - it sounds tendentious to me).

    As I said earlier, it seems likely to me that organisms may find it more efficient to harvest the biochemicals they need already pre-synthesised, if they have the chance. And consuming other organisms that use the same biochemical building blocks in their bodies seems an obvious strategy - just the sort of thing that one might expect natural selection to amplify, once it has occurred.
     
  8. Wexler Gadfly Registered Senior Member

    Messages:
    114
    I am not arguing against the possibility of the "strategy" for survival, and for natural selection to amplify...in fact, quite the contrary.

    I guess another way to try to present my argument is the possibility that organisms are a reflection of an environment they evolve in...thus why I keep going back to the number of potential suns, the number of potential habitable planets, how life is "easy" to start, how life could start from other molecules, and then ultimately resources and environment...all that adds up to behavior of the life form...a survival strategy if you will.
     
  9. exchemist Valued Senior Member

    Messages:
    6,637
    Well if all you are trying to say is that there must be numerous alternative paths for life evolving on various planets to take, I don't think anyone could disagree. But you seemed earlier to be saying something far more specific, namely that things eating each other only arises due to the stress imposed by scarcity of resources. And I am explaining why I think that idea does not stand up.
     
    Kristoffer likes this.
  10. Wexler Gadfly Registered Senior Member

    Messages:
    114
    Not just a scarcity of resources...it could be environment (like a "broken" planet)...it could be energy source (like an average sun)...it could be a multitude of factors...

    (Sorry, I am rushing through this...but...and it probably belongs in the "philosophy" part of the forum...)

    To be fair, I should explain where this all came from...I was thinking about Fermi's Paradox...

    • The Sun is a typical star. There are billions of stars in the galaxy that are billions of years older.
    • With high probability, some of these stars will have Earth-like planets.[2][3] Assuming the Earth is typical, some of these planets may develop intelligent life.
    • Some of these civilizations may develop interstellar travel, a technology Earth is investigating even now (such as the 100 Year Starship).
    • Even at the slow pace of currently envisioned interstellar travel, the galaxy can be completely colonized in a few tens of millions of years.
    According to this line of thinking, the Earth should already have been visited by extraterrestrial aliens.

    And then The Great Filter...

    The Great Filter
    With no evidence of intelligent life other than ourselves, it appears that the process of starting with a star and ending with "advanced explosive lasting life" must be unlikely. This implies that at least one step in this process must be improbable. Hanson's list, while incomplete, describes the following nine steps in an "evolutionary path" that results in the colonization of the observable universe:

    1. The right star system (including organics and potentially habitable planets)
    2. Reproductive molecules (e.g., RNA)
    3. Simple (prokaryotic) single-cell life
    4. Complex (archaeatic and eukaryotic) single-cell life
    5. Sexual reproduction
    6. Multi-cell life
    7. Tool-using animals with big brains
    8. Where we are now
    9. Colonization explosion.

    And that the only thing that keeps us from step 9 is "catastrophe"...either self induced or by a more "advanced" life form...and that's what got this idea going...


    I kept asking why would another life form in the universe want to proactively terminate another life form?


    The only thing I kept coming back to was "behavior" of those life forms...both on this planet and others (and in the case of others, it might just be that we are projecting our own behavior on them)...it's like why would anyone want to eliminate someone from a conversation? Behavior. Quite simply, the Earth "peoples", if you will, like an apple tree produces apples.


    Since we have a general knowledge of life on this planet, I kept going backwards through evolution...and a repetitive pattern kept coming up...resources and catastrophe...all the way back to the start of life and the formation of this planet.

    So what if we were to eliminate the catastrophe element, from the formation of the planet to today, and the resources we much more stable? Would life have evolved "differently"? I say absolutely.

    Another thing I kept seeing was that when the environment was "nurturing" reproduction flourished. If the environment was more stable, would life have evolved "differently"? I say absolutely.

    7 major catastrophic extinction events (counting the oxydation event)...99% of all life forms wiped out...a wet planet that possibly already had life forms, and a core formed in part out of collision...that created all these instability factors for the environment...thus, "broken"...which I could have probably used a better word...but maybe it was a good "headline" to get the conversation going?

    Please Register or Log in to view the hidden image!



    I realize this explanation probably didn't help my cause...again, I'm rushing.
     
  11. Wexler Gadfly Registered Senior Member

    Messages:
    114
    That was pretty sloppy, but none the less explains most of it...one of the things I forgot to mention was the concept of what would the planet look like 65M light years away? It would not reveal humans, but dinosaurs...eating each other...and that as part of The Great Filter exercise, if those aliens that were to take a look at life on this planet, they would see a planet filled with odd creatures eating each other...the further back in time...or better yet, the further they are away from the planet, the more they would see things eating each other...that, and the sequence of incredible extinction events...
     
  12. Wexler Gadfly Registered Senior Member

    Messages:
    114
    For the lazy guy accusing me of "trolling"...read this...

    1. In mathematics, a self-similar object is exactly or approximately similar to a part of itself (i.e. the whole has the same shape as one or more of the parts). Many objects in the real world, such as coastlines, are statistically self-similar: parts of them show the same statistical properties at many scales.
    What if that's true for the Universe? That there is some form of pattern of Self Similarity?

    Next, read this...it's the transcript of that TED video...and the explanation of scaling...


    Despite the fact that this is the most complex and diverse system in the universe, there's an extraordinary simplicity being expressed by this. It's particularly astonishing because each one of these organisms, each subsystem, each cell type, each gene, has evolved in its own unique environmental niche with its own unique history. And yet, despite all of that Darwinian evolution and natural selection,they've been constrained to lie on a line.

    7:22Something else is going on. Before I talk about that, I've written down at the bottom there the slope of this curve, this straight line. It's three-quarters, roughly, which is less than one -- and we call that sublinear. And here's the point of that. It says that, if it were linear, the steepest slope, then doubling the size you would require double the amount of energy. But it's sublinear, and what that translates into is that, if you double the size of the organism, you actually only need 75 percent more energy. So a wonderful thing about all of biology is that it expresses an extraordinary economy of scale. The bigger you are systematically, according to very well-defined rules, less energy per capita. Now any physiological variable you can think of, any life history event you can think of, if you plot it this way, looks like this. There is an extraordinary regularity. So you tell me the size of a mammal, I can tell you at the 90 percent level everything about it in terms of its physiology, life history, etc.

    8:25And the reason for this is because of networks. All of life is controlled by networks -- from the intracellular through the multicellular through the ecosystem level. And you're very familiar with these networks.That's a little thing that lives inside an elephant. And here's the summary of what I'm saying. If you take those networks, this idea of networks, and you apply universal principles, mathematizable, universal principles, all of these scalings and all of these constraints follow, including the description of the forest,the description of your circulatory system, the description within cells. One of the things I did not stress in that introduction was that, systematically, the pace of life decreases as you get bigger. Heart rates are slower; you live longer; diffusion of oxygen and resources across membranes is slower, etc.

    9:19The question is: Is any of this true for cities and companies? So is London a scaled up Birmingham,which is a scaled up Brighton, etc., etc.? Is New York a scaled up San Francisco, which is a scaled up Santa Fe? Don't know. We will discuss that. But they are networks, and the most important network of cities is you. Cities are just a physical manifestation of your interactions, our interactions, and the clustering and grouping of individuals. Here's just a symbolic picture of that. And here's scaling of cities.This shows that in this very simple example, which happens to be a mundane example of number of petrol stations as a function of size -- plotted in the same way as the biology -- you see exactly the same kind of thing.

    10:09There is a scaling. That is that the number of petrol stations in the city is now given to you when you tell me its size. The slope of that is less than linear. There is an economy of scale. Less petrol stations per capita the bigger you are -- not surprising. But here's what's surprising. It scales in the same way everywhere. This is just European countries, but you do it in Japan or China or Colombia, always the same with the same kind of economy of scale to the same degree. And any infrastructure you look at --whether it's the length of roads, length of electrical lines -- anything you look at has the same economy of scale scaling in the same way. It's an integrated system that has evolved despite all the planning and so on. But even more surprising is if you look at socio-economic quantities, quantities that have no analog in biology, that have evolved when we started forming communities eight to 10,000 years ago. The top one is wages as a function of size plotted in the same way. And the bottom one is you lot -- super-creatives plotted in the same way. And what you see is a scaling phenomenon. But most important in this, the exponent, the analog to that three-quarters for the metabolic rate, is bigger than one -- it's about 1.15 to 1.2. Here it is, which says that the bigger you are the more you have per capita, unlike biology -- higher wages, more super-creative people per capita as you get bigger, more patents per capita, more crime per capita.

    11:46And we've looked at everything: more AIDS cases, flu, etc. And here, they're all plotted together. Just to show you what we plotted, here is income, GDP -- GDP of the city -- crime and patents all on one graph.And you can see, they all follow the same line. And here's the statement. If you double the size of a city from 100,000 to 200,000, from a million to two million, 10 to 20 million, it doesn't matter, then systematically you get a 15 percent increase in wages, wealth, number of AIDS cases, number of police,anything you can think of. It goes up by 15 percent, and you have a 15 percent savings on the infrastructure. This, no doubt, is the reason why a million people a week are gathering in cities. Because they think that all those wonderful things -- like creative people, wealth, income -- is what attracts them,forgetting about the ugly and the bad.

    12:46What is the reason for this? Well I don't have time to tell you about all the mathematics, but underlying this is the social networks, because this is a universal phenomenon. This 15 percent rule is true no matter where you are on the planet -- Japan, Chile, Portugal, Scotland, doesn't matter. Always, all the data shows it's the same, despite the fact that these cities have evolved independently. Something universal is going on. The universality, to repeat, is us -- that we are the city. And it is our interactions and the clustering of those interactions. So there it is, I've said it again. So if it is those networks and their mathematical structure, unlike biology, which had sublinear scaling, economies of scale, you had the slowing of the pace of life as you get bigger. If it's social networks with super-linear scaling -- more per capita -- then the theory says that you increase the pace of life. The bigger you are, life gets faster. On the left is the heart rate showing biology. On the right is the speed of walking in a bunch of European cities, showing that increase.



    Now, could the mathematics of scaling possibly apply to planets and suns? My guess is "yes". As I said earlier in the thread, it's all about the math.

    50,000,000,000,000,000,000,000,0000 possible planets that are habitable in the universe.
    1,000,000,000,000,000,000,000 stars in the universe.


    That's not trolling, it's math.
     
  13. rpenner Fully Wired Staff Member

    Messages:
    4,833
    When you eat a salad, you are eating lifeforms. So Wexler's non-broken ideal biome would consist only of autotrophs and scavengers of the dead. But that is a ridiculous world, from the viewpoint of natural selection. Only autotrophs would lead to a green hell of life clamoring to monopolize every last square inch of sunlight or every last drop of chemical nutrition while climbing on top or around of the dead of the past. With scavengers, they need some way to break down and ingest the dead. In short, a mouth analogue -- something for which no natural barrier exists to predation on the living. It's unstable against evolution, and thus inherently broken as a model of how planetary life should be.

    Wexler's non-broken ideal biome has no fruits. Successful fruits are tasty and nutritious for others to ingest with the main benefit of scattering the seeds of one's own offspring. Thus evolution shapes predation into a mutually beneficial relationship. Likewise, the mutualism of elaborate flowers and pollenating insects likely arose from behavior that would best be described as predation.

    Does Wexler's non-broken ideal biome support philosophical thought? Or intelligence? What need is there for more than simple photo- or chemo-tropism in a world free from predation? If nothing is hunting you, is there a need to run? If there is no need to run, is there a need for optical imaging of one's environment? And if there is no need to see rainbows and stars, is there a need for a brain to wonder about them? Evolution is not an ascent up the Great Chain of Being -- while complexity of organisms tends to increase over time, functionality which is expensive to maintain with no benefit to survival of the population is strongly selected against. So the example of blind cave fish suggests eyesight and intelligence are "use it or lose it" propositions.

    Is Wexler's non-broken ideal biome free from theft and murder? Cannot unthinking vines strangle a slower-growing tree? Does not the Eucalyptus poison the soil about it to thwart the competition (allelopathy)? Neither of these is predation, but both involve disadvantaging other life for the benefit of the self. Eliminating predation doesn't solve the drives of competition to generate behaviors incompatible with altruistic description.
     
    Hipparchia likes this.
  14. rpenner Fully Wired Staff Member

    Messages:
    4,833
    You badly misunderstood the TED video if you thought it supported your viewpoint. The point was there are scaling laws due to geometry. Geometry of biological multicellular organisms, Geometry of interpersonal networks, Geometry of city infrastructure. Thus it doesn't not support your assertions about what is possible in the universe because each planet is separated, giving the discrete geometry of a single point and no network.

    Did you mean to write \(5 \times 10^{25}\) possible planets or \(5 \times 10^{26}\) ? The last group of zeros has four zeros, which makes your intent unclear.

    In any case, you estimate at least \(\frac{5 \times 10^{25}}{10^{21}} = 5 \times 10^4 = 50,000 \) possible planets per sun. That does not seem compatible with observation.

    Naming numbers is not "math" in the sense you have made no reasoned argument.

    Also, you repeated talk about crustal iron as if it "leaked out of the core" which is a baseless and probably backwards way to think about it. The Earth formed by accretion of rocky and metallic source material which imperfectly melted and imperfectly separated by density. So during the history of life, there always was iron in the biosphere.

    Some iron is introduced into the biosphere via hydrothermal vents, but that represents the action of water leaching iron out of subsurface rocks, not iron leaking from the core.
     
    Last edited: Jul 3, 2015
  15. Wexler Gadfly Registered Senior Member

    Messages:
    114
    It was in response to whatever his assertion was regarding "making up" scaling laws and self-similarity as a form of "trolling".

    I am not disputing any of that...and yes, maybe "leaking" is a wrong word to use...it was a quick reference. I am trying to find the last article I read in which I am pretty sure they used "leaking"...in which is why I wrote it that way.

    Either way, the question is what was the impact of iron on the primordial cell? And yes, I realize our bodies still need iron to function...
     
  16. Wexler Gadfly Registered Senior Member

    Messages:
    114

    Why is any of that a "ridiculous" world?

    None of that is unstable against evolution, in a different, stable and energy / resource rich environment. In a nutshell, that's the point of the initial question - could life have evolved "differently" in a different environment?

    To think that consciousness can only arise based on how life forms arose on this planet feels rather...dogmatic.
     
  17. rpenner Fully Wired Staff Member

    Messages:
    4,833
    There can be no such thing as a resource-rich environment when evolution rewards populations that exploit resources with greater numbers of offspring. It's trivial to abuse language to talk about things that can never be, but the burden is on you to demonstrate such things are possible.

    You can't have purely altruistic populations in a stable evolutionary setup because that altruism is a differentially exploitable resource. Every small betrayal is rewarded in proportion to the betrayal.

    You can't have perfect mutualism and a stable evolutionary setup because 1) inter-population cooperation is a function of conditions, so what is perfect at one time need not be perfect at another and 2) evolution doesn't reward perfection, just better so you only expect to find "good enough" solutions throughout.
     
  18. billvon Valued Senior Member

    Messages:
    12,818
    Because eventually you run out of raw materials. You could have a planet the size of Jupiter containing nothing but sugars and amino acids. Introduce one yeast cell and in a few years every bit of raw material would be inside a yeast cell. Then evolution stops. There is no more raw material no matter how much energy you have. (Other than the raw material inside yeast cells, but since nothing in your hypothetical world can eat them, that's all she wrote.)
     
  19. Wexler Gadfly Registered Senior Member

    Messages:
    114

    I think it might just literally come down to chemistry...and I am not a chemist...the catalytic nucleic acids seem to be the culprit.

    So, on my "world" so to speak, if life formed without nucleic acids (I have no idea how...and don't care to go down the rabbit hole of a discussion), then there is the potential for life to evolve without absorbing, engulfing, consuming, eating...etc. other life forms.


    I get that, and agree, thus why I asked the question in the first place...and despite this thread somehow repeatedly on the verge of devolving into some sort of message board bloodsport, I sincerely appreciate the responses that have challenged the idea. It has helped.
     
  20. Wexler Gadfly Registered Senior Member

    Messages:
    114

    After doing some more reading on the subject, Bill, I realized the issue comes down to chemistry...

    Thanks!
     
  21. Wexler Gadfly Registered Senior Member

    Messages:
    114
    Just found these two articles...before anyone decides they "need" to take me to task with a chemistry lesson, the way I am interpreting the articles is simply that they open to door to the "possibility" of an alternative form of evolution.


    http://io9.com/5903221/meet-xna-the-first-synthetic-dna-that-evolves-like-the-real-thing

    The researchers, led by Philipp Holliger and Vitor Pinheiro, synthetic biologists at the Medical Research Council Laboratory of Molecular Biology in Cambridge, UK, say their findings have major implications in everything from biotherapeutics, to exobiology, to research into the origins of genetic information itself. This represents a huge breakthrough in the field of synthetic biology.

    The "X" Stands for "Xeno"
    Every organism on Earth relies on the same genetic building blocks: the the information carried in DNA. But there is another class of genetic building block called "XNA" — a synthetic polymer that can carry the same information as DNA, but with a different assemblage of molecules.

    The "X" in XNA stands for "xeno." Scientists use the xeno prefix to indicate that one of the ingredients typically found in the building blocks that make up RNA and DNA has been replaced by something different from what we find in nature — something "alien," if you will.

    Please Register or Log in to view the hidden image!





    http://www.newscientist.com/article...-at-life-without-dna-or-rna.html#.VZf79_lVhBc


    Now, they have taken a step closer to mimicking early life on the planet by showing that XNAs can also serve as enzymes – indispensible catalysts for speeding up chemical reactions vital for life.

    One of the first steps towards life on Earth is thought to be the evolution of RNA into self-copying enzymes.

    Big steps
    So by showing that XNAs can act as enzymes, on top of being able to store hereditary information, Holliger has recreated a second major step towards life.

    The XNA enzymes can't yet copy themselves but they can cut and paste RNA, just like natural enzymes do, and even paste together fragments of XNA.

    It's the first demonstration that, like prehistoric RNA, XNA can catalyse reactions on itself, even if it can't yet copy itself as RNA can.

    Holliger argues that RNA and DNA may have come to dominate Earth by chance, simply because they were the best evolutionary materials to hand. "You could speculate that on other planets, XNAs would dominate instead," he says.

    Primal molecules
    "This work is another nice step towards demonstrating the functional capabilities of XNAs," says Nobel prizewinner Jack Szostak of Harvard University, who studies the origins of life on Earth .

    "The possibility that life elsewhere, on exoplanets, could have started with something other than RNA or DNA is quite interesting, but the primordial biopolymer for any form of life must satisfy other constraints as well, such as being something that can be generated by prebiotic chemistry and replicated efficiently," Szostak says. "Whether XNA can satisfy these constraints, as well as providing useful functions, remains an open question."

    Holliger says that XNAs may also have roles to play in medicine. Because they do not occur naturally, they can't be broken down in the human body. And since they can be designed to break and destroy RNA, they could work as drugs for treating RNA viruses or disabling RNA messages that trigger cancers.

    "We've made XNA enzymes that cut RNA at specific sites, so you could make therapies for cleaving viral or oncogenic messenger RNA," says Holliger. "And because they can't be degraded, they could give long-lasting protection."
     
  22. rpenner Fully Wired Staff Member

    Messages:
    4,833
    It's not life until you have homeostasis and reaction to the environment (so that you can distinguish life from non-life, individual from one life form from another, healthy versus sick), and stable multigenerational reproduction (so that the grandchildren are still identifiable as individuals of the same life form).

    Stable multigenerational reproduction requires coordination of materials and a duplication of state. Thus both material control, information transfer and a net influx of energy are required. All that is required for evolution is variation and differential reproductive success. To halt evolution, without killing everything, there needs to be no variation and eternally perfect duplication of state. But that leads to the "green hell" scenario mentioned above, where autotrophs compete for every square millimeter of sunshine and every drop of source materials, and choke to death on their own waste.

    This happens everytime beer is made -- the monoculture yeast reproduces, consumes all food (sugar) to exhaustion and dies out in a pool of its own waste (alcohol and CO₂) without opportunity to find another solution. This happens sometimes when fertilizer is introduced into a lake or ocean -- a mat of algae growth cuts off sunlight and ironically leaves the waters more oxygen-starved before the fertilizer was introduced. A planetary monoculture of perfect clones is not one that can adapt to adversity or take advantage of new food sources.

    It seems to me that your ideal biome is much like Thomas Hobbes' ideal state (as discussed in Leviathan) -- with the will and life-plan of every individual in accord with that of some overseeing authority. We have that (approximately) in biology -- it's the relation between the cells and their multi-cellular life form. It requires every cell to do its job. In humans, it requires cells to die so that we might have individual fingers and tough skin, some cells to generate non-viable offspring offspring so that we might have efficient red blood cells and blood that clots, some cells to eat the dead to make room for more living, and some cells to police the other cells for both infiltrators and turncoats. The authority is not that of the brain, but rather that of the information at the heart of every cell in the organism. Even evolution is made (mostly) subservient to the will of that authority in that the immune system rewards production of effective antibodies in an effort to keep pace with infiltrators and turncoats (cancerous cells). Even the most repressive police states in Earth history only combatted expression of wills not aligned with that of the state -- in Hobbes' ideal the citizens would actually share that central will. Not a lot of room for "liberty" or "academic freedom" or "human rights" in such a state. Probably not inclined to view outsiders kindly.

    Your article doesn't support your claim that evolution of XNA-based life would be qualitatively different than Earthly life in the qualities that matter to your central premise that your aesthetic dislike of predation is a universal value.

    It does, however, strongly support the notion that XNA is a nucleic acid which means your foray into chemistry is clutching at straws.
     
    Last edited: Jul 4, 2015
  23. Wexler Gadfly Registered Senior Member

    Messages:
    114
    I am a Steven Pinker fan (met him twice)...

    Please Register or Log in to view the hidden image!

     

Share This Page