Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How did evolution begin?

  1. Aug 17, 2007 #1
    Dear Zapper,

    I have read about evolution and agree with its explainations, atleast to the most part. My question is a bit deeper than the pressures of the environment.

    The universe is made up of all these tiny "particles" (lets keep the wave nature aside for the moment) and they formed atoms and molecules and so on. Cosmos took shape (how ever improbable that is) and in that, our little tiny planet earth, and there were conditions(arguably) that were conducive for the creation of a bunch of molecules who could replicate themselves. From then on, it is said that natural selection takes over and ensures that the "fittest" survive. Its a mechanism by elimination, and eliminating the weak, it keeps the strong going and again selects from within the strong and so on. (Ignoring the obvious gaps) we can see a continuous "evolution" of things that turned (evolved) into what we see today as the life forms.

    I understand uptill here. This is "how" evolution works. But my question is more fundamental. Science, as far as I know today, never explained "Why" certain molecules wanted to become more and more complex. For example, lets say, the first self replicating molecules kept replicating. With slight variations you might say, which I agree to. All these variations are but molecules and variation in their structure and "function". Out of these variations, some replicated more successfully than others. Agreed. But then suddenly, it seems, different types of molecules that eventually branched out of this whole pool of initially identical ones (may be several groups of identical ones, I dont know the specifics here), decided to "stick" to one another so that they can survive better. Light sensing tissue, for example, working together of a completely differently functional set of tissue. But the question is this. Did the molecule (of the building blocks of a certain tissue) decide to stick first and then survive later? or survived because it accedentally sticked to? If its the former, one must explain the continuation of that mutual dependence and the "tendency" to do so. New molecules that developed from these, need not grow up to stick to one another, let alone talk of whole tissues sticking together and replicating together. You see what I mean?

    Not only that. Molecules replicating one another as being their "functionality" is fine. But processes involving "time" as in "cycles of functionality" is much more complex. All the living organisms that we see today are not just collections of molecules replicating independently. What we are seeing is collection of molecules working together over time in specific processes that ensure their survival. When did molecules learn "time"? Individual molecules, how ever complex, cannot be said to be "aware" of time. Yet, some how, whole systems work based on time and feedback loops!

    Perception of time and working "in time" is one thing. Add to this, perceptions, judgemental capablities, assessment of environment and so on are also part of the systems that evolved. No question that they evolved. Evolution works. An overall outline of how it might work is also agreed upon. But the "why" does it work in such a way still needs to be explained.

    A simpler way to ask this question, limited way is this.
    Molecules started replicating using other molecules in the vicinity and the concepts of chemical bonding play a role there. Physical and chemical conditions needed for that, are a given. But after a certain level of complexity, we see molecules "Actively seeking" ways to preserve. Like searching for food. I mean, molecules can sit there and if at all anything then can work with comes into close contact with it and then utilize it for its survival is one thing. Molecules working in unison in recognizing "food" and searching and hunting for it is a whole lot more complex. The complexity is a matter of the birth of "perception" in this case. So, the question, "why did the molecules develop systems of perception?" is what I am asking. Did they "will" to survive? If so, when did that "will" appear, where did it come from and why did it come in the first place.

    If molecules are "non living" and "unconscious" by nature, why did they move towards the complexity that produces such effects such as "life"? They could end up just being molecules replicating with variations and the variations surviving as long as they are more suited for their environment. But why did the whole concept of "making a conducive environment that is suitable for survival" come about? Even little concepts like preservation of body heat in higher organisms is enough to raise this question. Why do these seemingly non-living molecules actively work in precission to make the system work? They could simply stop working in precission and remain molecules.

    You see where I am getting at? I am asking "when" and "why" did life arize in the first place. What does "perception" really mean at the molecular level? For any of the complex systems to happen, there needs to be a "learning" and "appreciating" mechanism. For example, even basic organisms that survive on algae, display a mechanism of "seeking" algae. What does this mean at the molecular level? When do the newly replicated organism realizes that it needs "algae" without experimenting for itself? How does it percieve algae as "edible"? What does "edible" mean to a molecule that functions precisely in a remote place of the cell?

    Let alone the statistical probablity of the sustainance of complexity. "why" is a pertinent question. Several such "why"s can be asked. The more the complexity of the evolutionary organism, the more these questions are, and the more these are to be answered by science. All I am asking is "why did the molecules decide to form such complex mechanisms?" That tendency could not be explained by the chemical structure of the molecules. Simple questions of the mechanics of cellular reproduction (fission or fusion for example) are well beyond the "molecular" level. They are more at the "organism" level. The system level. But why do the individual molecules with in that organism work so well to preserve the entire organism? Do they have "information" that it is better? Are they built exactly for that? If so, why did that happen?

    Evolution beautifully explains everything from biodiversity to food chains (and recently even to suggest that morals are hard wired into us by "evolution"). The theory works by saying that because this particular trait is helpful for the survival of this species, that trait must have been there in the survivers which carried forward through the generations. Others who lacked that particular trait died out. Its music to my ears.

    But when did molecules learn to act by "traits"? Complex traits that individual molecules might never understand? Why do molecules "work" in precission to maintain something that they cant even comprehend? Workings of the RNA are an example of how complex these processes can be. Many such processes involve passing of time. Individual molecules cant possibly be "aware" of time and cycles. Yet they work beautifully well even in those frameworks. But why? A molecule can just stop working in an orderly fashion at any given time, right? Still, complex molecules of protien with huge numbers of atoms work as though they are meant to be.

    A giraffe's neck for example (since you have taken it). The individual molecules that form the giraffe's neck will never even comprehend what a "neck" is. All the molecules that work within that system need to work precisely for a neck to grow. The neck of each giraffe is certainly seperate from the neck of another "older" giraffe. The sustainance of information that makes it possible for the neck to grow is also in the form of molecules. Molecules working with molecules at the minute level (remember, I am not even starting to go into the quantum levels of individual atoms of each such molecule) is what makes the whole thing possible. Molecules working with molecules of different types, over long periods of time, working in precission to work into "cells" (complexity of protiens is well known, one can imagine the complexity of a whole cell here) and cells working together to work as tissues, which inturn work to form parts of a bigger system and so on, shows the incredible complexity at work in each giraffe's neck. All this complexity needs to work like clock work (right from which parts of the DNA switch on and off (why do they do that is another question)) to create each giraffe's neck. All of the information needed for it to work must be there, somehow, within the DNA of the single "sperm" or "egg" that caused that Giraffe. Somehow, molecules work together from there on, copying the information and working according to it in each cell, creating different types of tissues (how each individual molecule that takes part knows the distinction between tissue types and configurations is yet another level of complexity) and then the mechanisms of maintaining such tissues has to come into place and the whole thing is very complex!

    Much of the survivablity of a species started to depend on "perception" long long ago, in the age of micro organisms. Sensing heats, electrical field fluctuations, sensing light patterns (which lead to the creation of the eye in steps, through natural selection) and so on are some of the concepts that made the complexity possible. Yet theres no hint of how any single molecule or a small collection of them can develop such a sense is in question.

    So, why does it all work? Why did self-regulating mechanisms occur? No individual molecule can comprehend the concept of self-regulation. yet, many of them work in feedback loops to maintain systems of self-regulation. Yet, until the system is formed, theres no sense of how the concept can be sustained. But systems are formed and then maintain self regulation. More over, systems replicate so beautifully as though they have "self regulation" hard wired.

    self regulation happening as an accident in the original chemical soup is understandable. Sustaining it, and replicating it with precission are of whole different level.

    Now after this long post explaining "why" does it work so well (not just how does it work, i know how it might work) is my question. Why do molecules form systems that self-regulate so that they dont disintegrate owing to the second law of thermo-dynamics? Self regulation, being so complex, need not be sustained unless there is a sense of survival within that system. If its just molecules, then there should not be any sense of replicating the whole. Still, "whole"s are replicated. Not just individual molecules.
    Why?

    Now they are so complex, that these systems start arguing about themselves and their innerworkings, innerworkings of the universe they "percieve", attribute sense to morals and what not. At a molecular level, none of this makes sense. Yet, molecules work perfectly in keeping up this system working. WHY?

    Whole evolution seems to be working towards "more and more complex". I ask why. Why that direction. Why not work towards "simplification" so that structures exist (like structures of iron molecules. They survive longer than any organism that I know of). Infact, we find that the simpler things are, the longer they can be sustained(generally, not always. also, I think there is a simplicity threshold beyond which sutainance is again a problem, i am not sure, but somehow, i feel that there is.. i need some more research into simplicity and chaos). But no! Evolution seems to be creating more and more complex lifeforms that are more and more fragile (fragile in the chemical and molecular and system sense. not in terms of survival sense).

    I know that evolution is a mechanism ( i dont know the technical term here ) that simply works! But why that prolonged sustainence of increase in complexity? protien molecules survive better than humans with lesser requirements for survival, for instance. I am simply asking "why".

    That was my question.

    Sheesh.. Thats a long post. It was just to prove that I wasnt applying sweeping generalities. I dont have such a habbit.

    I had to write all this to get a proper answer to my question. Again, please dont think of this as an "attack". I dont intend to. I dont need theories to fall for my survival. I am just asking out of curiosity as to what scientists think about this and to improve my knowledge of it.

    DJ
     
    Last edited: Aug 17, 2007
  2. jcsd
  3. Aug 18, 2007 #2

    Ivan Seeking

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    This may address part of your question.

    http://www.space.com/scienceastronomy/solarsystem/comet_life_010405.html
     
  4. Aug 18, 2007 #3

    Danger

    User Avatar
    Gold Member

    Man, that has got to be one of the longest posts that I've ever seen.
    First and foremost, Science never answers 'why'—only 'how'.
    Secondly, you can't anthropromorphize. None of those chemicals or early molecules 'decided' to do anything. It was just a matter of compatible molecules accumulating by chance.
     
  5. Aug 18, 2007 #4
    Hey Danger,

    thanks for the response.

    Just to ease things on the forum readers, i want to request a list of books that you guys on this forum would prescribe as "standard" and "latest" and "accepted by science" on these topics. Any web links to such resources are also wonderful.

    The topics I would like to study are :

    1. Evolution.
    2. Neuroscience.
    3. Psychology, especially relating to mystic, spiritual and religious explainations as well as those that are about hallucinations.
    4. Scientific methodology. How science works, and especially, how can a layman like me propose and formulate my own experiments that are up to scientific standards. And how can i approach scientific authorities to take my experiments to the next level. I am especially considering psychology experiments.


    That would spare long posts and long answers. I would take time to read them before asking questions.

    Thanks a lot in advance. Great to know that science doesnt explain "why" but only "how". Is this view scientifically accepted?

    Sustained increase in complexity due to evolution is something that keeps bugging me, especially considering that "will to survive" being a mechanism of higher organisms and not of the lower (who are not even said to be conscious).

    And one more request.

    How is "life" and "living things" defined in science? How are "consciousness" and "awareness" defined? Accurate definitions will help me discuss more accurately and spares people from pointing it out to me.

    Thanks.
    DJ
     
  6. Aug 18, 2007 #5

    Danger

    User Avatar
    Gold Member

    The part about Science not asking or answering 'why' is that the term implies some sort of 'purpose'. There is no purpose; things just happen by chance in accordance to scientific principles.
    As for some basic books, I'm going to risk being hissed at by everyone else on this site: I would suggest that you pick up a copy of 'The Dragons of Eden: Speculations On the Evolution of Human Intelligence' by Carl Sagan. It's 'popularized' science, and a lot is purely his own ideas, but Sagan was a well respected scientist. You will find no crackpottery in it.
     
  7. Aug 19, 2007 #6

    Astronuc

    User Avatar

    Staff: Mentor

    One could ask - how did life begin.

    Here's one possible answer.

    Scientist: Calculations Prove Life Began in Comet
     
    Last edited: Aug 19, 2007
  8. Aug 20, 2007 #7
    Why it is that some people find it more likely that life came from a floating space rock rather than right here on Earth where the conditions are more suitable is beyond me..... :rolleyes:

    d_jnaneswar, you seem quite preoccupied with "WHY". That seems to me to be more the territory of philosophy or religion. I agree with Danger, science doesn't concern itself with why....just what, how, and when.

    Why ask why? :smile:

    I think you summed it up rather nicely and sort of answered your own question there. It is a mind-boggling and wonderful thing (life is), isn't it?:!!)
     
  9. Aug 20, 2007 #8
    Why not ? scientists most surely ask "why" questions, some examples:

    Why are hummingbirds attracted to color red ?
    Why does water flow downhill not uphill ?
    Why is the sky blue ?
    Why does the physicist study the massless spring ?
    Why can it be said that every determinate dynamic system corresponds to a single-valued transformation ? (a type of why question of science of cybernetics) ?

    "At the end of the day, the spark of innovation still comes from someone asking, 'Why, why, why, why, why?'" - Glenn Edens, Director, Sun Microsystems Laboratories
     
  10. Aug 21, 2007 #9

    Pythagorean

    User Avatar
    Gold Member

    Sometimes 'what' and 'why' are used interchangeably. Conceptually, though, there's a clear difference: why determines motive (generally associated with humans or animals) and what determines the actual physical events that take place. (Furthermore, one could argue that motive is a physical event in the brain)

    It seems something that could easily be at the root of a semantics argument.
    The 5 w's were always kind of a tragedy.

    "What did you do that for?" (what used for motive)
    "Why did you do that?" (why used for motive)
    "What happened?" (what used for a physical event)
    "Why does this happen?" (why used for the physical conditions for an event)
     
    Last edited: Aug 21, 2007
  11. Aug 21, 2007 #10
    What an interesting forum. Tonight in other areas I found myself at odds with Danger (no pun intended). But on this thread I totally agree with him. In the context considered, "Why" is not even a scientific word.

    If one would prefer to believe there was some conscious thought involved in the beginnings of life I suggest that they simply pretend that their chosen deity ordered the Big Bang and then decided to let nature take it's course from there. This eliminates the pointless "why"s when discussing the chaos of creation.

    Natural selection is not that complicated. What works lives on and reproduces more that work. What doesn't work dies out. Chaos brings mutation. Some mutations work better than the original and they live on and reproduce some of the same. The rest die out. Humans are the only creatures that have ever consciously manipulated and avoided this process. As of late, we've been supplementing machines in place of our physical evolution. Our technology evolves exponentially while our bodies suffer natural selection to decreasing degrees.

    It seems obvious to me that life was simply an accident. One needn't think of the probability involved to accept it as such. It's scientifically possible. And here we are, complex carbon based life forms, suddenly self aware and looking for the answers to everything. But the answer to "why" is simply "because". More than that and we're writing and believing fictional stories to calm the primitive fear of death that only originated from natural selection in the first place.

    Scientific minds are truly the bravest and thereby the deepest.
     
  12. Aug 21, 2007 #11

    Danger

    User Avatar
    Gold Member

    Having an intellectual disagreement about something doesn't make us enemies. :smile:
     
  13. Aug 21, 2007 #12
    None of those questions seem scientific in the slightest. Now change them around a little and they do:

    HOW do hummingbirds discern colors and WHAT is the reason for red being preferred?
    HOW does gravity effect the flow of water?
    HOW does light produce a blue color in our atmosphere?

    Etc....:wink:
     
  14. Aug 22, 2007 #13
    Science answers both why and how, it is just that the answer to why is unfulfilled to some, who demands a stronger, metaphysical answer. Why does not necessitate a purpose.

    'How' is a descriptive approach, whereas 'why' asks for cause independent of a or no purpose of that cause.

    The sun shines. How does it shine? By emitting electromagnetic radiation.
    Why does it shine? Because of nuclear fusion.
     
  15. Aug 22, 2007 #14

    jim mcnamara

    User Avatar
    Science Advisor
    Gold Member

    Since this is not a primum movens (first cause) theological discussion, rather one based on science maybe you should consider why evolution started this way: evolution is an emgergent phenomenon.

    One definition is that a discernable and complex order arises from large number of random starting points. It uses fixed, simple rules.

    Do you know the computer game/simulation 'Life'? The one invented by John Conway?

    A very simple description - this game will create predictable, repeating , VERY complex patterns from different starting "positions" of black and white squares on your PC screen. Predicting which starting positions end up as predictable/repeating/complex can be difficult.


    This is exactly what evolution does. It arises out of competition for resources and survival to reproduce. The rules are simple. It's hard to see a why-it-started to create more complex life forms because it began playing the 'game' billions of years ago. We can't work backwards to see the starting positions. Because a very large number of "starting positions" could possibly result in what we have now.

    If you want see see what I mean - google for conway's game of life
     
  16. Aug 22, 2007 #15

    Danger

    User Avatar
    Gold Member

    As a side-note here, did anyone catch on the news that a virus within a computer game has mutated? I think that it's 'World of War Craft'. A disease that was supposed to infect only a limited population in a particular area got loose and caused a pandemic. Epidemiologists (right term?) are studying it for clues into real-life infection patterns.
     
  17. Aug 22, 2007 #16
    http://news.bbc.co.uk/2/hi/technology/4272418.stm
     
  18. Aug 22, 2007 #17
    Very interesting side note. What I like is how the virtual plague was carried by a player's virtual pet. I wonder if the pet was a rat. WoW.
     
  19. Aug 30, 2007 #18
    Interesting discussion about "why" and "how".

    I recently read (from sciam mind, i think) that scientists are trying to define consciousness and awareness "objectively" so that it can be tested and studied without the constrains of the subjective. Sounds really interesting.

    Scientists have identified chemicals that supposedly "create" emotions and effect how we behave, like dophamine and others. Also is said how different little things like aging, brain matter percentage (grey vs white) and others effect our intelligence (which again is yet to be fully understood, by the source of the article) and other things.

    I was wondering if any studies have been done where a person's psychological state "caused" chemicals. You know, like "he is depressed and so this chemical is released BECAUSE of that" and so on.

    What im mostly interested in, regarding this relation ship between the so called "mind" and "brain", is the "will" of the person.

    That is, if someone makes fun of me in public, lets say, i got upset. That means, the stimuli of my senses and the "mental picture" that my brain built (how it builds is not completely known, isnt it?) released certain chemicals and electrical impulses in certain parts of the brain and body and thats what I call "upset". Is this right? Am I missing something in this?

    But if I have a predisposition that its a "fun" thing and not an "insult" then the same words and stimuli will not make me upset, for instance. Now, what does this mean?
    Does it mean that my disposition effected what chemicals are released for the same stimuli? Or is my disposition another "chemical bias" that my brain worked out?

    I am reading through the wonderful links in the brain science, cognition section of the forums, and am trying to find out what scientists say of this.

    Does anyone have any links to papers or resources that explain this?

    If its just chemicals creating what we call "awareness" and "consciousness", then "pre-disposition" should also be just a chemical thingy right? If so, all of our endeavors are limited by the "chemical composition" of our brains, including our ideas, inspirations, inventions and discussions, right?

    Does this mean that we are ultimately paralyzed by our chemical limits from finding out everything about everything? Doesnt that mean that we cannot claim as to what we think is true, but just "apt" only under the chemical dispositions and limits of our brains that make all this possible?

    If this is so, can we ever hope to say that any explaination of this universe is correct?

    I am wondered about how scientists are so "confident" (which again is the chemical disposition) about what they find. Did they find a way around this argument?


    DJ
     
  20. Aug 30, 2007 #19
    The "why" and "how" thing comes up often. The content of the question should be 'looked' at more than anything else, I believe. I think the controversy started in philosophy, probably when physics was part of philosophy (subsets->science and religion) and 'scientists'/ ('physicists') have been trying to separate it ever since.

    -----------------------------

    And for evolution, I bet there will be a lot more theories involving epigenetics in the role of evolution.
     
    Last edited: Aug 30, 2007
  21. Aug 30, 2007 #20

    Astronuc

    User Avatar

    Staff: Mentor

    I think evolution has much to do with success of the biological units which are evolving. Something that happens to be successful will live long enough to reproduce and ostensibly will produce successful offspring.

    http://en.wikipedia.org/wiki/The_Origin_of_Species

    The interesting question would be - how do simple organisms develop an affinity for whatever it is that makes them successful?

    Perhaps jim mcnamara's posts in Pythagorean's thread "Origin of Life and Consciousness - Physical View" in this forum provide some insight into this question.
     
    Last edited: Aug 30, 2007
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?