blike Posted October 20, 2002 Posted October 20, 2002 (I decided to change the title of the series of posts because not all deal directly with evolutionary theory) However improbably we regard this event [the start of all life], or any of the steps which it involves, given enough time it will almost certainly happen at least once. And for life as we know it...once may be enough. Time is in fact the hero of the plot. The time with which we have to deal is of the order of two billion years. What we regard as impossible on the basis of human experience is meaningless here. Given so much time the "impossible" becomes possible, the possible probably, and the probably virtually certain. One has only to wait: time itself performs the miracles. -Nobel laureate and Harvard University professor of Biology George Wald. ["The Origin of Life," Scientific American, August 1954] Wald's statement rested firmly on research done in the previous year by Stanly Miller, then a graduate student at the University of Chicago. Miller had mixed a flask with gases thought to have been present in the Earth's atmosphere 3.8 billion years ago. He then discharged sparks, simulating lightning into the gasses. Their energy induced random chemical reactions among the gases. After a few days, a reddish slime appeared on the inner walls. The slime was found to contain amino acids. The importance of Miller's experiment was enormous. Given enough time, it is possible that life would emerge on its own. As Wald had pointed out, two billion years had passed between the appearance of water on earth and the appearance of life. Wald's article was replubished 25 years later in a 1979 special edition Scientific American. However, this time the article appeared with a retraction. Although stimulating, this article probably represents one of the very few times in his professional life when Wald has been wrong. Examine his main thesis and see. Can we really form a biological cell by waiting for chance combinations of organic compounds? Harold Morowitz, in his book "Energy Flow and Biology" computed that merely to create a bacterium would require more time than the Universe might ever see if chance combinations of its molecules were the only driving force". Articles authored by Nobel laureates are not lightly retracted. The statistical computations by Morowitz may have cast a shadow of doubt on Wald's claims for the power of chance, but I doubt Scientific American would have actually retracted the article based on statistical calculations alone. The article was withdrawn because research performed by another Harvard professor proved Wald wrong. In the 1970s, Elso Barghoorn, a paleontology professor, discovered micro-fossiles of bacteria and algae in rocks close to 3.5 billion years old. That is also when the first liquid water appeared on earth, and hence the first time that life could survive. There were no "billions of years" for the amino acids to combine randomly in life, as Wald as suggested. Life formed suddenly with the appearance of water. So suddenly did life arise on Earth that the theoretical biologist Francis Crick wrote, "Given the weaknesses of all theories of terrestrial genesis, directed panspermia [deliberate planting of life on earth] should still be considered a serious possibility." ["Profile: Francis H. C. Crick," Scientific American, February 1992] Crick certainly understands the complexity of life. He shared the Nobel Prize for discovering the shape and functioning of DNA. Science has no agreed-upon explanation for the cause of life. Whatever theories are put forth, the fact remains: as soon as the conditions on Earth arose for life to exist, life appeared. There were no 'billions of years' for chance reactions to take place.
aman Posted October 20, 2002 Posted October 20, 2002 I'm torn between life being planted and the idea that there is some natural law or pressure that forces life to be generated relatively quickly in certain conditions. It seems even now that in an abundance of energy things have a tendency to grow more complex, using the energy. Something I feel is beyond the microcosm with building instructions that capitalize on energy and materials. It pushes and pressures small things to grow into an ordered greater complexity. I just thought I'd throw that in for thought. Just aman
aman Posted October 23, 2002 Posted October 23, 2002 :zzz: :zzz: :zzz: :haha: Don't strain youself Fafalone. Just aman
blike Posted October 24, 2002 Author Posted October 24, 2002 I kinda have the notion that life arose by directed planting of it. By whom or what? Thats up to you. The universe is an expression of wisdom, but whose?
fafalone Posted October 24, 2002 Posted October 24, 2002 What are the odds of chemicals naturally combining to form life? 1 in a billion? 1 in a trillion? Every galaxy has billions of stars, the universe has billions of galaxies. Would the odds catch up sometime? something to think about.
blike Posted October 24, 2002 Author Posted October 24, 2002 Even if life[in the most primitive sense] WERE to form, the first generation would have to be able to reproduce, otherwise it would degrade back to its less ordered state. I'll address your point soon, faf
aman Posted October 25, 2002 Posted October 25, 2002 I think there are instructions or pressure from the microcosom that forces life to evolve in any situation it can. Soon we will know Just aman
fafalone Posted October 25, 2002 Posted October 25, 2002 Amino acids form RNA... and there's strong evidence RNA might have been able to self-replicate in the past. Translation now involves enzymes that bind to RNA... but there are some cases where other parts of the RNA chain itself acts as the enzyme. These could be remnants of how it used to work.
Ami Posted November 3, 2002 Posted November 3, 2002 it is true that amino acids can become rna, but seeing as how the can also replicate and continue their species as RNA or at least a form very close to rna, then why would it need to furter evolve, evolution is based on the need for survival, is it not?
Ragnarak Posted November 3, 2002 Posted November 3, 2002 Originally posted by Ami evolution is based on the need for survival, is it not? no it's based on having the best chance of surviving they are quite different things if you think about it
blike Posted November 3, 2002 Author Posted November 3, 2002 Its based on who reproduces more. A hypothetical cell that reproduces 100 times in its 2-day lifespan is more evolutionarily successful than a cell who lives 100 days and reproduces twice. So if surviving longer means more reproduction, then longer surviving cells would become the dominant cell.
fafalone Posted November 4, 2002 Posted November 4, 2002 Originally posted by blike Its based on who reproduces more. A hypothetical cell that reproduces 100 times in its 2-day lifespan is more evolutionarily successful than a cell who lives 100 days and reproduces twice. Not if that cell has a telomerase deficiency...
aman Posted November 4, 2002 Posted November 4, 2002 Energy niches is involved also. A small change and a new energy source might be made available. Another change and the concept of parasite might make stealing energy a source. Every niche possible will be filled. Just aman
Giles Posted January 9, 2003 Posted January 9, 2003 No one is sure yet what constitutes 'conditions for life', nor do we know quite what the chemistry of every part of prehistoric earth was like. So we can't actually tell how likely life (even just the 'RNA world') was, nor how quickly (compared to expectations) it arose. we need to be careful not to ignore the anthropic principle. life may have had only a few hundred years to appear on hundreds of billions of earth-type planets. Originally posted by blike Its based on who reproduces more. A hypothetical cell that reproduces 100 times in its 2-day lifespan is more evolutionarily successful than a cell who lives 100 days and reproduces twice. a cell's life cycle is measured from the reproduction that produces it, until it divides itself. change 'cell' to 'organism' and all is well tho.
Ahmad Posted January 9, 2003 Posted January 9, 2003 Originally posted by blike Harold Morowitz, in his book "Energy Flow and Biology" computed that merely to create a bacterium would require more time than the Universe might ever see if chance combinations of its molecules were the only driving force". Hmmm. Now start thinking about a human being with all its complexities. How a single cell can give raise to functoining human being. Not only that, think of the environment as a whole. Some plants need some insects to reproduce, and these insects need them to survive.
Ahmad Posted January 9, 2003 Posted January 9, 2003 Originally posted by fafalone What are the odds of chemicals naturally combining to form life? 1 in a billion? 1 in a trillion? Every galaxy has billions of stars, the universe has billions of galaxies. Would the odds catch up sometime? something to think about. I have something in my mind. Maybe I should think more about it. But I'm thinking that this is not a simple division over the number of plants you have. The probability here is for a multiple step process, where you multiply each steps probability by the other, assuming in each step that the previous one occured. So, just maybe, by each planet you add, you are lessening the probability of the steps to occur in a single planet. I mean, if one step occurs in one planet, and the other occurs in the other, then it's of no use.
Radical Edward Posted January 9, 2003 Posted January 9, 2003 Originally posted by Ahmad The probability here is for a multiple step process sort of, you can include the occurance of liife as a single step though, since if any part is incomplete, it never really happened. so you consider that as the probability, and then consider all the others separately.
mister_me Posted January 9, 2003 Posted January 9, 2003 The chances of us being created by a supreem being like God and the chances of us evolving from cosmic soup. They both require alot of faith. With God, your believing in what billions of people recognized and adored from the beginning of our existence before our smart-ass scientists decided to question our past. If you believe in the start of life from cosmic soup and that if a cell was formed that it existed in an environment perfect for it to evolve into what life is now, then it's like believing that out of 10 trillion people with one winner in a Lottery draw, you will be the winner. Believe whatever you want to believe. It's easier to believe in God, though. So go screw your lives over science or something like that.
Radical Edward Posted January 9, 2003 Posted January 9, 2003 mister_me: millions of people believed that the earth is flat. It isn't.
blike Posted January 10, 2003 Author Posted January 10, 2003 Though I believe in God, "It's easier to believe in God" is one of the worst things that can be said by a theist
DocBill Posted March 22, 2003 Posted March 22, 2003 I thought I explained this VERY well in my second book (which by the way earned me a nomination to the Royal Accademy). For the members who want to read it...it is a free-be (You gets what youse pays for). It i on my site..download it and read the chapter on the Permian era. Bill
atinymonkey Posted March 22, 2003 Posted March 22, 2003 Well, seeing as how you are dropping names, which Royal Academy were you nominatd for?
spuriousmonkey Posted March 27, 2003 Posted March 27, 2003 Originally posted by blike Science has no agreed-upon explanation for the cause of life. Whatever theories are put forth, the fact remains: as soon as the conditions on Earth arose for life to exist, life appeared. There were no 'billions of years' for chance reactions to take place. people are starting to doubt this notion, because there is uncertainty now that the earliest microfossils are really microfossils. Instead they are just remnants of the primoridial soup. The first real genuine known microfossils are therefore not from around 3.8 billion years ago, but something like 2.7 billion years. If this is true than life didn't just appear. It took actually quite some time. About 1.5 billion years since permissive conditions for life arose.
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