Cell Division

Why did the first cell divide? How could it have programmed itself to do that? Why would the first cell divide, why didn't it just live its life and then die? If there are actual, plausible scientific answers I am interested in hearing them.

Thread copied here from the Cell Division thread in the Proposed New Topics forum.

Most likely it was simply physics; it grew to a sufficient size that the physical forces on it were sufficient to tear the cell into two parts. That's what lipid vesicles do.Of course it was then just luck whether the two halves contained what they needed to survive. Sometimes one part would contain everything; sometimes both of them wouldn't. This, then, applies a strong selective pressure towards mechanisms that control the process of division and ensure that both daughter cells contain the correct elements - and we have the beginnings of mitosis.

Lipids will spontaneously form liposomes --- (roughly) spherical cells with bilipid layers, and these will spontaneously divide and fuse. (When I say spontaneously, I mean that no biological mechanism is required, it's just down to the physics of the lipids.) Note that fission does not spill the contents of the liposomes.So you could perfectly well have cell fission, in this sense, before you actually had life! --- and then life co-opted this ready-made process. The challenge then would be how best to regulate it.In this paper, the author comments: So protocells didn't have to be programmed to divide, as such --- but once life started using these membranes, it was adaptive to acquire control over the process of division. It seems reasonable that any control would have been better than none, and more better than less, making this adaptation a prime candidate for evolution.Edited by Dr Adequate, : No reason given.

Why does ice form hexagonal crystals, and how did it program itself to do that? It is entirely possible that the first cell did just that. It lived it's life and died leaving no descendants. If you think about it for just a few seconds I think the answer to this questions should be very obvious. Why is it that we only see the descendants of dividing cells in today's world?Edited by Adminnemooseus, : Eliminate redundant and blotched quote.

Very astute and much to think about, thank you very much!

Hi Drevmar. and welcome to the fray. This is a great site for learning things, and finding out where your preconceptions may be in error when discussing things with people educated in the various fields that visit and share. I know I've learned a lot here/Enjoy.

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Thanks for the info on that I will attempt it in the future!

Drevmar, your welcome.Thanks for your question. btw - you may want to read Self-Replicating Molecules - Life's Building Blocks (Part II) and watch the video on the possible protocells that have been discussed here.EnjoyEdited by RAZD, : ...

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razd posted; Hi Razd, I watched the video. The music was great. But if this is science's answer to the orgin of life, you guys are in big trouble.On this board I have been critized for speculating, dreaming, not showing the evidence etc. and then you have the nerve to show this video?I think Dr. Szostak should take a couple of years sabbatical and think about his life and studies.I acutally laughed through most of the "important parts" of the video.Yes maybe life began that way, and maybe my grandsons theory of the easter bunny is valid.I would but my money on my grandsons, and they are only 2yr, 18mo. and 7mo.I'm sure Anthony Flew would get a kick out of that video. Remember he said;"My departure from atheism was not occasioned by any new phenomenon or argument. Over the last two decades my whole framework of thought has been in a state of migration.This was a consequence of my continuing assessment of the evidence of nature. When I finally came to recognize the existence of a God, it was not a paradigm shift, because my paradigm remains, as Plato in his Republic scriped his Socrates to insist: 'We must follow the argument wherever it leads'."The argument for the orgin of life does not lead to Dr. Szostak's thoughts or theory.

Hi shadow71, Amusingly the application of the video to this thread was about the formation of proto-cells and how cells divide, as discussed in the other posts and which this video showed in detail, based on actual experiments conducted in actual labs. Perhaps you should read Message 1 and the replies first. Cognitive dissonance is like that. Did you read the rest of the article? You will see that each element is referenced. If you want to discuss the actual science with Dr Szostak, he has a website where you can contact him: Szostak Lab: Home - see people and I believe that it is referenced in the video. Which, curiously, is all we can say at this time. Nobody is claiming that this is what happened, only that it is one possibility, one that works with known science and natural processes.Enjoy.Edited by RAZD, : clrty

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we are limited in our ability to understand
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Rebel American Zen Deist
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Incredulity is not an argument. Do you have any specific and science-based criticism, or do the fact that you laughed and an irrelevant quotation from Dr Flew constitute all you have to say for yourself?We can watch liposomes dividing in a laboratory; we know it happens. If, as I suspect, you have a magic-based hypothesis, I should like you to produce equally strong evidence for the occurrence of magic. Otherwise I shall prefer the reality-based hypothesis to yours unless and until I have further data.Edited by Dr Adequate, : No reason given.

I appreciate the link to the Self-Replicating Molecules, I haven't looked at it yet, but I will, thank you.

Okay, I went to the link you provided and I have to admit, I had to look up "self-polymerize" - this stuff is really slow reading for me. I'll have to look at it a few times before I am gonna get it. But I think the main gist is that we are talking about chemicals getting together, forming into a very basic cell-like structure, replicating and then picking and choosing this and that until they achieve life-form? The attached reading material is somewhat difficult as well and has a lot of "out of my league" stuff. I feel the need to ask if a life-form has been developed in a lab? or, is the current state of development still chemical compounds? No insult intended I just want to know!

I believe that's a pretty accurate description of the hypothesis presented, yes. Although I'd note that it's just one suggestion; one that is popular among those on this board, but by no means the "accepted" account. An alternative view has life evolving initially in the microstructure of rocks, and only later developing cell membranes. No origin of life experiment so far has come close to anything that might be called living from non-replicating components.