August 26, 2004

Evolution Porridge: Not Too Hot, Not Too Cold, but Just Right

STONE SOUP MEETS GOLDILOCKS as told by Paul Shlichta at
The American Thinker

[T]he concept of the spontaneous origin of the first cell is on very shaky ground. You must start by making a quasi-primordial soup, rich in amino acids and other building blocks of life, as Stanley Miller and Harold Urey did in the 1950's. Then you must somehow stir it and shake it until the components spontaneously assemble to form long chains of DNA, RNA, proteins, and numerous other macromolecules—with all of the multi-thousand amino acid sequences exactly right and mutually compatible. Then you must continue stirring until the macromolecules sort themselves out into the proper groups and somehow surround themselves with membranes, with just the right sort of ion transport properties, to form organelles such as a nucleus, lysosomes, ribosomes, mitochondria, and all the other cellular components. Then you must keep stirring until all these organelles pack themselves into a cell membrane, with just the right composition of fluid in it. You have only a few billion years to shake up all these dice and have them all come up right at the same place and time.. Ready, set, go, and good luck -- but I don't think you're going to succeed. However, if you think this scenario is scientifically plausible, then sit down and start calculating probabilities.

Posted by Vanderleun at August 26, 2004 10:12 AM
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"It is impossible to speak in such a way that you cannot be misunderstood." -- Karl Popper N.B.: Comments are moderated and may not appear immediately. Comments that exceed the obscenity or stupidity limits will be either edited or expunged.

As stated it can't happen. As stated is also a misuse of probability.

But that is not the way it is hypothesized. The various bits and pieces have been shown to form under a number of conditions. For them to come together over the billions of years does not require that everything fall into place at once. All that is required is a slight edge for any configuration to acquire material from the environment, at first non-living, and then, as the various versions changed, at some part obviously living for it to become dominant with changes occuring in the seconds to minutes range for billions of years.

My own interpretation is that it took almost 4 billion years of "experimentation" before something stable enough in its replication to take off, hence the Cambrian explosion.

I am a theist AND and evolutionist. The two are compatable. I have argued in various forums that ID and evolution should have a vigorous debate. It would point out the weaknesses and strengths of both. Both are abstractions and interpretations of the same or selected sets of the same data. My money is on evolution, but I think the debate would be valuable to both sides.

Posted by: Bill at August 26, 2005 11:06 AM

In general, I'm in agreement with that point of view.

Posted by: Gerard Van Der Leun at August 26, 2005 11:30 AM

What keeps me scratching my head is that if life arose spontaneously "under a number of conditions," why aren't we seeing new lifeforms arising now? The earth still has plenty of places that are still closer to primordal ooze than Garden of Eden.

Posted by: Mike Anderson at August 26, 2005 12:01 PM

What gets me scratching my head beyond that are the billions of years it takes to get an Earth on which the four billion years of trial and error can take place.

Posted by: Gerard Van Der Leun at August 26, 2005 12:27 PM

A lot of the places that are closer to primordial ooze are already colonized by successful lifeforms. They would prevent the arising of new ones through better competition for the resources.

The times become incomprehensible except through the use of mathematics. I have a lot of head scratching with the cosmological models. All the important stuff happens in the first few seconds and the rest is just cooling. Especially bothersome to me is the inflationary model. It always smacks of something from nothing to me. Smoke and mirrors from quantum mechanics.

Posted by: Bill at August 26, 2005 1:08 PM

Oh, jeeez, guys. The number of molecules invlolved is probably in the order of 10^40; the time scale of the reactions is in the order of 10^-4 seconds or less; and the time span is 4*10^9 years, or about 10^12 reactions' times'.

So in your 4 billion years, random choice has something like 10^40! * 1-^12 chances ... and only one of them has to start successfully replicating to give us "life".

Posted by: Charlie (Colorado) at August 26, 2005 2:47 PM

Sorry, Charlie. That's not a good application of the math. The process does not consist of any and all atoms interacting randomly. There are a lot of constraints that favor certain reactions and disfavor others. That improves the odds for some things and decreases them for others. Statistical attempts in this area are doomed from the start because the starting conditions are insufficiently defined to properly calculate the probabilities.

It is far more valid to define possible processes and demonstrate their possibility in the laboratory. It is still conjecture, but with some grounding in physical reality. The attempt to put numbers to this is garbage in, garbage out,

Posted by: Bill at August 26, 2005 7:28 PM

why aren't we seeing new lifeforms arising now

Among other things, there's O2 all over the place at this point, and free oxygen is corrosive. Oxygen is necessary to us so we don't think of it as a poison, but the first plant cells to photosynthesize and excrete oxygen created a huge ecological crisis. We are descended from the relatively few oxygen-tolerant survivors.

Posted by: jaed at August 28, 2005 3:22 PM

Well, yes and no. If one accepts Nick Lane's "Oxygen, the molecule that made the world" at face value, there was no 'oxygen holocaust' from the first plants, because the amount of oxygen in the atmosphere has been between 20 and 30 percent since before the Cambrian 'explosion', probably due to a succession of ice ages, and the chemical reactions resulting there from. Its the water, and the O2, not just the O2.

Gerard's itch about why it took so long for the Earth to form given the accepted age of the Universe and Earth is more interesting to me, but your milage may vary.

What came before the big bang?

Posted by: Eric Blair at August 29, 2005 12:59 PM