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Explaining how a cell works is not the same as explaining how cells first came to exist. Once a cell exists, given certain conditions, it can replicate itself

by o_nate 11y ago

Explaining how a cell works is not the same as explaining how cells first came to exist. Once a cell exists, given certain conditions, it can replicate itself - we can explain each step in the process with reference to laws of chemistry. However, a different question is: How did this process get started? That's the question this article is addressing.

trhway 11y ago
>Explaining how a cell works is not the same as explaining how cells first came to exist to me it became much clearer when i read somewhere (just dont' remember where) along these lines - imagine a "stick" shaped pretty simple organic molecules with one end being hydrophobic and the other hydrophilic (there are a bunch of such molecules known in organic chemistry). Having a soup of those molecules in water, some of the molecules would naturally clump together with hydrophilic ends outside and hydrophobic ends inside - kind of a small bubble. Now if on contact of a bubble with another molecule, the molecule is added into the bubble (similar like a bunch of magnets clumped together "assimilate" another magnet piece correctly orienting it), the bubble gets bigger and at some point it would naturally splits into 2 smaller bubbles (surface tension, etc...) and each bubble would continue the "assimilation"/growth and division in their turn as long as there are such molecules around... Of course it isn't even "pre-cell", it is just showing how natural physics laws can drive the initial pre-life stages.
- Nevermark 11y ago
  Another route starts with chemistry near deep sea vents where energy loaded compounds are continually spewing from hot water into cold water. There will be a continual cascade of chemical changes at the vent, and if some random chemicals appear that increase the chances that each other are formed in that cascade, a self-reinforcing metabolic loop could occur. The metabolic loop could optimize itself as it occasionally produced slightly more efficient self-reinforcing chemistry. Eventually this optimization might take advantage of self-organizing membranes to compress the metabolism into individual units, i.e. the first cells. At that point we would have "life". Maybe that happened. Maybe not. But it is an alternate way for life to start in which distributed replication occurs before single replicators.
arjunnarayan 11y ago
> However, a different question is: How did this process get started? That's the question this article is addressing. I consider this issue pretty much answered by Chapter 2 of the Selfish Gene, "the replicators". Link: http://www.evolbiol.ru/gene/index_2en.html#02 http://www.evolbiol.ru/gene/index_2en.html#02
- DougMerritt 11y ago
  Please. I've always liked that book quite a lot, but Dawkins did not present (and did not claim to present) a theory of abiogenesis. No one has ever presented an actual theory of abiogenesis, the current article notwithstanding, as opposed to some intriguing but speculative hypotheses that might (or might not) turn out to be part of an eventual theory (RNA world, clay catalysts, deep sea smokers, lipid membranes, etc. etc.) Considering a totally open subject to actually be answered and finished is just saying you personally don't care to pursue the topic in more depth.

by o_nate 11y ago

trhway 11y ago

>Explaining how a cell works is not the same as explaining how cells first came to exist to me it became much clearer when i read somewhere (just dont' remember where) along these lines - imagine a "stick" shaped pretty simple organic molecules with one end being hydrophobic and the other hydrophilic (there are a bunch of such molecules known in organic chemistry). Having a soup of those molecules in water, some of the molecules would naturally clump together with hydrophilic ends outside and hydrophobic ends inside - kind of a small bubble. Now if on contact of a bubble with another molecule, the molecule is added into the bubble (similar like a bunch of magnets clumped together "assimilate" another magnet piece correctly orienting it), the bubble gets bigger and at some point it would naturally splits into 2 smaller bubbles (surface tension, etc...) and each bubble would continue the "assimilation"/growth and division in their turn as long as there are such molecules around... Of course it isn't even "pre-cell", it is just showing how natural physics laws can drive the initial pre-life stages.

Nevermark 11y ago
Another route starts with chemistry near deep sea vents where energy loaded compounds are continually spewing from hot water into cold water. There will be a continual cascade of chemical changes at the vent, and if some random chemicals appear that increase the chances that each other are formed in that cascade, a self-reinforcing metabolic loop could occur. The metabolic loop could optimize itself as it occasionally produced slightly more efficient self-reinforcing chemistry. Eventually this optimization might take advantage of self-organizing membranes to compress the metabolism into individual units, i.e. the first cells. At that point we would have "life". Maybe that happened. Maybe not. But it is an alternate way for life to start in which distributed replication occurs before single replicators.

arjunnarayan 11y ago

> However, a different question is: How did this process get started? That's the question this article is addressing. I consider this issue pretty much answered by Chapter 2 of the Selfish Gene, "the replicators". Link: http://www.evolbiol.ru/gene/index_2en.html#02 http://www.evolbiol.ru/gene/index_2en.html#02

DougMerritt 11y ago
Please. I've always liked that book quite a lot, but Dawkins did not present (and did not claim to present) a theory of abiogenesis. No one has ever presented an actual theory of abiogenesis, the current article notwithstanding, as opposed to some intriguing but speculative hypotheses that might (or might not) turn out to be part of an eventual theory (RNA world, clay catalysts, deep sea smokers, lipid membranes, etc. etc.) Considering a totally open subject to actually be answered and finished is just saying you personally don't care to pursue the topic in more depth.