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Dna And Its Origins
189 Answers
In the light of new findings, DNA is even more beautiful and complex than we imagined, considering that it was in existence in the early life-forms on the planet, doesn't any theory of the origin of life by a blind series of chemical accidents seem preposterous ?
Surely only the most unimaginative and feeble-minded could believe in this.
Surely only the most unimaginative and feeble-minded could believe in this.
Answers
Hmm. They are different achievements
14:01 Sun 11th Oct 2015
People haven't joined in this particular argument yet and you're already dismissing their intellect. Not the most promising of starts...
It's not even a particularly effective argument. A "blind series of chemical accidents" implies that only the purest of random chance can have been involved -- but no-one has ever proposed this, so far as I know. DNA has, after all, a certain amount of symmetry to its structure, which suggests that behind the complexity there could be something rather simpler that drove its existence. It also appears to me to overlook the fact that chemical processes, while apparently random, are still governed by simple laws that are far from random (eg the minimalisation of free energy).
And finally, no matter how preposterous the spontaneous emergence of DNA may seem, this provides exactly no extra support whatsoever for any competing idea, that could be just as preposterous, if not more so, but certainly will have to be considered on its own merits.
It's not even a particularly effective argument. A "blind series of chemical accidents" implies that only the purest of random chance can have been involved -- but no-one has ever proposed this, so far as I know. DNA has, after all, a certain amount of symmetry to its structure, which suggests that behind the complexity there could be something rather simpler that drove its existence. It also appears to me to overlook the fact that chemical processes, while apparently random, are still governed by simple laws that are far from random (eg the minimalisation of free energy).
And finally, no matter how preposterous the spontaneous emergence of DNA may seem, this provides exactly no extra support whatsoever for any competing idea, that could be just as preposterous, if not more so, but certainly will have to be considered on its own merits.
Jim;//".... blind series of chemical accidents" implies that only the purest of random chance can have been involved -- but no-one has ever proposed this, so far as I know.//
Well here's one taken at random;
"The study discovered a path from simple to complex compounds amid Earth’s prebiotic soup. More than 4 billion years ago, amino acids could have been attached together, forming peptides. These peptides ultimately may have led to the proteins and enzymes necessary for life’s biochemistry, as we know it."
Extracted from;
https:/
Well here's one taken at random;
"The study discovered a path from simple to complex compounds amid Earth’s prebiotic soup. More than 4 billion years ago, amino acids could have been attached together, forming peptides. These peptides ultimately may have led to the proteins and enzymes necessary for life’s biochemistry, as we know it."
Extracted from;
https:/
And what a lot of random chances there were. Billions of molecules, tens or hundreds of molecular collisions per second, 31,556,736 seconds per year, for a billion or so years.
It all adds up.
Some hormones contain as few as 20 amino groups. Human insulin contains only 51.
Peptide chains fold up and adopt a certain shape just because some chemical side groups are hydrophobic and some are hydrophilic. Energy minimisation, as jim said.
It has the outward appearance of order from disorder and looks like a violation of entropy but macromolecules are under bombardment by water molecules all the time and the entire planet has been receiving heat from the sun all this time so processes can be as endothermic as you want but still proceed because the free energy is always on tap.
It all adds up.
Some hormones contain as few as 20 amino groups. Human insulin contains only 51.
Peptide chains fold up and adopt a certain shape just because some chemical side groups are hydrophobic and some are hydrophilic. Energy minimisation, as jim said.
It has the outward appearance of order from disorder and looks like a violation of entropy but macromolecules are under bombardment by water molecules all the time and the entire planet has been receiving heat from the sun all this time so processes can be as endothermic as you want but still proceed because the free energy is always on tap.
Other random thoughts:-
It is the mRNA/t-RNA(s)/ribosome combo which builds peptide chains so I am willing to accept the idea that DNA came as a secondary innovation.
Phosphorylated ribose (the "backbone") strikes me as a product of something biologically active, transducing available energy (hydrothermal vents or sunlight) into chemical bond energy.
An unexplained glut of DNA subunits spontaneously assembling into chains and then shuffling code sequences for millenia until a functional sequence arises is NOT how I imagine it occurred.
What is needed (to be theorised about) are processes which lead to manifold chemical possibilities, not ones which trap them into the confines of a narrow range.
(didn't see O_G's post until after writing mine but they dovetailed remarkably neatly).
It is the mRNA/t-RNA(s)/ribosome combo which builds peptide chains so I am willing to accept the idea that DNA came as a secondary innovation.
Phosphorylated ribose (the "backbone") strikes me as a product of something biologically active, transducing available energy (hydrothermal vents or sunlight) into chemical bond energy.
An unexplained glut of DNA subunits spontaneously assembling into chains and then shuffling code sequences for millenia until a functional sequence arises is NOT how I imagine it occurred.
What is needed (to be theorised about) are processes which lead to manifold chemical possibilities, not ones which trap them into the confines of a narrow range.
(didn't see O_G's post until after writing mine but they dovetailed remarkably neatly).
You should read " The Deeper Genome" by John Parrington. OUP, 2015, 9780199688739. When you have finished it, you will find you have had full the explanation which you so desire. The genome's evolution is laid out chronologically - you have only to read it - unless you prefer to stick with prejudices.
Hypo;//Always bear in mind that what we see today is the competition winner//
You're steering away towards a discussion on evolution which isn't relevant and is universally accepted - by all but the seriously weird. I refer to the recent findings of DNA, which we now see contains the ability to self-repair and must have been able to do so millions of years ago - why is this, and does this extraordinary quality come about by accident?
And as a sub-question; aren't you absolutely staggered in wonder?
You're steering away towards a discussion on evolution which isn't relevant and is universally accepted - by all but the seriously weird. I refer to the recent findings of DNA, which we now see contains the ability to self-repair and must have been able to do so millions of years ago - why is this, and does this extraordinary quality come about by accident?
And as a sub-question; aren't you absolutely staggered in wonder?
-- answer removed --
Let's all read Professor Parrington's book, noted by me above, and come back and argue when we are all better informed. He is a fellow of Worcester College (Oxford) and of the British Science Association. He has had over 80 articles published in the academic press, and regularly lectures on this subject. I have heard him speak and have read the book, and it would be entirely pointless to continue this argument without the facts he provides.