One question of the origin of life in particular remains problematic: what enabled the leap from a primordial soup of individual monomers to self-replicating polymer chains? A new model proposes a potential mechanism by which self-replication could have emerged. It posits that template-assisted ligation, the joining of two polymers by using a third, longer one as a template, could have enabled polymers to become self-replicating. More.
Not again. Yawn. Isn’t this a point where we should be asking fundamentally different questions?
When Charles Darwin published his seminal On the Origin of the Species in 1859, he said little about the emergence of life itself, possibly because, at the time, there was no way to test such ideas. His only real remarks on the subject come from a later letter to a friend, in which he suggested a that life emerged out of a “warm little pond” with a rich chemical broth of ions. Nevertheless, Darwin’s influence was far-reaching, and his offhand remark formed the basis of many origins of life scenarios in the following years.
Yes. And all were a waste of time. See Maybe if we throw enough models at the origin of life… some of them will stick? None did.
So who cares what Darwin thought anyway? Has anyone ever thought of challenging this crap on an evidence basis? Or is he the deity in whose name these guys fight?
Today, it is widely believed (though by no means universally accepted) that at some point in history, an RNA-based world dominated the earth. But how it got there — and whether there was a simpler system before it — is still up for debate. Many argue that RNA is too complicated to have been the first self-replicating system on earth, and that something simpler preceded it.
Like we said before, if we really wanted them to fail, we’d be sure to encourage them to keep on trying this stuff. But curiously, we aren’t the ones doing so.
See also: Welcome to “RNA world,” the five-star hotel of origin-of-life theories
Here’s the abstract:
Self-replicating systems based on information-coding polymers are of crucial importance in biology. They also recently emerged as a paradigm in material design on nano- and micro-scales. We present a general theoretical and numerical analysis of the problem of spontaneous emergence of autocatalysis for heteropolymers capable of template-assisted ligation driven by cyclic changes in the environment. Our central result is the existence of the first order transition between the regime dominated by free monomers and that with a self-sustaining population of sufficiently long chains. We provide a simple, mathematically tractable model supported by numerical simulations, which predicts the distribution of chain lengths and the onset of autocatalysis in terms of the overall monomer concentration and two fundamental rate constants. Another key result of our study is the emergence of the kinetically limited optimal overlap length between a template and each of its two substrates. The template-assisted ligation allows for heritable transmission of the information encoded in chain sequences thus opening up the possibility of long-term memory and evolvability in such systems. Open access – Alexei Tkachenko and Sergei Maslov. Spontaneous emergence of autocatalytic information-coding polymers. The Journal of Chemical Physics, 2015 DOI: 10.1063/1.4922545
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