The first step from molecules to life: Formation of large random molecules acting as micro-environments

The mathematician John von Neumann, through his work on universal constructors, discovered
a generalized version of the central dogma of molecular biology biology in the 1940s, long 
before the biological version had been discovered. While his discovery played no role in the 
development of molecular biology, we may benefit from a similar mathematical approach to find 
clues on the origin of life. This then involves addressing those problems in the field that 
do not depend on the details of organic chemistry. We can then consider a general set of 
models that describe machines capable of self-maintenance and self-replication formulated in 
terms of a set of building blocks and their interactions. 

The analogue of the origin of life problem is then to explain how one can get to such 
machines starting from a set of only building blocks. A fundamental obstacle one then faces 
is the limit on the complexity of low fidelity replicating systems, preventing building 
blocks from getting assembled randomly into low fidelity machines which can then improve due 
to natural selection [1]. A generic way out of this problem is for the entire ecosystem of 
machines to have been encapsulated in a micro-structure with fixed inner surface features 
that would have boosted the fidelity [2]. Such micro-structures could have formed as a result 
of the random assembly of building blocks, leading to so-called percolation clusters [2].

This then leads us to consider how in the real world a percolation process involving the 
random assembly of organic molecules can be realized. A well studied process in the 
literature is the assembly of organic compounds in ice grains due to UV radiation and heating 
events [3,4,5]. This same process will also lead to the percolation process if it proceeds 
for a sufficiently long period [2].

In this talk I will discuss the percolation process in more detail than has been done in [2], 
explaining how it leads to the necessary symmetry breakings such as the origin of chiral 
molecules needed to explain the origin of life.   

 

[1] Eigen, M., 1971. Self-organization of matter and the evolution of biological 
macromolecules. Naturwissenschaften 58, 465-523.

[2] Mitra, S., 2019. Percolation clusters of organics in interstellar ice grains as the 
incubators of life, Progress in Biophysics and Molecular Biology 149, 33-38.

[3] Ciesla, F., and Sandford.,S., 2012. Organic Synthesis via Irradiation and Warming of Ice 
Grains in the Solar Nebula. Science 336, 452-454.

[4] Muñoz Caro, G., et al., 2002. Amino acids from ultraviolet irradiation of interstellar ice 
analogues. Nature 416, 403-406.

[5]  Meinert, C,., et al., 2016. Ribose and related sugars from ultraviolet irradiation of 
interstellar ice analogs. Science 352, 208-212.