INANIMATE TO ANIMATE--ABIOGENESIS

 

It is an irony that despite our authors dishing out books and novels on extra-terrestrial life forms in the thousands, there is not a single instance where our scientists could credibly establish that alien life exists. Instead we only have Hocus Pocus stories about UFO sightings mostly in the USA none of which have any credible proof.

Yes, as life exists on the Earth, it is a logical necessity that it should exist in other planetary systems going around other stars like the Sun which are too numerous in the Universe. However, there is an immense problem in finding life in other planets if the life forms there are under developed, because they give out very less in terms of signatures (markers that life leaves around) that can be seen as life from other planets.

Living beings on Earth are so minuscule compared to the planet that they inhabit that it is actually like searching for a needle in a haystack. For example the weight of all the living organisms on earth is estimated to be 550 billion metric tons or 55* 10 raised to the power of 9. While the Earth weighs about 6.5 billion trillion tons OR 6.5* 10²¹ tons. That means earth has almost a trillion times higher mass than the entire life on earth combined. So if any alien life forms are searching for life on Earth, for them it would have been very difficult to find us if we never had any electricity that lights up the planet in the night. But again, even those so called numerous lights cannot be seen from the nearest star to us.  

Another thing that is hindering our discovery of other life forms is our bias. We tend to interpret life as it had developed on our planet and place riders on its appearance and composition.

We interpret the creation through Chemistry which is subject created by the human brain. We interpret the interaction between molecules in a certain way as per our structured thinking, but are not in a position to visualize how the structure of matter operates from another view that is totally different from ours. But then, in this we are constrained in our thoughts and cannot think differently than what we do.  

Earth was formed 4.5 billion years ago (this is also called GA or Gigannum) while life began on the Earth some 3.8 billion years ago. So for 700 millions of years after earth formed there was no life. At its formation earth had an atmosphere that was intensely hot and it was far denser than the current atmospheric blanket.  Active volcanoes spewed out massive amounts of steam, CO2, Methane & Ammonia into the air. There was no free Oxygen then as plants and Oxygen producing photosynthesis had not yet evolved.

As the hot earth cooled down, the huge amount of water vapour in the air began to condense and fall as rain. That formed the first oceans. The high energy radiation from the young Sun broke down volcanic ammonia molecules and slowly freed the Nitrogen in the atmosphere.

Life is mostly emptiness pretending to be solid. The thing called “You” is 99.9% nothing. Your atoms are separated by distances that proportionately make Galaxies look crowded. But somehow this organized void learnt to want things to grow and to think.  

Life started at the very edge of nothingness itself, in structures so tiny that they barely qualify as things at all. 20 nanometers ( 1 nano meter equals 10^-9  mtrs or one billionth of a meter) . These things/proto life are called Nanobes and they are tiny threadlike structures found in rocks and sandstone deep underground. This is the smallest level where life can physically exist. Below this size it is so small that it is impossible for any metabolism to exist and Physics breaks down. It is a fundamental law written into the laws of Physics themselves.

According to an article published in 2024 in “Nature”, the minimum viable proto cell  requires about 4 basic components; A membrane to contain it, genetic material to store information, enzymes to catalyse reactions, and Ribosomes to build proteins. If these are packed into anything less than 20 nanometres the cell just cannot function. However about 4 billion ago, life started anyway and Chemistry found a way to be Biology.

We know this because the genetic code is universal. Everything from bacteria to blue whale uses the same basic molecular alphabet, the same 20 amino acids, the same 4 nucleotide bases, the same genetic code that translates DNA sequences to proteins. This universality is almost impossible to explain unless all life descended from a common Ancestor. Scientists call this hypothetical organism LUCA (Last Universal Common Ancestor).

Researchers at the University of Bristol led by Dr Timothy Lenton developed algorithms that can trace the genetic sequences backward through time. Then they calculated back as to how much time this process from the non-living to living would take.  LUCA is incredibly simple, simpler than any living thing that we ever found. It had fewer than 400 genes compared to the 4000 found in the simplest modern bacteria. It was tinier than any cell that exists today. It was found by the researchers that LUCA was somewhere between 20 and 50 nanometres in diameter.     

Amazingly LUCA outsourced most of its requirements from the environment. This is the RNA world hypothesis proposed by Nobel winner Walter Gilbert in the 1980”s. Before DNA, before proteins, before the complex molecular machinery of modern life, there was RNA, a molecule that can store Genetic information like the DNA and catalyse chemical reactions like proteins. But the RNA is fragile and can be easily destroyed by the environment, so how did it survive?

In 2024, researchers from the University of Colorado have shown that RNA could be stable and functional at temperatures exceeding 100 degrees centigrade, but under specific conditions. These exact conditions exist on the walls of the alkaline hydrothermal vents, deep sea structures where mineral rich water erupts from the ocean floor.  This is where there are perfect conditions exist. However, the proto cells that form are incredibly small and are from 10 to 50 nanometres across.

This is also known as Omni. Dr Jack Jostack’s team at the Massachusetts general hospital embarked on a journey to build a proto cell, the complete configuration that can be absolutely genuinely alive at the smallest level. It is they arrived at the 20 nanometres barrier beyond which Physics breaks down.

How did such a profoundly small thing pass on to become higher level of cells? By cooperation. They were too small to thrive independently so they outsourced their functions across thousands or millions of such organisms.  Dr Sara Imari Walker of the Arizona State University is developing theoretical framework for understanding the transition from non-living to the living.

Her research published in Nature Physics in 2024 suggests that life is not the property of individual molecules. It is emergent property of information processing networks. So the first cells were living systems together to produce something larger than the sum of their parts. It is like a distributed computer with many processors. Early life worked the same way. When two protocells come into contact their contents mix, allowing the materials to flow. This was replicated in the laboratories.

That means early life forms could overcome the limitations of Physics via sharing of resources like a cellular internet. But how did these networks stay coordinated? How did they function as a single cell? This is answered by latest research on Horizontal Gene transfer. In modern biology genetic information flows vertically from parent to offspring but in the earlier stages of life genetic material flowed horizontally flowing between different unrelated organisms. It was the primary mechanism for genetic inheritance. Dr Carl Wos revolutionised our understanding   called it the progenate stage of life, a phase where genetic innovation spread rapidly through entire populations. In this the genetic information is passed on to the entire network and not just to the offspring. The network as a whole becomes smarter, more efficient and more adaptive.

The fossil evidence supports this picture. The earliest signs of life dating                3.8 billion ago are not isolated but are vast microbial mats, communities of organisms working to transform their environment. These structures called Strumatalytes still form today in some places like Shark Bay Australia. Being small forced the earlier life to be collaborative,       being simple forced it to become networked. Being limited forced it to become something entirely new. Modern organisms are descendants of this networked stage, but they have lost most of the collaborative abilities their ancestors had. We have traded network intelligence for individual complexity, horizontal sharing for vertical inheritance, collective adaptation for competitive evolution, but traces of the ancient network still exist.

For decades what puzzled the scientists was how random chemical reaction could give rise to the genetic code, the universal language that translates RNA sequences into proteins. What the scientists discovered recently changes what we thought about the origins of the genetic code. In research published in 2024 it was found that information processing does not evolve gradually from random chemistry. It appears suddenly through a process they call informational phase transformation.

Below a certain threshold of molecular complexity RNA sequences behave like ordinary chemicals reacting randomly with the environment. But above that threshold they begin to exhibit properties we associate with information; Pattern recognition, error correction, selective replication. The transition happens at exactly 12 Nucleotides. RNA sequences shorter than 12 bases remain purely chemical. Sequences of 12 or more nucleotides can form stable secondary structures that give them specific repeatable functions. This is the minimum length needed for an RNA molecule to fold into a shape that can catalyse its own replication.

At below 12 Nucleotides RNA is just Chemistry, but at 12 Nucleotides and above it becomes information. Work by scientists now indicates that information processing might be an inevitable outcome of certain type of chemical networks. When you have a system of enough components, enough connections and enough energy flow informational properties emerge automatically. Not through design, not through selection but as a direct consequence of the systems organization. This is called Autocatalytic emergence.

The chemistry creates conditions that favour information processing, and information processing creates chemistry that becomes more organized. It is a feedback loop that drives increasing complexity without any external guidance.

Labs around the world are creating artificial chemical networks that spontaneously develop informational properties. These systems are not designed to process information. They are just mixtures of organic molecules.

Dr Lee Cronin of the University of Glasgow has built chemical computers using nothing but organic reactions in solution. No DNA, no Proteins, no biological components at all. Just carbon based chemistry that has learned to perform computational operations. They are doing computation, but their computer is made of ordinary chemistry rather than silicon and electrons.

Remarkably, these chemical computers can evolve, introduce random mutations into the reaction networks, and the systems develop new computational abilities over time. Not only are they processing information, they are learning to process information more effectively.  This suggests that the transition from chemistry to information processing is not a rare unlikely event that happened once in Earth’s history.  

Metabolism is the life’s solution to the Universes’s most fundamental problem. The 2^nd law of Thermodynamics guarantees that all organized systems will eventually decay into random heat and disorder. Yet everything on Earth somehow builds and maintains complex molecular structures that become more organized over time and not less. This is not a violation of the law of Thermodynamics but it requires something remarkable, a continuous flow of energy that can be captured transformed and used to drive chemical reactions uphill against their natural tendency.

Mitohondria in your cells use Oxygen to extract energy from Glucose through a chain of precisely orchestrated reactions. Chloroplastin plants capture light and use to build sugar molecules from carbon dioxide. These systems are incredibly complex involving hundreds of different              enzymes working in perfect coordination.