{"id":64,"date":"2021-10-19T14:56:27","date_gmt":"2021-10-19T14:56:27","guid":{"rendered":"https:\/\/journalofcosmology.com\/?p=64"},"modified":"2021-11-16T16:15:48","modified_gmt":"2021-11-16T16:15:48","slug":"abiogenesis-origin-of-life-everything-we-know-so-far","status":"publish","type":"post","link":"https:\/\/journalofcosmology.com\/life100.html","title":{"rendered":"Abiogenesis (Origin Of Life) – Everything We Know So Far"},"content":{"rendered":"\n

Abiogenesis, the origin of life from inorganic matter some 3.5 billion years ago, remains one of the central mysteries of biology. The confounding and engaging nature of how life began is also a question of how (or why) human life began. <\/p>\n\n\n\n

The very question seems to destroy something of an implacable binary central to our understanding of the world. It suggests that the relationship between animate and inanimate matter between ourselves and the ground we walk on is more of a continuum than a line in the sand.<\/p>\n\n\n\n

An Autocatalytic Reaction<\/h2>\n\n\n\n

There is a significant debate amongst scientists in the field as to the precise nature of life\u2019s first origins from inorganic matter. Still, most consider one foundational idea to be factual. <\/p>\n\n\n\n

Most scientists now believe an autocatalytic chemical system<\/a> was in play before life began, the existence of which was key to life\u2019s origin.<\/p>\n\n\n\n

What do we mean by autocatalytic? In chemistry, a catalyst is a thing that helps engender chemical reactions or allows those reactions to function more quickly (or more efficiently). A catalyst catalyzes. In the human body, several well-known catalysts help keep our bodies healthy and running. <\/p>\n\n\n\n

Take lactase, for example. Lactase is a catalyst that the human body produces that helps us break down milk for our consumption. When human beings are lactose intolerant, they lack properly functioning lactase in their body to help break down the milk.<\/p>\n\n\n\n

An autocatalytic reaction would be a catalyzing chemical process that produces more catalysts to continue the catalysis. In other words, the autocatalytic system is autonomous because it creates the material required for its perpetual existence.<\/p>\n\n\n\n

The autocatalytic reaction theory\u2019s broad acceptance ends at the thought of its existence. Beyond the fact of an autocatalytic chemical reaction engendering life\u2019s origins, scientists have demonstrated two different theories as to the nature of the autocatalytic reaction that began life on Earth.<\/p>\n\n\n\n

Theory 1: Replication First<\/h3>\n\n\n\n

The first theory of autocatalytic reactions that created life is known as \u201creplication first.\u201d In this theory, there are compounds known as oligomeric compounds (some commonly known oligomeric compounds in the human body include hemoglobin and peptide) that helped catalyze the emergence of life through their self-replicating ability. <\/p>\n\n\n\n

The self-replicating nature of oligomeric compounds is not under debate and has been a firm establishment for more than 100 years<\/a>. What is up for discussion with the \u201creplication first\u201d theory is whether or not such replication could feasibly allow life to form from nothing. <\/p>\n\n\n\n

Theory 2: Metabolism First<\/h3>\n\n\n\n

In the second theory, it is not a self-replicating system that allowed for the emergence of life but, as Stuart Kaufmann suggests in Investigations<\/a>, cyclic metabolic systems formed before the advent of life.<\/p>\n\n\n\n

The so-called \u201cmetabolism first\u201d theory demonstrates a model of life whereby a system existed via catalysis, creating energy of its own accord. This energy is what stimulated the emergence of a self-replicating life form from the primordial soup. <\/p>\n\n\n\n

Theory 3: Metabolism and Replication<\/h3>\n\n\n\n

The third and final theory for a pre-life system that engendered the existence of life on Earth is a compromise between the first two theories. It states that systems may have simultaneously existed — that is, those of self-replication and metabolism that paved the way for life. <\/p>\n\n\n\n

Is Pre-Darwinian Evolution Possible?<\/h3>\n\n\n\n

A single hypothesis unifies the three theories outlined above: namely, that evolution existed before life. In other words, an evolution not related to the passing on of genetic traits from parent to offspring, but rather a non-competition-based shift that allowed Darwinian evolution to form.<\/p>\n\n\n\n

In Marc Tessera\u2019s paper<\/a>, Is Pre-Darwinian Evolution Possible, he brings to light two significant problems that an autocatalytic self-replicating system would need to address to \u201cevolve\u201d such that Darwinian evolution as we know it would be possible. <\/p>\n\n\n\n

The first is the question of heredity. For evolution to exist, Tessera argues that there must be a \u201cpassing-down\u201d of genetic information, whereby mutations can occur and progress towards efficiency may be achieved. <\/p>\n\n\n\n

The second is the question of chirality. Chirality is a complex topic<\/a> in biology that is beyond the scope of this article. Still, we may state a simple definition. Chirality describes a molecule whose shape is asymmetrical, but that forms a symmetrical shape when put next to its mirror image.<\/p>\n\n\n\n

Though the question of symmetry may seem obscure and unimportant in the grand scheme of life, we can boldly claim that, in fact, life as we know it would not exist without chiral molecules. Most significantly, our genetic material (DNA in humans, although it would have been RNA in the first molecules) is chiral. The fact that they are chiral allows them to replicate. Their replication is central to life.<\/p>\n\n\n\n

1, 2, or 3: Choose a Door <\/h3>\n\n\n\n

With Tessera\u2019s contention that the question of chirality and heredity must be present in a pre-Darwinian system, he brings up problems with all three theories mentioned above in his paper. <\/p>\n\n\n\n