The problem of the origin of life

In a previous post titled Paul Davies, popularizer of science, I mentioned the two hard problems of modern science, so called because after several centuries trying to solve them, and although considerable progress has been made, the solution to these problems seems to recede further as we move forward, a paradigmatic case of the horizon effect, which I discussed in another post in this blog with the same title. These problems are: on the one hand, the origin of life, and on the other, the origin of free will, which is sometimes identified with the problem of consciousness, although they are not exactly the same, but are closely related. In this post, I will discuss the first problem. The next post will deal with the second.

The problem of the origin of life is not scientific. It is historical. Happened only once in the history of our planet, and is impossible to reproduce, so it is beyond the reach of experimental science. Even if we were able to create synthetic life (not to be confused with artificial life, a branch of computer science), we would not know if that method of generating life was the same as what took place shortly after the origin of the Earth.

What is the problem? The origin of life has left no fossil traces because the first living beings were microscopic and lacked hard parts. Furthermore, it seems likely that these beings first emerged in environments far beyond our reach, such as hydrothermal vents located on the ocean floor, in places where the Earth's crust is getting apart due to the pressure of magma ascending from the Earth's mantle.

An additional problem is the fact that we cannot agree on a definition of what is life, one more reason why the origin of life eludes us.

The book Free Agents by Kevin Mitchell, in chapter 2, titled Life Goes On, details the current theory about the origin of life, which, although it seems plausible, will never be conclusively proven.

This is the currently proposed scenario: In hydrothermal vents, rocks are riddled with countless fissures and holes, where hot water accumulates. The energy input from the mantle could have triggered the formation of many chemical precursors of life, which would have been enclosed in microscopic rock compartments that could have acted as cell membranes, later originated from lipids. Once these membranes appeared, nascent life was able to detach from the rocks, spread throughout the rest of the ocean, and take advantage of other energy sources.

This book uses criterions to define life, not usually found in this context:

Living beings are autonomous entities, imbued with purpose and able to act on their own terms, not yoked to every cause in their environment but causes in their own right... What distinguishes living organisms is that they do things, for reasons.

...living things, to stay organized, must keep working against what is known as the second law of thermodynamics... life is not a state; it is a process.

Continuity is the defining property of life. In a unicellular organism, the whole imposes constraints on the parts: all the interlocking feedback interactions keep all the biochemical processes organized in a certain pattern. The organism is not a pattern of stuff; it is a pattern of interacting processes, and the self is that pattern persisting. 

The book describes the evolution of life from the perspective of the emergence of living beings with ever-increasing freedom of choice in their activities. The first four chapters describe how prokaryotes, eukaryotes, and the first animals with a nervous system (the freshwater hydra and the nemathelminth Caenorhabditis elegans) perceive to the world and respond to that perception. The development of this section is parallel and overlaps with the first part of my book, The Fifth Level of Evolution.

In chapters 5 and 6, the book jumps to the mammalian and human level and describes the neurophysiology of vision and cerebrum in considerable detail. And in subsequent chapters it analyzes the other difficult problem of modern science: free will and consciousness. But that will be the subject of the next post.

The same post in Spanish

Thematic thread on Primitive Life: Preceding Next

Manuel Alfonseca