Review | El Origen de la Vida: Evolucion quimica y evolucion biologica

Ever since I was a child, I was fascinated by the possibility of life in other parts of the cosmos. Among my children’s library was an atlas of the universe, full of photographs and illustrations of galaxies, nebulae and supernovae. On those hypothetical planets, filled with amazing landscapes, I imagined the nature of other living beings. Science fiction drove my passion for exobiology even more, but it was popular science that led me to study physics. Antonio Lazcano is a Mexican biologist and scientist specialized in evolutionary biology and the origin of life. Like me, he is a graduate of the School of Sciences of the National Autonomous University of Mexico, where he founded the Origin of Life as a course and laboratory. Today I bring you the review of a book in Spanish that he wrote in 1976 and that was published by Trillas at the end of the 80s, which is an excellent complement to Oparin’s book ‘The Origin of Life’, a masterpiece of evolutionary thought.

In the first two chapters of “El origen de la vida: Evolución química y evolución biológica” Lazcano introduces us to the historical panorama surrounding the question that remains unresolved today: what is the origin of living beings? Thus, we go back to antiquity, where the first cosmogonies regarding spontaneous generation began to develop, whose corollary was the vitalist doctrine, which establishes that the functions and processes of life are due to a vital principle different from the physicochemical forces, and that the laws of physics or chemistry, by themselves, cannot explain such vital processes and functions. As an alternative to this perspective we find materialism, a narrative that holds that matter is the fundamental substance of nature, and that all things, including life, are the result of their interactions.

Although it is true that many authors prior to the second half of the 19th century had been concerned with the problem of the origin and evolution of species, it was Charles Darwin who proposed that living beings are not immutable and are constantly changing by means of natural selection. But it was not until the first part of the 20th century that we find the Oparin-Haldane theory, an inflection point in scientific thought regarding the origin of life, which proposes the idea that on the early Earth there were certain temperature conditions that affected the substances that existed then in the primitive seas, giving rise to living beings. This overthrew the vitalist scheme, placing us in an extraordinary panorama: we are all connected, to each other biologically, to the earth chemically, to the rest of the universe atomically.

From this point Lazcano takes us by the hand to study the evolution of matter in general. First, he studies the origin of the chemical elements, where the stars and their remnants acted as colossal furnaces capable of synthesizing heavy elements. Gravity, as if it were the hand of an apprentice baker, molded the clouds of interstellar dust, thus forming the first solar systems. In the darkness there was already a primitive Earth, where condensation reactions fueled by solar radiation, the heat of volcanoes and other primitive energy sources produced the first polymolecular systems. When studying the origin of precellular systems, the author lists a couple of models that turn out to be strong candidates as protobionts. These include coacervates, proteinaceous microspherules, sulphobes and colpoids.

When we go back to the origin of living beings, the author begins by introducing the genetic code as a fundamental piece for the functioning of life, perhaps being what gave rise to the distinction between protobionts and eubionts. At this point Lazcano introduces us to the study of viruses, small protein capsules surrounding a nucleic acid molecule, whose simplicity has not prevented them from lasting for billions of years and being a potential source of complexification in life forms. Despite being an introductory book, the text offers us a fascinating compendium on the possible (and potential) evolutions of metabolism, as well as the multiple theories that explain how life came to diversify. This is undoubtedly an excellent bibliographical reference that will allow high school students to enter the amazing world of the origin of life.

Closing with a flourish we come to my favorite part of the text. Although the origin of life on Earth is a fascinating topic, in order to characterize life in mechanistic terms it is necessary to observe instances of organisms beyond our planet. In this way, Lazcano introduces us to the study of exobiology, analyzing the possibilities of biological analogues in our solar system, from Venus and Mars to the moons of Jupiter and Saturn. Although the author does not delve into life forms based on exotic chemistries or how the physical qualities of a solar system can influence the development of living things, he still offers a glimpse into the fascinating world of astrobiology, stimulating the reader’s curiosity. At the same time, at the end of his text he recommends a list of specialized readings on the subject, ranging from the basic to the advanced, which function as a complement to his book.

Science popularization today remains a fundamental pillar for the development of science as we know it. Although it is now less and less common to find popular science texts, we can observe the emergence of websites and social media accounts whose purpose is the same: to transmit complex knowledge to the general public in a friendly and inspiring way. El origen de la vida by Antonio Lazcano is part of the collection El Universo de la Biología. Each book synthesizes the content of a particular area of biology, without losing sight of the big picture and thus allowing a better understanding (and management) of the concepts, their ramifications and implications. Like this collection, there are many others (in mathematics, physics or chemistry) that continue to motivate curious young people to study natural sciences. Particularly I was one of those who found in pop-science a way to satisfy their curiosity.