A (Very) Short History of Life on Earth

The book was published in 2021 by Henry Gee. The title of this book is “A (Very) Short History of Life on Earth”, and the subtitle stresses book’s briefness by quantifying it: “4.6 Billion Years in 12 Pithy Chapters”!

The book begins with explanation of how our world was shaped; and continues describing every major change made in our world, until the time when humans were able to conquer the world. Final chapter is a predication of destiny of our world into the future. Each chapter of the book begins with a graph. First graph at the beginning of the first chapter describes in brief the beginning and ending of our galaxy. It estimates that our galaxy began its life ten billion years ago and will die (or will merge with another galaxy) five billion years from now.

Various geological periods and certain scientific terms are repeated throughout the book; however, the book is written in a simple, humorous language readable by a layman. For instance, first chapter that is titled “A Song of Fire and Ice”, begins by describing the death of a star. The process of a star losing its energy and suddenly disappearing is described, along with the birth of a new star, our sun. After million of years, our earth is born. Hundred million years later, life begins on earth. The earliest life form is bacteria, which is explained in detail how it was shaped, including variation of such life form: “Life entered the lists as a range of peaceable seaweeds, algae, fungi, and lichens,” (P. 13).

Second chapter is titled “Animals Assembled”, and it begins with the breakup of supercontinent Rodinia over eight hundred million years ago. The environment goes through sever revolution and heavy weathering. The sea level rises, which creates more space for more variety of marine animals. Some simple life forms are shaped at the beginning of this period. By the end of the period, all marine animals present on earth are shaped and formed: “By the end of the Cambrian period, all the major groups of animals still around today had made their first appearance in the fossil record,” (P. 27).

Next chapter is titled “The Backbone Begins”, and as it sounds, this chapter provides the defense mechanism evolved during this period. In order to survive, every living thing needs to find nourishing materials. Animals survived on consuming other living things, whether in the form vegetation or flesh and bone. During their evolution, animals found out that size was important. The bigger the size of the animals, smaller chance to be eaten. Another way to survive was by creating armors. It is explained in this chapter how early animals started inventing and creating various kinds of armors for defense. In describing one of these animals, its form of defense is also explained: “Another difference from Dunkleosteus- and every other placoderm- was that the jaws were fringed with bones recognizable by comparison with a modern bony fish: there was a distinct upper jaw (maxilla) and lower jaw (mandible). This creature, Entelognathus, was the earliest vertebrate that could crack a smile that we would recognize,” (P. 40).

Chapter four is titled “Running Aground”, which is the time sea creatures ventured stepping out of the water. It explains why animals did not approach moving to the land earlier, because of the scarcity of the land and the harshness of living on land versus continuing living in the sea. As it was mentioned earlier, some animals survive by consuming each other, and moving to the land would seem to remove them from the access of the predators. Accordingly, animals began moving out of the sea and into land around 470 million years ago. Plants started growing on land as well, and there were woodlands of nematophytes, mosses, and ferns eighty million years later. However, for million of years plants were not a source of animal foods. Some animals began new way of reproduction on land, such as laying eggs. It would be more dangerous to lay eggs in the water, as those eggs were easily consumed by other animals: These were animals that would, one day, evolve into reptiles, birds, and mammals,” (P. 55).

“Arise, Amniotes” is the title of the fifth chapter. It was mentioned in the previous chapter that animals did not feed on vegetation. In fact, this chapter explains how trees of that period differed from today, with a root system that absorbs nutrients from the ground water and grows and lasts for many decades. Trees of those periods not only did not look like trees of today, but the way they received their nourishment was also different. Advancement of forests, along with adaptation of some species are subjects discussed in detail in this chapter as well. At the time that vegetation and animal life was established on the surface of the land, a disaster destroyed almost all. Near the end of the Permian period Hell broke out, as the book termed it: “The ground fractured. Lava oozing from myriad fissures eventually paved an area the size of what is now the continental United States, from the Eastern Seaboard all the way to the Rocky Mountain front, in black basalt thousands of meters thick,” (P. 71) As a result, a great majority of life on earth vanished: “By the end, nineteen of every twenty species of animal in the sea and more than seven out of every ten on land had been driven to extinction. Among the dead were animals that have left no descendants or close relations,” (Ps. 73&74). As a result, some amphibians who had ventured to the land, were driven back to the water, if they had survived. The event happened in present China and Western Siberia, but it engulfed a great space and caused extinction of most of the plant and animal lives.

The next chapter is titled “Triassic Park” and it begins with what was left off in the previous chapter, by mentioning that the time of recovery from the disaster took tens of millions of years. It details the species who survived the disasters, and continues with other species emerging in water, on land, and in the air. For example, a marine reptile called Shonisaurus grew to the size of twenty-one meter in length, was one of these sea animals. Many events, including the birth of Atlantic Ocean is mentioned to have happened in this period. Of course, each event causes extinction of some species and birth of new ones: “That the dinosaurs survived, when so many similar crocodile-like creatures did not, remains a mystery,” (P. 89).

Next chapter is titled “Dinosaurs in Flight”, which is clearly the story of flying dinosaurs. It begins with claiming that dinosaurs, being bipedal, were built to fly. The book explains that by this period, dinosaurs had concurred a land mass and they were ready to fly in the air. One of the reasons for flying was to scape from predators. Dinosaurs are known for being large in size, however, there were smaller dinosaurs, such as microraptor. Considering that the range between the size of the dinosaurs is very wide, it is explained why dinosaurs could have such a variety of sizes, due to their breathings. Also, their survival and expansion are also explained, to have occurred due to their reproduction method, as they laid eggs. How mammals could progress in the absence of dinosaurs is also explained, which is in brief due to shedding hair, and other physical changes. Flying methods and how dinosaurs got the capability to fly is explained in detail. Dinosaurs enjoyed ruling the earth much longer than humans did, and they were killed off and wiped out of the face of the earth suddenly and forever: “The impact of an asteroid some sixty-six million years ago brought the world of the dinosaurs to a sudden end,” (P. 108).

The title of chapter eight is “Those Magnificent Mammals”! The chapter begins by explaining various mammalian functions, such as hearing, speaking, chewing, breathing, and other purposes, in order to arrive at the brain and its functions. Mammals, like other species, laid eggs as a means of reproduction. In order to have larger brains, change from laying many eggs to mostly delivering one baby at the time, became an option for most mammals. As long as dinosaurs were roaming the earth, mammals had to stay small, not larger than an opossum. “By the time dinosaurs died out, all but four of these lineages, bubbling and vivacious as they were, had become extinct,” (P. 122). By disappearance of dinosaurs, mammals lost their biggest threats, although there were other predators threatening them as well. As Africa separated from South America, it was cut off from the rest of the world for forty million years.

“Planet of the Apes” is the title of the ninth chapter. It begins by explaining in detail separation of various continents from each other, and the effect of changing weather on those continents. Changes in the atmosphere resulted in changes in habitation, as some hominins, human lineage, started walking upright, around seven million years ago. Changes made in the body, to accomplish this bipedality is explained in detail. There is an interesting observation about the achievement made by walking on two feet, instead of four, that with all the progresses of science in subatomic particles and discovering black holes and visioning beginning of the universe, humans have not been able to create a robot that can walk on two legs! Using tools by hominins is another subject discussed here, especially when they started to eat meat. Another revolutionary achievement after standing upright was that: “they learned how to run,” (P. 139).

Chapter ten is titled “Across the World”. This chapter begins with explaining why the turn of the earth around the sun is elliptical instead of circular. It also discusses in detail the turning of the earth around its own axis, and the advantages of such event. Homo erectus is the next subject the book discusses in detail. Working together as a team for hunting, discovering advantages of cooperating resulting in living together, discovering fire, all created stronger relationships. Creation of hand axe by homo erectus is described in detail, along with their departure from Africa of two million years ago, and before they were extinct fifty thousand years ago. Neanderthals are next species discussed. By the end of the ice age, the book mentions why hominins survived.

The title of chapter eleven is “The End of Prehistory”. There are a few interesting and unique subjects discussed in this chapter. For example, the subject of birth, followed by menopause which is unique to humans. Humans are also unique in a sense that not only they learn, like other species, but elders teach the young ones. Three hundred thousand years ago, homo sapiens appeared in Africa, and years later, started migrating. Human migration to other parts of the world, such as Arabia, Asia, Australia, Europe, and India, is also discussed. “After 4.5 billion years of mindless tumult, the Earth had birthed a species that had become aware of itself,” (P. 179).

Last chapter is titled “The Past of the Future”. In this chapter, the author looks at the past one more time, in order to be able to foresee the future. Events of extinctions are briefly reviewed again, including twenty ice-ages. Humans’ forms of living and their population is examined, and its rapid advancement since the industrial revolution is noted. The remaining of the chapter is prediction of environmental disasters in various parts of the earth. Although it is, timewise, far into the future, final paragraph of this chapter is very disappointing: “In a billion years or so, life on Earth, which has so adroitly turned every challenge to its existence into an opportunity to flourish, will have, finally, expired,” (P. 200).

There is an epilogue at the end of the book, which is more optimistic. However, with the recent events, such as global warming and destruction of the ice sheets, one would wonder if the human being can survive even for the time period this book is foreseeing. Our history shows many empires rising and falling. However, we have witnessed or have read about falling empires, none of which has disappeared peacefully, and they all accepted their fall after a bloody war. Considering that the United States is the current empire who has already ignited a war in Ukraine, and with the knowledge that military spending and number of military garrison owned by this country around the world surpasses any other country by far, and with the knowledge of so many countries stockpiling nuclear bombs that can destroy our globe several times over, one would be hesitant to think of humanity existing passed this century alone.