“A (Very) Short History of Life on Earth: 4.6 Billion Years in 12 Pithy Chapters” by Henry Gee
I came across this book when I first listened to Henry Gee’s interview at Inquiring Minds podcast, which was intriguing and hilarious. Now this is a guy who really knows his stuff about science, but have a twisted sense of humour to go along with it. My kind of guy.
But it wasn’t until I finish reading The Brief History of Time by Stephen Hawking that I really look for this book (which apparently I have already bought months ago – talking about Tsundoku), because to be frank I didn’t understand half of what professor Hawking was saying and I thought maybe I can understand the universe better when it is accompanied by jokes.
Little did I know that in this book Gee puts all the jokes at the appendix and instead writes a serious, condensed, and very organised history of Earth, from the ground up. Which is surprisingly brilliant. While professor Hawking’s book was about the theories of space, this book is more focused on the evolution occurring inside Earth. A 4.6 billion years worth of evolution in a very readable style of writing with a nice flow, which is very useful to help us understand a difficult subject.
The book seems to cover everything, from the supernova, to the formation of the sun and Earth, then to the focus of the book inside our planet: the beginning of life at the bottom of the sea, the many weird-sounded bacterias, the evolution of animals, the beginning of life at land, the several extinctions, the ice ages, the evolution of plants and their exponential growth, when animals began to crawl, the different environments in the several supercontinents, the range of types of dinosaurs and pterosaur (and their evolutions), and many more, including the emergence of the many different types of human.
Meanwhile, every once in a while there are amusing facts that is just mind blowing. For instance, I never knew that the Earth once had a ring like Saturn, at the beginning there was no ozone layer to protect the living things from direct sunlight, there once a Great Oxidation Event between 2.4 – 2.1 billion years ago where the concentration of oxygen first rose sharply (greater than today’s 21%) then collapsed to below 2% which had a tremendous effect on life on Earth, and how the development of anus eventually leads to the evolution of larger life forms at sea.
It’s also so fascinating to see how different eras on Earth looked very different from one another, with different flora and fauna (like Therapsids that dominated Pangea), different continent formations, even different atmosphere and temperature. Indeed, the Earth keeps evolving and changing, with many different new animals and plants eventually replace the extinct ones, and where the inhospitable place slowly turned to the goldilocks environment for all Earth’s current creatures to thrive today. All of these are vividly described in this book.
Which got me thinking. What would the world looks like in 10,000 years? In 1 million years? Will homo sapiens survive or will we be replaced with other superior beings? Will we have futuristic towns or will our megacities be eaten back by the forests?
Gee actually has an answer to this, a calculated guess based on the trajectory of the biological history that he has just presented. “Within the next few thousand years, Homo sapiens will have vanished,” he remarked, “The cause will be, in part, the repayment of an extinction debt, long overdue.”
The first in line in the extinction debt is the failure to re-polulate. As Gee analyze, “The human population is likely to peak during the present century, after which it will decline. By 2100, it will be less than it is today.” This can be predicted using the Total Fertility Rate (TFR) – the rate where babies must be born to outpace the death rate – where 183 out of 195 countries that were studied show they would have a TFR lower than 2.1 children per mother by 2100, which indeed suggest the global population will be smaller than today.
And this will occur due to a combination of habitat loss, reproductive failure due to changes in the environment and human behaviour, events deep in prehistory (whatever that means), and local problems such as a small tribe find themselves cut off from other of the same kind.
Another factor in the extinction debt is indeed the issue of global warming. As Gee noted, “The atmospheric concentration of carbon dioxide over the past eight hundred thousand years or so has never exceeded about [sic] 300 ppm. In 2018, it exceeded 400 ppm as a result of human activity, a concentration not seen for more than 3 million years.”
As a consequence the greenhouse gas effect from the excess carbon dioxide will eventually makes our planet warmer, and “The glaciers will, nonetheless, grind onward and recede, advance and recede, many more times. The human-induced injection of carbon dioxide will set back the date of the next glacial advance, but when it comes, it will be all the more sudden. Climate-induced calving of icebergs into the oceans, especially the North Atlantic, will add so much fresh water to the ocean that the Gulf Stream will seize up, and Europe and North America will be plunged into a full-scale glaciation over the course of less than a human lifetime. But no humans will be there to feel the cold.”
Bleak stuff, I know, but judging from the history of the Earth, this is just part of the evolution, even if the warming is greatly enhanced by human activities. Because it has always been like this since 4.6 billion years ago, and we’re just happen to live in a relatively calm period on Earth that makes life for us sapiens possible.
And as it has always been, the Earth is constantly changing – scientists are even unanimous that there will be another supercontinent formed in another 250 million years – while the creatures from our period will vanish and be replaced by the new ones, or replaced by nothing for another millions of years.
As Gee added, “Models of the carbon cycle suggest that life will die out between 900 million and 1.5 billion years in the future. A billion years after that, the oceans will boil away. What happens after that depends on how fast the oceans boil. Fast, and the Earth will dry out and become a hot desert planet. Slow, and much of the atmosphere will shroud the Earth, creating a greenhouse effect so powerful that the surface of the planet will melt.” What happened with the planet Venus comes in mind when reading about this sentence.
The book ends at the 67% mark on Kindle, with the remaining pages serve as the massive appendix of notes, references, and jokes (with personal stories too). Make sure not to miss them. All in all, it is an excellent book that shows the grand evolution of planet Earth but written in a digestible way that makes it easy to understand. No wonder that this book won The Royal Society’s Book of the Year Award in 2022.
THE CHAOS THEORY 