PROGRESS UPDATE FOR LIFE: AN UNAUTHORISED BIOGRAPHY BY RICHARD FORTEY
Reading this book is like listening to a conversation by your favourite eccentric professor or grandfather - some random, rambly digressions stuffed between loads of beautifully and richly written natural science. The author's enthusiasm for his subject shines through, making the digressions charming rather than annoying.
Chapter 1 rambles a bit about the author's undergraduate field trip to the Arctic (this guy has far too much fun while freezing his toes off in the middle of nowhere!), but he does explain the vastness of geological time, how geological time is measured/determined, how much information is missing from the fossil record due to the nature of the fossilization process - delicate, squishy, or land-dwelling organisms are less likely to be fossilized than heavier-boned or marine creatures, and a great deal of the fossil record is either buried too deep to be accessible or has been destroyed by subduction or volcanism.
Chapter 2 briefly describes the creation of the Earth, then moves on to discuss early life on the planet, starting with organic chemistry, continuing on to single celled bacteria and then cooperative bacterial mats such as stromatolites, to chemolithoautotrophic hyperthermophiles, archaea, photosynthesis and the Great Oxygenation Event.
I especially enjoyed his information on stromatolites and the visual picture he paints in describing the oxygenation of the Earth with each bacterial "cell exhaling the merest puff of oxygen, such as would fill a balloon smaller than a pin head. Then imagine a world thick with such cells, billions of them, dividing and dividing again, and each time the divide another minute puff of oxygen is given to the air. Then this process continues through generations that can only be reckoned as numerous as the stars in the Universe, And for every generation a thousand billion tiny balloons of oxygen released..."
Chapter 3 briefly covers the development of cells, tissues and bodies. Fortey makes is abundantly clear that the division between plant and animal isn't always clear cut and that their are several great divisions of life. He uses fungi (which are closer to animals than plants) and slime-mould as examples of this. This chapter also focuses on the earliest know complex multicellular organisms found in the Precambian seas, the Ediacaran fauna (e.g. jellyfish, frond-shaped Charnia, amoeba, stromatolites), the organelle capture hypotheses which allowed for complex cells to be created, and the invention of sex which allows for an exchange of genetic material.
Chapter 4 discusses the Cambrian explosion (its fossils and life forms) and the secretion of skeletons and shells. In this era, animals with skeletons appeared for the first time; such creatures as the first diminutive molluscs, earliest brachiopods, trilobites and other arthropods. These were not primitive organism as they had fully developed nervous systems, a brain, eyes (trilobites had crystal eyes!), limbs, gills and antennae. Fortey spends some time showing us that the importance of the Cambrian fossils is "not as a potpourri of zoological strangeness but rather as a key to understanding the state of the animal world close it its birth". The Cambrian evolutionary explosion is the threshold where leisureliness disappeared from the story of life. The animals that evolved in the Cambrian would have crawled, mated, evaded predators, hunted, scavenged, grazed and vied with one other: "competition was introduced into ecology."
So far, I have found this book an enjoyable and informative reading experience with lovely, rich language one can savour.
OTHER BOOKS THAT COVER TOPICS DISCUSSED IN CHAPTER 1-4
The Planet in a Pebble - Jan Zalasiewicz
The Goldilocks Planet - Jan Zalasiewicz
Oxygen - Nick Lane
Power, Sex, Suicide - Nick Lane
Trilobite - Richard Fortey
Tales from the Underground - David W. Wolfe
Life's Engines - Paul G. Falkowski
I Contain Multitudes - Ed Yong
Amoeba in the Room - Nicholas P Money