It’s his last book Darwin wrote a book on worms. He was interested in worms because they were a metaphor. The worms slowly churn the topsoil beneath our feet, we never notice. We think they are insignificant because they’re so small and lowly, but they are in fact producing the very soil that is the basis of agriculture.
Darwin understood the importance of apparently tiny things that are extended over long periods of time. And that’s what evolution is, the extension of small change over vast periods of time. So the worms become a metaphor for evolution and for the whole process of temporal change, a very fascinating book.
“Stephen Jay Gould: The Unanswerable” (Aug 30, 2016) VPRO, A Glorious Accident (6 of 7) 22:01.
A billion years is 40,000,000 lifetimes of 25 years. A billion years is a vast period of time. It is generally agreed that the world or at least our corner of the universe is just under 5 billion years old, 4.54 ± 0.05 billion years to be somewhat inexact because that is a tolerance of ± 0.05 of a billion is a tolerance of ± 2,000,000 human lifetimes of 25 years.
4.54 billion years ago a primal supernova seeds our galactic neighborhood with heavy elements that will be incorporated into the Earth. That supernova results in a shock wave in a dense region of the Milky Way galaxy. 100 million years pass and a Proto-Earth forms at the outer (cooler) edge of the habitable zone of the Solar System.
The Precambrian period of geological time from the formation of our Earth to the time when creatures first developed exoskeletons (i.e., hard outer parts) and thereby left abundant fossil remains is 85% of the life of the earth.
4,500 Ma – Hadean Eon, the Earth–Moon system forms, possibly from an impact that vaporized a large amount of the crust, and sent material into orbit around Earth, which lingered as rings, similar to those of Saturn, for a few million years, until they coalesced to become the Moon. During this early bombardment phase, energy is released by the planetary core forming. Outgassing from crustal rocks gives Earth a methane, nitrogen, hydrogen, ammonia, and water vapour atmosphere. Over time the Suns solar wind sweeps the Earth-Moon system clear of debris
c. 4,100 Ma – Late heavy bombardment of the Moon and Earth by asteroids, produced possibly by the planetary migration of Neptune as a result of the forces of Jupiter and Saturn. “Remains of biotic life” were found in 4.1 billion-year-old rocks in Western Australia. According to one of the researchers, “If life arose relatively quickly on Earth then it could be common in the universe.”
c. 3,500 Ma – The Last universal ancestor: split between bacteria and archaea occurs as “tree of life” begins branching out.
c. 2,707 Ma – Blake River Megacaldera Complex begins to form in present-day Ontario and Quebec – first known Precambrian supervolcano – the earlist signs of the Canadian Sheild created from the Misema Caldera – coalescence of at least two large mafic shield volcanoes.
And that is the first point in our journey of 5 billion years, half way thru at about 2.5 billion years you might be able to stand on the spot that is now our little farm with its beaver ponds, cattle pastures and forests of maple, red oak and basswood.
Of course it would look different, you would be within a stones throw of volcanic crater that stretched 8 miles wide and 40 miles long that was possibly still spewing out what is today the Canadian Shield. But all this will change, what is needed is another billion years, an ice age and a big thaw.
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This article was summarized from 2 Wikipedia sources
The age of the earth
The natural history of the early earth