During a long quarantine such as we are now undergoing it’s a good time for stories, as the locked-up Florentines of 1348 famously told, in Boccaccio’s Decameron. Although the seven young women and three young men of his devising were in self-imposed quarantine, they were not enjoined to keep six feet of social distance as we are, making the conviviality of storytelling possible. We today, not only more separated but more used to being entertained than to entertaining ourselves, are more likely to be reading to pass away the hours than inventing our own stories.  

Some are reading mysteries long on our lists, others are attacking recent best-seller fiction.  Yet others are glad to re-visit the classics of their youth, now all but forgotten and so read as new by selves grown older and wiser.  For me, however, when locked in, and locked up, the best thing to read is of travel, through time as well as space.  Thus, Lewis Dartnell’s Origins: How the Earth’s History shaped Human History was my choice for the first weeks of confinement.

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He brings us a geo-history of mankind, which is to say, how geology, geography, earth spin and rotation, and the climate patterns resulting, shaped human history — not only in long term evolution from single-celled creatures to homo sapiens but in relatively recent times.  The Huns did not sweep into Eastern Europe because they were mad orientals with a taste for bloody excitement, but likely because climatic conditions –drought– severely reduced their grazing lands and the herds they could sustain.  Like people throughout human history, they did what they knew how to do to remedy the situation; they went out looking for more.  The boundary limits of mountain and desert shaped the limits of the Roman Empire, ditto the Quin dynasty of China  The tripartite divisions of Christendom into Roman Catholic, Orthodox and Protestant settled into regions created by the geography of rivers and mountains. 

It’s fascinating stuff, and told with an enthusiastic sharing of ‘big ideas.”  Like an introductory survey course aimed at giving the big picture, he sweeps along, laced with enough new terms and ideas to intrigue, or befuddle, depending on the reader, but not loading the ride with exotic or specialist matters.  There are footnotes and references for those interested.

Dartnell opens with  a review and update of the  more-or-less familiar story of the expansion of homo sapiens across the globe in about 50,000 years, from leaving east Africa about 60,000 years ago ( more recent work suggests even earlier, say 80,000 ya ) to arrival at the southern tip of South America, Patagonia, some 12,500 years ago. 

Though the routes they took were not determined by geological and climatological conditions they did provide the opportunity.  Trekkers out of Africa did not go straight north, for example, guided by the stars, or commands from early gods, but roughly north-east — along rift troughs.  Tectonic activity created conditions for water, seeping up in some areas and running down cloud-catching mountains in others; water meant forage, forage meant game; water forced erosion and settling meant traversable terrain.  Generation after generation they moved north and north-east. Somewhere in what is now eastern Turkey,

This is just the beginning, however.  While much of the focus is on recent human history –the Holocene Epoch of the last 11,700 years — he ranges easily back millions of years to show how  tectonic forces, topography, climate, water were the ever-changing stage for humans and other creatures as well.   It is fascinating to realize that although the place marker we all have now, of the destruction of the dinosaurs 65 million years ago clearing the way for the arrival of mammals, is misleading by about 10 million years.  It took that long and then a fast, 10,000 year period for an enormous release of CO2 into the atmosphere, and related temperature spike,  to create the conditions for everything we understand today as the world: the grasses and fruits and flowers we eat, the even-toed pigs and camels, sheep, goat and cow, the odd-toed  horses and donkeys and of course our cousin primates and ourselves. 

As it is understood today, volcanic eruptions released enough CO2 to warm the oceans which released, in turn, methane from methane-ladened ice deep under water.  It was this “methane flatulence” that drove the PETM (Paleocene-Eocene Thermal Maximum) temperature jump of 5-8 deg C°. Within 200,000 years temperatures had settled down into the ranges of today through sequences of cooling and drying leading to the expansion of the grasslands world wide, and the three great orders of mammals that  followed the food – the odd-toed and even-toed ungulates and the mammals, including us. 

Following Jared Diamond’s paradigm breaking methodology of Guns, Germs and Steel (1997,) science-writer Dartnell shows the beginnings of modern capitalism in the Dutch response to sea water incursion into arable land. Joint stock companies were formed to raise the funds for such large enterprises.  The success of those companies led to ventures in capitalizing merchant ships, and fleets, the Dutch East India Company and the first mercantile imperial adventures. 

The dominance of Europe over Africa in seafaring and trading is traced to the geology of the northern Mediterranean with its thousands of bays, inlets and protected harbors created by the African plate pushing up and crumpling the Eurasian plate.  The rivers running south through towns and cities to the sea gave ample opportunity for risk and reward, culture mixing and the spread of ideas and technology.  The relatively “boring” southern Mediterranean coast, a small sliver of arable land with only two large ports and a vast desert to its south, did not provide a similar foundation. 

Following the nautical thread, Dartnell, has interesting passages about winds and currents, the Coriolis effect of the circulation of the upper atmosphere, the discoveries of early Portuguese and Spanish navigators.  The prevailing south-easterly trade winds of the Atlantic placed the origin of the Atlantic slave trade between the equator and about 15 south in West Africa.  Not coincidentally because of the same winds, the lack of modern ship design and sailing techniques,  of the 10 million slaves taken from Africa 40% went to Brazil, 40% to the Caribbean, 5% to what would become the United States and 15% to Spanish America. 

The most singular hidden connection across millions of years is that of the “Black Belt” of the American south. Today it can be seen as a “blue belt” of voters running in a broad arc through the red-voting south.  Geologists noticed that it mapped to a large degree the edge of an ancient, shallow ocean, the “Western Interior Seaway” that ran well up into the continent. The ancient Appalachians, blocking the sea to the east, eroded over millennia, settling as sediment which became slate which, as the seas fell and climate took its course became prime cotton-growing land.  Slaves were brought in, and after emancipation stayed – becoming the solid Democratic voters of today.

Good maps and illustrations show the claims being made: early civilizations and their proximity to plate boundaries,  the Milankovitch cycles of earth’s rotation and axis shift, the origins of crop domestication.  You’ll feel smarter just thumbing through the  images.  Morsels are offered for those with archaeological or metallurgy interests, or who have questions about the ancient Silk Road. 

It looks like our Covid confinement will be a long one, plenty of time to learn more about the world we inhabit, and by implication what we are in for if we don’t change things back to normal pretty damn quick