Journeys Written in DNA

Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past by David Reich. Pantheon. 2018.

Image: pixabay.com and pmgimage.com

When I spent a summer on the campus of Saint John’s College in Santa Fe, New Mexico, in 1987, one of the groups meeting there was comprised of researchers working on planning the Human Genome Project. The project, which ran for about fifteen years, starting in 1990, cost several billion dollars and produced a single composite DNA sequence for Homo sapiens. Hard to believe that today, thousands of sequences are run routinely at a cost so low that you can get your own sequence in one to two days for $1000.

David Reich provides an account of the recent developments in studying ancient DNA, which is beginning to provide a picture of the evolution of our genus, Homo, over the last 50-150 thousand years, roughly the time that enough DNA remains in old bones or teeth to allow sequencing. The field is rapidly expanding, as more labs open across the world to explore the accumulated human remains in museums, as well as newly excavated material.

Among the findings he reviews are the discovery that early modern humans did indeed hybridize with the archaic populations of Homo that were already in Europe and Asia when the first Homo sapiens moved out of Africa. These earlier people included the Neanderthals and the newly recognized Denisovans. Another finding is that the spread of Indo-European language and culture was indeed accompanied by a spread of people with steppe genotypes into Europe as far west as the British Isles ( see my post on The Horse, the Wheel and Language) The modern human population of Europe turns out to have been the result of multiple waves of migration, bringing not only cultural innovations like farming, but also new human lineages that displaced or blended with the earlier people.

In fact, everywhere that geneticists examine ancient genomes, they find that multiple migrations have shaped human destiny. In North and South America, the most recent areas of human occupation, at least three different migrations can be seen in the genes, and there is still much more work to be done. Likewise, the Indian subcontinent holds a story of migration of Indo-European speakers from the steppes of Central Asia, displacing and blending with the earlier Dravidian language speakers. East Asia has similar patterns, spilling out into the Pacific. These are truly epic journeys of the human species.

Reich discusses the implications of these findings at length. The chapter on genetics and inequality was particularly interesting. The subject is the differences between and within sexes in numbers of offspring produced, as shown by the frequency of distinct gene sequences from a single ancestor among descendent populations. Because men can produce offspring with very little direct effort compared to women, it is possible for men to have many more children in a lifetime. I recall my world history teacher in high school saying that Augustus the Strong of Saxony, “only had about four hundred children.” Circumstantial evidence suggests that Genghis Kahn, thirteenth century Mongol conqueror is the male ancestor of millions, though this is disputed. Certainly, powerful rulers, if fertile and with access to a succession of willing or unwilling consorts, can father many, many sons and daughters.

Reich cites data that indicate that a number of individuals were the fathers of similarly large numbers of descendants during the period between five thousand and three thousand years ago as Neolithic farming peoples began to feel the effects of new technologies: pastoralism, the horse, the wheel and metalworking. In The Horse the Wheel and Language, David Anthony discusses the idea that the new technologies made it possible for tribal chiefs to accumulate power, wealth and prestige. Such men may have led aggressive expansions into new territory, like Genghis, fathering enough descendants for their distinctive Y-chromosomes to show up in genetic analyses. When peoples mix by this mode of male driven conquest, the result is that Y- chromosomes are from the conquering group, while mitochondrial DNA, which is maternally inherited, is from the original inhabitants.

I heard a similar idea many years ago in a seminar on the shift from mother goddess based religion to male sky god religions. Anthony suggests this too in his account of the steppe peoples whose culture and Indo-European language spread widely in this period. The long ago speaker attributed it to mining for metals de-sanctifying the earth, but I suspect it more likely related to the technologies listed above allowing a subset of males to accumulate power. There are now many other cases, from ancient China to medieval Ireland documented by genetic researchers.

Another point Reich makes is that genomics can become a very touchy issue for contemporary descendants of our diversified ancestors. Ethnocentrism is alive and well, from scientists from India who maintain that there were no migrants from the Asian steppes to Navajo elders who refuse to countenance genetic testing arguing that they already know how the Dine were created. Origins are disputed territory: how many Americans still believe in Adam and Eve? Reich points out the falsity of the politically motivated myths of Aryan origins promulgated by German nationalists and still alive today. These crumble in the face of incontrovertible evidence that the modern inhabitants of Northern Europe originated from an amalgam of previous populations with invaders from Central Asia. Migration and mixing of populations and cultures, as we know only too well, is often seen as a threat.

Reich is sensitive to the ethical issues raised by these powerful technologies. He finally consulted a rabbi on the question of whether it was morally right to disturb the dead to obtain genetic material from bones. The answer: only if the knowledge gained will contribute to human  understanding. On the even more fraught question of what population wide genetic studies may reveal about average differences between identifiable groups of people, Reich says two things: First, the question must be faced with accurate data, lest it become the province of pseudoscientific or politically motivated interpretations. Second, whatever the facts are, we know that all groups contain a wide range of potentialities, all of which deserve a chance to be fully realized. Even if a person is not in the upper percentiles of learning ability or athletic ability, the human capacity for hard work makes it possible to succeed. I think Reich means that while  admire the extreme standouts, the Einsteins and Usain Bolts, the bulk of the useful work in the world gets done by those of us closer to the average.

Finally, Reich discusses individual genetic testing. He is in favor of the study of DNA at the population level for medical reasons and also at the individual level, if this helps reduce the incidence of illness caused by recessive mutations. He doesn’t object to individual testing to discover ancestry, but he is not interested in learning about his own genetic background. He seems to feel that focusing on our own unique genomes distracts us from the heritage we share with everyone else, of which the most important part is non-genetic. The simple fact that we are alive tells us that we come from an unbroken genetic line of survivors. Being able to claim descent from particular populations really doesn’t prove much of anything about your own worthiness. Moreover, making such claims can lead to embarrassment, as Elizabeth Warren has discovered.

Humans have been evolving culturally for much longer than the period for which we can get DNA data. Given how much of our behavior is learned, it is likely that our cultural milieu has been a major part of our environment for a long time. Cultures evolve. In doing so, they change the selective environment for humans and the things that live with them. Cultural change drives natural selection. That is, culture shapes our genes indirectly through natural selection as much as genes shape our culture.

As a social species, cultural traditions matter as much or more than our particular DNA in shaping how we live. Many of us, however, know very little of that tradition, or only slivers of it, dependent on our nationality, ethnicity, religion or profession. Too many people grow up with almost no knowledge of any tradition. Even though he professes no religion now, Reich was raised in a deep cultural tradition, Ashkenazi Judaism. He recognizes that all human populations have come out of similarly rich traditions. Together, they represent the most important heritage of the human species; as much as DNA, they are who we are and how we got here.

The Journeys of Holling C. Holling

Paddle to the Sea. 1941. Tree in the Trail. 1942. Seabird. 1948. Minn of the Mississippi. 1951

Each of these books tells a story about travelers. Paddle to the Sea is a small wood carving of a Native American in a canoe, placed by its maker into the water north of Lake Superior. Paddle finds his way to the Gulf of St. Lawrence after years of travel through each of the Great Lakes in turn. Seabird follows the career of a boy named Ezra on a New Bedford whaler and his son’s on yankee clippers, accompanied by a carving in walrus ivory of an ivory gull. Father and son grow to manhood in the age of sail, but the story ends with Ezra’s great-grandson still carrying the white bird as he pilots airplanes over the ocean.  Minn is a snapping turtle, who hatches in Lake Itasca, headwaters of the Mississippi, and who travels slowly south, ending up as a moss covered ancient in the deep backwaters of the Delta. Only the tree in the trail stays put; it begins as a young cottonwood sapling by a tributary of the Arkansas River near present day Great Bend, Kansas. It is witness to generations of Native American Buffalo hunters, the arrival of the Spanish and then the Americans – trappers, traders, settlers and all along the Santa Fe Trail. After hundreds of years, the dead tree is carved into an ox yoke and travels the Santa Fe trail at last. All the books are filled from beginning to end with the natural and human history of the places the travelers pass through. These books are about journeys, but even more about the passage of time.

As a child, I loved Holling’s illustrations, both the large color ones on nearly every other page and the monochrome drawings that filled the margins – maps and diagrams of everything from whales to ships to arrowheads and rivers. I’ve never had difficulty picturing the outlines of the Great Lakes, because Holling, in Paddle to the Sea, provided an object to fit each shape: A wolf’s head for Superior, a summer squash fruit with leaves for Michigan, a trapper carrying a pack of furs for Huron, a lump of coal for Erie and a carrot for Ontario. The forms connected to the regional economies: trapping in the north woods around Superior and Huron, farming in  the midwest around Lake Michigan and in the lake plain of central New York, heavy industry from  western Pennsylvania through northern Ohio to Michigan. Even Lake St. Clair, by Detroit, had a shape like a heart: that region was at the time Holling wrote and illustrated, the industrial heart of the continent.

His marginal illustrations include beautiful maps, both historical and contemporary of the regions his travelers pass. He shows how glaciation shaped the upper Mississippi and the Great Lakes. Showing the history of Minn’s evolution, he goes back to the age of dinosaurs, and there are numerous geological diagrams. his painting of the 1811 New Madrid Earthquake in Minn of the Mississippi is unforgettable.

He illustrations and drawings take you back in time through the history of the regions he depicts.  He illustrates whaling ships and steamboats and covered wagons, often in great detail, showing the different types and how they were used. There are diagrams, beautifully lettered, showing the parts of tools and machines, plans for corrals, sawmills, river locks and how pearl buttons were cut from mussel shells.

In his scenes of life, whether aboard ships at sea or in the bayou country of Louisiana, Holling illustrates the people with sympathy and an absence of satire or irony (he studied anthropology as well as art).  He draws plants and animals in great detail (he was a taxidermist at the Field Museum in Chicago when he was young) and with the same sympathy as his people. Landscapes, wild, rural or industrial are usually shown from a human perspective, as if one were in the scene, with dramatic effect when he shows storms, floods or wildfires. Much of what he depicts he had seen firsthand; he and his wife and collaborator, Lucille Webster Holling, were great travelers themselves.

The Hollings left a legacy of beautifully illustrated books for children. While in many respects, the world they show has changed tremendously since they were published in the 1930s to 1950s, they are still wonderful. There is a love of the natural and the human  coming through these pages that is impossible to miss.

[Here’s another fascinating bit from Wikipedia: “Holling wrote and illustrated a full-page Sunday comic strip titled The World Museum. Each strip included a diorama, which could be cut out and assembled into a 3-D scene of, for example, a buffalo hunt or an undersea panorama.”]

Note: I first found Holling’s books when I was in grade school in the Mary Bailey Pratt Children’s Library in Chapel Hill NC. The library was housed on the upper floor of the elementary school on Franklin Street. It was there, as well as at home, that my love for books developed, thanks to the librarians, especially Mrs Hardee. I worked for her at least one summer, learning how to care for the books. Books with pictures by great American illustrators from N. C. Wyeth to Doctor Seuss, made up a large part of the collection, and two large, framed watercolors, done years before by a student, hung on the wall opposite the desk. One was of Ichabod Crane, walking down the road, reading a book, the other was of Tom Sawyer, heading off to go fishing. After the old school was demolished in the late 1960s, I wondered what had become of those pictures. Years later, I was delighted to find them hanging in the new Chapel Hill Public Library children’s section.

Worst Camping Trip Ever?

Endurance. An Epic of Polar Adventure by F.A. Worsley. W.W. Norton and Co. New York. 1931. (With an Introduction by Patrick O’Brien, 1999)

 Worsley was in command of Endurance, the ship that carried Earnest Shackleton’s 1914 expedition to cross Antarctica. Caught in the pack ice in the Weddell Sea, from February to November 1915 the Endurance drifted until she was crushed and sunk. From then until April, the twenty-eight men camped on the ice in thin canvas tents, without floors, on limited rations. They made several attempts to march north, an exhausting job over the rough and broken ice, until they were finally able to launch their three lifeboats to cross to Elephant Island, one of the last bits of land off the tip of the Antarctic Peninsula. Here, most of them camped under the shelter of two overturned boats, while Shackleton, Worsley and four others made a dangerous sixteen-day trip in the third boat to South Georgia. That they arrived there and did not simply sail on into the endless South Atlantic to sink or starve is testimony to the nearly legendary navigational skill of Worsley, who learned the craft traveling to remote islands while working for the British South Pacific Service. To cap this remarkable feat, Shackleton, Worsley and a third man had to cross the island to reach the whaling station on the south shore. This they did during the only window of weather for months when it was possible to struggle over the mountains and glaciers with any chance of surviving.

 Having found help and picked up the other three men, they headed straight for Elephant Island, but the pack ice blocked the way. Only on the fourth try, in their fourth borrowed ship, starting from Punta Arenas, Chile, near Tierra del Fuego, did they reach the stranded crew on August 30, 1916. All twenty-eight of Shackleton’s men had survived. Ironically, several soon perished while serving in the First World War, which had been going on the entire time they were away. Before they returned to England, however, they were honored by the Chileans of Punta Arenas with a banquet. The Chilean guests rose one by one to drink a glass of wine with the Brits, resulting in each hero having to consume multiple glasses while their hosts remained relatively sober. Shackleton, who drank little, was permitted to withdraw, but when the rest tried to follow a bit later, they were sent back at bayonet point by Chilean soldiers, who were under orders to allow no sober English, nor even any not sufficiently drunk, to pass.

Afterwards, Worsley served in the Royal Naval Reserve, commanding an anti-submarine ship. He sank a German U-boat by ramming it. He was also in the British Northern Russia Expedition against the Red army. After the war, he knocked around, leading several difficult trips to the Arctic but usually ending up in financial difficulties. Finally, in 1922, Shackleton took him on again for another Antarctic expedition, but Shackleton died on the trip south. After one more arctic voyage and an unsuccessful treasure hunt on Cocos Island, Costa Rica, Worsley spent the interwar years writing and lecturing. He lied about his age to secure a command in the Merchant Navy in 1941, but he was soon found out and put to work as a training officer on shore. He died in 1943 of lung cancer.

All I can say is that, as far as putting up with cold, hunger and strenuous exercise, even more than the early Mount Everest climbers, those guys were tough. Furthermore, the men in charge of the different parties were good at maintaining discipline and morale, keeping up a routine that included regular musical performances as well as hunting expeditions. In more than two years, there seems to have been only a single hint of mutiny: at one point, the ship’s carpenter, claiming (like Steven Hopkins – see my earlier post on the Sea Venture) that the loss of the Endurance set them free from Shackleton’s command, refused to go on. Shackleton stood firm and convinced him to stick. The other factor in the crew’s favor was that unlike the early English voyages to places like America, there were neither indigenous people to antagonize nor much in the way of infectious diseases to contend with. One man lost a foot to gangrene following frostbite, but there were two doctors in the party and an anesthetic, so it went well. They also got enough fresh meat to keep scurvy at bay. A final minor miracle of the trip was that a large number of their photographic negatives survived, giving us an amazing visual record of what they endured.

 Worsley is a good writer; the book is the sort to read in a few big chunks with much satisfaction and amazement.

Nearctic Travels: Shipwreck and Shakespeare

A Brave Vessel: The True Tale of the Castaways Who Rescued Jamestown and Inspired Shakespeare’s The Tempest by Hobson Woodward. New York. Viking Press. 2009.

[Image from A young people’s history of Virginia and Virginians. 1896 by D.H. Maury]

 Woodward tells the story of the Sea Venture, the flagship of the 1609 supply fleet sent by the Virginia Company to support its colony at Jamestown. Caught in a hurricane and run aground on Bermuda, Sea Venture’s crew and passengers survived and spent nearly a year on the islands, until they could construct two new ships to complete the trip to Virginia. Among the passengers was William Strachey, a down on his luck gentleman, who aspired to literary fame. He was made secretary to successive governors of the Jamestown Colony and sent an official report and a private letter describing the events of the voyage. Woodward believes, largely on the basis of textual similarities, that the private letter was a major source for The Tempest.

The first part of the book covers the experiences of the Sea Venture castaways from England to Bermuda and Virginia and back to England, using Strachey and other historical sources. The second part deals more speculatively with how Shakespeare composed The Tempest, drawing out in detail similarities and coincidences between Strachey’s letter and the plot, characters and language of the play. Woodward has little to go on here, but he at least makes a plausible case for Shakespeare having read a copy of Strachey’s account.

 My interest in this very readable book was sparked by its references to another passenger on the Sea Venture, Steven Hopkins. Described as a “shopkeeper from Hampshire” who knew the Scriptures well enough to become clerk to the minister aboard ship, he is notable for having attempted to organize a mutiny on Bermuda. His goal was apparently to remain on the island and not be taken to Virginia, on the grounds that the passengers’ contract with the company was voided by the shipwreck. He was informed on to the military commander of the expedition, Thomas Gates, who put him on trial for his life. According to Strachey, Hopkins was so eloquent in pleading that his wife and children back in Hampshire would be ruined if he were hanged that most of the gentlemen in the group argued for leniency. Gates relented, and Hopkins survived his time in Bermuda and Virginia and returned to England. He later joined the Mayflower, with his second wife and children. Though not a member of the Pilgrims’ sect, he was taken on as someone who knew the land and native people of Virginia, which is where the Mayflower was supposed to be going. Hopkins’s wife gave birth while at sea, and his family was one of only two not to lose anyone on the voyage. In Plymouth, he helped negotiate a treaty with the natives that remained unbroken for the life of the signers and also ran the settlement’s first tavern. His female descendants married into some of the leading families of Massachusetts. I find it amazing that this man was part of three of the most remarkable English ventures in North America, especially since I may be distantly related through a female ancestor from one of those New England families. I’m currently learning more about him, because whether or not we are related, his story deserves to be more widely known.

A Brave Vessel is well worth reading for a sea story, as gripping as Joseph Conrad’s Typhoon, and as a look at the struggles of the English to establish a foothold in America. Woodward describes all the suffering that followed from the conflicts between colonizers and natives as well as within the English society attempting to transplant itself across the ocean. He also touches on the ecological and climatological factors that helped and hindered their efforts. The severe drought that bracketed the early years of the Virginia colony greatly increased the stress on both natives and colonists and led to the “starving time” in the winter of 1609-1610, which the arrival of the ships from Bermuda helped relieve. During those same months on Bermuda, the castaways lived well on fish, nesting seabirds and their eggs, green sea turtles, and the introduced pigs, left by earlier Spanish seafarers. The native plants, including palmetto and Bermuda cedar furnished food and drink as well as timber for building the two ships, Deliverance and Patience. The plenitude and mild climate of the islands undoubtedly were factors in Steven Hopkins near fatal desire to remain there.

 Bermuda became an English colony and suffered great ecological changes, including the near extinction of its endemic cedars and the cahow or Bermuda petrel, whose strange nocturnal calls helped give the islands their early reputation as haunted by devils. Bermuda’s roles in supporting the earliest ventures of England into North America and in inspiring one of the greatest English plays remain points of local pride. I wonder if Steven Hopkins dreamed of Bermuda during the dreary New England winters.

Palearctic travelers

The Horse, the Wheel and Language by David W. Anthony, Princeton University Press, 2007.

 This very rich and fascinating book details the development of our understanding of the history of the Indo European family of languages, from the latest common set of dialects spoken by people living in the steppes north of the Black and Caspian seas in southeastern Europe and southwestern Asia. David Anthony covers the time from the earliest diffusion of agriculture and domesticated animals out of Mesopotamia into southeastern Europe and the subsequent gradual spread out into the steppes. His key thesis is that the domestication of the wild horses of the steppes and their subsequent use as mounts, followed by the introduction of the wagon and the war chariot gave steppe tribes a mobility that enabled them to move long distances, eventually into central Europe and the Indian subcontinent, creating a bridge across cultural regions that by the late bronze age extended as far as China. Thus their language became the dominant family of languages over a vast geographic area.

 To begin with, Anthony, an archaeologist, provides an account of the linguistic evidence for a common ancestral language. The history was derived from careful analysis of phonetic and morphological changes among closely and distantly related languages. This work has been going on since the 18th century, when Europeans first began to suspect that their languages and those of India were akin to one another. This process is very much like reconstructing a biological lineage from genetic and morphological data on living or fossil specimens. It is always only the best hypothesis to explain the data at hand, but lots of work gradually leads to trustworthy results. Interestingly, linguists and evolutionary biologists employ many of the same computer programs. Anthony argues that with the predictive capacity of these explanations and the help of inscriptions dating to some of the earliest writing, we can be reasonably certain that we know some 1500 root words of Proto Indo European as well as many more terms derived from them.

 In a long series of chapters, he goes through the archaeological evidence to reconstruct the culture and characteristics of the speakers of Proto Indo European as well as how they came to be capable of leaving their steppe home and spreading out so far. Technological change is a key factor: the period covered extends from the late Neolithic to the Bronze Age. Tools, weapons, household goods and prestige items were all important. So was the domestication of the horse and the new kinds of both herding and livestock raiding that riding horses made possible. Climate change was another key factor: cold, dry periods favored herding over farming and led to wars that destroyed thriving agricultural settlements on the edges of the steppes. Cultural change was evident all along as settlement patterns, burial styles and material goods changed, indicating, according to Anthony, the rise of more male centered and hierarchical societies on the steppes – in other words the rise of the chieftain and possibly the priest, as had also happened in the city states of Mesopotamia. At some point the wheel spread into the steppe from the south.

 In the steppe, horseback riding and the wagon facilitated an mobile style of herding that also could be accompanied by cattle raiding, looting and trading, which in turn led some to accumulate greater wealth in herds and goods, including copper and bronze weapons and ornaments. Harsher climates also contributed to this increase in social inequality. Anthony argues from linguistic evidence that the speakers of Proto Indo European developed two key social systems that enabled them to dominate the cultures that they encountered in their expansion out of the steppe: patron-client and guest-host. The former stabilized and solidified the pattern of social inequality; the latter made possible firm alliances among groups from both similar and different cultures on the basis of reciprocal obligation (the Indo European root for “guest” and “host” is the same). These, plus the ability of mobile herders to make long distance migrations and easily establish themselves wherever pasture could be found, profoundly shaped the future history of Eurasia. Sometimes raiding and warfare must have been involved in the spread of these peoples, but not the sorts of mobile armies (think of the Mongol hordes) seen in the iron ages and Medieval times; those were a much later development. The primary way the Indo European culture spread, according to Anthony, was incremental. A few powerful chiefs established themselves in new territory, either as patrons or as guest/hosts, and their superior wealth, culture and technology gradually won over the locals. Horseback riding and chariots (possibly invented in the steppe) were rapidly adopted in Europe, the Middle East and China, while the Indo European language evolved into multiple major branches, eventually extending from the British Isles to India.

 Since the publication of this book, genetic studies of ancient Europeans have been published that are consistent with the overall picture given here. About the time suggested by Anthony for the initial spread of Indo European dialects into Eastern Europe, there was an significant spread of DNA, especially that of males, from the steppes north of the Black Sea into Europe. News reports from Science in 2015 and 2017 describes these studies as does a recent news article in Scientific American. The evidence, however, raises many questions. For instance, there are also significant indications that European genes spread into the steppes. This could be explained if long distance trading or raiding, involving wives or children brought back by returning parties were significant, as well as children fathered by the migrants/visitors in Europe. It doesn’t rule out long distance migration and colonization by steppe peoples as well, but it suggests that the picture was complicated. Genes, culture and language spread together, with or without large-scale migration, in Anthony’s scenario.

What makes Anthony’s account particularly cogent, and better than any of the news stories, is his attention to detail, particularly in laying out the linguistic and archeological evidence. It’s a lot to take in, but we can be grateful for his scholarship and willingness to cross disciplinary boundaries.

Global Voyager

Maya Jasanoff. Dawn Watch. Joseph Conrad in a Global World. Penguin Press. 2017.

Jasanoff’s biography is both an appraisal of Conrad’s career as an author and the influences on his life and work of the rapid global expansion of commerce and imperial ambition in the second half of the nineteenth century. She describes his childhood in partitioned and occupied Poland, where his father was a idealistic revolutionary, exiled for much of his life. Conrad was inspired to go to sea at age sixteen after reading, among other works, the seafaring novels of James Fenimore Cooper, which I did not realize the author of Leatherstocking Tales had written. He eventually made his way to England, at that time the country most open to expatriates and the greatest maritime power.

 Rising through the ranks of the merchant navy to become a licensed master, he voyaged across the globe, but mostly to Australia and Southeast Asia, mostly on sailing ships or the lesser steamers, rarely having the opportunity to serve on the better classes of fast passenger ships. When he began to write and publish his own stories, they were set in the locales familiar to him, aboard ships at sea or in the ports and backwater towns and villages of the great Asian archipelago. He focused on sailors and on the various exiles, dreamers of wealth or those escaping the past, who found their way into the remote places where they encountered indigenous rulers and other adventurers in constant conflict, much of it driven by the outside forces of expanding trade and European imperialism. His one trip on the Congo provided the framework for his most famous and controversial work, The Heart of Darkness. There he saw firsthand how the unbridled force of European greed brought out the savage potential of nearly everyone who became involved in the enterprise.

 Conrad did not like to be thought of as a writer of sea stories, although he certainly wrote vivid and hair raising tales of the struggles of ships and crews, Typhoon being one of my personal favorites. He thought of himself as writing about the struggles of human beings, mostly, but not exclusively, men, caught up in the web of impersonal forces, both natural and societal that he saw driving the history of his times: oppression and the revolutionary impulse, personal ambition and political intrigue and the “material interests,” which he associated most powerfully with the United States.

 Jasanoff does an excellent job of drawing out the threads that connect Conrad to our own day, arguing that more than any other author of his time, he saw and made his readers see the historical forces at work that we would now call “globalization.” Much has changed, as she is careful to describe from personal experience, both in material circumstances and our perspectives, but the seeds were present and can be perceived clearly in Conrad’s work. She herself, to gain first hand experience, made a river journey down the Congo, following the route of Conrad and his fictional Captain Marlowe, but she saw none of the darkness that they did, only poor but very enterprising people, making their way in a complex world, where bushmeat sellers from villages of bamboo houses buy toothpaste and batteries and watch satellite television showing European football matches. Some things she says, do not change much: the camaraderie of a long sea voyage (for her, on a giant container ship, following the long established route from Hong Kong to England) and the ravishing beauty of the dawn over a smooth sea.

 Jasanoff sees Conrad as deeply pessimistic about human beings, carried along by winds and currents of history. Although we can master the literal forces of nature by our machines, we unleash consequences we cannot control, and the forces within ourselves are even less manageable. But, she says, Conrad does show us those times when however precariously, we can make choices that alter the course of ours and others’ lives. I find Conrad himself a clear case in point: in choosing to go to sea, the Polish boy, Konrad Korzeniowski became Joseph Conrad, master mariner and one of the greatest English novelists.

When Worlds Collide

The_Conquest_of_Tenochtitlan

The Conquest of Tenochtitlan  And when we saw all those cities and villages built in the water, and other great towns on dry land, and that straight and level causeway leading to Mexico [i.e. Tenochtitlán], we were astounded. These great towns and cues [i.e., temples] and buildings rising from the water, all made of stone, seemed like an enchanted vision from the tale of Amadis. Indeed, some of our soldiers asked whether it was not all a dream. It is not surprising therefore that I should write in this vein. It was all so wonderful that I do not know how to describe this first glimpse of things never heard of, seen or dreamed of before. . . .I say again that I stood looking at it, and thought that no land like it would ever be discovered in the whole world…. But today all that I then saw is overthrown and destroyed; nothing is left standing. True History of the Conquest of New Spain by Bernal Díaz del Castillo (1492-1580)

1491 (Second Edition): New Revelations of the Americas Before Columbus. Audible recorded edition, original publication 2006 by Charles C. Mann

1493: Uncovering the New World Columbus Created. Audible recorded edition, original publication 2011 by Charles C. Mann

These two books form a pair of inquiries, first into what the New World, comprising the nearctic and neotropical biogeographic realms, were like prior to the coming of Europeans (and Africans) after 1492 and second into what the resulting “Columbian exchange,” wrought in biological and cultural terms across the world.

Mann collected the latest scientific and historical evidence from a wide range of first hand sources, mostly working archaeologists, anthropologists, demographers, historians and others. He traveled through North, Central and South America to see the discoveries that are changing our notions about the human population of the Americas from the end of the ice ages to the present. He revisited the first hand accounts of the earliest European explorers, who often reported densities of human settlements that were disbelieved by those who followed just a couple of generations later, after European diseases had depopulated vast regions. He recounts the epic battles of the scientific past: how new discoveries were often flatly denied by the powerful authorities of the time, even in the face of hard evidence. Some academic scientists took all the credit for discoveries which were originally made by amateurs and lay people. The history of Native Americans has been contested ground for centuries, and now the Native Americans themselves are becoming more deeply involved, not always, as far as I can see, on the side of the best science. This may partly be blamed on postmodern and post colonialist concepts of truth, but a lot is simply the difficulty of making sense of the evidence. Betty Meggars, author of Amazonia: Nature and Culture in a Counterfeit Paradise, which I greatly admired as a young ecologist, is an example of someone who, at the time 1491 was published, opposed the idea that humans could have lived in the Amazon Basin in large settlements with permanent, as opposed to shifting agriculture. I think her basic ideas about ecological limitations are sound, but it seems as if she was refusing to see that the ecology of the Amazon forest was more complex than was understood in the 1970s. Since those early days of the save the rainforest movement, we have learned a lot about the Amazon and other forests that contradicts ideas about primeval forests, undisturbed for centuries, being what Europeans encountered as they ventured to Africa, Asia and the Americas. Many environmentalists are reluctant to accept these findings, because they rightly fear that they could be used to justify unregulated exploitation by destructive modern methods. Still, I see no use in denying hard won understanding. I, for one, accept the idea that across the earth, humans have played a much greater role in  shaping the landscape and for a longer time than we previously believed. Mann’s detailed accounts of the latest understanding of life of Native Americans prior to 1492 point to just how much was lost in the collision between the peoples, plants, animals and diseases of two formerly isolated realms.

Mann’s second book, 1493, takes up the story to try to see how this fatal, but pregnant, collision transformed the rest of the planet. Central to this was trade: the rapid exchange of all sorts of goods, including new crops, new livestock and unfortunately, new pests and diseases across the globe. The trade was facilitated by the new sea routes opened up, especially the Spanish route from Mexico to Manila, made possible by the vast deposits of silver and gold in the new Spanish colonies. Chinese silks and porcelin flowed east to New Spain and then Europe, while silver, especially, flowed to China. Along with the coin went crops like maize, chili pepper and sweet potato, whose conquest of Asian diets Mann details. Meanwhile, across the Atlantic, sugar, tobacco and later, cotton began to flow to Europe, made possible by the labor of enslaved Africans. Transplanted Europeans, their crops and their livestock began to replace the native populations from Argentina to Quebec, remaking the landscape in a melded version of the old and new. Escaped slaves formed a crucial part of the ecological and cultural heritage of areas like Brazil and the southeastern US (see my post on Exiles of Florida).

All this history and ecology, so different from what I learned in school, and even as a graduate student forty years ago, is a reminder that very little of our understanding of ourselves and the world we inhabit can be taken as fixed and certain. Perhaps my favorite bit of revisionist history in either book is the notion that the famous passenger pigeon did not darken the skies in vast flocks containing billions of birds back before Columbus. Instead, it rocketed to huge numbers when the demographic collapse of Native Americans led to a regrowth of deciduous forest across formerly densely inhabited landscapes in eastern North America. How do we know they were not so abundant back in the day? Because passenger pigeon bones are scarce in archeological sites from pre-Columbian times, despite the historical fact that the birds were good to eat and easy to obtain in the early 19th century.

There were surely be further developments in this fascinating field of inquiry, but for now, these two books are not a bad place to begin.