Tag Archives: prehistory

Rogues and heroes

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Reading Sam Miller’s Migrants: The Story of Us All for the Telegraph, 23 January 2023

The cultural opprobrium attached to immigration has been building at least since Aristotle’s day, according to Sam Miller’s flawed, fascinating stab at a global history of migration.

Today, “having a permanent home and a lifelong nationality are considered normal, as if they were part of the human condition.” On the contrary, says Miller: humankind is the migratory species par excellence, settling every continent bar Antarctica, not once, but many times over.

Mixed feelings about this process have a deep anthropological foundation. Forget national and regional rivalries; those came later, and are largely explanations after the fact. What really upsets settled people is the reminder that, long ago, their kind chose to live an urban life and became less as a consequence: less wily, less tough, less resilient. The emergence of the first cities coincided with the first poems in uneasy praise of wild men: think of Mesopotamian Enkidu, or Greek Heracles. Aristotle, writing in 330 BC, declares that “he who is without a city-state by nature, and not by circumstance, is either a rogue or greater than a human being” — a wonderfully uneasy and double-edge observation that acknowledges a pre-urban past populated by formidable feral heroes.

Athenians suppressed this awareness; they were the first Western people to take pride in being, in Herodotus’s words, “the only Greeks who never migrated.” Ming Dynasty China performed the same flim-flam, a 15th-century administrator declaring: “There exists a paramount boundary within Heaven and Earth: Chinese on this side, foreigners on the other. The only way to set the world in order is to respect this boundary”.

“History books have, on the whole, been written by the sedentary for the sedentary,” says Miller, and naturally reflect a settled people’s chauvinism. The migration stories we learned at school are often wrong. The Vandals who “sacked” Rome in 455, did not, as a general rule, kill or rape or burn.

Alas, neither did they write; nor did the Roma, until the nineteenth century; nor did the (handsomely literate) Chinese of Victorian London. Migrants rarely find time to write, and where first-person accounts are missing, fantasy is bred. Some of it (Asterix) is charming, some of it (Fu Manchu) is anything but.

Miller thinks that humans naturally emigrate, and our unease about this is the result of pastoralism, cities, and other historical accidents.

The trouble with this line of argument is that there are umpteen “natural” reasons why people move about the earth. Humans naturally consume and lay waste to their immediate environment. Humans naturally overbreed. Humans naturally go to war. Why invoke some innate “outward urge”?

Different distances on the human story allow one to tell wildly different stories. If you follow humanity through deep time, our settlement of the almost the entire planet looks very much like manifest destiny and we’ll all surely end up on Mars tomorrow. If on the other hand you trace the movements of people over a few dozen generations, you’ll discover that, absent force majeure, people are homebodies, moving barely a few weeks’ walking distance from their birthplaces.

What is migration, anyway? Not much more than a hundred years ago, women regularly “migrated” (as Miller says, “it might take as long to cross a large English county as it would to fly halfway around the world today”) to marry or to work as governesses, domestic servants and shop workers. And yet they would never have called themselves “migrants”.

Miller, in a praiseworthy bid to tell a global story, adopts the broadest possible definition of migration: one that embraces “slaves and spouses, refugees and retirees, nomads and expats, conquerors and job-seekers.”

Alas, the broader one’s argument, the less one ends up saying. While they’re handsomely researched and stirringly written, I’m not sure our concepts of migration are much enriched by Miller’s brief tilts at historical behemoths like slavery and the maritime spice route.

What emerges from this onion of a book (fascinating digressions around no detectable centre), is, however, more than sufficent compensation. We have here the seed of much more enticing and potentially more influential project: a modern history that treats the modern nation state — pretending to self-reliance behind ever-more-futile barriers — as but a passing political arrangement, and not always a very useful one.

In view of the geopolitical crises being triggered by climate change, we may very soon need (or else be forced by circumstances) to come up with forms of government outside the rickety and brittle nation state. And in that case, peripatetic perspectives like Miller’s may be just what we need.

 

Never say die

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Reading Remnants of Ancient Life by Dale Greenwalt for New Scientist, 11 January 2023

What is a fossil made of? Mineralised rocky fossils are what spring to mind at a first mention of the word, but the preserved fauna of the burgess shale are pure carbon, a kind of proto-coal. Then there are those tantalising cretaceous insects preserved in amber.

Whatever they are made of, fossils contain treasures. The first really good microscopic study of (mineralised) dinosaur bone, revealing its internal structure, was written up in 1850 by the British palaeontologist Gideon Mantell.

Still, classifying fossil organisms on the basis of their shape and their location seemed to be virtually the only weapon in the paleobiologist’s arsenal — until 1993. That was the year Michael Crichton’s novel Jurassic Park famously captured the excitement of a field in turmoil, as ancient pigments, proteins, and DNA were being detected (not too reliably at first) in all manner of fossil substrates, including rock.

Jurassic Park’s blood-sucking insects fossilised in amber were a bust. Though seemingly perfectly preserved on the outside, they turned out to be hollow.

Mind you, the author of Remnants (a dull title for this vivid and gripping book) has himself has managed to get traces of ancient haemoglobin out of the bloated stomach of a fossilised mosquito — so never say die.

Greenwalt, who spends eleven months of every year “buried deep in the bowels of the Smithsonian’s National Museum of Natural History in Washington, DC,” has brought to the surface a riveting account of a field achieving insights quite as revolutionary as any conjectured by Crichton. The finds are extraordinary enough: a cholesterol-like molecule in a 380-million-year-old crustacean; chitin from the exoskeleton of a fossil from the 505-million-year-old burgess shale. Even more extraordinary are the inferences we can then draw about the physiology, behaviour, and evolution of these extinct organisms. Even from traces that are smeared, fragmented, degraded, and condensed, even from cyclized and polymerized materials, valuable insights can be drawn. It is even possible to calculate and construct putative “ancestral proteins” and from their study, conclude that Earth’s life had its origins at the mouths of deep ocean vents!

The story of biomolecules in palaeontology has its salutary side. A generation of brilliant innovators have had to calm down, learn the limitations of their new techniques, and return, as often as not, to the insights of comparative anatomy to confirm and calibrate their work. Polymerase-chain-reaction sequencing (PCR) is the engine powering our ever older and ever more complete ancient DNA sequences, but early teething problems included publication of a DNA sequence thought to be from a 120-million-year-old weevil that actually belonged to a fungus. Technologies prove their worth over time.

More problematic are the cul-de-sacs. In 2007 Greenwalt’s colleague, the palaeontologist Mary Schweitzer reported her lab had recovered short sequences of collagen from the femur of a 68-million-year-old Tyrannosaurus rex. As Matthew Collins at the University of Copenhagen complains, “It’s great work. I just can’t replicate it.” Schweitzer’s methodology has survived 15 years’ hard interrogation, it may simply be that animal proteins cannot survive more than about 4 million years. That still makes them much hardier than plant proteins, which only last for about 30,000 years.

Against these fascinating controversies and surprising dead-ends Greenwalt sets many wonders, not least “the seemingly unlimited potential of ancient DNA to shed light on the ancestry of our species, Homo sapiens”. And for short-changed botanists, there’s an extraordinary twist in Greenwalt’s tale whereby it may become possible to classify plants based, not on their morphology or even their DNA, but on the repertoire of small biomolecules they leave behind. “The biomolecular components of plants have been found as biomarkers in rocks that are two and a half billion — with a ‘b’!—years old,” Greenwalt exclaims (p204). The 3.7-billion-year-old cyano-bacteria that produced stromatolites in Greenland are the same age as the rocks at Mars’s Gale Crater: “Are authentic ancient biomolecules on Mars so implausible?” Greenwalt asks.

His day job may keep him for months at a time in the Smithsonian’s basement, but Greenwalt’s gaze is set firmly on the stars.

Clay moulded by time

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Reading Thomas Halliday’s Otherlands: A world in the making for the Telegraph, 5 February 2022

Earlier books have painted tableaux of life at other epochs, but few ever got the scale right. Thomas Halliday’s visions are monstrous.

Halliday is a paleoecologist. That’s a branch of biology, which in turn has become a troublesome cousin of physics, borrowing its technology as it penetrates the living machineries of heritability and development. “My own scientific work,” writes Birmingham-based researcher Thomas Halliday, “has mostly happened in basement museum collections and within computer algorithms, using shared anatomical features to try and work out the relationships among the mammals that lived in the aftermath of the last mass extinction.”

But Halliday is also a child of Rannoch — that glacier-scoured landscape of extinct volcanoes that dominates Scotland’s central highlands. And anyone familiar with that region will see instinctively how it underpins this epic near-hallucinatory natural history of the living earth.

Otherlands works backwards through the history of life, past the icebound Pleistocene 20,000 years ago and the Chicxulub asteroid strike 66 million years ago, past the deeply weird Triassic and the lush Devonian, all the way back to the first stirrings of multicellular life in the Ediacaran, 550 million years ago.

Many readers will come for the jump-scares. The paleocene Mesodma, which looks like a rodent until it opens its mouth, revealing a terrifying notched tooth, as though a buzzsaw were buried in its gum. The Gigatitan, a Triassic forerunner of the grasshopper, whose stridulations generate a bullfrog-like baritone song. The Tully Monster, the herring of the Carboniferous, with a segmented torpedo body, two rippling squid-like tail fins and at the front, “something like the hose of a vacuum cleaner, with a tiny tooth-filled grabbing claw at its end”.

Halliday weaves these snapshots of individual plants and animals into a vision of how carbon-based life continually adapts to its shifting, spinning home. It’s a story that becomes increasingly uncanny as it develops, as how could it not? In the normal course of things, we only ever get to see a single snapshot from this story, which is governed by rules that only start to make sense in geological time.

Anyone who’s looked at a crab feeding — a wriggling mass of legs that are tongues that are teeth — will not be surprised to learn that arthropods are the Swiss Army knives of the animal world, “with each segment containing a flexible, jointed appendage that can be adapted to a huge variety of functions.” But arthropods are weird-looking to begin with.

It’s when the cuddly end of nature starts to morph that the flesh begins to creep. In Gargano, that was once an island in the Mediterranean, home to dwarf elephants, giant swans and metre-long barn owls, we learn that everything on an island tends towards one particular size.

In the cold, though, this process goes into reverse. Getting big means your bulk can keep you warm for longer. Getting small means you can hibernate. Seymour Island in Antarctica, in the Eocene, boasted much wildlife, but nothing in size between a rabbit and a sheep.

So far, so Alice-like. More unnerving are the ways in which living things, quite unrelated, converge to exploit similar settings. The pangolins of Africa and South Asia are more closely related to humans than they are to South American armadilloes. At first glance, though, you’d be hard pressed to tell these two animals apart.

If nature fitted together neatly, this sort of thing might not seem so disquieting. But things don’t fit together. There is no balance, just a torrent of constant change, and plants and animals lost in its eddies. When threatened, the slow loris raises its arms up behind its head, shivers and hisses. Why? Because it’s trying to look like a cobra, though the ranges of slow loris and cobra haven’t overlapped in tens of thousands of years.

Slowly, but very surely, the the six-metre long sea serpents of the Triassic come to see almost benign next to the Giant Dormouse or Terrible Moon-Rat which, in their uncanny resemblance to familiar animals, remind us that we humans, too, are clay moulded by time.

In the story of life on Earth, the activities of Homo sapiens are an eyeblink. We’re a sudden, short-lived, energetic thing, like a volcanic eruption, like a rock from space. It doesn’t really matter what they are, or whether they take a split-second, a couple of hundred years, or a few thousand years to wreak their havoc. Sudden energetic things destroy.

But rather than fall into the contemporary cliche and attempt to conjure up some specious agency for us all — “you too are a governor of the planet!” — Halliday engages us as Victorian writers once did, filling us with wonder, not anxiety — and now with added nuance, and better evidence to hand. The chapter “Deluge”, on the filling of the Mediterranean basin in the Miocine, and the chapter “Cycles” describing Eocene polar rainforests, were personal favourites, dazzling me to the point where I wondered, dizzily, how accurate these visions might be.

I don’t mean that Halliday has taken short cuts. On the contrary: the story he tells is handsomely evidenced. I mean only that his story will eventually date. Not far from where I live, Benjamin Waterhouse Hawkins sculpted the first full-scale representations of dinosaurs, setting them in a landscape designed by Joseph Paxton, for the delectation of visitors to the Crystal Palace, once it relocated near Penge.

People now point and titter at Hawkins’s inaccuracies — the horn on one beast turns out to be the thumb belonging to another and so on — but what’s really staggering is how accurate his models are, given the evidence available at the time.

Halliday stands on the shoulders of Hawkins and other giants. He knows about dinosaur coloration, and dinosaur vision (they could see into the ultra-violet). He can trace the wax on fossilised leaves, and tell you how the seasons worked, and about the prevailing winds. He can trace our ancient insectivorous past through genes we all carry that code for digesting chitin. Picking among countless recent discoveries, he can even tell you how four-limbed flying pterosaurs came in to land (“hind-feet first, a jump, skip and hop to a stop”).

I wonder what Halliday cannot yet know?

As the author says, “Nothing provokes debate quite like the hunting of monsters.”