by Heidi Norman
‘That’s why I’m willing to sign up to go one way.’
Job description
Uncharted waters
An uneasy alliance
The vanishing writers
Fiona McMillan
Start a blog, I told myself. Then you can write about anything you want.
The idea was enticing, but the possibility of writing about anything led very quickly to indecision and that led rather rapidly to no writing at all.
Galaxies, immune cells, archaeological digs, neurons, human behaviour, string theory. Where to begin? Specialise, they say, and there is indeed wisdom in that. But part of the fun of blogging, I felt, was the chance to explore, to tread new ground, to learn new things, to be amazed, puzzled, delighted, and to then share all of that.
I went for a walk to figure it out. On my way I saw a tree. I slowed. I stopped. I took a good look at this tree I’d passed many times before without so much as a glance. Standing there, it became quite clear that if you want to explore the entire universe, you can start quite close to home. This tree had a story. It had been, quite literally, scribbled all over. The markings were rough beneath my fingertips, the author nowhere to be seen.
A tale to decipher.
A decision made.
The universe starts here.
(Actually it does, by the way. The universe starts everywhere, so this is as good a place as any.)
So this is how the Luminous blog begins: with the story of a tree that took me more than 180 million years into the past.
Let me explain.
The eucalypts grow everywhere around here. This is Australia after all. This neighbourhood was carved out of bushland, and farmland that had once been bushland. But the creeks and the catchments were mostly left alone. There’s a path that winds through. It’s a little bit wild in there, a bit dangerous. It’s marshy in some places, dry in others. Trees tower, some leaning precariously, ready to fall. The underbrush is dense and beautiful. Venomous snakes hide in the tall grass and bulbous spiders dangle patiently on expansive webs.
Some of the wildlife are more benign. There are rainbow lorikeets, kookaburras, and brush turkeys. Recently, I spied a wallaby. It regarded me for a moment then hopped away, almost dismissively. It’s summer now, and the cicadas are singing. They chorus in perfectly synchronised waves, the crests of which are deafening. The sound thrums in your chest and drowns out the human world. The cicadas are here because they rather like the eucalyptus trees. And the eucalypts, in turn, have brought something else: tiny, elusive writers.
Australia is home to several hundred species of eucalypt. And it seems a modest variety make their home in this narrow stretch of wilderness. One of the most curious is the Scribbly Gum.
The name Scribbly Gum actually refers to a cluster of different eucalypt species found on the eastern seaboard of Australia. Their common signature, as it were, are the scribbles all over their pale, smooth-barked trunks. These markings have become something of a national icon, weaving their way into Australian folklore and literature.
The tiny writers are exquisitely shy, they leave their marks and vanish. They’re the elusive graffiti artists of the natural world. The work of beetles, was a common guess. Then in 1934 the culprit was identified: a moth, scarcely a few millimetres big. A specimen was sent to England into the care of a school teacher named Edward Meyrick. Meyrick himself was a curious entity. An amateur entomologist, he had a remarkable hobby of describing, naming, and cataloguing insect species. Moths were a particular favourite. Over his lifetime, he bestowed carefully thought out scientific names to more than 14 000 of them. And so, with due care, he named this one Ogmograptis Scribula. Literally, the writer of the Ogam script. It’s said that he chose the name because the scribbles bore some resemblance to an ancient Celtic writing form called Ogam. There is also a second layer of meaning. Ogmos is not Celtic, it’s Greek, and it means furrow – a groove or a narrow trench. When you look closely at the meandering lines on the scribbly gum, you’ll see that’s exactly what they are. To Meyrick, these strange patterns were unique. For all his expertise, his meticulous cataloguing of thousands of moth species, and his passion for taxonomy, Ogmograptis presented an enigma. Where it fitted with all the other families, genera and species of moths, he couldn’t say.
And so the story of the diminutive creature remained unreadable for many years. This was exacerbated by the fact that they are difficult to capture in the wild. In defiance of the wide reputation of many moths, Ogmograptis is not lured by light. The larvae are equally recalcitrant. They are so dependent on the eucalypt, they’re difficult to rear in captivity.
In the 1990s, CSIRO entomologist Ted Edwards AM suggested that the scribbles were formed by the larvae as they mined their way through the bark, feeding as they grew, zigzagging, then doubling back. Still the scribbles had never been quantified in detail. The math of these moths remained a secret.
Then a unique collaboration set the little moth’s story on a new course. Julia Cooke was a high school student who wanted to do a project on scribbly gum moths. Edwards had retired, but agreed to mentor Julia. So together they embarked on a study of the scribbles of three different species of eucalypt in the Canberra area. They measured everything they could. The height, the width, the length. The thickness of the furrow, the direction, the distribution. Were they on the north side of the tree, or the south? The east or the west? Were the paths random, or was there something more to it, an innate algorithm? How many zigs, how many zags?
No matter where the scribbles were found, they each showed three clear stages. ‘A’ is the beginning, a very thin random scrawl that follows no rhyme or reason on any tree. ‘B’ is the thicker, darker, zigzag, the tunnelling in earnest. ‘C’ is the loop – they all do indeed make a U-turn and follow the path back to the start of ‘B’. And yet, there were distinct differences. In each of the three species of eucalypt they studied, there were slight variations, particularly in the length of the furrow and in the number of direction changes. It was as if these scribbles represented different dialects. A new theory emerged. There wasn’t one species of scribbling moth, there were at least three, possibly more.
This finding inspired a new endeavour. This time the now retired Ted Edwards and other botanists and entomologists at CSIRO – including retired scientists Marianne Horak, Max Day AO and Celia Barlow – teamed up with geneticists and imaging specialists. Pairing field data with DNA analysis and scanning electron microscopy, they discovered that there are 14 different species of this tiny Ogmograptis moth, and that they can be divided into three distinct groups. They were also able to achieve what Meyrick had been unable to. They now knew how to classify it.
Their analysis, particularly the high-resolution images of the jaw, linked Ogmograptis with the Australian Tritymba moths and the African Leucoedemia moths. Together they form the southern group of a larger family called Bucculactricidae. The implication of the African connection is profound – it suggests they share a common ancestor who lived on the supercontinent of Gondwana. In addition to this, the recent discovery of a eucalyptus fossil in South America contributes to strong evidence that eucalypts also have a Gondwanan origin. They seem to have thrived there, and where the eucalypts went the moths followed.
It’s a hot day and I’m walking along the path with my young daughter. Over the song of the cicadas, I tell her to keep an eye out. Smooth bark, not rough, I say. Look for the scribbles.
I see the tree first, but let her find it on her own. ‘There!’ she calls out.
The tree is tall and covered in Ogmograptis graffiti. I cannot tell how far up they go, they disappear into the brightness of the day. There must be thousands of them. We take a good look at the ones right in front of us. My daughter reaches out, picks a scribble that she has decided is the best, traces its path. It follows the pattern perfectly. The random thin scrawl, like a languorous, drunken scratch. Then the regular zigzags, where the larvae grow larger, gnawing through the cork layer. T
his is why it doubles back. It doesn’t just tunnel, it harvests. It’s a neat trick: the first pass wounds the tree; as the tree repairs itself, it produces a scar tissue – tiny, thin-walled cells full of nutrients. The larvae then does its best 180 – some species have a tighter turning circle than others – and eats its way back again. When it’s had its fill, it bores to the surface, finds its way to the base of the tree, pupates, emerges, and flies away. When the bark sheds, the scribbles are revealed.
* * * * *
Somewhere around 180 million years ago, during the Jurassic period, the Gondwanan supercontinent began to split. During this slow, tectonic tantrum Australia separated from Africa. Primates had not yet evolved. Dinosaurs roamed, and the world was still millions of years from the asteroid impact that would trigger their demise (well, not the demise of all of them, but that’s another story).
Ogmograptis’ life cycle is annual, an evolutionary refinement in keeping with the yearly shedding of eucalyptus bark. The scribbles you see are this year’s scribbles. It is feasible, then, that the scribble my daughter has traced is at least the 180 millionth generation. Arguably more.
It’s time to head back. The day is getting on and my fellow explorer wants lunch. We leave without finding the adult moth, though I didn’t expect to given its reputation for being furtive and so profoundly small. Its body is only 2 millimetres long. Its wingspan is 10–12 millimetres, if that. Yet what it has written, and left behind, is larger than it will ever be itself.
And I think there’s poetry in that.
Love bug
Field guide to the future
Lost in a floral desert
I, wormbot:
The next step in artificial intelligence
Gillian Terzis
Even before they began to stake a claim on our jobs, our boardrooms, our battlefields and our bedrooms, robots have long activated our existential anxieties, forcing us mortals to ponder our own planned obsolescence. Advances in artificial intelligence deepen these feelings.
Supercomputers with artificial intelligence, such as IBM’s Watson and Deep Blue, have declared emphatic victories on Jeopardy! and against world chess champion Garry Kasparov. And earlier this year, it was announced that a program created by scientists at the University of Alberta is invincible at heads-up limit Texas hold ’em poker. Not only can the program bluff – a seemingly cognitive trait – but it is said to ‘learn’ from its mistakes through an algorithmic process known as ‘counterfactual regret minimisation’.
For all these developments, artificial intelligence systems are still fairly primitive. Yet Ray Kurzweil, futurist, Google engineering director and prominent AI hype-man, believes machines could surpass human intelligence in 15 years. Still, the dawn of the so-called ‘technological singularity’ – the point at which the intellectual capacity of machines exceeds our own – often feels more like speculative fiction than reality. Sentient machines, which would exhibit consciousness, curiosity and emotions, remain a long way off. Human–robot relations are stilted; anyone who’s ever shouted at Apple’s Siri will know such interactions are not yet seamless.
Simulating human traits remains the principal bugbear of artificial intelligence developers. But an increasing number of them believe they can design sophisticated and intelligent machines by going back to first principles – that is, by replicating the neural circuitry of simple organisms. Timothy Busbice is one such developer keen to fuse the knowledge of the neural circuitry of a worm with the aim of building intelligent, autonomous robots.
Late in 2014, Busbice and a team of scientists uploaded a simulation of the nematode worm’s neural networks into a small programmable Lego robot. A video of the result is on YouTube, and it shows the three-wheeled robot skating jerkily around on the floor – if you didn’t know the project’s background you might think it is simply being controlled, somewhat clumsily, with a remote.
Busbice claims the robot’s movements had not been preprogrammed, and its behaviour was directed by the simulation of the worm’s brain. For example, touching the robot’s ‘nose’ resulted in the machine beating a spontaneous and hasty retreat, while activating a ‘food sensor’ made the robot advance. The video has elicited vociferous debate about the project’s validity and accuracy, as well as the metaphysical implications.
Busbice emphasises that although his simulation aims for a high degree of biological fidelity, it inevitably lacks the mess and noise of a real-life central nervous system. And this would seem to be the overarching flaw in computational simulations of neural activity, which play a central role in the nascent discipline known as ‘executable biology’. Monash University associate professor and bioethicist Robert Sparrow believes such simulations are destined to be incomplete portraits of brain activity. ‘There is still some uncertainty over whether we are capable of characterising all the behaviour of neurons,’ he says. ‘It’s not clear to me that just capturing the neuronal activity is enough to capture consciousness.’
The simulation of multicellular organisms is no easy feat. No scientist has yet managed to create a comprehensive model of a bacterial cell, let alone a living organism with a brain. It’s no surprise that at about 100 billion neurons, the human brain remains something of a black box for neuroscientists; even a mouse has one million neurons. Making a computational simulation of these nervous systems would be an arduous task, but as researchers such as Busbice have proposed, there are simpler places to start: at present, the focus is on the microscopic, soil-inhabiting nematode (roundworm), otherwise known as the Caenorhadbitis elegans.
The C. elegans worm has been the organism of choice for biologists for decades, for reasons that are practical and scientific. It is transparent, which permits scientists to observe each one of its 959 somatic cells and 302 of its neurons under a microscope; its size (one millimetre in length) allows it to be bred in large quantities in a Petri dish; and it shares physiological traits – muscles, a central nervous system, reproductive capabilities – with animals much higher up the food chain.
28 years ago, a team of scientists led by John White and Sydney Brenner published a map of the C. elegans’ neural connections, otherwise known as a connectome. Tracing cross-sections of the worm’s anatomy and figuring out where the neurons connected was a painstaking process that had taken close to 13 years.
Today, an open-source science project named OpenWorm, of which Busbice is a co-founder and former member, is trying to create a 3D computer simulation of the C. elegans. From this similar initiatives have also spawned: scientists are also trying to create simulations of the common fruit fly and the jellyfish.
Another of OpenWorm’s founders, Stephen Larson, says that while he thinks the Lego robot was a ‘fun and interesting application of the open science approach’, their efforts are concentrated on computer simulations.
‘It’s exciting that folks are getting creative,’ he says, but adds that he hasn’t seen the finer details of Busbice’s robot and couldn’t speak to its scientific validity. ‘We feel very strongly about peer review. We want to be doing real science.’
A computer simulation may be a simplified model of reality, subject to certain controls, but Larson believes it still has value. He hopes that as computer simulation technology becomes more advanced, physics and chemistry can more closely approximate reality. ‘We now understand enough about living systems to appreciate that they are built on the foundations of physics and chemistry, that they are carrying out physical operations and transformations that are knowable.’
Equally intriguing is what still remains unknowable, and most likely unquantifiable. While these experiments in executable biology explicitly challenge the dichotomy between the living and non-living, the scientists themselves are reluctant to delve into the slippery liminal space in between. Busbice does not believe his robot to be alive in a biological sense, and both he and Larson appear content to leave the task of defining life to philosophers.
‘As a scientist, I don’t have
any feelings towards it,’ Busbice says of his Lego experiment. ‘I do kill it.’
Nonetheless, during the course of our conversation he occasionally speaks about the robot with the sort of fondness one might reserve for a family pet. ‘I liken it to a cat,’ he says. ‘You can try to entice it with food and things like that, but a cat pretty much does what it wants to do.’ The robot often scurries about his office, ‘wandering around like an animal, observing and interacting with its environment. It kind of makes you think it is alive to some degree – as much as a worm is alive.’
* * * * *
The degree of the ‘aliveness’ of things is surprisingly debatable. Is a worm alive in the same way as a mammal? As Sparrow notes, there are organisms in the natural world for which a binary categorisation of life and non-life seems unsatisfactory. Viruses, for instance, share some characteristics of the living: they can reproduce (albeit within the cells of other living organisms) and they have an evolutionary history.
Perhaps a more pertinent question, Sparrow suggests, is whether virtual organisms are worthy of moral consideration. If a virtual organism were to reach the functional equivalent of a living one, ‘there would be questions about whether it would be wrong to cause it pain’. Most humans would place animals in an ontological category similar to our own, but the same cannot be said for computers or robots.
Many of us would hope that our existence is more than a pneumatic network of neurons, valves and ventricles. Such biological determinism may seem depressing – and has been vigorously contested by critics – but Busbice is unfazed. For him, the ghost is the machine.
‘What I’ve done with the technology, I guess, reduces humans to a bunch of connections. That scares people, that we’re not this benevolent creature, unique in the universe … we’re just a bunch of wires connected together.’
