06 April 2020: Possible new date for arrival of Homo sapiens in Australia

In an earlier blog I mentioned a letter to Nature that suggests up to 2% of the Papuan genome originated ‘ … from an early and largely extinct expansion of anatomically modern humans (AMHs) out of Africa.’

If correct, this is important because it pushes back the earliest currently accepted dates for the human occupation of Australia (well, Sahul back then) beyond 50,000 – 60,000 years.

New evidence for a possible earlier date has now come from a site near Warrnambool, a town on the southwest coast of Victoria, where scientists have been investigating a site at the mouth of the Hopkins River. In a paper from CSIRO, it is described as an ‘erosional disconformity of last Interglacial Age’ where the shells of edible molluscs and transported stones were discovered.

Hopkins River mouth

The mouth of the Hopkins River. (Photo from Warrnambool local government website.)

It is not known for sure whether humans or animals such as seabirds made the formation, but the site has been confirmed as a midden, and evidence for fire damage to the stones suggests they may have been used to make a hearth.

Thermoluminescence analysis of the stones, together with independent stratigraphic evidence, suggests the hearth could date back between 100,000 – 130,000 years.

If true, not only does this double the possible dates for the earliest occupation of the Australian landmass, it also considerably pushes back the earliest currently accepted dates for the first successful emigration – an emigration resulting in living descendants – of AMHs out of Africa by as much as 20,000 – 50,000 years.

(The research was presented to the Royal Society of Victoria by, among other academics, Jim Bowler, who discovered Mungo Man in 1974. The Guardian’s Paul Daley wrote about the paper and interviewed Bowler in March last year. Also, see this from the Royal Society of Victoria’s own website.)

30 March 2020: Walls

I live in a compound in the Johannesburg district of Fourways, a favourite location for expats, the white middle class and the growing black and coloured middle class. Our compound is surrounded by a 2.5-metre wall topped with a ring of metal spikes and electric fencing. Our townhouse abuts the north wall. East of our house, and still in the compound, is a children’s playground and a tennis court; before the current lockdown, most weekdays I heard small children laughing and shouting in the playground, supervised by parents and nannies. I like that about where I live: it’s a community, with all age groups.DSC07154

When I call it a compound, I’m sometimes corrected by locals. ‘It’s a complex, not a compound,’ someone will say. Or, ‘It’s a gated community.’

I get that. ‘Compound’ sounds like a kind of prison, except in this case it’s built to keep people out, not keep people in. Having said that, there are times when it feels like we are being kept in, especially early in the morning when I look out north and east and see glimpses of what appears a less restrained city draped across the Gauteng landscape.[i]

But whether you call them compounds, complexes or gated communities, they are small villages separated from the rest of Johannesburg by walls and wires and gates and guards. These compounds have, as Lynsey Chutel wrote in Quartz Africa, ‘created pockets of development – ranging from middle class suburbia to opulence – walled off from South Africa’s socio-economic reality.’

Compounds are not as old as apartheid, and nor is it true to say they are the spatial descendants of apartheid geography[ii], but as Chutel points out there is a direct link in the mentality behind the construction of compounds and their popularity as places to live in cities such as Johannesburg: ‘The prevalence of gated communities may also reveal what South Africans think constitutes middle class life. As it did under apartheid, it often means avoiding the poor unless they are servants, nannies or gardeners.’

As more and more black and coloured South Africans join the country’s middle class, compounds like the one I live in can be seen as the expression of economic rather than racial division, where the better off are made to feel more secure by being separated from the poor, the unemployed and the underemployed. The fact that a large number of well-off South Africans are white can blur the distinction[iii], but compounds are ultimately the concrete expression of an economic divide, and an expression of what I think is the single biggest stumbling block to a more united, more progressive and ultimately wealthier society: the unwillingness to tear down the walls. I don’t see this simply a physical problem, but more importantly, a deeply psychological one.

When I lived in Phuket, one of the things that struck me about Thai society was how the rich and poor lived cheek by jowl. A drive along Thepkrasatree Road would have us passing a palatial estate sandwiched between a two-bedroom concrete box and a refugee camp filled with tin shacks, all of them spouting television aerials and satellite dishes. It wasn’t that the family living in the palatial estate liked living next to a refugee camp, or for that matter that the refugees in the camp liked being constantly reminded of how little they owned, but that there were no 2.5 metre walls and electric fences reinforcing the division. The rich, the aspiring middle class and the desperately poor tolerated each other.

Thai society isn’t without its problems, including crime and violence, but the different classes seem more willing to share common ground, and more than willing to accept the poor becoming middle class and the middle class becoming rich. In Phuket, unlike Johannesburg, divisions aren’t fanned by a history of oppression on one side and fearful insecurity on the other.

Compounds are most common in Gauteng Province, especially its two main cities: Johannesburg and Pretoria. Divisions certainly exist in cities like Cape Town, but I didn’t see many examples of whole communities being fenced off from the world outside.DSC07729

What strikes me most about South Africa and its people is its sheer potential. South Africans I have met are hardworking, smart, confident and optimistic at heart. The country has natural resources aplenty and for its size a large but not excessive population for Africa (around 60 million people in a state somewhat larger than New South Wales). The people genuinely value democracy, freedom, education, initiative and creativity. It seems to me that all the important elements of a successful society are in place; the fact that it is not yet a successful society speaks to its recent history and the scars it’s left behind.

I have to stress that these are impressions on my part, and I’m an interloper. I come from a wealthy, predominantly white middle-class background from a land far, far away. I am a member of the most privileged class of human beings that has ever lived. I have no right to give advice to anyone who lives here, to all those who have struggled through decades of repression and fear, let alone to the new generations that came after the end of apartheid – the ‘Born Frees’. I also know how hard it is to talk about a society as rich and complex as South Africa’s without making generalisations, some of which are unfair to all those who struggle every day against any division, racial or economic.

But I cannot help feeling that greater progress in South Africa cannot be made until there is genuine social and economic freedom for everyone, and I cannot help feeling that will not occur until the walls come down.

[i] The thing you notice most of all about Johannesburg is all the trees. For a city that has grown in South Africa’s Highveld, dry rolling plains that resemble the dry rolling plains around Canberra and Yass, there’s an awful lot of perpendicular vegetation. It’s sometimes claimed that Johannesburg is home to the world’s largest artificially created forest, and I can believe it. A lot of the trees are introduced – eucalypts, lillipillies, jacarandas – but the city still manages to look very African, as if at any moment the traffic weaving along the streets inside the forest could be replaced by herds of wildebeest.

[ii] Where ‘apartheid willfully set out to beggar the Black community for the benefit of the White.’ https://www.sahistory.org.za/article/johannesburg-segregated-city

[iii] https://mg.co.za/article/2016-08-04-00-figures-suggest-sa-has-the-highest-concentration-of-wealth-in-the-hands-of-a-few/, and see https://businesstech.co.za/news/wealth/133164/south-africas-skewed-income-distribution-when-measured-by-race/

10 January 2019: A tale of unrequited love

dsc01509 (2)

Southern masked weaver in our back yard, Johannesburg

What follows is a tragedy. Admittedly, a minor tragedy in the scheme of things, but one that played out in front of AJ, our daughter and myself at our home in Johannesburg just after Christmas. It involves a hardworking bird called a southern masked weaver and its failed attempt to win a mate.

Weaver birds, as their name suggests, weave intricate nests. They are a family of birds mostly native to sub-Saharan Africa, with some species living in tropical Asia.

According to Weaver Watch, one of their number, the red-billed weaver or red-billed quelea, ‘ …is one of the most abundant bird species in the world and its post-breeding population has been estimated to be 1.5 billion birds, leading to its nickname “Africa’s feathered locust”’. Since it readily eats crops, this makes the red-billed quelea a serious threat to subsistence farmers.dsc01471 (2)

Most weaves, however, are harmless. They are beautiful birds, small and compact, and during mating season (September to January) the males are brightly coloured, brilliant architects and hardworking builders.

Since arriving in South Africa six months ago, AJ and I have admired weavers and the intricate nests they make, and were planning to build a feeder and bird bath to attract to them to our home. Then to our surprise, on Boxing Day, AJ and daughter (visiting from Australia over Christmas) noticed a southern masked weaver starting a nest hanging from a branch about halfway up the jacaranda in our backyard.

In fact, by the time we noticed its existence the nest had already been started: the first central ring of long fronds had been weaved together, and an inner lining of fern (or possibly jacaranda) leaves laced in to help make the nest more comfortable.

As we watched over the next two days, the weaver worked virtually non-stop on building the new home. Its skill, agility and determination were remarkable, and the product of its labour a thing of beauty. I wouldn’t be surprised if our distant ancestors learned to weave from watching these little birds at work.dsc01478 (2)When the male has finished building the nest, a female flies in to assess its suitability. While the male of the species is a brilliant architect and hardworking builder, the female is a severe critic and, occasionally, expert demolisher. If she doesn’t like the nest, she will often tear it to pieces; the male will then start again, or choose another location to build a completely new one.

Three days after first noticing the nest in our jacaranda, we left home for most of the day. When we returned, the nest was gone, its ruins laying on the lawn below the tree. At the time AJ theorised it was a young male, new at the game, and a female had let it know in no uncertain terms that its efforts weren’t good enough. But then we remembered that there had been a brief but violent storm while we were out, and it seems likely this was what brought down the nest.dsc01537 (2)

Sadly, we didn’t end up with a happy couple residing in our backyard and raising a new brood of southern masked weavers. On the plus side, male weavers usually build a series of nests; we can only hope our male successfully found at least one female willing to put up with his efforts and share with him a clutch of eggs.

15 September 2018: The not-so-big (but still mightily impressive) ten

Last weekend, AJ and I went camping at Pilanesberg National Park. Well, I say camping. Our tent had a refrigerator in it. And a kettle. And power points for our mobile phones.


Extraordinarily rough camping conditions prevailed at Pilanesberg.

Anyway, together with some fellow teachers from AJ’s school we went comfortably camping at a park famous for providing visitors the opportunity to catch sight of the Big Five: Cape buffalo, elephants, leopards, lions and rhinos.

While we did manage to see a line of lying lions in the distance – we needed binoculars to find them – for the most part the Big Five managed to elude us.

This is probably because AJ and I decided to forgo the chance of getting up before sunrise and braving subzero temperatures to tour the park in an open truck. Those who did make the effort not only managed to see the Big Five but cheetahs as well. However, they were cold. Very cold. Their fingers snapped off trying to focus their Nikon 70-300 zoom lenses.

We, on the other hand, got up at a civil hour, had a hot breakfast, and entered the park about 9.30 am, courtesy of the generous school librarian and his huge red ute. Although most of the predators and large herbivores had by then decided to migrate to warmer climes, we did see plenty of impressive wildlife, including kudus, wildebeest, zebras and giraffes.


Grey heron.

And our fingers didn’t drop off focusing our zoom lens. Not just because it was warmer, but because our camera decided to stop working, forcing us to rely on the cameras on our mobile phones.

In fact, we didn’t really have to leave our tent to see some very impressive locals. Our camping site had been colonised by a several groups of impala, vervet monkeys, chacma baboons, banded mongooses, hornbills and helmeted guinea fowls.

The impala were the most impressive of all. They’re magnificently streamlined antelopes with a colour scheme designed by an Italian fashion house. The males sport magnificent horns shaped like ancient Greek lyres. The effect is somewhat spoiled when the males start practicing for the rutting season by pretending to come to blows and blowing through their noses, sounding like a parcel of agitated pigs with head colds.


Impala cleaning his nose in preparation for a good snort.

The funniest sight is watching the normally docile guinea fowls suddenly scatter, running one way and then the other. AJ said the bird reminded her of a fusty old women from the 19th century picking up her skirts and pelting down the street.

The vervets spend most of their time high in trees or sitting like sandstone statues on the roof line of the campsite’s restaurant. They look down on their fellow primates with aloof disinterest.


Vervet practising aloofness.

One of the highlights of the expedition was totally unexpected. We came across the ruins of an iron age kraal not far from the park’s entrance. The area’s fenced off, and if the main gate’s red light is flashing – meaning something like a lion or leopard or elephant is also touring the ruins – you’re advised to stay out. On this occasion we were the only visitors.

The kraal was built by the Tswana chief Pilane, hence the name of the park. The ruins are well signed, giving a brief history of the kraal and what the various buildings and spaces were used for. The kraal’s main lookout provided wonderful views of the park. It reminded AJ and me of some of the ancient hill forts on the border of Wales and England we visited in 2010. Although those hill forts weren’t surrounded by thorn trees. I managed to get one long branch wrapped around my left leg. It took some doing to disentangle myself, and the small wounds made by the thorns itched for hours afterwards.


Warning outside the iron age kraal.


The kraal itself!


View from the kraal lookout.



A second highlight was the visitor’s centre, where people can eat and drink on a wide deck overlooking the bush. A large salt lick is placed not far from the deck, drawing giraffes, zebra and wildebeest, although when we were there only one giraffe, the biggest, got to enjoy the lick. He’d tolerate other giraffes having a go, but didn’t hesitate kicking any wildebeest who came for their turn. The zebras were pluckier than the wildebeest, but no more successful.


A giraffe. Not a zebra or wildebeest.

The landscape between Johannesburg and Pilanesberg is eerily familiar. Geographically and botanically it’s very similar to the Southern Tablelands, especially the stretch between Canberra and Yass. It’s not surprising, I suppose: South Africa and Australia were once joined at the hip. The soft landscape is covered in grasses and acacias and other plants adapted to a hot, dry climate. True, South Africa has lions while Australia has sheep, and South African kopjes are rockier than Australian hills, but nonetheless …

The similarity even extends to bushfires. Pilanesberg hosted its own bushfire the week before we arrived, and large parts of the park were black and ash grey, again strangely familiar to anyone from inland New South Wales.


Bushfire damage.

It’s not like AJ and I are looking for similarities, but perhaps a little homesickness makes you look for them instead of the differences.

In October, we hope to make our way southeast to Durban for a few days, stopping over at the Drakensberg on the way.

24 August 2018: When did humans first leave Africa?

This blog post is titled ‘When did humans first leave Africa?’ I confess, it’s a trick question, but we’ll come back to that later.

So to start with, let’s attempt to answer not a trick question but a trickier question: when did Homo sapiens first reach Australia?

This has been a contested debate for several decades, with proposed dates stretching from 75,000 years ago to 40,000 years ago. The bottom mark was established by the dating of the remains of Mungo Man, the oldest remains  of anatomically modern humans (AMH) yet found outside Africa.

Mungo Man

Mungo Man

Towards the upper end, luminescence dating of sediments around artefacts recently found at Madjedbebe in the Northern Territory give a date of around 65,000 years, although this is contested.

In a recent article in The Conversation, ‘When did Aboriginal people first arrive in Australia?’, authors Alan Cooper, Alan N. Williams and Nigel Spooner state the ancestors of Aboriginal Australian first reached Australia sometime between 50,000 and 55,000 years ago, just after AMH left Africa.

This date comes from geneticists working on Neanderthal ancestry in the modern human genome. In ‘Tracing the peopling of the world through genomics’, authors Nielsen et al. write that:

‘All non-African individuals studied so far contain around 2% Neanderthal ancestry, suggesting that admixture mostly occurred shortly after the dispersal of anatomically modern humans from Africa … the date of hybridization has been estimated to be approximately 50–65 kyr ago …’

33.1 H. neanderthalensis Amud 1 0.4-0.04 mya

Cast of H. neanderthalensis (Amud 1) from the Australian National University. Photo: Simon Brown

This date is now generally accepted by palaeoanthropologists.

But that presents us with a quandary. As I wrote in an earlier blog, fossils from the cave of Jebel Irhoud in Morocco, together with genetic data from a 2,000 year old Khoe-San skeleton, suggests our species arose in Africa at least 300,000 years ago. So why did it take our species a quarter of a million years to find the exit?

Well, as it turns out it, it didn’t.

In a January 2018 report in Science, authors Chris Stringer and Julia Galway-Witham note that recent fossil evidence from Israel suggests our species had left Africa by 180,000 years ago. The report also recounts genetic analyses of Neanderthal fossils from two caves, Denisova in Russia and Hohlenstein-Stadel in Germany, that ‘indicate at least one earlier phase of introgression, from H. sapiens into Neandertals … estimated at 219,000 to 460,000 years ago’.

At this stage, it seems that AMH could have left Africa over 200,000 years ago, and yet DNA evidence strongly suggests the ancestors of all non-African members of our species left Africa no earlier than 60,000 years ago.

So what’s going on?

Nielsen et al. write that the latter date indicates when the ‘ultimately successful’ dispersal of H. sapiens from Africa occurred. In other words, those members of our species who left earlier are now extinct and left no trace in our genetic record.

Stringer and Galway-Witham write that there is evidence there were several humid phases between 244,000 and 190,000 years ago. But these phases were bracketed by severe periods of aridity, which meant ‘the region was probably more often a “boulevard of broken dreams” than a stable haven for early humans.’

Chris Stringer

Chris Stringer, Research Leader in Human Origins, Natural History Museum

On the other hand, a letter published in Nature in 2016 suggests that earlier migrations of H. sapiens from Africa may have left their mark on some of us after all; specifically, Papuans.

After analysing ‘a dataset of 483 high-coverage human genomes from 148 populations wordwide … ‘ Pagani et al. found ‘ … a genetic signature in present-day Papuans that suggests that at least 2% of their genome originates from an early and largely extinct expansion of anatomically modern humans … out of Africa.’

This brings us back to the article in The Conversation. Cooper et al. discuss how Aboriginal Australians moved to and occupied Australia around 50,000 years ago. Of course, 50,000 years ago it wasn’t Australia, it was Sahul, a single landmass comprising Australia, Tasmania and Papua New Guinea.



Yet the letter in Nature suggests that Sahul might in fact have been occupied by H. sapiens before that date. Its authors hypothesise either that these people came from an unsampled archaic human population that split from modern humans ‘either before or at the same time as did … Neanderthal’, or that they were a modern human population that left Africa ‘after the split between modern humans and Neanderthals but before the main expansion of modern humans in Eurasia’.

The data from all this research is sometimes confusing and contradictory. Over the last quarter century palaeoanthropology has undergone a great revolution driven partly by discoveries of new hominin fossils (eg H. floresiensis and H. naledi), and partly by new and refined techniques in analysing DNA. There is a lot of data to sort through, doublecheck and assess. Nevertheless, as measurements are refined and new discoveries are made, we learn more about our past and so more about ourselves.


So, why is the header a trick question?

H. habilis

Homo habilis

All the above information deals with the history of just one species, our own. But H. sapiens were not the first humans to leave Africa. For example, some members of H. heidelbergensis left Africa around half a million years ago, evolving into H. neanderthalensis in Europe. Those that remained in Africa almost certainly gave rise to H. sapiens.

And if the conclusions of a recent paper by Argue et al. studying the phylogeny of H. floresiensisis are correct, then another and possibly earlier human migration out of Africa occurred. This species’ forebears are closely related to H. habilis, the oldest species in our genus, Homo.

It’s almost as if the need to migrate is as defining a feature of our genus as bipedalism, a large brain and an opposable thumb.

14 December 2017: Colin Groves (24 June 1942 – 30 November 2017)


My friend Colin Groves died two weeks ago this day. It came a surprise, although I knew he was in palliative care. He seemed invincible as those with a great intellect always seems invincible, as if death could be put off indefinitely. Although aged he was never an old, and although physically ill his mind was as sharp as an Acheulean hand-axe.

In a real sense his work makes him immortal, at least as far as any human can be immortal. I knew him chiefly as a friend and fellow skeptic, and more recently as a co-writer. Although I had some knowledge of his standing among taxonomists, anatomists, biological anthropologists, primatologists and palaeontologists, he was overwhelmingly modest. Just the preceding list of fields should give you some idea of the breadth of his knowledge.

When Jane Goodall was asked what it felt like to be the world’s foremost primatologist, she replied ‘You’re mistaken. The world’s foremost primatologist is Colin Groves.‘[i]

At his funeral, colleague Professor Kristofer Helgen noted that Colin had named more than 50 new kinds of mammals, and that the first, the Bornean Rhino, remains the largest living mammal described in recent generations.[ii]

‘Colin was the most influential large-mammal taxonomist of the last half-century. His discoveries and impacts are astonishing … The last species he named, in a paper which appeared … in the last month of his life, was the Tapanuli orangutan, one of only eight living great apes on our planet … ‘

As Professor Helgen points out, Colin is probably best known for describing Homo ergaster in 1975, together with Vratislav Mazák. Homo ergaster, which lived in Africa between 1.4 and 1.9 mya, was probably one of our direct ancestors.


Homo ergaster. ANU cast of cranium KNM ER 3733, discovered at Koobi Fora, Kenya, in 1975 by Bernard Ngeneo.

Professor Helgen said Colin Groves was an original.

‘He was a gentle soul, but could be an immovable opponent. And he was genuinely brilliant, yet every bit as genuinely modest … When I think of Colin, I see him in my mind’s eye in his office at the ANU, decked from floor to ceiling with books and journals and reprints, all of his key resources, usually reckoned obscure to all others, within arm’s reach.’

This rings a cathedral of bells. Whenever something came up in our conversation about – well, almost anything – Colin would have a book, journal or anecdote to clarify, correct or corroborate any fact, no matter how obscure.

But my overriding memory of Colin isn’t his intellect or reputation, but his enormous kindness and placidness. He was never overtaken by anger, only bewilderment at the occasional fecklessness or waywardness of his fellow Homo sapiens.

He was one of my dearest friends, and his passing leaves a gaping hole in the lives of everyone who knew him.

Below is the eulogy I delivered at his funeral last Thursday.

Colin Peter Groves

As I look up at the Canberra’s first blue sky in five days, I’m tempted to think that while Colin did not believe in god, god almost certainly believed in Colin.

Although I knew him for 30 years it wasn’t nearly long enough, but perhaps long enough to discern the three great loves of his life.

Most importantly of all, his partner, best friend, constant companion and carer, Phyll.

Second, his love of science, particularly biology of course, and how it revealed to him the universe he shared with his fellow-primates, ungulates, big cats, avian dinosaurs, tardigrades, dogs, bats and cetaceans.

Third, his love of chinwagging. All the creatures I just mentioned could happily be included in a single lunchtime conversation with Colin. You might start discussing sexual dimorphism among species of African antelope and end by discussing the size of Donald Trump’s genitalia. (Amazingly, and somewhat distressingly, size does matter in nature.)

Let me deal briefly with each of these three great loves, from last to first.

It seemed to me that Colin was in his element when he shared conversation with friends and colleagues. If food and drink were included, so much the merrier, which added a cruel twist to the illness that eventually took him from us.

Although most discussions started with and usually revolved around science, his interests were catholic: skepticism, history, music, art, literature, film and television, and a hundred other subjects. He didn’t possess a ‘comfort zone’ as such; he was happy drifting on a sea of titbits, anecdotes, quotes, and bad puns (because, as Colin would patiently explain, a good pun isn’t a pun but a joke, and the quality of a pun is directly proportional to the volume of the groan it elicits).

He also had a deep and abiding love for startling and unexpected facts.

I remember how much he enjoyed discovering that the Great Pyramid of Khufu, built around 2560 BC, was the tallest building in the world until succeeded by – of all things – Lincoln Cathedral in 1311. A 3,800-year old record. He was just as delighted to learn that when Lincoln Cathedral’s centre spire collapsed in 1549, the Great Pyramid couldn’t resume its title as the world’s tallest building because erosion had reduced its height to below that of a church in Germany.

While an hour’s conversation with Colin could be filled with minor revelations such as these, they were never random thoughts. They were either staging posts that guided you safely to the end of a conversation, or points that illustrated a greater truth Colin was pursuing with the gentle doggedness of a modern-day Socrates.

In a conversation about intelligence and self-awareness, he might include the latest research about the Theory of Mind among corvids, Mozart’s Marriage of Figaro, gorillas studying their reflection in mirrors while trying on different hats, and the British television series Peaky Blinders. But every diversion would have a point, and every point would add weight in support of an argument for or against a main proposition.

I briefly mentioned Donald Trump. It seemed to me that while Colin never avoided discussing politics, what he cared about were the issues important to all of us in a free and democratic society, issues shaped and sometimes decided by politicians, pundits and lobbyists. It was people that Colin cared about, not cant. It was ideas Colin cared about, not ideology. What Colin wanted for our society was equality, opportunity, fairness and boundless curiosity.

Colin’s second great love was science, particularly anthropology and taxonomy. To say he was a biological anthropologist, while absolutely accurate, is entirely insufficient. Robert [Attenborough] has already talked about Colin’s amazing academic career, but I first met Colin because of his opposition to those forces that set themselves against science, particularly religious inerrancy, with a special focus on the shallow, silted stream of creationism.

From the first time I attended a meeting of the Canberra Skeptics, Colin immediately stood out as the most determined, the most knowledgeable and the most resilient opponent of creationism I have ever encountered. I never imagined someone as steeped in science as Colin would also be so utterly familiar with the Christian bible he could quote chapter and verse.

It wasn’t the idea of opposition that excited him, but the idea of investigating claims and when found wanting, standing up against them. I never once saw Colin angry, at least not in the sense most of us would understand the word, but when confronted by blind stupidity or blind faith, his eyes would open slightly in surprise, then narrow as he marshalled his arguments in defence of rationality.

The only other time I saw this response was when he was confronted by casual arrogance, wilful pride or careless prejudice. He understood how all these were used to stifle debate or to keep underdogs in their place, and he resented it.2

Colin was not a skeptic for the sake of it. It was just the flipside of the scientific method he applied to his everyday investigations of the natural world. It was as much a part of him as that sense of wonder that shone from him whenever he talked about the discovery of a new hominin fossil, or a new species of orangutan, or gravity waves.

Ultimately, forever and always, Colin’s greatest love was Phyll. On those few times I visited when Colin showed off just how much he knew about obscure science or history or culture, he wasn’t doing it to impress me. I think he was doing it because he just loved flirting with Phyll.

Phyll was his touchstone and keystone, his measure and the source of his strength. When she spoke, he listened. Even when he disagreed, he listened, and he listened closely.

And one never visited Colin, one always visited Colin and Phyll. They were as close to being a single unit as any two people I’ve ever met. Two minds, two voices, often two very different opinions, but a single soul, a word even Colin would agree with in this context.

They generously shared their life with family, friends, colleagues and students.

For that I will always be grateful.

[i] Mittermeier, Russell A. & Richardson, Matthew. Foreword to Extended Family: Long Lost Cousins, by Colin Groves. Conservation International, Arlington, 2008.

[ii] Helgen, Kristofer M. 2017. ‘Eulogy for Colin Peter Groves’, Canberra, 7 December.

09 November 2017: the eighth great ape and the problem with ‘species’

Until recently, only seven species made up the group of primates known as the great apes, or Hominidae. Two orangutan species (Sumatran and Bornean), two gorilla species (eastern and western), two chimpanzee species (chimpanzees and bonobos), and us.

But in a report recently published in Current Biology, an international team of scientists announced a new hominid with fewer than 800 members, Pongo tapanuliensis, found just south of Lake Toba in Sumatra. To save your tongue twisting around that particular binomen, we can call it the Tapanuli orangutan.

The scientists compared skull, jaw and dental characteristics of a Tapanuli specimen with those of the Sumatran and Bornean species, and analysed 37 orangutan genomes as a second line of evidence.


Three species of orangutan: from left, Bornean, Sumatran, Tapanuli. Photo credits: Eric Kilby, Aiwok, Tim Laman

The report gained a great deal of media attention: not only because we humans had a new cousin, but because the Tapanuli is an endangered species.

However, there were dissenting voices. In an interview with the ABC, for example, Lee Christidis from Southern Cross University pointed out that the analysis had been carried out on only one specimen and that the DNA evidence was at best ambiguous.

It’s only fair to point out that it’s often the case that a species will be described by a single representative organism, or, as happens frequently in palaeontology, those fragments of a single organism that have been fossilised or otherwise survived over many millions of years.

The report also generated discussion about what we mean by the word ‘species’. Jerry Coyne, professor emeritus at the University of Chicago and author of the excellent Why Evolution is True, wrote in his blog:

‘Not only do I see this new “species” as merely an isolated and genetically differentiated population (as are many human populations regarded as H. sapiens), but I’d also contend that there is only one species of orangutan overall, with these three groups all being subspecies. Sadly, a lot of systematists don’t see it that way, as they seem to think that any isolated population, if it can be told apart morphologically or genetically from others, warrants being named as a new species. Yet to evolutionists, a “species” is not an arbitrary segment of nature’s continuum, but real entities that maintain their “realness” because they don’t exchange any (or many) genes with other such entities where they cohabit in nature.’

But is this indeed the definition of species with the greatest currency among most biologists?

To start with, there has to a definition that works across all fields. A primatologist cannot have a different concept of species from, say, an entomologist, or the whole point of taxonomy – the orderly classification of living things that demonstrates their evolutionary relationships – starts to fall apart.

This doesn’t mean that definitions in biology – or any scientific endeavour, for that matter – are written in stone. As our knowledge of the world around us grows, the language we use to explore, explicate and explain that knowledge must also grow.

The definition I was taught at school is not dissimilar to Coyne’s quoted above, and is based on what is called the Biological Species Concept (BSC), developed by Ernst Mayr and Theodosius Dobzhansky in the early 1960s (Coyne did some graduate work under Dobzhansky at Rockefeller University). As Colin Groves, professor emeritus at the Australian National University, wrote, ‘This concept states that under natural conditions a species ‘should not exchange genes with other species’[i]. Groves goes on to point out that ‘ … the popular idea that two species are “unable” to interbreed is  a misunderstanding: it is not that they cannot interbreed, it is that they do not.‘

The BSC was further refined by Mayr and Jared Diamond in a paper on Melanesian birds in 2001, and then in 2004 by the aforementioned Jerry Coyne with H. Allen Orr in a book about speciation called, appropriately enough, Speciation.

Groves argues that the modified definition of BSC risks different standards of comparison in different taxonomic groups: it’s a definition that won’t work across different fields, in other words.

Groves again: ‘If a genus contains a pair of sympatric[ii] sibling species (species that differ only slightly, inconspicuously), the standard for species recognition will be set much “lower” than in a genus in which sympatric species pairs are grossly different. It is the search for objective standards – for an operational means of distinguishing species – that has been responsible for the controversies that marked taxonomic discussions over the past 15 or 20 years.’[iii]Taxonomy

Many biologists now use what is called the Phylogenetic Species Concept (PSC), developed by American biologist Joel Cracraft from the early 1980s. Put very simply, in this concept a species is the smallest population of organisms that is measurably different from other populations sharing the same ancestry. Note that this concept says nothing whatsoever about species sharing genes, such as happened between Homo sapiens and H. neanderthalensis around 100,000 years ago.

It’s important to note that both the BSC and the PSC are attempts to operationalise the evolutionary concept of species; that is, that a species is an evolutionary lineage.

While the report in Current Biology describing the Tapanuli orangutan as a new species of great ape has, for the most part, been received positively, the fact that many distinguished scientists question the findings shows that the debate about what constitutes a species is ongoing.

[i] Groves, Colin. ‘Speciation in hominin evolution’; African Genesis: Perspectives on Hominin Evolution; ed Reynolds, Sally C. & Gallagher, Andrew; Cambridge University Press; Cambridge; 2012, p 46.

[ii] Sympatry occurs when two or more species live in the same geographic area.

[iii] Ibid.

07 November 2017: Dreaming in the Dark anthology wins World Fantasy Award

For the second time, one of Jack Dann’s Dreaming anthologies has won a World Fantasy Award.


Dreaming in the Dark, ed Jack Dann, PS Publishing

Last night, Dreaming in the Dark, edited by Jack and published by PS Publishing, won the 2017 World Fantasy Award for Best Anthology.

In 1999, the first in the series, Dreaming Down-Under, edited by Jack and his partner Janeen Webb, won the same award.

I was fortunate enough to have stories included in both.

That the anthologies should receive such an honour says a great deal about Jack’s dedication to Australian writers of speculative fiction. We all owe him a great debt.

Congratulations, Jack!

17 October 2017: Walking statues, colonialism and free speech

I am a white male living in a society largely designed by white males for the benefit of white males. As such, I am a member of history’s most privileged group, a group that numbers no more than a few hundred million in a world inhabited by over seven billion human beings.

What got me here, together with every other member of that group, was a toxic mixture of imperialism and colonialism. Not toxic for me, I hasten to point out, but toxic for billions of other human beings.

It’s not necessary to point out how many first peoples suffered because of European expansion from the 15th through to the 20th centuries. Nor should we defend that expansion by referring to the benefits brought by the introduction of ‘Western’ inventions such as double-entry bookkeeping and modern farming methods, as if they were handed out by the Conquistadors and Australia’s first settlers at the same time as the distribution of smallpox and musket balls.Imperialism

Imperialism and colonialism also transformed slavery into a global business. The fact that Europeans didn’t invent slavery shouldn’t stop us acknowledging that developments such as double-entry bookkeeping helped Europeans perfect it, in the same way the musket ball helped perfect total war.

In a very roundabout way that brings me to the topic of walking statues. Specifically, Rapa Nui’s moai – the monumental statues of Easter Island.

Rapa Nui has been used as the example par excellence of ‘ecocide’, what happens to a society that selfishly exploits its own environment beyond recovery and thereby destroys itself. I swallowed without questioning this explanation for the island’s depopulation and deforestation, promoted in books like Jared Diamond’s Collapse: How Societies Choose to Fail or Survive.

But it may not be true.

University of Bristol researcher Catrine Jarman explains in her article in The Conversation, that many decades of archaeological research on Rapa Nui ‘paints a very different picture’.

As Jarman writes:

‘The ecocide hypothesis centres on two major claims. First, that the island’s population was reduced from several tens of thousands in its heyday, to a diminutive 1,500-3,000 when Europeans first arrived in the early 18th century.

‘Second, that the palm trees that once covered the island were callously cut down by the Rapa Nui population to move statues. With no trees to anchor the soil, fertile land eroded away resulting in poor crop yields, while a lack of wood meant islanders couldn’t build canoes to access fish or move statues. This led to internecine warfare and, ultimately, cannibalism.’

Essentially, there is no convincing evidence that Rapa Nui’s population declined before first European contact in 1722. Furthermore, recent evidence suggests that the island’s population successfully sustained itself for centuries despite deforestation occurring soon after the island’s initial settlement by humans, deforestation caused by the accidental introduction of the Polynesian rat which ate palm nuts and saplings.

So what did happen to the people of Rapa Nui?

Again, in Jarman’s own words:

‘Throughout the 19th century, South American slave raids took away as much as half of the native population. By 1877, the Rapanui numbered just 111. Introduced disease, destruction of property and enforced migration by European traders further decimated the natives and lead to increased conflict among those remaining.’

The disaster that befell the people of Rapa Nui came about because of the slave trade of the 18th and 19th centuries, itself a result of European imperialism and colonialism. Effectively, the victims of that depopulation subsequently were found guilty of the crime.

If the forests weren’t cut down to move the moai, how did the islanders transport the statues from where they were made to where they were eventually sited?


Rapa Nui moai

It turns out they probably moved them in the same way you or I would move a heavy washing machine or refrigerator … they walked them. Admittedly, this involved a great deal more human muscle power and coordination than two people clumsily angling white goods through a narrow corridor. Recent experiments show that this was perfectly possible.

(For a full explanation of how this was done, and the true story of how Rapa Nui became depopulated, check out The Statues that Walked, by Terry Hunt and Carl Lipo.)

I can’t argue that imperialism and colonialism had no benefits. It benefitted me, for example. Without them I wouldn’t be here now, a middle-aged male living in middle-class splendour in Australia, a collection of ex-colonies. Nor can I argue against the proposal that the modern world is a direct result of those movements. Nor can I argue against the proposal that industrialisation and modernisation, two direct products of those movements, hasn’t improved the lot of billions of human beings over the last two centuries.

What I can’t argue, however, is what Portland State University’s Bruce Gilley suggests in an article recently published in Third World Quarterly. An associate professor of political science, Gilley proposes that ex-colonies that develop their Western colonial legacy do better that those that reject that legacy. One of the examples he uses is the modern nation of Singapore.

I suspect Gilley is wrong, especially in the case of Singapore where its success is almost entirely due to the self-created ‘Singapore model’, a mixture of democracy, authoritarianism and meritocracy that has delivered remarkable growth and one of the world’s highest standards of living. But I strongly believe Gilley has every right to express his academic opinion in an academic journal.


Singapore skyline

As reported by Andy Ngo in Quillette, both Gilley and the journal’s editor-in-chief Shahid Qadir received threats of violence after the appearance of the article on 8 September, and the publishers of Third World Quarterly have withdrawn it. I recommend reading Ngo’s piece to get the full story.

I do not think hate speech or speech inciting violence should ever be published, whether it is an article written for a journal, an opinion piece in a newspaper, or an enraged Tweet by an American president. But I do not think it is right to censure someone’s research because you disagree with its conclusion. In fact, that kind of thinking encourages hate speech and incites violence. Worse, ultimately, it shuts off debate, dialogue and intellectual curiosity.

The problem for those who think that the evils of colonialism are so great that any defence of it is anathema and should be closed down is simply this: it allows history to be written by those who shout the loudest. It establishes a precedent, a precedent that may one day lead to the censorship of articles that explain why colonialism was wrong, and how the moai of Rapa Nui came to walk.

(NB Jared Diamond has responded to some of the claims made in Hunt and Lipo’s book, The Statues that Walked. You can check that out here. Thanks to friend, physicist and fellow-writer Rob Porteous for the heads-up.)

07 October 2017: New evidence suggest we are much older than 300,000 years

In a recent blog I wrote about new dates for skulls found in the cave of Jebel Irhoud in Morocco in the 1960s. Originally assessed as belonging to Homo neanderthalensis (an assessment that was soon challenged), a reappraisal published in Nature this year confirmed they were in fact H. sapiens skulls; the great surprise was that the reappraisal determined them to be at least 300,000 years old.

Jebel Irhoud

Cast of Jebel Irhoud 1 from the Australian National University. Photo: Simon Brown

New work done by scientists in Sweden and South Africa, and reported in Science, have now dated DNA obtained from a 2000-year-old Khoe-San skeleton apparently unmixed with Bantu or Eurasian DNA, as having separated from other H. sapiens sometime between 260,000 and 350,000 years ago.

The San are the First People of South Africa, Botswana and Namibia. Indeed, they may be the First People, the ancestral group all modern humans are descended from, or at the very least very closely related to them.

The San are the most genetically diverse of all humans living today. In an episode of Catalyst on the ABC about her research on San DNA, Professor Vanessa Hayes said, ‘There’s more similarity between myself and a Han Chinese than between two San people.’


San hunter/gatherer

As reported in Science, the recent work on San DNA involved several ancient individuals, but the standout dates were given by DNA from the genome of a hunter-gatherer boy known as Ballito Bay A. The scientists concluded that, ‘ … our results show that the deepest split among modern humans (the estimated latest time for the emergence of H. sapiens) occurred at between 350 kya and 260 kya.’

Given that the skulls found in Morocco have been dated to at least 300,000 years ago, it would seem not unreasonable to consider the older dates for the emergence of H. sapiens – 350,000 years ago – being closer to the mark than the lower date of 260,000 years ago.

This new evidence also adds weight to the theory that our species may have partly evolved in South Africa.

In the last eight months, we have seen conservative estimates for the age of our species jump from 190,000 years old to almost double that. It’s been an extraordinary year for palaeoanthropology.