15 April 2021: Growing up coloured in South Africa – an interview with Clinton Keet

‘The first time I heard the South African anthem was at funerals, and if the police heard you singing it they would fall on you.

‘Eleven years ago I sang the full South African anthem on South African soil for the first time. It was at a school soccer game in a Johannesburg school gym, and I felt immense pride. Now every South African knows the words.’

Clinton Keet, now a teacher at the very same school he first sang that anthem, says he cannot help smiling when he sees a sporting team representing South Africa and everyone in the stadium stands and sings the national anthem together.

Clinton Keet. (Photo: Simon Brown)


Clinton started life in a divided Cape Town, living in a district set aside for non-white South Africans. Through hard study, hard work and the support of his family, he became a teacher, and then an international teacher working in countries as diverse as Vietnam, Italy and China before returning to his native country, now freed from apartheid.

‘I was born in District 6, about the ten minutes walk from the centre of Cape Town. I don’t remember a lot about it – we were forced out of the district when I was about five years old. I remember it was very urban, mainly concrete and tar, and the only grassy area was the fringe around the TB clinic across the road.

‘It was a busy area, so if my parents and grandmother were out working I was put in the care of our neighbour; if she was housecleaning I had to sit on a small spot on the front porch and not move. There was a local gangster on the street corner 30 metres away who made sure I wouldn’t wander.’

Gangsters were locals who belonged to territorial gangs and dealt mainly with illicit drugs and alcohol. They rarely troubled civilians, but were strict about who could cross into their territory.

‘Sometimes gangsters would use us kids to help make a stack of bricks they could use against other gangs crossing the line.’

Destroying homes in District 6 – ‘The regime didn’t like the fact that District 6 was a bit of a melting pot, what they called a “grey area” … ‘ (Photo: courtesy of Creative Commons, photographer unknown)

In 1970 the government forcibly moved Clinton and his family to Penlyn Estate, a district set aside for coloured people in an area called Cape Flats.

‘The apartheid regime didn’t like the fact that District 6 was a bit of a melting pot, what they called a “grey area”, where coloured, Indian and black South Africans mixed freely and made families together. Keeping the different groups apart made us easier to control.

‘On the day we ordered to leave, government workers came about midmorning and piled our stuff into the back of a truck with a tarpaulin over it. The rest of us piled into our uncle’s old Hillman and drove off as the neighbours watched.

‘Most of District 6 was emptied pretty quickly, but some people hung on to the outskirts; it took a long time to clear out the whole area.’

Clinton admits the name Penlyn Estate sounds wonderful, but when they arrived the streets were still all gravel.

‘In the months before we moved, my dad took me there every few weeks and we’d stop by an empty field and stand there for a bit. But slowly a house was built on the land, and all the plots nearby. It was like a giant Meccano set.’

Clinton recalls that after moving in he and other children used to play on the sites still going up, despite warnings from parents to stay away from them.

‘There were small brass rings on the light switch fittings I used to put on my fingers; sometimes they’d get stuck and I had to run to my grandmother to help me get it off. So of course she’d know I’d been playing where I wasn’t supposed to go.’

He also remembers the area was pretty wild at first. They were robbed a few times.

‘The estate bordered on a really dodgy area called Hanover Park, an area with high unemployment and rife with gangsters. It was another coloured area, but poorer. Much of the housing was what the regime called “sub-economic”: flats and apartments.

‘I was personally threatened a couple of times. Once when some friends and I were crossing the canal that ran through the middle of our estate on the way to football, with our soccer boots hanging around our necks by their laces, an older guy appeared and demanded money. We told him we didn’t have any so he told us to hand over our football boots. One of my friends, Bones – a small kid who never stood back from a fight, hit the guy with his boots instead.

‘Another time someone wanted a friend’s new tennis outfit. We threw rocks at him until he drew a knife and then we ran away.’

Clinton says the policing was not very good in coloured areas.

‘Just like today, really, it’s the wealthier areas that get the most patrols and the most police stations instead of the areas that really needed them.

‘But the dads at Penlyn Estate got together and arranged a duty roster to keep residents safe. They were factory workers and had grown up rough. They kept the estate safe from when residents returned from work and through the night until residents left for work the next day. They worked in three shifts over 12 hours. When someone was caught stealing they might be beaten up in the process of being apprehended. Then the police were called to take them away.

‘After a year Penlyn Estate was known for not taking any crap. Houses and cars were no longer broken into.’

Clinton loved growing up in Penlyn Estate.

Cape Flats, which includes Penlyn Estate. ‘ … the area was pretty wild at first.’ (Photo: courtesy of Creative Commons, photographer unknown)

‘I didn’t know any better. Under apartheid communities were separated from each other by 4-lane highways, railway lines, industrial estates and barbed wire.’

Penlyn Estate was a coloured area.

‘We had our own schools and clinics. Even the ambulance to hospital had to be one designated for coloureds; if there wasn’t one available you might have to wait for three or four hours.’


Clinton remembers it wasn’t until he was about 13 years old that he became aware that things were different elsewhere.

‘Our next door neighbour was a student activist with a massive Afro. He was a well-known DJ, and known to the security police. One day he rushed into our house and asked my mum to cut his hair.

‘While his hair was being cut he asked me to rush next door and find the black bags filled with paper under his bed. “Dig a hole in my back yard and throw in the bags.”

‘I did as he asked, but looked at some of the papers. They were Roneo documents, banned pamphlets about the African National Congress in exile, for example. I became more aware about what it all meant after talking to my mum about it afterwards.

‘It was also about this time, when I was starting middle school, that people started burning tyres in the middle of the street, and we could hear shots in the distance. Police were always driving through the neighbourhood.’

Clinton says the locals burned tyres to attract the police so they could have an altercation.

‘People were getting a bit bolshie. They wanted to show they controlled their own lives in their own space. The actions weren’t organised or strategic as they later became in the 1980s when the plan was to help make the country ungovernable by stopping economic traffic. In the 1970s it was sporadic and unplanned.’

Clinton recalls the African National Congress later claiming they were there to give structure to the demonstrations, but in fact it was just sporadic action by locals.

He became more political in 1980, at the age of 15. ‘During the 1970s I was on the sideline, but what was happening all around me inculcated me with what needed to be done in the future.

‘I went to Harold Cressey High School, situated opposite Cape Town’s oldest prison and just up the street from the parliament. You had to pass an entrance exam to get into it; there was a long waiting list.’

One of his teachers was Mr Farrel. ‘He was a great person, very down to earth. He taught geography, English and social studies, and when he talked about the world he took you there with him.

‘He was held in high esteem as a man of great integrity. As well, he was a cricket umpire who umpired all of Cape Town’s top games.

‘He was one of those responsible for starting a teachers organisation. It wasn’t an official trade union – the regime kept strict control over the creation and running of “official” unions – but more of an intellectual organisation. Meetings were used to discuss the politics of the time. Many members ended up being barred as teachers and many belonged to the Unity Movement, which unfortunately never had the mass following of the African National Congress or Pan-African Congress. It did end up being in South Africa’s first open election in 1994 as the New Unity Movement.’

Clinton says his political wakening was due partly to his teachers, who often spoke about politics and society, and why it was structured the way it was.

‘It was so sad, but Mr Farrel ended up managing a restaurant.’

Clinton stresses his mother was important in his political awakening. ‘She was almost a Trotskyist and surreptitiously used to leave political pamphlets and writings on my desk. Over time I took on my mum’s political leanings.

‘She ran monthly meetings in the lounge room that were attended by prominent politicians and community leaders such as school principals; I would listen in while doing my homework. I gained a lot of political insight from what was said at those meetings.’

Clinton says he became more political in his last two years at school, boycotting classes and entering debates and discussions with other students from his school as well as others.

‘We’d talk about how to get things done despite obstacles such as principals collaborating with the regime or teachers preventing students from leaving classes to attend meetings.

‘The police would raid the school when there was any demonstration or boycott. They used tear gas and dogs because our school was in the city and they didn’t want trouble spilling out onto the streets. The police often reacted violently, and although they were often of mixed colour, it was white officers, usually speaking Afrikaans, on the megaphones delivering the ultimatum, threatening the use of tear gas or rubber bullets and even live rounds. As far as the apartheid regime was concerned it was open season on anyone in the way, students or teachers.’


Clinton says he was not raised with a coloured identity.

‘I was raised just as Clinton, although I understood myself not to be white when I was in other communities. The apartheid regime did a great job of dividing and conquering non-white communities – just like Donald Trump did in the US when he was president. But a coloured identity is something that really only developed after 1994, to some extent filtering down from the earlier black empowerment movement. Some coloured people are still struggling with the idea of identity, still driving the bus, but “coloured” culture is probably the big driver today, expressed in everything from popular music to slogans on T-shirts.

‘There are serious divisions among non-whites in parts of South Africa, if not so much in Cape Town. For example, Penlyn Estate was right next to an Indian designated section called Rylands, an Indian district. We went to school, to church and played sport with Indian South Africans; the division was very porous.

‘But Cape Town was regarded as a preferred coloured employment area, and we were sometimes seen as Uncle Toms. This was aggravated by the apartheid regime’s creation of the Tricameral Parliament in the 1970s, which allowed political parties for white, coloured and Indian South Africans, but not for black South Africans. This is an example of the regime producing a government that excluded blacks and divided the coloured people between Indian and others.’

Clinton’s father, Reggie, was designated coloured. ‘I’m not certain what his ancestry was: some Javanese, Filipino … his great-grandfather was German.  There’s no paperwork to find out these things; births and deaths weren’t registered back then. I’ve seen a photograph of my great-grandfather, and it shows a tall, light-skinned man with a Schwarzenegger hairdo. His dad was so light-skinned he could get into a whites-only queue at a Cape Town fish shop by faking a British accent.’

He laughs when he remembers he once attempted pulling the same trick once. ‘I tried getting cold beer at a place in Knysna by faking a cockney accent. We got the cold beer, but I didn’t fool anyone.’

Reggie was a freehand cutter at a leather factory, specialising in exotic skins such as elephant and crocodile hide to make bags and other luggage.

‘But that job ended when he lost his cool with a young administrator straight from the parent company in Germany who was telling Reggie and others their productivity was too low. My dad asked for the ledger the administrator was quoting from and smacked him in the head with it, then walked out. After that he worked at a spray-painting company.’

Clinton’s mum, Rosie, was at least part-Khoisan.

‘It wasn’t until the 1990s that anyone celebrated their ancestry. Being Khoisan to some degree could be a shameful thing. Being called a “Bushman” was the equivalent of being called “nigger”.’

Besides being a teacher she supplemented the family income with hairdressing and needle work, making things like wedding dresses.’

When he was a child, Clinton didn’t feel that apartheid was particularly repressive.

‘The first time I was made to feel powerless I was about 14 years old. I was on a train to school when some white boys threw dirty water over me and my friends. One of those friends retaliated the next day by slapping one of the white boys across the side of the head with a T-square. When we got off the train we were accosted by one of the white passengers. It really caused us to think of ourselves as different, and was the first time where I was involved in an altercation where race was the issue.’

Clinton says he always moved in a coloured area and so felt cocooned. ‘There were subtle reminders of apartheid, like which beach I could go to, but I became more aware of the whole situation as I got older.’

Clinton remembers he became very serious about apartheid in high school. ‘I was a very serious young man. With the example set by others in what we called ‘The Struggle’  – family and friends – I felt the need to help overthrow apartheid, that had a role to play as well as a student organiser and activist.

‘Not all my friends in high school felt the same way and I sometimes felt disjointed from them. It wasn’t until later that I realised how much I’d missed out on, but a “normal” teenage life was very difficult because of my activism.’

By the mid-1980s the apartheid regime was under such great internal and external pressure they extended an olive branch by entering into discussions with the ANC.

Clinton went straight to university after school.

‘I got a bursary to the University of Cape Town to study geography and anthropology – Mr Farrell’s influence! – with the intent of becoming a teacher. I became interested in other subjects like environmental studies, but the bursary proved to be a two-edged sword: it paid for my university fees, but restricted what subjects I could do.

‘I didn’t realise how cornered the regime felt until one day while playing cards at  uni, some friends and I made up a political party called the South African Liberation Front to “heal the wounds of the people”. It was done as a kind of Monty Python joke – Salf was the name of a medical ointment at the time. But the next day someone who’d been at our table sprayed the name and the credo in the library elevator, and the police went ape, pulling people into “interviews”.’

University of Cape Town (Photo: courtesy of Creative Commons, photographer unknown)

Clinton learned good manners from his gran, Gussie, who came from a small agricultural town in the Karoo called Ladysmith to take up domestic work in Cape Town.

‘Sometimes I’d go with her to visit Ladysmith. It was a totally different world. No grass anywhere, just gravel. Everyone there played Rugby instead of soccer. As young kids do, I spent a lot of time looking for scorpions and snakes, and I still fondly remember waking up to the smell of bread freshly baked in a woodfired oven.

‘Gussie instilled in me a good work ethic, and taught me the importance of introspection, about thinking before you speak or act. She said people will know in the first minute they meet you by your manners. She often used my uncle as an example of someone with good manners; his nickname was Dennis the Manners.

‘Dennis will strike up a conversation with anyone. He emigrated to Australia and taught art in schools in Kiama, New South Wales. He also helped establish the Kiama Jazz and Blues Festival.

‘From my mum I learned to be serious about work and about politics, and the value of reading. In fact, one of our neighbours, Mrs Kaylor, used to throw the neighbourhood kids into the back of her old Ford Cortina station wagon every weekend and drove us to the library so we could get three new books out to read. Her little effort made a big difference to us.

‘I also got my love of hiking from my mother.

‘From my dad I learned to love sport. He was sternly protective, and I inherited some of that. I also got my love of music from him, especially jazz. I remember when we were still living in District 6, going inside the house when it got dark and the first thing I’d hear would be jazz music coming from the turntable in the loungeroom and finding my dad by the glowing ember at the end of his cigarette.’


In 2021, Clinton says he feels he is South African, but hard done by. ‘The leadership has sold out by looking after themselves. There is a gulf between the wealthy and everybody else, something created post-apartheid. You can see it now during the current pandemic. We should have had better structures in place to better help those in poverty.

‘We were a country willing to stand up to lose its chains but is now being shackled again. No one’s willing to stand up and say ‘No!’ – this is not right. We allow it to happen. The faces of the new regime we recognise as coming from our community.’

Clinton thinks the Truth and Reconciliation Commission that followed majority rule might have prevented a civil war from happening.

‘There were forces at work who wanted to destabilise the government, to prove that majority rule could not work. But I believe the TRC stopped short of delivering real justice. Many members of the apartheid regime’s police and security police got away with murder and working well beyond the limits of the law.

‘A great deal was swept under the carpet by the TRC, and was proof to some that you could get away with a great deal and not be punished for it. Many of those in power now are as corrupt as those in power during apartheid. The TRC should have established a better precedent.’

Clinton thinks that South Africa needs a change in political will.

‘We need to step forward. The current pandemic, for example, has highlighted the fact that some in government are still trying to line their own pockets despite the suffering of the people.

‘If the pandemic doesn’t change things, I don’t know what will.’

31 March 2021: Photosynthesis without sunlight

An organism has been found that photosynthesises from light coming from hydrothermal vents 2400 metres below the sea. It is the first photosynthetic organism discovered that does not rely on sunlight.

As reported in a paper pithily titled ‘An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent’ published in the journal of the Proceedings of the National Academy of Sciences, the green sulphur bacteria was found living near a thermal vent off the coast of Mexico called 9 North.

One of the paper’s authors is Professor Robert Blankenship from Arizona State University’s chemistry and biochemistry department. In an interview with Skip Derra (posted on the university’s website) , Blankenship said the bacteria uses a chlorosome complex which acts like a satellite dish to collect any light it can and transfer it to the organism’s reaction centre where the photosynthesis takes place.

Blankenship also said the discovery was important not just for what it meant for life on earth, but what it means for the search for life outside of Earth.

‘This shows that photosynthesis is something that is not limited only to the very surface of our planet,’ he says. ‘It lets you consider other places where you might find photosynthesis on Earth, as well as on other planets.’

As the original paper’s abstract reflects:

‘The abundance of life on Earth is almost entirely due to biological photosynthesis, which depends on light energy. The source of light in natural habitats has heretofore been thought to be the sun, thus restricting photosynthesis to solar photic environments on the surface of the Earth. If photosynthesis could take place in geothermally illuminated environments, it would increase the diversity of photosynthetic habitats both on Earth and on other worlds that have been proposed to possibly harbor life.’

Something for us science fiction writers to ponder.

Another amazing aspect of this paper is its relative obscurity: the paper was published in June 2005. If not for the heads-up in a recent post by Jerry Coyne on his website Why evolution is true, I doubt I would ever have learned about it.

02 November 2020: Harrie and the Moon Dogs

A story for Harrie from Alison and Simon

It was a cold, clear Tuesday night. Harrie ate her dinner so quickly she was done by the time Maggie and Rachel were still munching on their third forkful.

‘I don’t think we gave her enough,’ Rachel said.

‘Do you want more dinner, Harrie?’ Maggie asked.

Harrie shook her head, but wasn’t looking at either of her mothers. She was staring out the window behind them. The sun was down and only a pink light softened the horizon. Just above, where the pink became violet, she could just make out the twinkle of Venus, the evening star and the first light to appear in the night sky. It was one of her favourite things to look at with her telescope – but tonight she had other plans.

‘Are you sure you don’t want more food?’ Rachel asked, looking over her shoulder to see what Harrie was gazing at. ‘Remember, it’s a full moon tonight and it will be so bright it will be hard to see anything else.’

Harrie nodded. ‘I know. That’s why I want go out. I want to look at the moon.’

Creative Commons (photographer unknown)

‘That’s a good idea,’ Maggie said. ‘You haven’t looked at it through your telescope for some time; you’ve been too busy with Jupiter and Mars and Orion’s Belt – ’

‘Twenty-two nights ago,’ Harrie said, her voice very definite. ‘And point-two.’

‘Point two?’ Maggie asked.

‘Twenty-two-point-two nights ago.’ Harrie’s face scrunched up in thought. ‘Can you have a point-two night?’

Her mothers shrugged at the same time. ‘I guess,’ Maggie said. ‘You sound very sure of yourself, though.’

‘Uh-huh. The last time I looked at the moon through my telescope was when it was in its last quarter, and that was twenty-two-point-two nights ago.’ Harrie took a deep breath: that sentence was long even for her.

‘When does it come up?’ Rachel asked.

Harrie pointed to the side of the house opposite the window. ‘It should already be up. But the best time to see it will be … ’ Her voice trailed off and her face scrunched up in thought again. She moved her dinner plate out of the way, stretched out her arms and placed her straight hands on top of one another, palms inward. ‘That’s twenty degrees and the moon moves half-a-degree every hour and the moon is about here and the best time to see it is when it’s here … ’ She wiggled fingers to show exactly where the moon was each time she mentioned it.

‘So the best time to see it is when it reached the little finger on your right hand,’ Rachel observed, smiling slightly.

Harrie nodded, taking another deep breath.

‘You are very clever,’ Maggie said matter-of-factly.

Harrie sighed. ‘Yes,’ she agreed, as if it was a burden.

‘So, just to make sure I understood what you’re saying,’ Rachel said, ‘the best time to see the moon is about half-an-hour from now?’


‘That’s about your bed time.’


‘Hmm,’ both mothers said at the same time.

‘But it has been twenty-two-point-two nights since I saw the moon with my telescope,’ Harrie pointed out reasonably.

Maggie and Rachel looked at one another. ‘True,’ Maggie said.

‘And in the life of five-year old, twenty-two nights is quite a long time,’ Rachel added.

‘Not to forget the point-two,’ Maggie pointed out.


The mothers fell silent as they considered whether or not to let Harrie stay up past her bedtime.

‘We could ask Banjo what he thinks,’ Harrie suggested. ‘Banjo?’

A young black-and-tan kelpie bounced into the room with more haste than dignity as his back paws skidded out from underneath him and he ended up sliding on his bum for the last two metres. He came to a stop right next to Harrie and gazed up at her adoringly, as if the whole tangled, embarrassing entrance had been planned.

‘One day he’ll grow into those large paws of his,’ Rachel whispered to Maggie. ‘Hopefully.’

‘Banjo, I have an important question for you,’ Harrie said, solemnly meeting the dog’s gaze.

Banjo barked once. Everyone in the family knew that meant ‘yes’, except when it meant ‘no’.

‘Do you think I should stay up late so I can see the full moon in my telescope?’

Again, Banjo barked just once, and Harrie turned back to her mothers. ‘See?’

‘Well, no arguing with that,’ Rachel said.

Maggie let out a small sigh. ‘All right, but just this once. You are not to take this as permission for you to stay up every time you want to go out and look at the night sky.’

‘Maybe once every twenty-two days?’ Harrie suggested.

‘Don’t push it, kiddo,’ Maggie said. ‘Now go and get some warm clothes on. The last thing we need is for you to freeze out there.’

Harrie grinned at her mothers as she left the table, then hurried to her room, eagerly followed by a scurrying Banjo who this time somehow managed stay upright on all four paws.


Although winter was officially over and spring had sprung, Harrie’s home town was high up in the mountains and it got cold there when the sun was down. But it did make for spectacular nights, when the stars and the planets danced across the black velvety sky.

Harrie loved looking up at them even when she didn’t have a telescope, but now that she could see them up close the night sky seemed twice as special. And the most special thing in the whole universe to see with a telescope was the Moon.

The first time she had looked through the eyepiece and the Moon suddenly swung into view it seemed to jump right out at her and she forgot to breathe for a long time, and when she finally did breathe out it came in a great big gush.

The Sea of Tranquility
(Creative commons: photographer unknown)

Harrie never got tired of looking at it. She knew all the big craters now – like Copernicus and Kepler – and all the big seas – like the Sea of Nectar and the Sea of Islands. But most especially she knew the Sea of Tranquility, because that is where the first humans who walked on the moon landed their spaceship, called the Lunar Module.

The night was getting colder and colder. But Harrie didn’t feel it. Even Banjo was getting cold, and tried snuggling up against her legs, almost tipping her over. But Harrie didn’t care. Her mothers were softly calling to her to come back inside. But Harrie didn’t hear them. Staring through her telescope at that great white globe with all its craters and seas and mountains was more important than being warm or going to bed.

One day I’ll go there, she thought. One day I’ll go the Sea of Tranquility and touch the dark soil and then look up and see Earth, and with my telescope I’ll find home and wave at my mothers and Banjo and everyone else I know.

Maggie tapped her gently on the shoulder. ‘It’s time, Harrie. We’ve let you stay up for a long while. Come inside now. Your cheeks are as hard and cold as ice.’

Slowly she drew back from the telescope. When she looked up into the sky again the Moon was still there but much smaller.

‘Still pretty,’ she said, ‘no matter how big it is.’

Maggie and Rachel stared up at the Moon as well. Even Banjo, who was wondering what everyone was staring at that seemed so interesting. There wasn’t a rabbit to be seen anywhere.

‘Look!’ Harrie said, pointing at the soft nebula of light that surrounded the Moon. On either side of it was a little light. ‘Are they planets or stars?’

Moon Dogs (Creative Commons:
photographer unknown)

Maggie laughed. ‘I’ve heard of them but never seen them before.’

Rachel and Harrie looked at her expectantly. ‘What are they?’ Harrie asked.

‘They’re called Moon Dogs. It’s so cold up there that the light from the Moon is being caught by ice crystals. They almost look like miniature moons, don’t they?’

Harrie sighed, a deep and immensely satisfying sound. She patted Banjo on the head and started back the house, the moonlight shining in her hair and on his fur.

She stopped for a second, looked back up at the sky, and said, ‘Look Banjo, Moon Dogs.’

Banjo barked once, meaning, ‘Yes, what else would they call them?’

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.

20 August 2015: Shine on Pluto


Pluto as seen by New Horizons. Image credit: NASA/JHUAPL/SwRI

AJ and I ducked out of the house on the night of August 11 to have a quick wine or two at King O’Malley’s pub in the city. When we got there we discovered the place had been invaded by Science in the Pub, and the two of us spent a pleasant hour drinking white wine, eating free food, and watching a slide show about the New Horizons mission to Pluto.

What’s more, it was a presentation hosted by John Berry, the American ambassador to Australia, and featured Nobel prize winner Brian Schmidt from the ANU, science communicator and astrophysicist Alan Duffy from Swinburne University of Technology, and Glen Nagle, Education and Outreach Manager at Canberra’s Deep Space Communication Complex at Tidbinbilla.

It was a pretty crowded affair and the screen was sometimes obscured by jostling customers, excited science addicts and through-traffic, but the mood was positive and the atmosphere … well … sciencey. (If this isn’t a word already, I bag naming rights.)

What follows are some of the amazing facts we learned about the New Horizons mission and Pluto, plus a few extra tidbits.

The mission was launched on 19 January 2006, when Pluto was still classified as a planet. Eight months later it was demoted to a dwarf planet. Furthermore, in 2006 only three moons had been identified orbiting Pluto. Before the probe reached its destination, we knew of five moons.

The probe’s closest approach to Pluto occurred nearly nine months after launch, on 14 July 2015, and after a journey of approximately 7.5 billion kilometres. Disappointingly, New Horizons was 7.5 seconds late for its appointment.

Still, not too bad when you consider that to travel the same distance travelling at a highway speed of 100 kph, it would take you around 8,560 years. In other words, to arrive in 2015 you would have had to start driving about the same time the world’s first city walls were being built around Jericho.

Shots of Pluto’s night side were made possible because of reflected sunlight from Pluto’s largest moon, Charon.

Pluto’s atmosphere expands as its eccentric orbit brings it closer to the sun, and then freezes when Pluto recedes from the sun. Since its last closest approach to the sun in the 1990s, Pluto’s atmosphere has halved. This was confirmed by a radio signal sent from Earth to New Horizons through the atmosphere when the probe reached the other side of Pluto. The signal had to hit a piece of equipment about the size of a credit card, and enabled scientists to measure the signal’s radio occultation.

Scientists were surprised to discover that ultraviolet light broke up some of the methane in Pluto’s atmosphere create more complex hydrocarbons such as ethylene and acetylene. They were even more surprised to learn that about 50% of this UV comes not from our sun, but from other stars.

Pretty exciting stuff for a dwarf planet.

All in all, an excellent night at the pub.