Science

04 February 2021: Family, community and conservation – a conversation with Dr Patricia Mupeta-Muyamwa

‘We need to codesign programs that move away from  disempowering communities and indigenous people to giving them the power to be  strong stewards of the natural resources and the lands,’ says Dr Patricia Mupeta-Muyamwa, Strategy Director for the African Indigenous Landscape program at The Nature Conservancy, a charitable environmental organisation with its base in the US.

Her job involves working with local communities to protect and nurture the natural environment. Patricia says she fell into the work more by accident than design.

Dr Patricia Mupeta-Muyamwa (Photo: Simon Brown)

‘I did my undergraduate degree in wildlife ecology at the University of Zambia in Lusaka, and in my last six months did an internship monitoring wildlife and vegetation in a national park. The job involved interacting with the park scouts, and after listening to their experiences I realised that it was people and not wildlife that was the problem, and I asked myself how do we empower people to make them better stewards of nature?

‘I did my Masters in conservation and tourism in the UK, and learned about different models of conservation. Because of the chequered history between national park administration and local communities, which left a great deal of animosity towards the state, my work promotes the importance of getting the rights to land and natural resources to the people that live closest to them.

‘Historically, African national parks and nature reserves were created for aesthetic reasons using an American model first developed for Yellowstone National Park.

‘Up until the 1990s, the state and not the local people ran national parks and conservation areas; it was a relic of Africa’s colonial past, and part of my work is to help address this injustice by reconciling local people so they’re a part of the conservation solution.

‘Local communities were forced out. People were seen as part of the conservation problem and not as part of the solution. For example, in South Africa national parks are still state run in a very centralised way; there are many communities around Kruger but few are getting any real benefit from it except a few people that find employment.’

Patricia says her long job title came from her work as it evolved.

‘A large part of the job is focused on protecting wildlife corridors spanning across parks, private and community-owned lands.

‘The work itself has three main objectives. First, giving land and resource rights back to the local community. Second, developing community skills to manage natural resources for example protecting and monitoring wildlife . Third, helping develop community opportunities for making a living from conservation, for example with tourism and programs that empower women.’

Patricia stresses this is a bottom-up approach. ‘A big part of my job is to consult with communities and their leaders to find the best conversation solution. I listen to their stories about living and interacting with the land.’

Patricia leads teams that are managing  four big landscape projects, one in Kenya involving 39 separate communities, two in Tanzania and one in Zambia.

Patricia with two young Hadza girls in Tanzania (Photo: Dr Patricia Mupeta-Muyamwa)

‘We’ll soon be starting a fifth one in Angola, based around the headwaters of the Okavango River.’

As an example of what these projects can achieve, Patricia cites the work done with a local partner Northern Rangelands Trust  with 39 separate communities.

‘Establishing wildlife corridors between these communities has been successful in increasing numbers of previously threatened animals such as elephants.

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Patricia was born and raised in Kitwe, a mining town in Zambia’s Copper Belt on the Kafue River, Zambia’s third largest river. This is also where she first met her husband Andrew, now a Maths Studies high school teacher. The two of them have fond memories of growing up in this small, quaint mining town.

‘My parents worked for a mining conglomerate. My father worked for 27 years as a human resources manager for a copper mining company. He was a real people person, and connected with people from all walks of life.

‘My mother was a teacher, training first in Zambia to teach home economics, but later she studied in Liverpool in the UK to become a Montessori teacher; and was the first Zambian to achieve this.’

Patricia grew up in a one-party state created by independent Zambia’s first president, Kenneth Kaunda. Following a period of instability, the 1973 signing of the Choma Declaration banned all parties except Kaunda’s own, the United National Independence Party (UNIP). He remained in power until he was ousted after being forced to hold multi-party elections in 1991.

‘Kitwe’s British-South African owned mining company was nationalised by the Zambian government, so I grew up thinking it was normal to grow up in a black-run black society. It was a source of pride for us that Zambians were in charge of the company.’

Kenneth Kaunda, Zambia’s first president (1964-1991) (Photo: Creative Commons)

Patricia says that even though she grew up in a one-party state, she only became aware of that as she finished high school.

‘But living in it as a child you don’t necessarily feel authoritarian measures, for example restricted access to the world outside Zambia. We were cocooned, but that didn’t feel bad. In some ways I would rather live in that state than what exists now. Things worked: there was  infrastructure that worked, equity for all seventy-two tribes and a sense of security. I believe Kenneth Kaunda was motivated for the greater good of society. He created an environment that allowed everyone  to  have access to healthcare,  education and employment regardless of background.

‘Kaunda created a system where we didn’t feel black, but Zambian. My father’s generation, which grew up under colonial rule in what was then Northern Rhodesia, was taught British, European and American history at school; my generation was taught pre- and post-colonial African history.

‘Kaunda led the way in institutionalising a Zambian identity. As a kid I didn’t really appreciate the gravity of this, but looking back now I see that it helped me navigate through life as a Zambian. Kaunda called this philosophy “humanism” – in the sense that the core values were about recognising our common humanity, and that we should always be aware that history was judging us and so be peaceful, respectful and good to each other.’

But things started to change in the late 1980s and early 1990s.

‘The economy was stalling and there were food shortages. Up to then the majority of Zambians had been politically passive; there wasn’t a lot of collective activism. The system that existed helped make it that way. But at that point the multi-party democracy movement challenging Kaunda was slowly taken up by the people.

‘When I was sixteen I was apolitical, but then my dad took me and my older brother to my first political rally just before Kaunda left. It wasn’t simply an anti-Kaunda rally, but more about a wind of change. It was huge and exciting – there was a great desire for change – and when it came I was hopeful. Everything felt new and that at last we were going places and fighting for a better Zambia. There was a sense of entrepreneurship in the early 90s, and new markets were opening up. The mines were privatised, for example, and different assets were being sold, like the mining homes, and many Zambians became home owners for the first time.

‘But in the euphoria we forgot what Kaunda had done for Zambia. The current political system in Zambia is not as effective as the old political system. There is less equity and less access to health, work and education. The Zambian economy is on life support.’

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The future Dr Patricia Mupeta-Muyamwa in 1976 with older brother Chris, left, and younger brother Michael, centre (Photo: Dr Patricia Mupeta-Muyamwa)

The one great source of stability for Patricia is her family.

‘I come from a very strong nuclear family, which is not the norm for families in Africa. It is a central part of who I am. My husband, parents, siblings and my maternal grandmother have all influenced my life in different aspects.’

Patricia says her grandmother, Dorika, was independent, strong-minded, political and entrepreneurial. Born in the early 1920’s, she witnessed  her country move from a colonial to a post-colonial era.

‘She was a Kaunda supporter and freedom fighter from the colonial era. She later became a strong organizer in the women’s league of the United National Independent Party (UNIP).

‘Towards the end of the colonial period she accompanied her husband, a community development officer, to different postings all over the country. In one posting he was sent to a district in the northwest at the same time as the colonial authorities imprisoned Kaunda there; when Dorika saw Kaunda being taken for his daily walk she would go up and talk with him, much to the distress of the local British officials. During one encounter she was reprimanded by the District Governor for this action. She held her ground, and continued with her actions. This upset the Governor and he later transferred my grandfather  away from the district because of his “troublesome wife”.

‘During the time when there was a call for change from Kaunda’s rule, she said “No! No change!”’

Dorika and Bilson Muzi, Patricia’s grandparents, taken in 1963 at Kabompo, North Western Province, where Dorika upset local authorities by talking with the imprisoned Kenneth Kaunda. Patricia’s future mother is standing on the right. (Photo: Dr Mupeta-Muyamwa)

After her husband died, Dorika supported her family of eight children by selling bread and other baked goods from home and at the market.

‘With two other women she set up one of the first female trading markets in Kabwe, a small mining town in central Zambia; it’s still operating to this day.’

Patricia says she drew a great deal from her grandmother.

‘I admired the way she navigated through life and survived as a woman and as a leader. She did so much in her life and in her own way. The older she got the stronger she got, and she was a great female model. She really lived life in her own terms.’

Patricia’s father, David, was the biggest male influence on her life. ‘My love of reading came from him. I loved going into his library. I read his 12-volume encyclopedias over and over.’

Patricia says growing up she never gave her mother the same attention she gave her father.

‘I was a “daddy’s girl”, and she wasn’t in my “cool space” back then. Now I realise just how similar we were. She was a trail-blazer. She was the first Zambian to study and teach Montessori; that took a lot of initiative and courage.’

Perhaps the biggest influence her mother had on her life was her decision to send Patricia and her sister, Edith, to an all-female boarding school run by German nuns; one of the oldest and best schools from its establishment in the early 1900s. She remembers the school was run under a very strict regime.

‘I did not like it at all. The nuns worked us very hard. When I tell people I went there they ask me if my parents hated me! But in hindsight, the education I gained from that time was invaluable.’

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Patricia says she wasn’t really conscious of her skin colour until she travelled to the UK and, especially, the US, for study.

‘I’m not sure whether or not that was a peculiarly Zambian experience. I’ve heard very different stories about encounters with racism from other black people, many of them heartbreaking.

‘Up to then I never thought of myself as a “black” person. My first racist encounter was in the UK when I was in my early 30s, when a hobo at a train station yelled at me to go “home”. I was shocked more than hurt by it because for the first time I became truly aware that this society was different from the one I grew up in.’

She says that while studying for her masters at the University of Kent she felt she was living in a bit of a bubble because she was very familiar with the British tradition and culture that had been such a part of Zambia before independence.

‘Growing up in Kitwe I had many encounters with non-racist and progressive Brits. It wasn’t until I was studying in the US that racism really hit me.

‘Soon after I arrived at the town where I was going to study I started looking for accommodation and came across a poor black neighbourhood. I began to understand how a community placed like this, separated from better-off communities, institutionalised racism.

‘US culture was strange and interesting. I was living in a diverse and liberal university town in northern Florida, but you didn’t have to drive far from the town to find Confederate flags flying in front yards. It was a totally different society.

‘For the first time I felt and identified as “black”. I found myself gravitating towards black student unions and organisations helping black communities.’

Patricia was saddened to see great poverty in some black communities in the US. ‘I had seen poverty in Africa, of course, but here it was like the lights had gone out. There was a lot of hurt and anger in that tribe – a tribe I can relate to – but the hurt and anger also existed in the academic environment which was so different from my previous experience it threw me off guard somewhat.

‘What I also found interesting was the way the black community was divided among African Americans, Caribbeans and Africans. It could be hard to cross the divide, but I’m not sure how much that was due to my own naivety. The black student union had a good ethos, for example, but it’s leadership was African American, and they defined the union’s agenda and this is where a lot of the union’s energy was spent. I had to think about what it meant to be an African in this situation. My initial enthusiasm at being part of the union started to wane because I couldn’t see what my role might be.’

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Patricia says she identifies as Zambian but feels African.

‘I especially feel broadly connected to sub-Saharan Africa. African countries like Zambia, Kenya, Botswana and South Africa have more in common than not.

Patricia at the farm owned by her and her husband Andrew in the village of Chifwema, southeast of Lusaka, Zambia’s capital. (Photo: Dr Mupeta-Muyamwa)

‘There is a connection around tradition, culture and how we think about family. There is a very strong “oneness” around family events that goes with a sense of community. This means there is still an especially strong tie in many countries between urban and rural communities; people working in the big cities still go back  to their families living in rural areas for important occasions.’

Patricia hopes those values will see sub-Saharan Africa through to a better future. ‘Right now, for example, that rural link for urban dwellers means many of them have a comparatively safe refuge during the current COVID-19 pandemic.

‘Strangely, this isn’t what’s happening in Zambia, where the rush to urbanise seems to have cut many of those ties to the country. I don’t know the village where dad came from, for example.

‘Africa needs to reconnect to its core identity. I believe we lost this connection as we urbanised. My hope is that we will see those links repaired in Zambia and other parts of Africa.’

11 November 2020: Venomous statistics

Some Australians take perverse pride in the legion of venomous animals infesting the continent and its surrounding seas, from the very small members of the Irukandji group of box jellyfish[i] up to the very large mulga snake[ii].

On the face of it, Australia seems to have had the bum run when it comes to its snakes, spiders, ants, octopuses, cone shells and jellyfish, and this hardly exhausts the list of venomous creatures that call Australia home. On the face of it, if venomous wildlife is your thing then you should be calling Australia home, too.

(As an unpleasant aside, Australia’s venomous biota is not even restricted to its animals; I dare you to read this with the lights off: Australia’s venomous trees.)

If we exclude the 120 kg drop bear[iii], which is sometimes erroneously claimed to use venomous claws to subdue its prey, then the big three that dominate most conversations after a few beers at the pub are the inland taipan, the box jellyfish (particularly the sea wasp), and the Sydney funnel-web spider.

The inland taipan[iv]

For a timid and rarely seen snake, in recent years the inland taipan has garnered a fearsome reputation for itself. In fact, one of its alternative names is the fierce snake, but this is entirely due to its venom, milligram for milligram the most lethal of any of the world’s reptiles. It is often reported that the venom from a 110 mg bite, if carelessly (or maliciously) injected, could kill 100 adult men. The fact that the average dose delivered by an inland taipan is about 44 mg is rarely mentioned, although since this is still enough to kill at least 40 adult men it could be argued I’m being pedantic. Compare this to the most lethal member of the saw-scaled vipers[v], which can reportedly kill six adult males with the amount of venom it delivers with one bite. (We’ll be returning to the saw-scaled viper a little later.)

The chance of encountering the inland taipan, which inhabits that semiarid corner of hell-on-earth between Queensland and South Australia, is vanishingly small. Indeed, in Australia your chance of dying from thirst or a camel stampede is probably greater than dying from a snake bite from any species. It’s also worth noting that the inland taipan has been described as placid and reluctant to strike; of course, if cornered or mishandled it will not hesitate to bite with remarkable speed and precision, and more fool you.

The sea wasp[vi]

The sea wasp is another matter altogether, not because it is remotely vicious, but because it just doesn’t give a damn. All envenomations are accidental. The largest of the box jellyfish, it spends its life floating in the warm tropical waters off northern Australia, Papua New Guinea and Southeast Asia. Well, floating isn’t entirely correct. The sea wasp does swim, but not in the determined way that would get it a place in Australia’s Olympic swimming team; apparently at full pelt they can cover about six metres in a minute. In the right season and the right place, the chance of accidentally bumping into one of these almost transparent jellyfish is depressingly high. Beaches all along the northern, tropical shorelines of Australia have signs warning swimmers of the danger.

Sea wasp.
Photo Creative Commons

An adult sea wasp is made up of a roughly square-shaped bell about 30 centimetres in diameter; 15 tentacles trail from each of the bell’s corners, each of which can be up to three metres long and are covered in around 5,000 cells called cnidoblasts, each of which in turn houses a nematocyst, which is Latin for ‘this will hurt’.[vii]

Nematocysts are the business end of a sea wasp’s venom delivery mechanism. When its prey, usually prawns or small fish, brush against the tentacles, the cnidoblasts release the nematocysts. The nematocysts penetrate the skin of the victim like miniature harpoons and then release their venom. Despite having actual eyes, the sea wasp seems incapable of restraining the cnidoblasts from releasing their load if the tentacles accidentally brush against something which isn’t prey, such as a human. Since this means the sea wasp is missing out on a meal and must now spend what I assume is a lot of energy to rearm the cnidoblasts, this is a serious design fault. Admittedly, that’s small comfort for anyone writhing in the water in unbearable pain, but one can only imagine the cuss words going through what passes for a sea wasp brain.[viii]

According to one study[ix], a sea wasp carries enough venom to kill 60 adults, which considering its size compared to, say, the inland taipan, is some achievement. Nonetheless, most encounters with a sea wasp don’t end with a fatality. The quick application of vinegar to neutralise any nematocysts still attached to the skin, and ice to relieve the pain, is often all that’s necessary. Having said that, one study[x] shows that 8% of envenomations require hospitalisation:

‘Because of the rapidity of fatal C. fleckeri envenoming, the critical window of opportunity for potentially life-saving use of antivenom is much smaller than that for snake envenoming, possibly only minutes. Furthermore, from animal study data, it was calculated that around 12 ampoules of antivenom may be required to counter the effects of a theoretical envenoming containing twice the human lethal dose of venom.’

The lesson here is if you come across a sign at a beach that says beware of box jellyfish (or for that matter crocodiles) consider something marginally safer and decidedly less painful for your daily outing, like jumping off a cliff.

The Sydney funnel-web spider[xi]

I’m an arachnophobe, and this spider pretty well defines the content of my worst nightmares.

I readily admit I’m scared of vampires, malevolent ghosts, land sharks, Brussel sprouts and omelettes – for that matter, any food made mainly from eggs – but my fear of spiders is on a whole other level. Even if I catch a glimpse from the corner of my eye of the completely innocuous daddy longlegs a long shiver will pass down my spine. I don’t know what it is about arachnids that gets me all goosebumpy or triggers my fight or flight instinct (to be honest, my fly or fly-twice-as-fast instinct), but it might have something to do with spiders like huntsmen, wolf spiders, tarantulas and funnel-webs being so damn hairy. It just isn’t right; it’s as if they’d killed a dog or cat, skinned it and donned the fur. Then there’s the eight legs. Six legs on creatures such as ants and earwigs are hard enough to put up with, but eight seems a serious case of overengineering.

Sydney funnel-web.
Photo Creative Commons

Anyway, of all the world’s spiders, the Sydney funnel-web ticks every yuck box: wears dog fur, tick; eight legs, tick; lives in a hole in the ground, tick; likes entering human households, tick; has more than two eyes, tick; has fangs long enough to pierce your toe nail to get to the vulnerable flesh underneath, tick; can kill you with single bite, tick.

Indeed, I cowrote a short story about the Sydney funnel-web with good friend, colleague and fellow-arachnophobe Sean Williams. The story, ‘Atrax’, must have hit a nerve with quite a few people: it won the Aurealis Award for best horror short story in 1999.

The Sydney funnel-web’s lethality can be put down to an extraordinary compound in its venom called δ-atracotoxin (sometimes referred to as delta-hexatoxin[xii]), which bizarrely is brilliant at killing its normal prey of insects, but in small doses causes no harm to mammals … with the single exception of primates. And humans, regrettably in this single instance, are primates. Why the venom should be so damn selective is anyone’s guess, and there have been a few.[xiii]

The other peculiar fact about the Sydney funnel-web is that the male’s venom is up to six times more toxic than the female’s[xiv]. The best theory to explain this is that the male goes wandering during the mating season looking for females and has to defend itself against hungry predators, as hard as it is to imagine any predator being so hard up it needs to feed on such an ugly, hairy and extraordinarily venomous assassin. Admittedly, this doesn’t quite explain why the venom is so effective against primates; I assume almost every human on the continent, like myself, would go to great lengths to avoid antagonising any spider let alone one that can kill you, and as far as I know, humans are the only primates to have made their home in Australia.

Ultimately, the venom’s ability to kill humans is just an accidental byproduct of its evolutionary development.

But, and this is a big ‘but’, no human has died from the bite of a Sydney funnel-web spider since an antivenom became available in 1981.

Most venomous versus most dangerous

And this is where we return to the saw-scaled viper. One of these smallish snakes, the largest will grow no bigger than 90 cm, may only be able knock off six fully grown adults, as opposed to the inland taipan’s potential 100 victims, but nonetheless, to my mind the viper is the more dangerous of the two snakes.

Before I set out my reasons for this, we should remember the saw-scaled viper and the inland taipan only have to kill you once to ruin your day, not six or a hundred times, which would seem – and please excuse the pun – something of an overkill. As far as the average human is concerned, a bite from either of these snakes will see your life flashing before your eyes.

And why do I think the saw-scaled viper is the more dangerous of the two?

First, your chance of encountering a saw-scaled viper on its home turf – anywhere dry in Africa, the Middle East and southern Asia – is dramatically higher than your chance of encountering the inland taipan on its home turf.

Saw-scaled viper.
Photo Creative Commons

Second, the saw-scaled viper is a much testier beast than the inland taipan, and seems inclined to bite anyone passing within striking distance, something the inland taipan is not inclined to do.

Third, your chance of getting good medical care through much of the saw-scaled viper’s range, let alone the appropriate antivenom, can be very small.

Indeed, the saw-scaled viper may be responsible for more human deaths than any other snake, whether we’re talking about other vipers, adders, taipans, cobras, rattlesnakes, kraits or mambas. It’s reported to be responsible for up to 90% of all snakebites in Africa.[xv]

But rather than picking on any one snake, it’s important to understand that snakebites are a serious health problem in most developing countries. According to the World Health Organization[xvi]:

‘Worldwide, up to five million people are bitten by snakes every year. Of these, poisonous (envenoming) snakes cause considerable morbidity and mortality. There are an estimated 2.4 million envenomations (poisonings from snake bites) and 94 000–125 000 deaths annually, with an additional 400 000 amputations and other severe health consequences, such as infection, tetanus, scarring, contractures, and psychological sequelae. Poor access to health care and scarcity of antivenom increases the severity of the injuries and their outcomes.’

It seems to me these statistics, which barely reflect the pain, misery and social desolation that can be caused by a snakebite, are the ones we should obsess over, rather than how many humans can be killed by a single and remarkably shy Australian snake.

One final point. On average, more Australians die each year from the stings and bites of ants, wasps, bees and ticks than snakebite, largely thanks to anaphylactic shock (and not prophylactic shock as I once tipsily declaimed). From 2000 to 2013, 27 Australians died from snakebite; over the same period, 32 Australians died from animals that fly and crawl around us every day of our lives without us giving them a second thought. In the same period, no one died from a spider, scorpion or centipede bite, and only three people died as a result of envenomation from a marine creature[xvii].

To put these statistics into proper perspective, horses were responsible for the deaths of 77 Australians between 2000 and 2010[xviii]. To make the perspective even sharper, consider that between 2000 and 2013, more than 21,000 Australians died in car accidents[xix].

By the way, in those same thirteen years, two people were recorded to have died from an unknown animal or plant. I’m betting it was a drop-bear.


[i] Genus Carukiidae.

[ii] Pseudechis australis.

[iii] Thylarctos plummetus – in my humble opinion, the best species name ever.

[iv] Oxyuranus microlepidotus.

[v] Echis carinatus.

[vi] Chironex fleckeri.

[vii] Disappointingly, and rather mundanely, nematocyst is Latin for ‘a cell with threads’.

[viii] In fact, sea wasps don’t have a brain as such, or anything else we might recognise as a central nervous system. But it does have something: ‘The box jellyfish’s nervous system is more developed than that of many other jellyfish. They possess a nerve ring around the base of the bell that coordinates their pulsing movements … ’ See https://en.wikipedia.org/wiki/Box_jellyfish.

[ix] http://emedicine.medscape.com/article/769538-overview

[x] https://www.mja.com.au/journal/2005/183/11/prospective-study-chironex-fleckeri-and-other-box-jellyfish-stings-top-end#authors

[xi] Atrax robustus

[xii] For example, see:

https://theconversation.com/i-didnt-mean-to-hurt-you-new-research-shows-funnel-webs-dont-set-out-to-kill-humans-146406

[xiii] For an explanation that makes sense to me, see: https://biology.stackexchange.com/questions/8825/why-is-funnel-web-spider-venom-so-lethal-to-humans-and-not-so-much-for-other-mam

[xiv] https://en.wikipedia.org/wiki/Delta_atracotoxin

[xv] James Cook University toxinologist Professor Jamie Seymour carefully lays out what makes one venomous animal more dangerous than another in the National Geographic documentary World’s Worst Venom, not only comparing and ranking the inland taipan with other snakes, but also including sea stingers, spiders, scorpions and many other venomous creatures. Well worth a look if you can get your hands on it. See:

https://www.imdb.com/title/tt1132196/?ref_=rvi_tt

[xvi] https://www.who.int/en/news-room/fact-sheets/detail/animal-bites

[xvii] https://biomedicalsciences.unimelb.edu.au/news-and-events/archive-news/professor-daniel-hoyer-and-dr-ronelle-welton-featured-academics-in-pursuit-article

[xviii] https://www.australiangeographic.com.au/topics/wildlife/2016/03/here-are-the-animals-really-most-likely-to-kill-you-in-australia/

[xix] https://en.wikipedia.org/wiki/List_of_motor_vehicle_deaths_in_Australia_by_year

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.)

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.

Sahul

Sahul

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)

1

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.

3

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.

Orangutan

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 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.’

Bushman

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.

22 May 2016: Crows got smarts

Corvus_corax_tibetanus

Corvus corax, the common raven. Photo: Pkspks [CC BY-SA 4.0]

It’s no secret that corvids – crows and ravens – are exceptionally smart for birds, especially at problem solving. Now an experiment carried out with ravens provides evidence they may have a basic Theory of Mind as well; this means they have an ability to attribute mental states they experience to another raven.

In a paper published in Nature in February, researchers Thomas Bugnyar, Stephan Reber and Cameron Buckner from the universities of Vienna and Houston, carried out an ingenious experiment that tested how ravens caching food behaved when they thought they were being seen by another raven.

There is increasing evidence that the Theory of Mind exists in chimpanzees, bonobos, scrub jays and ravens. How equivalent the experience of a ToM is between species is, so far, untestable, but the strong possibility that some form of ToM exists in different animals provides yet more evidence of the complexity of the mental life of species apart from humans.

Not only does this add weight to calls that humans should reconsider the way they relate to other animals, especially the often appalling way we treat farmed and domesticated animals, but firmly places Homo sapiens as the product of the same evolutionary process that produced ravens, dogs and garden slugs.

04 September 2015: Neither one thing nor the other

P. myojinensis

P. myojinensis. The blue structure is the nucleus, the red structures the endosymbionts.

A remarkable creature discovered in the ocean southeast of Japan – that doesn’t quite seem to belong to any of the three known domains – may provide evidence of how complex multicellular life evolved on Earth.

In 2010, a scientific expedition to the Myojin Knoll, about 35 kilometres southeast of the Japanese island of Aogashima, collected biological samples from a hydrothermal vent more than 1,200 metres below the surface.

The samples were frozen and then embedded in epoxy resin; the resin was then prepared for study by being sliced into ultrathin sections.

That’s when the researchers discovered they had collected one truly remarkable specimen, a single-celled organism that lays somewhere between prokaryotes, organisms like bacteria and archaea, and eukaryotes, the basis of complex organisms such as fungi, plants and … well … us.

The main differences between prokaryotes and eukaryotes are that the former do not have a nucleus surrounded by a membrane, or any membrane-bound organelles such as mitochondria or chloroplasts.

As described in the journal Microscopy, the cell, dubbed Parakaryon myojinensis, was discovered on one of the bristles of a type of Polychaete called a scale worm. It was 10 micrometres long and three wide, much larger than most bacteria. Inside the cell the researchers discovered a nucleus with a membrane. As well, they discovered three endosymbionts, organisms that live symbiotically inside another, also surrounded by membranes. Obviously, then, the cell was not a prokaryote.

However, the nucleus of P. myojinensis was surrounded by a single membrane and consisted of DNA fibres, whereas a nucleus in a eukaryote cell has a double membrane and consists of chromosomes.

The endosymbionts also had only a single membrane. Mitochondria in eukaryotes, like the nucleus, have a double cell wall. As well, the endosymbionts closely resembled bacteria rather than mitochondria.

This last point is what makes the discovery of P. myojinensis so important.

There are two major theories about how eukaryotes evolved. The autogenesis theory proposes that a eukaryote’s structures developed from primitive prokaryotic features. The symbiogenesis theory – first properly described by Russian Konstantin Mereschkowski in 1910 and subsequently advanced by Lynn Margulis in 1967 – proposes that eukaryotes evolved from a symbiotic relationship after a bacteria was absorbed by larger achaean, eventually becoming an integral and working part of the cell.

P. myojinensis seems to be an organism that has incorporated endosymbionts into its structure but not yet developed the full range of eukaryotic functions.

As the authors of the paper suggest, “ … it may even be a conservative descendant of the transitional lineage between prokaryotes and eukaryotes.”

For a fuller description of the possible implications of the discovery, read this article on ABC online by British scientist Nick Lane, whose latest book The Vital Question: Why is life the way it is?, is a rewarding and thought-provoking read.