A Perplexing Comment by David Attenborough

“A Life On Our Planet” claims that 10,000 years ago, our ‘hunter-gatherer’ ancestors had no option but to live ‘sustainably’. It’s more complicated than that…..

Sir David Attenborough’s latest documentary, ‘A Life on Our Planet', is a welcome critique (in the sense that he finally got around to it) about just how badly we’ve messed our Earth up. His focus is on biodiversity, or rather how we’ve depleted it — and how by restoring biodiversity, we might be able to mend our planet.

It’s a well-made and hard-hitting documentary, and ought to be a wake-up call for those of us who aren’t already in a horrified daze. But in some of its detail, ‘A Life on Our Planet’, is thought-provoking. There’s probably more puzzlement over what Attenborough didn’t say, as over any comments he did make. In this piece, I highlight one curious thing he did say and will leave what he didn’t for another.

Hunters and Gatherers: The Initial Mistake

In ‘A Life on Our Planet’, Attenborough tells us how in 1971 he “set out to find an uncontacted tribe in New Guinea”. We’d frown on such behavior now, but … it was different times I suppose. Archival footage shows him and the tribe he eventually met — they were, so he tells us, “hunter-gatherers — as all human-kind had been before farming”. That aspect of the encounter clearly made a deep impression on him, with him adding: “Living with their traditional technology, they were living sustainably”.

Later in ‘A Life on Our Planet’ (at 1:12:15), we learn the relevance of including those nearly fifty-year-old New Guinea scenes. Attenborough tells us:

“Ten thousand years ago, as hunter gatherers, we lived a sustainable life — because that was the only option. All these years later, it’s once again the only option.”

Weeeeel…. [sound of sucking in air through my teeth]…

Options

Actually, 10,000 years ago, those ‘hunter-gatherers (well, some of them), did have an option — to start farming. That option was to make what has been described as the ‘worst mistake in the history of the human race’ (Diamond, 1987). And they took that option. Why they did it at that particular point in time, about 10,000 years ago, was probably climatic. As a round-figure, that’s when the Earth came out of the long glacial period and entered the warmer and generally more stable, Holocene.

Why a few groups of hunter-gatherers chose that option — a life of farming-toil over a relatively easy life of hunting and gathering is a fascinating story. As a leg-in to the subject, I would recommend James Scott’s ‘Against the Grain’. He looks at farming in the context of the evolution of states, and things like social hierarchy, inequality, and taxation.

Diamond’s comment about farming being human’s ‘worst mistake’ is debatable, with writers such as Steven Pinker (2018) arguing that humans, at least now, have never had it so good, and others who seem to simply like bashing Jared Diamond. But while that argument does have its pros and cons, re-wording it, so that the great mistake of farming was more a disaster for the health of planet Earth, is on firmer ground. It is farming that has, for example, cleared vast areas of biodiverse vegetation and replaced it with monocultures, depleted soils (a great read on this is David Montgomery’s ‘Dirt: The Erosion of Civilizations’) and then poured massive amounts of chemicals onto said soils.

Are ‘Hunter-Gatherers Really That Benign?

When Attenborough visited New Guinea, some societies were hunter-gatherer, and some were farmers. That’s a telling-point, as it means that the ‘option’ for hunter-gatherers to become farmers had been taken by some societies, while others had looked at their neighbors slaving away, and gone “Nah!”. Of course, another option was for farmers to down-tools and go “stick-this!” and return to a hunter-gatherer way of life. Whether that option was ever taken over the thousands of years of New Guinea (or anywhere else) prehistory, I don’t know.

But perhaps Attenborough really meant to say:

“Up until 10,000 years ago, hunter gatherers, lived a sustainable life — because that was the only option”?

In other words, it was a kind of oblique way of saying that hunting and gathering are implicitly sustainable, whereas farming is not? But this can be picked apart as well because there are examples of unsustainable hunter-gatherer lifestyles (it doesn’t matter if the examples are pre or post 10,000 years) — or at least lifestyles that became unsustainable at some point.

Two famous ones come to mind — one is the extinction of large animals (‘megafauna’) apparently following the arrival of humans in Australia tens of thousands of years ago (Flannery, 1994) and the other is the extinction of large animals in America, again apparently following the arrival of humans at least 13,000 years ago (Martin, 1967).

Both are contentious — over the past few decades, the weight of evidence in both cases has swung between humans and climate change as the culprit. The argument may not be clearly resolvable, or more probably the question needs rephrasing — it’s probably not an issue of ‘either/or’. For example, Villavicencio et al. (2015) argue that it was a combination of humans, climate, and vegetation change that caused megafaunal extinctions in Patagonia, while Broughton and Weitzel (2018) argue that some of North America’s megafaunal extinctions were linked to hunting, some to climate change, and for others, both are implicated.

Megafaunal Extinction

Crikey, the debate around megafaunal extinction is one of the best examples of real active science that I know of. Take this for example: While we are currently facing a global-warming disaster, partly resulting from farming, a hypothesis put forward ten years ago argues that hunter-gatherers may have contributed to ancient global warming. Doughty et al (2010) argue that the extinction of the mammoths, for which humans may have been partially responsible, may have caused vegetation changes, which may in turn have caused regional warming up to 1 degree.

But an important point is that those arguing that ‘humans did it’ provide a mechanism — that when the first hunting and gathering humans arrived in a new land — the animals did not recognize them as a threat. This raised the possibility that animals which reproduced slowly, almost any new impact on their numbers, could quickly drive them to extinction. It’s at least theoretically possible that a simple hunting and gathering lifestyle can be unsustainable.

The argument that hunting and gathering humans caused major extinctions — and was therefore unsustainable, is on the more certain ground in New Zealand. The first humans arrived there just a few hundred years ago, finding several species of enormous, flightless birds called moa. The Polynesian settlers developed what has been called a ‘moa-hunting’ culture, and very soon after, the moa was extinct (Anderson, 1989; Holdaway et al., 2014; Perry et al, 2014).

It is likely that almost any human hunting pressure on the moa would have been enough to tip it into a decline. But note that the problem is not just the ‘hunting and gathering’ — but can be other activities of the ‘lifestyle’ — like widespread habitat modification by fire (McWethy, et al. 2009, 2010). It was likely both hunting the moa and massive burning of its habitat by hunter-gatherer people did the moa in. In any case, the actual lifestyle was unstainable. Once the moa became extinct, the hunting and gathering lifestyle focused around it was forced to change — where climate allowed (in the north of New Zealand), farming became important, and where it wasn’t (in the south), there was likely a sudden drop in population.

The take-home point is that a hunting-gathering lifestyle need not have been sustainable 10,000 years ago, or at any time. It depends on the circumstances.

Farming

And what about farming — is it inherently unsustainable? There are plenty of horror stories about ancient farming societies that became unstainable, and their culture and populations crashed. Sometimes they were doing fine until the climate changed. With others, it may have been actual farming practices, such as soil depletion or salinization of the soil (read Joseph Tainter’s classic ‘The Collapse of Complex Societies’).

And what is a ‘farming lifestyle’ anyway? Bruce Pascoe’s two ‘Dark Emu’ books (2014, 2018) collate a large amount of early European observations showing that some Australian Aboriginal tribes at contact — were farming. Aborigines are often assumed to have been typical ‘hunter-gatherers’, but if they were farming for thousands of years, not only should we be more careful with our cultural labels, but we might have something to learn about sustainable agriculture.

Synopsis

So behind Attenborough’s sound-bites, things are a little more complex and nuanced. Call me a pessimist if you like, but a ‘sustainable lifestyle’ is not humankind’s only option now. Based on past behavior, we definitely do have the option to barrel on until we have a population crash. The big difference between now and 10,000 years ago is that, with the benefit of a few centuries of research (including those authors cited here), we can predict what the likely outcomes will be.

References

Anderson, A. 1989. The mechanics of overkill in the extinction of New Zealand Moa. Journal of Archaeological Science, 16,137–151.

Broughton, J. M. and E. M. Weitzel, E.M. 2018. Population reconstructions for humans and megafauna suggest mixed causes for North American Pleistocene extinctions. Nature Communications, 9 (5441).

Diamond, J. 1987. The Worst Mistake in the History of the Human Race. Discover Magazine, May 1987. May: 95–98.

Doughty, C. E., et al. 2010. Biophysical feedbacks between the Pleistocene megafauna extinction and climate: The first human‐induced global warming? Geophysical Research Letters: https://doi.org/10.1029/2010GL043985.

Flannery, T. F. 1994. The Future Eaters. Melbourne, Reed Books.

Holdaway, R., Allentoft, M., Jacomb, C., Oskam, C., Beavan, N., and Bunce, M. 2014. An extremely low-density human population exterminated New Zealand moa. Nature Communications, 5, 5436. doi:10.1038/ncomms6436.

Martin, P. S. 1967. Prehistoric overkill. In: Martin P. S. and Wright H. E. (Eds.), Pleistocene extinctions, pp. 75–120. New Haven, CT: Yale University Press.

McWethy, D. B., et al. 2009. Rapid deforestation of South Island, New Zealand, by early Polynesian fires. The Holocene, 19: 883–897.

McWethy, D. B., et al. 2010. Rapid landscape transformation in South Island, New Zealand, following initial Polynesian settlement. Proceedings of the National Academy of Sciences of the United States of America, 107: 21343–21348.

Montgomery, D. R. 2007. Dirt: The Erosion of Civilizations. Berkeley, University of California Press.

Pascoe, B. 2014. Dark Emu: Black seeds: agriculture or accident?, Magabala Books.

Pascoe, B. 2018. Dark Emu: Aboriginal Australia and the Birth of Agriculture, Magabala Books.

Perry, G. L., Wheeler, A. B., Wood, J. R., & Wilmshurst, J. M. 2014. A high-precision chronology for the rapid extinction of New Zealand moa (Aves, Dinornithiformes). Quaternary Science Reviews, 105,126–135.

Pinker, S. 2018. Enlightenment Now: The Case for Reason, Science, Humanism, and Progress. Viking.

Scott, J. C. 2017. Against The Grain: A Deep History of the Earliest States. Yale University Press.

Tainter, J. 2017. The Collapse of Complex Societies (New Studies in Archaeology), Cambridge University Press.

Villavicencio NA, et al. 2015. Combination of humans, climate, and vegetation change triggered Late Quaternary megafauna extinction in the Última Esperanza region, southern Patagonia, Chile. Ecography, 39:125–140.