Half-Million-Year-Old Structure: Rethinking Cavemen, Origins

Wood generally doesn’t last long if left out in the open. That’s why finding interlocking logs near the Kalambo River is such a big deal. Well, part of the reason.

They’ve been submerged, it that’s the right word, in wet sediment. For something like a half-million years. Which makes them part of the oldest known wooden structure.

• Ancient Builders on the Kalambo River
  • Luminescence Dating and Carbon 14: a Nerdish Digression
  • Finally Finding Kalambo Falls
  • Cavemen, Labels, and Me
  • Lincoln Logs Long Before Lincoln
  • This Doesn’t Change Everything: But It’s a Big Deal
• ‘Friends, Romans, Hominins…’
  • Good News, Bad News, and (Slowly) Changing Attitudes
  • We’re Learning

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Ancient Builders on the Kalambo River

This is what caught my attention on Monday:

“Half-million-year-old wooden structure unearthed in Zambia“
Victoria Gill, BBC News (September 20, 2023)

“The discovery of ancient wooden logs in the banks of a river in Zambia has changed archaeologists’ understanding of ancient human life.

“Researchers found evidence the wood had been used to build a structure almost half a million years ago.

“The findings, published in the journal Nature, suggest stone-age people built what may have been shelters….”

Actually, what caught my attention was another BBC News article. It was about a sand dune called Lala Lallia in Morocco.

The sand dune write-up mentioned luminescence dating, and that brought me to Victoria Gill’s September 2023 article: which got me thinking about evolution, being human, and changing attitudes.

And luminescence dating.

Luminescence dating works just like carbon-14 dating, except for how it doesn’t.

Luminescence Dating and Carbon 14: a Nerdish Digression

Willard Libby, at the University of Chicago, worked the bugs out of Carbon 14 dating in the late 1940s. Don’t bother remembering those names, like I keep saying: there won’t be a test.

Carbon 14 dating works because when cosmic rays, tiny particles zipping along just under the speed of light, hit nitrogen atoms, we get protons and ¹⁴C — long story short, ¹⁴C is a radioactive isotope of carbon that can get metabolized by plants.

Animals eat plants or animals that have eaten plants, and all of the above stop metabolizing ¹⁴C when they stop living. Then the ¹⁴C stops getting refreshed in the formerly-living material.

Since ¹⁴C turns into ¹⁴N — that’s another topic, for another time — at a steady rate, scientists can tell when stuff like wood stopped living by measuring the ¹⁴C fraction.

After about 50,000 years, so much ¹⁴C has decayed that carbon-14 dating won’t work.

Complicated, isn’t it?

Luminescence dating works the same way, sort of. Except that scientists check the brightness of glowing minerals.

Here’s how it works. There’s a little radioactive stuff in soil and sediments, so buried minerals like feldspar and quartz keep getting energized. Until sunlight hits them. Then they release their energy as light, and that’s what scientists measure.

I’m oversimplifying the process something fearful, but that’s the basic idea.

Getting back to the Zambia site, researchers took 16 sand samples around the wood. They used optically stimulated luminescence (OSL) for the younger samples, and pIR IRSL (postinfrared infrared stimulated luminescence) for the older ones.¹

I’ve no idea how they pronounce pIR IRSL. It’s a newer and more accurate sort of luminescence dating: which is saying something, since we didn’t have luminescence dating before the 1950s.

Finally Finding Kalambo Falls

I spent more time than I probably should have, trying to work out exactly where the Kalambo Falls archaeological site is.

It’s on the UNESCO World Heritage Convention ‘tentative’ list, and they give latitude and longitude for the place. Problem is, when I put those coordinates into Google Maps, I got a spot that’s just over the border, in Tanzania.

That led me down several rabbit holes, until I got smart and looked for an accessible copy of the research paper.

The Kalambo Falls archaeological site is just upstream of Kalambo Falls, a spectacular waterfall, and just south of a town called Kalambo Falls. The town is in Tanzania.

The archaeological site is, by a few hundred yards, in Zambia.

The good news is that the Zambia-Tanzania border isn’t a war zone at the moment. In my considered opinion, folks in Africa would have tough rows to hoe, even if Leopold II of Belgium hadn’t turned the Congo/Zaire/Kongo/whatever basin into — enough of that.²

If there’s time, I’ll get back to non-archaeological issues involved here.

Cavemen, Labels, and Me

“Archaeologists discover world’s oldest wooden structure“
News, University of Liverpool (September 20, 2023)

“…This discovery challenges the prevailing view that Stone Age humans were nomadic. At Kalambo Falls these humans not only had a perennial source of water, but the forest around them provided enough food to enable them to settle and make structures.

Professor Larry Barham, from the University of Liverpool’s Department of Archaeology, Classics and Egyptology, who leads the ‘Deep Roots of Humanity’ research project said:

‘This find has changed how I think about our early ancestors. Forget the label “Stone Age,” look at what these people were doing: they made something new, and large, from wood. They used their intelligence, imagination, and skills to create something they’d never seen before, something that had never previously existed.

‘They transformed their surroundings to make life easier, even if it was only by making a platform to sit on by the river to do their daily chores. These folks were more like us than we thought.’…”

[emphasis mine]

There’s quite a bit going on here.

First of all, there’s researchers calling whoever built the Kalambo Falls structure(s) “humans”.

Since scientists figure that anatomically modern humans (AMH) or early modern humans (EMH) — apparently the terms are changing — weren’t around until somewhere between 200,000 and maybe 500,000 years back —

Whoosh. I’d better back up a bit.

Based on what we know today, the odds are that either the Kalambo Falls builders weren’t “human” by the old ‘cavemen aren’t human’ standards, or that AMH/EMH are a lot older than we thought.³

I’ll admit to a bias here. Seeing folks like Neanderthals and the like as “human” is easy for me, since I only look “Anglo-Teutonic” from the eyebrows up.

I’m the product of miscegenation. Or, as one of my ancestors said of my father’s father, “he doesn’t have family, he’s Irish”. I really don’t miss the ‘good old days’.

Lincoln Logs Long Before Lincoln

Whoever the Kalambo Falls builders were, they obviously didn’t have access to a Pleistocene Menards. Or if they did, that era’s home improvement products and services weren’t up to contemporary American standards.

That said, their structural technology should look very familiar. To anyone who’s had a Lincoln Logs set, at least: or a lower-cost equivalent.

I remember having a building set called “Linkin’ Logs” as a child, and my father remarking that they were in our price range. My guess is that whoever owns the Lincoln Logs trademark has swallowed whatever outfit made Linkin’ Logs, and that’s yet another topic.

I gather that Lincoln Logs were invented by John Lloyd Wright, son of Frank Lloyd Wright: and that the interlocking logs reflect the elder Wright’s interlocking log beam design for Japan’s Imperial Hotel.

The Imperial Hotel has a complicated history, and predates Frank Lloyd Wright’s input by decades.

Wright’s main building is noteworthy for not collapsing during the 1923 Great Kantō earthquake: damaged, yes; destroyed, no.

That, plus Abraham Lincoln’s place in American history and folklore, helped put Lincoln Logs on the map.

F. L. Wright’s design for the Imperial Hotel gets described as “innovative”. Maybe it is. My guess is that he took a cue or two from my country’s old-school log cabins.⁴

And maybe their Japanese equivalents.

I’m mildly surprised that Mr. Wright and Lincoln Logs haven’t been denounced and declared guilty of cultural appropriation. Maybe they have, and I missed it. I expose myself to only so much of the daily sound and fury. And that’s yet again another topic. Topics.

This Doesn’t Change Everything: But It’s a Big Deal

Based on results from luminescence dating, those scientists figure that the interlocking log structure at the Kalambo Falls site is 476,000 years old, give or take 23,000.

That doesn’t make it the oldest known bit of worked wood. There’s a fragment of polished plank, found at the Acheulean site of Gesher Benot Ya’aqov, Israel, that’s around 780,000 years old.

What sets the Kalambo “Lincoln Logs” apart is that they’re fairly large: and unlike anything else we’ve found from that period.

Besides the interlocking logs, the researchers found what’s left of four wooden tools. They’re much more recent: dating back 390,000 to 324,000 years before we learned that power tools with cast metal housings can give users unwanted electoshock therapy.⁵

I didn’t find the Kalambo Falls research paper until Thursday afternoon, so there wasn’t time to do more than skim the thing.

Frustrating, but this week’s been like that.

I’d say the odds are very good that we haven’t heard the last about the Kalambo Falls site in particular, and humanity’s early technologies in general.

I’ll be sounding off on Leopold II of Belgium, Congo/Zaire/Kongo/whatever, Zambia and Tanzania, and what I see as really good news connected with the Kalambo Falls research.

But first — an excerpt from that research paper’s introduction, and the caption for those photos you saw up there.

“…These new data not only extend the age range of woodworking in Africa but expand our understanding of the technical cognition of early hominins, forcing re-examination of the use of trees in the history of technology….”

“Extended Data Fig. 4 | Shaping marks on the upper surfaces of object 1033 and on the underlying treetrunk (Fig. 3). Clockwise, from left upper left; chop marks on Part 2 (Extended Data Fig. 3); cluster of small convex hewing marks on Part 1, near Part 2 (Fig. 4); cutmark (upper arrow) and small facets (lower arrows) on Part 1 near Part 3 (Fig. 4); intercutting chop marks on the upper right edge of the Part 3 taper (Fig. 4); underlying log midsection, intersecting cutmarks transverse to the grain (bold arrow, upper left, indicating direction of grain). Marks on underlying treetrunk interpreted as result of scraping, perhaps from debarking.”
(“Evidence for the earliest structural use of wood at least 476,000 years ago“, Lawrence Barham, Geoff Duller, I. Candy, C. Scott; Nature (September 2023) via ResearchGate)

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‘Friends, Romans, Hominins…’

“World’s oldest wooden structure defies Stone-Age stereotypes“
Gabriel Spitzer, Goats and Soda (Stories of Life in a Changing World), NPR (September 22, 2023)

“…’I would say we need to consider these humans as having the ability to abstract forms from the environment and make them happen, and to pass [that knowledge] on through generations,’ says Barham. ‘And that’s opened my mind to these pre-sapiens hominins being capable of what we would think of as quite complex behavior.’

“Barham even argues that the complexity of these technologies might have necessitated some form of spoken language — again, far earlier than conventional wisdom holds.

“For Maggie Katongo, this finding refutes stereotypes about human ancestors.

“‘When we make reference to these hominins we always perceive them as primitive. But from the technology that we’ve been able to discover at the site, you see how sophisticated these hominins were.’

“An important find for Zambia

“Katongo says the Deep Roots Project, with its extensive incorporation of local research talent, is creating a new model for archaeology in Africa.

“‘There’s been a long history of [European] researchers just coming in and working in isolation, discovering stuff and then going out there and sort of writing stuff in a very complicated, scientific way that doesn’t trickle back to the very community where these sites are. This new approach, where there’s active involvement of the local collaborators, I’m hoping this sets a standard to be followed or imitated by other researchers that would want to work in Zambia.’…”

[emphasis mine]

I can’t emphasize enough — actually, I could; but I won’t — how important these two phrases are: “these humans” and “pre-sapiens hominins”.

I’m guessing that there are still folks who see the Irish, the English, and Ethiopians as different “species”. Just as I’m pretty sure that some of my eight billion or so neighbors are convinced that an American president and the pope are the Antichrist.

Whoever built the Kalambo Falls structure may not have qualified as Homo sapiens sapiens: anatomically modern or early modern humans. And if they did, humanity’s current model has been around for longer than most scientists thought.

While I’m thinking of it: we’re in the Hominidae, Homininae, and Hominini groups.⁶ Sorting out who’s using which definitions for each is more than I have time for this week. Basically, they’re labels for various tailless primates: like chimps, gorillas, gibbons, and us.

That doesn’t mean I think we’re merely animals, or that chimps should have voting rights. And getting upset because we’re learning more about “the dust of the ground” God makes us from? To me, that doesn’t make sense.

And I’m drifting off-topic. Or maybe not so much.

Good News, Bad News, and (Slowly) Changing Attitudes

Good news: there’s an enormous wealth of resources — like timber, diamonds, and petroleum — in the Congo Basin.

Bad news: same thing.

Leopold II of Belgium was, I gather, mainly after rubber when he said that what he called the Congo Free State was his personal property.

Even by standards of his day, late 19th and early 20th century, the behavior of Leopold II’s enforcers was open to criticism.

On the other hand, his atrocities helped convince folks that “crimes against humanity” was a meaningful phrase. And, arguably, more generally palatable than Chesterton’s “sin against humanity”.

“…Mr. Blatchford set out, as an ordinary Bible-smasher, to prove that Adam was guiltless of sin against God; in manoeuvring so as to maintain this he admitted, as a mere side issue, that all the tyrants, from Nero to King Leopold, were guiltless of any sin against humanity….”
(“Orthodoxy“, G. K. Chesterton (1908))

Leopold II’s Congo Free State closed shop in 1908. He died the next year. Folks living in the Congo Basin — have not been having a good time since then.

République du Congo / Republic of the Congo was rebranded as Zaire for a few decades. Now it’s the Democratic Republic of Congo: and I gather that a fair number of its subjects escaped into Zambia.

Maybe, a few centuries from now, folks living in the Congo Basin won’t be trying to get out: and will be enjoying the comparative prosperity which their land’s resources could make possible. With prudent and rational management, and that’s still another topic.

Right now, I’m thankful that I live in a comparatively stable country. And that there’s reasonable hope that folks living around the Congo Basin are rebuilding their societies.

Tanzania has had the same constitution since 1977, Zambia’s has been in effect since 2016. And the Zambia-Tanzania border is, as I said, not a war zone.⁷ That’s hopeful.

Another hopeful sign, for me, is that attitudes can change.

Take, for example, the sovereign right of warlords to kill people they find distasteful. General acceptance of that cherished right has eroded since my youth.

“…When Lemkin asked about a way to punish the perpetrators of the Armenian genocide, a law professor told him: ‘Consider the case of a farmer who owns a flock of chickens. He kills them and this is his business. If you interfere, you are trespassing.’ As late as 1959, many world leaders still ‘believed states had a right to commit genocide against people within their borders’, according to political scientist Douglas Irvin-Erickson….”
(Genocide, Wikipedia
and see Raphael Lemkin, Early years, Wikipedia)

Can’t say that I’m disappointed.

We’re Learning

I’ll end this week’s post on an upbeat note.

Between calling the Kalambo Falls builders “human”, and accepting scholars whose ancestors actually lived in lands that other scholars find interesting, I’d say that many of us are learning that ‘those people over there’ are — people.

That, I think, is a good idea.

I’ve talked about Earth’s long story, and ours, before:

• “T. Rex, or Not T. Rex, That is the Question“
  (January 13, 2024)
• “Ancient Stone Tools: Hello, Fellow Humans?“
  (February 18, 2023)
• “Horses and Humans, Chimps and Muscles“
  (December 31, 2022)
• “Evolution: Science, Religion, Opinions and Me“
  (August 28, 2021)
• “Evolution and Tools“
  (March 26, 2018)

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¹ Carbon-14 and glowing rocks:

• Wikipedia
  • Carbon-14
  • Cosmic ray
    • Changes in atmospheric chemistry
  • Dune
    • Star
  • Ionizing radiation
  • Isotopes of nitrogen
    • Nitrogen-14
  • Luminescence dating
  • Radioactive decay
  • Radiocarbon dating (carbon-14 dating)
  • University of Chicago
  • Willard Libby
• “Star dune: Scientists solve mystery behind Earth’s largest desert sands“
  Georgina Rannard, BBC News (March 4, 2024)
• “Evidence for the earliest structural use of wood at least 476,000 years ago“
  Lawrence Barham, Geoff Duller, I. Candy, C. Scott; Nature (September 2023) via ResearchGate
• “Testing the accuracy of OSL and pIR IRSL dating of young geoarchaeological sediments in coastal Peru“
  J. Sanjurjo-Sánchez, W. Viveen, R. Vega-Centeno Sara-Lafosse; abstract; Quaternary Geochronology, Volume 73, article id. 101382 (November 2022)
• “Testing the potential of K-feldspar pIR-IRSL and quartz ESR for dating coastal alluvial fan complexes in arid environments“
  Melanie Bartz, Mathieu Duval, Dominik Brill, Anja Zander, Georgina E. King, Alexander Rhein, Janek Walk, Georg Stauch, Frank Lehmkuhl, Helmut Brückner; Quaternary International (April 2020)
• Luminescence Dating Laboratory
  U.S. Geological Survey
• “What is OSL dating?“
  Department of Geosciences, Baylor University

² Vaguely related to Kalambo Falls, but not very:

• Wikipedia
  • Democratic Republic of the Congo
  • Kalamgo River
  • Kalambo structure
  • Kingdom of Kongo
  • Lake Tanganyika
  • Leopold II of Beligium
  • Northern Province, Zambia
  • Rukwa Region
  • Ruzizi River
  • Tanzania
  • Ufipa Plateau
  • Zambia
• Kalambo falls archaeological site (prehistoric settlement site)
  Tentative Lists, UNESCO World Heritage Convention
• Kalambo Falls
  Tanzania Tourism
• Kalambo Falls
  Zambia Tourism

³ Filling in blanks on the family tree:

• Wikipedia
  • Denisovan
  • Early modern human (AKA anatomically modern human)
  • Homo erectus
  • Human evolution
  • Human taxonomy
  • Neanderthal
  • Thumb
    • Grips

⁴ Architecture, toy logs, a little history:

• Wikipedia
  • 1923 Great Kantō earthquake
  • Abraham Lincoln
  • Chibanian
  • Frank Lloyd Wright
  • Imperial Hotel, Tokyo
  • John Lloyd Wright
  • Kantō Massacre (killing foreigners as a response to stress)
  • Lincoln Logs
  • Log cabin
  • Mayan Revival architecture
  • Menards
  • Pleistocene

⁵ Tech and tools:

• Wikipedia
  • Acheulean
  • Electroconvulsive therapy (AKA electroshock therapy; and yes, it’s still being done)
  • Power tool
• ResearchGate
  • “Evidence for the earliest structural use of wood at least 476,000 years ago“
    Lawrence Barham, Geoff Duller, I. Candy, C. Scott; Nature (September 2023)
  • “780,000-Year-old wood from Gesher Benot Ya’aqov, Israel“
    Ella Werker, abstract, Israel Journal of Plant Sciences (September 2007)

⁶ Taxonomic terminology, and a really bad idea:

• Wikipedia
  • Ape
    • History of hominoid taxonomy
  • Clade
  • Historical race concepts
  • Hominidae
  • Homininae
  • Hominini
  • Human (Homo sapiens: me, you, us)
  • Human taxonomy
  • Race (human categorization)
    • Historical origins of racial classification
  • List of conspiracy theories
  • Scientific racism
• “Surveys and excavations under the ‘Deep Roots’ Archaeological Project“
  Technical, Archaeology Blog, The Livingston Museum (October 28, 2019)
• Genesis 1:27–31, 2:7

⁷ Learning from the past is an option:

• Wikipedia
  • Congo Basin
  • Congo Free State
  • Crimes against humanity
  • Democratic Republic of the Congo
  • Kingdom of Kongo
  • Leopold II of Beligium
  • Scientific racism
  • Tanzania
  • Zaire
  • Zambia
• Congo Basin
  World Wildlife Fund