Tag Archives: stone tools

Handaxe

1.46 – 1.39 million years ago

From around 1.4 million years ago, Acheulean hand axes appear in Africa. They will eventually show up in southwest Europe and as far east as India. Hand axes were long thought to be absent from further east, but now have been found sporadically in East Asia. (Bamboo might have been an alternative to stone in the east.) Wear analyses show that hand axes, “the Swiss Army knife of the Paleolithic,” were used for a variety of purposes: cutting wood, slicing meat, scraping hides.

The hand axe implies a great leap forward cognitively from earlier Oldowan tools (although you can flay an elephant with Oldowan flakes). People (let’s call them people) were not just choosing the right material and making the right hand movements, but choosing the right shape of stone, and imagining the hand axe inside it before they started.

Dietrich Stout, an experimental anthropologist at Emory University, has trained students to make modern-day Acheulean handaxes, and monitored their brains as they learn. (The students’ axes, after months of practice, still aren’t as good as the real thing.) See the video below:

Small tools, and dingoes, and Oz

Australia can seem like the Land That Time Forgot. Australian marsupials were largely isolated from competition with placental mammals from other continents. (Although humans seem to have done in a lot of the megafauna when they arrived.) And many discussions of human prehistory assume that outside contact had little effect on Australia from the time of first settlement, before forty thousand years ago, and the English settlement of 1788. Populations just rose and fell with changes in climate and home-grown innovations in technology.

But there have always been hints that the story was more complicated. Some of the evidence comes from language distributions. The distribution of Australian languages is extremely lopsided. There are a lot of language families in and around the northern peninsula of Arnhemland. Then just one family, Pama-Nyungan, (distantly related to some or all of the others) covers about 80% of the continent.

pama nyungan

This sort of distribution is seen with other language families, where it looks like the signature of population spreads. For example, three of four major branches of the Austronesian language family are found only on Taiwan. The fourth branch, Malayo-Polynesian, spans the world from Madagascar, to island Southeast Asia, to Easter Island. The explanation, supported by many lines of evidence, and almost universally accepted, is that Proto-Austronesian first diverged into separate languages on Taiwan. One bunch of Austronesian speakers then sailed to the Philippines, and thence to farther isles, their languages diverging along the way … and the rest is history (actually prehistory). A similar argument roots the Bantu expansion in the Nigeria-Cameroon border area.

So it looks like there was a similar expansion in Australia. Language change is hard to date, but it’s very hard to believe the expansion happened forty thousand years ago. There is other evidence suggesting a recent date. Some time before 2000 BCE, a new archeological culture, the Small Tool Tradition, swept over Australia. At the same time, natives began exploiting a far wider range of habitats and food sources than previously. And – strikingly – a new animal makes its appearance – the dingo, which must have been introduced from overseas. All of this makes it look like some outside contact, jump-started a continent-scale cultural expansion with new technology, and maybe new forms of social organization.

Just published work on Australian genetics suggests a complicated picture. Northeastern and southwestern Australia, separated by the interior desert, are also strongly genetically differentiated, reflecting a split probably going back sometime between 32 and 10 thousand years ago, i.e. well after initial colonization, but well before the spread of the Small Tool Tradition. But there is also evidence that the last 10 thousand years saw a population expansion in the northeast, a population bottleneck in the southwest, and some gene flow between the two. A scenario that fits the data would be Pama-Nyungan speakers expanding in northeast, and then some northeasterners migrating to the southwest, spreading their language and culture, but not arriving in such large numbers as to replace local populations.

We can expect that the picture will grow clearer as more data accumulate.

Two roads diverged

47.5 – 45.0 thousand years ago.

The broad outlines of the spread of Homo sapiens have been established for several decades now: origins in Africa, expansion out of Africa at least 50-45 thousand years ago. But we’re still arguing about the details. Just recently it was reported that modern humans reached Sumatra 73-63 thousand years ago, and that stone tools in Australia date back 60 thousand years ago.

Also, based on recent recalibrations of DNA mutation rates, it looks like the African/non-African split might have happened more like 100 thousand years ago than 50 thousand years ago. So the ancestors of non-African (or non-sub-Saharan-African) H. sapiens might have occupied a homeland somewhere north of the Sahara between 100 and 50 thousand years ago, before spreading through Eurasia. North Africa is one possibility. The Near East, maybe the Arabian peninsula, is another possibility. The (or “a”) homeland might be (gated, sorry) underwater, under the Persian Gulf (sea levels were lower then). Both possibilities have some archeological support. There might have been multiple homelands, and multiple expansions – south through Arabia and along the shores of the Indian Ocean, and north through the Levant and into Europe.

recent (2015) redating of archeological finds suggests that the Levant-to-Europe corridor was part of the story. A modern stone tool technology, coming from Ksar Akil, just outside Beirut, Lebanon, dates to about 50,000 years ago, a little before much the same technology appears in Europe, in the form of the Upper Paleolithic.

And many other “details” remain to be resolved: What did interbreeding with non-sapiens mean for the evolution of H. sapiens? And just what advantage(s) did H. sapiens have that allowed them (us!) to replace other species? Stay tuned for more on Logarithmic History

Handaxe

1.46 – 1.39 million years ago

From around 1.4 million years ago, Acheulean hand axes appear in Africa. They will eventually show up in southwest Europe and as far east as India. Hand axes were long thought to be absent from further east, but now have been found sporadically in East Asia. (Bamboo might have been an alternative to stone in the east.) Wear analyses show that hand axes, “the Swiss Army knife of the Paleolithic,” were used for a variety of purposes: cutting wood, slicing meat, scraping hides.

The hand axe implies a great leap forward cognitively from earlier Oldowan tools (although you can flay an elephant with Oldowan flakes). People (let’s call them people) were not just choosing the right material and making the right hand movements, but choosing the right shape of stone, and imagining the hand axe inside it before they started.

Dietrich Stout, an experimental anthropologist at Emory University, has trained students to make modern-day Acheulean handaxes, and monitored their brains as they learn. (The students’ axes, after months of practice, still aren’t as good as the real thing.) See the video below:

Two roads diverged

47.5 – 45.0 thousand years ago.

The broad outlines of the spread of Homo sapiens have been established for several decades now: origins in Africa, expansion out of Africa at least 50-45 thousand years ago. But we’re still arguing about the details. Just recently it was reported that modern humans reached Sumatra 73-63 thousand years ago, and that stone tools in Australia date back 60 thousand years ago.

Also, based on recent recalibrations of DNA mutation rates, it looks like the African/non-African split might have happened more like 100 thousand years ago than 50 thousand years ago. So the ancestors of non-African (or non-sub-Saharan-African) H. sapiens might have occupied a homeland somewhere north of the Sahara between 100 and 50 thousand years ago, before spreading through Eurasia. North Africa is one possibility. The Near East, maybe the Arabian peninsula, is another possibility. The (or “a”) homeland might be (gated, sorry) underwater, under the Persian Gulf (sea levels were lower then). Both possibilities have some archeological support. There might have been multiple homelands, and multiple expansions – south through Arabia and along the shores of the Indian Ocean, and north through the Levant and into Europe.

recent (2015) redating of archeological finds suggests that the Levant-to-Europe corridor was part of the story. A modern stone tool technology, coming from Ksar Akil, just outside Beirut, Lebanon, dates to about 50,000 years ago, a little before much the same technology appears in Europe, in the form of the Upper Paleolithic.

And many other “details” remain to be resolved: What did interbreeding with non-sapiens mean for the evolution of H. sapiens? And just what advantage(s) did H. sapiens have that allowed him (us!) to replace other species? Stay tuned for more on Logarithmic History

Blombos

74.5 – 70.5 thousand years ago

The period between the time Homo sapiens leaves Africa 120 thousand years ago, and the time when H. sapiens spreads far and wide through Eurasia, replacing Neanderthals and others, 45 thousand years ago, sees episodes of increasing cultural complexity in Africa. One of these occurs at Blombos cave, at the southern tip of South Africa. There, over tens of thousands of years, people make a cultural great leap forward.

blombos2


75 thousand years ago, we find that they produce finely crafted stone blades that are part of multi-part composite tools. They make shell ornaments.

blombos

And they etch ocher (a red stone useful as a dye, but not for tools).

Oddly though, this tradition doesn’t last. It’s over by 60 thousand years ago. It may be that people left as climate deteriorated. But Blombos cave is a reminder that cultural progress is not always a permanent thing. It looks like an early instance of Rise and Fall: a culture rises to new heights, and then falls back.

My handaxe

1,043 – 986 thousand years ago

By today’s date, Acheulean tools are well developed in Africa, and found in India too. Sophisticated tools like the Acheulean hand axe probably tell us something not just about cognition in relation to tool making, but also about social cognition. You wouldn’t make a hand axe, use it, and abandon it. Nor would you go to all the trouble if the biggest, baddest guy in the group was immediately going to grab it from you. So there is probably some notion of artifacts-as-personal-possessions by the time Acheulean appears.

Possession is a social relationship, a relationship between two or more individuals with respect to the thing possessed. Robinson Crusoe didn’t “own” anything on his island before Friday came along.

Linguists have noted something interesting about the language of possession that maybe tells us something about the psychology of possession: Expressions for possession are often similar to expressions for spatial locations. Compare spatial expressions:

João went to Recife.
Chico stayed in Rio.
The gang kept Zezinho in Salvador.

and corresponding constructions for possessions:

The Crampden estate went to Reginald.
The Hampden estate stayed with Lionel.
Thag kept axe.

Of course the Crampden estate didn’t go anywhere in physical space, but it still traveled in the abstract social space of possession. In some cases just switching from inanimate to animate subject will switch the meaning from locative to possessive. The Russian preposition y means at/near when applied to a place (People are at Nevsky street) but possession when applied to a person (Hat is “at” Ivan = Ivan has hat.)

What may be going on here: people (and many other creatures) have some mental machinery for thinking about physical space. That machinery gets retooled/borrowed/exapted for thinking about more abstract relationships. So the cognitive psychology of space gets retooled for thinking about close and distant social relationships, or time ahead and behind. In other words, we may be seeing a common evolutionary phenomenon of organs evolved for one purpose being put to another purpose – reptile jaw bones evolve into mammalian inner ear bones, dinosaur forelimbs evolve into bird wings. You can find Steve Pinker making this argument in his book The Stuff of Thought. And Barbara Tversky’s recent Mind in Motion: How Action Shapes Thought seems to make the argument at greater length. For a while most of the evidence of repurposing spatial cognition for more abstract relationships came from linguistics, but there’s now some corroboration from neurology.

And I’ve made the argument for the particular case of kinship: regularities in kin terminology across cultures tell us something about pan-human ideas of “kinship space.” (My kin and mybody parts are arguably the most basic, intrinsic primitive sorts of possessions, since long before my handaxe.) This implies that the evolutionary psychology of kinship has not just an adaptive component (adaptations for calculating coefficients of relatedness and inbreeding), but also a phylogenetic component  (homologies with the cognitive psychology of space).

We’ll see other possible examples, involving e.g. the evolution of speech sounds, as we move along.

Handaxe

1.46 – 1.39 million years ago

From around 1.4 million years ago, Acheulean hand axes appear in Africa. They will eventually show up in southwest Europe and as far east as India. Hand axes were long thought to be absent from further east, but now have been found sporadically in East Asia. (Bamboo might have been an alternative to stone in the east.) Wear analyses show that hand axes, “the Swiss Army knife of the Paleolithic,” were used for a variety of purposes: cutting wood, slicing meat, scraping hides.

The hand axe implies a great leap forward cognitively from earlier Oldowan tools (although you can flay an elephant with Oldowan flakes). People (let’s call them people) were not just choosing the right material and making the right hand movements, but choosing the right shape of stone, and imagining the hand axe inside it before they started.

Dietrich Stout, an experimental anthropologist at Emory University, has trained students to make modern-day Acheulean handaxes, and monitored their brains as they learn. (The students’ axes, after months of practice, still aren’t as good as the real thing.) See the video below:

Blombos

77.1 – 73.0 thousand years ago

The period between the time Homo sapiens leaves Africa 120 thousand years ago, and the time when H. sapiens spreads far and wide through Eurasia, replacing Neanderthals and others, 45 thousand years ago, sees episodes of increasing cultural complexity in Africa. One of these occurs at Blombos cave, at the southern tip of South Africa. There, over tens of thousands of years, people make a cultural great leap forward.
blombos2
75 thousand years ago, we find that they produce finely crafted stone blades that are part of multi-part composite tools. They make shell ornaments.

blombos

And they etch ocher (a red stone useful as a dye, but not for tools).

Oddly though, this tradition doesn’t last. It’s over by 60 thousand years ago. It may be that people left as climate deteriorated. But Blombos cave is a reminder that cultural progress is not always a permanent thing. It looks like an early instance of Rise and Fall: a culture rises to new heights, and then falls back.

My handaxe

101- 959 thousand years ago

By today’s date, Acheulean tools are well developed in Africa, and found in India too. Sophisticated tools like the Acheulean hand axe probably tell us something not just about cognition in relation to tool making, but also about social cognition. You wouldn’t make a hand axe, use it, and abandon it. Nor would you go to all the trouble if the biggest, baddest guy in the group was immediately going to grab it from you. So there is probably some notion of artifacts-as-personal-possessions by the time Acheulean appears.

Possession is a social relationship, a relationship between two or more individuals with respect to the thing possessed. Robinson Crusoe didn’t “own” anything on his island before Friday came along.

Linguists have noted something interesting about the language of possession that maybe tells us something about the psychology of possession: Expressions for possession are often similar to expressions for spatial locations. Compare spatial expressions:

João went to Recife.
Chico stayed in Rio.
The gang kept Zezinho in Salvador.

and corresponding constructions for possessions:

The Crampden estate went to Reginald.
The Hampden estate stayed with Lionel.
Thag kept axe.

Of course the Crampden estate didn’t go anywhere in physical space, but it still traveled in the abstract social space of possession. In some cases just switching from inanimate to animate subject will switch the meaning from locative to possessive. The Russian preposition y means at/near when applied to a place (People are at Nevsky street) but possession when applied to a person (Hat is “at” Ivan = Ivan has hat.)

What may be going on here: people (and many other creatures) have some mental machinery for thinking about physical space. That machinery gets retooled/borrowed/exapted for thinking about more abstract relationships. So the cognitive psychology of space gets retooled for thinking about close and distant social relationships, or time ahead and behind. In other words, we may be seeing a common evolutionary phenomenon of organs evolved for one purpose being put to another purpose – reptile jaw bones evolve into mammalian inner ear bones, dinosaur forelimbs evolve into bird wings. You can find Steve Pinker making this argument in his book The Stuff of Thought. And Barbara Tversky’s recent Mind in Motion: How Action Shapes Thought seems to make the argument at greater length; I’m looking forward to reading it. For a while most of the evidence of repurposing spatial cognition for more abstract relationships came from linguistics, but there’s now some corroboration from neurology.

And I’ve made the argument for the particular case of kinship: regularities in kin terminology across cultures tell us something about pan-human ideas of “kinship space.” (My kin and mybody parts are arguably the most basic, intrinsic primitive sorts of possessions, since long before my handaxe.) This implies that the evolutionary psychology of kinship has not just an adaptive component (adaptations for calculating coefficients of relatedness and inbreeding), but also a phylogenetic component  (homologies with the cognitive psychology of space).

We’ll see other possible examples, involving e.g. the evolution of speech sounds, as we move along.