The dispersal of humans.
June 15, 2010 2:05 AM Subscribe
Through the millennia of the history of our species, has every square meter of the planet, at one time or another, been trod upon by the human foot?
Obviously, before beginning this discussion, we need to list the exceptions: Oceans, inland seas, rivers and lakes; the polar regions, ice flows, and glaciers; inaccessible mountain slopes and summits; uninhabited dessert regions; remote atolls and islands. (This list is most likely incomplete, and can be added to as needed. However, it is equally true that even these regions have hosted human inhabitants or visitors from time to time.)
Apart from the obvious exceptions mentioned above, is it correct to assume that every square meter of the surface of the earth has, from the emergence of homo sapiens to the present, borne the imprint of the human foot?
Obviously, before beginning this discussion, we need to list the exceptions: Oceans, inland seas, rivers and lakes; the polar regions, ice flows, and glaciers; inaccessible mountain slopes and summits; uninhabited dessert regions; remote atolls and islands. (This list is most likely incomplete, and can be added to as needed. However, it is equally true that even these regions have hosted human inhabitants or visitors from time to time.)
Apart from the obvious exceptions mentioned above, is it correct to assume that every square meter of the surface of the earth has, from the emergence of homo sapiens to the present, borne the imprint of the human foot?
Homo early on expanded to occupy all the occupiable land at the carrying capacity - say where a band (or tribe) controls enough territory to feed themselves. Since the initial expansion of Homo there has rarely been unoccupied (or virgin) land. The American experience of free land just for the taking is a real aberration caused by introduced diseases that wiped out 95% of the native population.
The only real way that unoccupiable land has been made occupiable has been through technology. Such as the Esquimo who developed shelter and clothing to live in really cold places, or people who have used irrigation to grow crops in land that was too dry.
posted by MonkeySaltedNuts at 2:27 AM on June 15, 2010 [1 favorite]
The only real way that unoccupiable land has been made occupiable has been through technology. Such as the Esquimo who developed shelter and clothing to live in really cold places, or people who have used irrigation to grow crops in land that was too dry.
posted by MonkeySaltedNuts at 2:27 AM on June 15, 2010 [1 favorite]
I'd tend to agree with Happy Dave.
Also, bear in mind that the entire human population, for most of our history, has been pretty small and much less inclined to travel. And once routes had been established between neighbouring settlements, there was little incentive for most people to stray from those routes except to cultivate fertile land.
posted by le morte de bea arthur at 2:33 AM on June 15, 2010
Also, bear in mind that the entire human population, for most of our history, has been pretty small and much less inclined to travel. And once routes had been established between neighbouring settlements, there was little incentive for most people to stray from those routes except to cultivate fertile land.
posted by le morte de bea arthur at 2:33 AM on June 15, 2010
I think the answer is no, and that the answer is in your question. The list of exceptions is pretty long, and covers a lot of ground. So with those exceptions in mind I would say a phrase like "every square meter of the surface of the earth" is a little misleading.
If, however, you want to decrease "every square meter of the surface of the earth" down to "every square meter which is within one days walk from a place that is theoretically inhabitable using only pre-industrial revolution technologies", then I think the answer is still no, because, as Happy Dave points out, both the Siberian and Northern Canadian Tundra are inhabitable, but are both really sparsely inhabited (and have never been dense). And moreover, I suspect there will still be lots of random areas of a size of about 5m² - 20m² which are perfectly accessible, and even close to human populations, which just by chance have never ever been walked upon.
posted by molecicco at 3:12 AM on June 15, 2010 [3 favorites]
If, however, you want to decrease "every square meter of the surface of the earth" down to "every square meter which is within one days walk from a place that is theoretically inhabitable using only pre-industrial revolution technologies", then I think the answer is still no, because, as Happy Dave points out, both the Siberian and Northern Canadian Tundra are inhabitable, but are both really sparsely inhabited (and have never been dense). And moreover, I suspect there will still be lots of random areas of a size of about 5m² - 20m² which are perfectly accessible, and even close to human populations, which just by chance have never ever been walked upon.
posted by molecicco at 3:12 AM on June 15, 2010 [3 favorites]
God no, not even close. A foot is tiny, the world is large.
posted by smoke at 3:24 AM on June 15, 2010 [2 favorites]
posted by smoke at 3:24 AM on June 15, 2010 [2 favorites]
There are vast, vast tracts of land that are and have been inhabited for millenia, but which have always supported statistically tiny populations (i.e. most of the Russian Taiga, the Northern Territories of Canada, large areas of Australia, the Amazon basin). To put it another way - all of the people who have lived and died in the Amazon basin since humanity first arrived there have probably not, between them, managed to physically stand on every square metre of accessible space.
I think you are right for the other areas you mention, but hasn't there been recentish articles (including a FPP, I think) about how the Amazon was formerly intensively farmed, with large cities, etc? The current low population there may not reflect historical reality, in other words. (This may be what I'm thinking of.)
posted by Forktine at 3:36 AM on June 15, 2010
I think you are right for the other areas you mention, but hasn't there been recentish articles (including a FPP, I think) about how the Amazon was formerly intensively farmed, with large cities, etc? The current low population there may not reflect historical reality, in other words. (This may be what I'm thinking of.)
posted by Forktine at 3:36 AM on June 15, 2010
I would suggest "maybe yes", for two reasons:
1. Huge tracts of the Earth's surface have radically changed their character over time. Fossilised tree-trunks have been found in the Sahara, sea-shells are often found in European mountains. Experts on this could probably add many other examples/proofs. So what we now consider uninhabitable (or nearly so) may well have been inhabited in the distant past.
2. From the late 1400s to the early 1900s, mankind set out on a mission of exploration. "Doctor Livingstone, I presume." Having just come to the realisation that there was a lot of world out there that they hadn't seen yet, scores of intrepid explorers set out to do just that, and the concept was so widely accepted that they found little difficulty in getting a monarch or a millionaire to finance them, just for the kudos of finding somewhere new to walk. Now we're stuck with doing it off-Earth, because the bits of Earth left to explore (excluding the ones you listed in your premise) are pretty much exhausted.
In support of the "no" side, however, the population of the Earth has only recently grown to the present level, which for us appears to be "normal". So there were far less "human feet" (however you begin to define "human") to tread those square metres in the more distant past.
But I really doubt whether there is any empirical way to provide an authoritative answer to your fascinating question.
posted by aqsakal at 3:45 AM on June 15, 2010
1. Huge tracts of the Earth's surface have radically changed their character over time. Fossilised tree-trunks have been found in the Sahara, sea-shells are often found in European mountains. Experts on this could probably add many other examples/proofs. So what we now consider uninhabitable (or nearly so) may well have been inhabited in the distant past.
2. From the late 1400s to the early 1900s, mankind set out on a mission of exploration. "Doctor Livingstone, I presume." Having just come to the realisation that there was a lot of world out there that they hadn't seen yet, scores of intrepid explorers set out to do just that, and the concept was so widely accepted that they found little difficulty in getting a monarch or a millionaire to finance them, just for the kudos of finding somewhere new to walk. Now we're stuck with doing it off-Earth, because the bits of Earth left to explore (excluding the ones you listed in your premise) are pretty much exhausted.
In support of the "no" side, however, the population of the Earth has only recently grown to the present level, which for us appears to be "normal". So there were far less "human feet" (however you begin to define "human") to tread those square metres in the more distant past.
But I really doubt whether there is any empirical way to provide an authoritative answer to your fascinating question.
posted by aqsakal at 3:45 AM on June 15, 2010
I think you are right for the other areas you mention, but hasn't there been recentish articles (including a FPP, I think) about how the Amazon was formerly intensively farmed, with large cities, etc? The current low population there may not reflect historical reality, in other words. (This may be what I'm thinking of.)
Fair point, but quoted in your link is this:
posted by Happy Dave at 3:47 AM on June 15, 2010 [1 favorite]
Fair point, but quoted in your link is this:
"Schaan and colleagues estimated at least 300 people would be needed to build a geoglyph. This points to a regional population of around 60,000 people, which was then wiped out by diseases brought by European conquistadores in the 15th and 16th centuries.My emphasis. In an area that is, today, approximately 8.2 million km square and was historically larger before deforestation, that's still a hell of a lot of space and not many people.
posted by Happy Dave at 3:47 AM on June 15, 2010 [1 favorite]
1. Huge tracts of the Earth's surface have radically changed their character over time. Fossilised tree-trunks have been found in the Sahara, sea-shells are often found in European mountains. Experts on this could probably add many other examples/proofs. So what we now consider uninhabitable (or nearly so) may well have been inhabited in the distant past.
Absolutely, but by very small groups of hunter/gatherers (who moved around a lot but in relatively small areas, globally speaking) and later by subsistence farmers, who moved not very often and in even smaller areas (i.e. slash and burn agriculture).
2. From the late 1400s to the early 1900s, mankind set out on a mission of exploration. "Doctor Livingstone, I presume." Having just come to the realisation that there was a lot of world out there that they hadn't seen yet, scores of intrepid explorers set out to do just that, and the concept was so widely accepted that they found little difficulty in getting a monarch or a millionaire to finance them, just for the kudos of finding somewhere new to walk. Now we're stuck with doing it off-Earth, because the bits of Earth left to explore (excluding the ones you listed in your premise) are pretty much exhausted.
Agreed, there was an enormous boom in exploration, but most of it was of the 'sail around the edges of Country X to map the coastline' or 'Walk across Country Z to try and find the other coast/NorthWest passage/mineral resources, mapping by sight as you went'. This type of exploration had (and still has in the rare instances that expeditions are mounted) a very small physical footprint.
But I really doubt whether there is any empirical way to provide an authoritative answer to your fascinating question.
Agreed, it's both fascinating and unanswerable, especially by statistical arguments. On the flip side, there is not a square foot of visible land (so caves etc don't count, but they will be a vanishingly small percentage of accessible space) that hasn't been mapped via satellite. However, even that mapping is open to mystery, given how much of the Earth is covered in thick vegetation, snow and other things which obscure the terrain.
It makes my head hurt a bit thinking about how vast and unknowable our planet really is and then trying to fit that into a universe (hell, a solar system) in which Earth is an incredibly tiny blue/green dot.
posted by Happy Dave at 3:57 AM on June 15, 2010 [2 favorites]
Absolutely, but by very small groups of hunter/gatherers (who moved around a lot but in relatively small areas, globally speaking) and later by subsistence farmers, who moved not very often and in even smaller areas (i.e. slash and burn agriculture).
2. From the late 1400s to the early 1900s, mankind set out on a mission of exploration. "Doctor Livingstone, I presume." Having just come to the realisation that there was a lot of world out there that they hadn't seen yet, scores of intrepid explorers set out to do just that, and the concept was so widely accepted that they found little difficulty in getting a monarch or a millionaire to finance them, just for the kudos of finding somewhere new to walk. Now we're stuck with doing it off-Earth, because the bits of Earth left to explore (excluding the ones you listed in your premise) are pretty much exhausted.
Agreed, there was an enormous boom in exploration, but most of it was of the 'sail around the edges of Country X to map the coastline' or 'Walk across Country Z to try and find the other coast/NorthWest passage/mineral resources, mapping by sight as you went'. This type of exploration had (and still has in the rare instances that expeditions are mounted) a very small physical footprint.
But I really doubt whether there is any empirical way to provide an authoritative answer to your fascinating question.
Agreed, it's both fascinating and unanswerable, especially by statistical arguments. On the flip side, there is not a square foot of visible land (so caves etc don't count, but they will be a vanishingly small percentage of accessible space) that hasn't been mapped via satellite. However, even that mapping is open to mystery, given how much of the Earth is covered in thick vegetation, snow and other things which obscure the terrain.
It makes my head hurt a bit thinking about how vast and unknowable our planet really is and then trying to fit that into a universe (hell, a solar system) in which Earth is an incredibly tiny blue/green dot.
posted by Happy Dave at 3:57 AM on June 15, 2010 [2 favorites]
No, because 1. it's a silly question, for the reasons given above, and 2. Tane Mahuta, a kauri tree in New Zealand, is believed to be more than 1250 years old (possibly up to 2500), and has a trunk about 4 metres across. People are generally believed to have been in New Zealand for somewhat less than 1000 years. This means that there's a piece of ground that has had the same, solid, tree trunk on it longer than people have been anywhere near it. There's another tree nearby that's more than 5 metres in diameter, too.
posted by Lebannen at 4:01 AM on June 15, 2010 [4 favorites]
posted by Lebannen at 4:01 AM on June 15, 2010 [4 favorites]
Another possible exception - landforms change. Maybe the largest change would be the considerable seacoast areas drowned at the end of the last ice age. It seems like a safe assumption that some of them would have remained unexplored by the smaller human populations of the time.
Volcanoes and other tectonic activity would also create new square meters of land from time to time.
For that matter, would humans have yet stepped on every square meter of the now-dry Aral Sea?
posted by gimonca at 5:09 AM on June 15, 2010
Volcanoes and other tectonic activity would also create new square meters of land from time to time.
For that matter, would humans have yet stepped on every square meter of the now-dry Aral Sea?
posted by gimonca at 5:09 AM on June 15, 2010
Volcanoes and other tectonic activity would also create new square meters of land from time to time.
I was coming to make the same point; also landslides, and the deposition of silt at the mouths of rivers, among other mechanisms for creating new land surface. That may not be a lot, but there only needs to be one square meter that hasn't been trod upon yet for the answer to be "no".
posted by TedW at 5:15 AM on June 15, 2010
I was coming to make the same point; also landslides, and the deposition of silt at the mouths of rivers, among other mechanisms for creating new land surface. That may not be a lot, but there only needs to be one square meter that hasn't been trod upon yet for the answer to be "no".
posted by TedW at 5:15 AM on June 15, 2010
I don't think this is true even for the relatively well-populated continental US: Wyoming has a population density of 5.4 people per square mile. It's pretty empty in the back woods, and not exactly on any major trade routes where people would wander through. Alaska is even emptier, with a population density of 1.2 / square mile.
posted by jenkinsEar at 5:33 AM on June 15, 2010
posted by jenkinsEar at 5:33 AM on June 15, 2010
There are more than a few peaks in the Himalayas that haven't been climbed.
posted by deadmessenger at 5:35 AM on June 15, 2010
posted by deadmessenger at 5:35 AM on June 15, 2010
In 1800, the population of the world was about 1 billion people. Of which around three quarters would have been in China and Europe.
In other words, vast tracts of perfectly habitable parts of Australasia, Russia, Asia, Africa and South America likely weren't touched at all then. Where subsistence or nomadic farming still occur there will still be large tracts of land where humans haven't set foot. The same will be true even of somewhere like Canada, Kazakhstan or outback Australia, where unless there is a reason for someone to have gone there, they likely won't have done. Even where humans might have a reason to venture there, they won't have done so in sufficient numbers to have set foot everywhere. This will have been compounded to some degree by the formalisation of transport routes by train or road.
Prior to the middle of the last century, in some places humans will have kept relatively small areas over which they moved. Disease, a lack of healthcare and a lack of industrialisation of agriculture in any form will have meant populations stayed low and, unless nomadic, quite static.
posted by MuffinMan at 5:43 AM on June 15, 2010
In other words, vast tracts of perfectly habitable parts of Australasia, Russia, Asia, Africa and South America likely weren't touched at all then. Where subsistence or nomadic farming still occur there will still be large tracts of land where humans haven't set foot. The same will be true even of somewhere like Canada, Kazakhstan or outback Australia, where unless there is a reason for someone to have gone there, they likely won't have done. Even where humans might have a reason to venture there, they won't have done so in sufficient numbers to have set foot everywhere. This will have been compounded to some degree by the formalisation of transport routes by train or road.
Prior to the middle of the last century, in some places humans will have kept relatively small areas over which they moved. Disease, a lack of healthcare and a lack of industrialisation of agriculture in any form will have meant populations stayed low and, unless nomadic, quite static.
posted by MuffinMan at 5:43 AM on June 15, 2010
@Anything: I'll voice a slight doubt on that, since those two would have had to take about 75 trillion (US) steps each, which would take an ordinary human quite a bit longer than a million years, even when stepping very quickly.
The original question: No. Take Antarctica as an example, 14 million square kilometers of land without permanent human habitation until the 20th century.
This IS an interview question, right? So, here go the numbers: There are (generously) 5 000 inhabitants of Antarctica, (generously) for a century, giving us 500 000 person-years of habitation. A person usually takes less than 10 000 steps a day, so definitely less than 5 000 000 a year. So, less than 2 500 000 000 000 steps taken since the colonization. Land area: 14 000 000 000 000 square meters. This gives us a probability of less than 17% for a square meter to have been trod upon, even (absurdly) assuming that every step falls on a different untrod square meter. In the absence of an organized "let's step on every square meter of Antarctica" program, I'll even believe that the vast majority of square meters in Antarctica have never been trod upon.
posted by themel at 5:44 AM on June 15, 2010
The original question: No. Take Antarctica as an example, 14 million square kilometers of land without permanent human habitation until the 20th century.
This IS an interview question, right? So, here go the numbers: There are (generously) 5 000 inhabitants of Antarctica, (generously) for a century, giving us 500 000 person-years of habitation. A person usually takes less than 10 000 steps a day, so definitely less than 5 000 000 a year. So, less than 2 500 000 000 000 steps taken since the colonization. Land area: 14 000 000 000 000 square meters. This gives us a probability of less than 17% for a square meter to have been trod upon, even (absurdly) assuming that every step falls on a different untrod square meter. In the absence of an organized "let's step on every square meter of Antarctica" program, I'll even believe that the vast majority of square meters in Antarctica have never been trod upon.
posted by themel at 5:44 AM on June 15, 2010
would humans have yet stepped on every square meter of the now-dry Aral Sea?
Well, I've stepped on some of it...
posted by aqsakal at 5:49 AM on June 15, 2010
Well, I've stepped on some of it...
posted by aqsakal at 5:49 AM on June 15, 2010
i'm wondering: does this question require we freeze the world precisely as it is right now to do our survey of available square meters? otherwise, we'll have to do some composite rendering over a period of 200,000 years or so to account for the regular transformations of the earth's surface due to erosion & other natural processes
the coastlines are going to be a problem not to mention canyon systems... and there's probably some doozy cave systems too
even that square meter of earth right outside right now is probably not entirely the same square meter it was 100 years ago - or even just last week (e.g., if you've been having some of the torrential rain we've been having in my region lately)
posted by jammy at 5:49 AM on June 15, 2010
the coastlines are going to be a problem not to mention canyon systems... and there's probably some doozy cave systems too
even that square meter of earth right outside right now is probably not entirely the same square meter it was 100 years ago - or even just last week (e.g., if you've been having some of the torrential rain we've been having in my region lately)
posted by jammy at 5:49 AM on June 15, 2010
Oh, I missed your exceptions, sorry. It's still a No, but with your murky question, arguing it becomes too much of a PITA.
posted by themel at 5:51 AM on June 15, 2010
posted by themel at 5:51 AM on June 15, 2010
In 1800, the population of the world was about 1 billion people. Of which around three quarters would have been in China and Europe.
Yeah, this. There really haven't been very many people around until very recently.
posted by shakespeherian at 7:27 AM on June 15, 2010
Yeah, this. There really haven't been very many people around until very recently.
posted by shakespeherian at 7:27 AM on June 15, 2010
I have often wondered who walked my neighbourhood before the Europeans came to Canada.
Estimates of how many First Nations and Inuit lived in what we now call Canada in the 1400s range from 200,000 to two million. Even if there were two million (highly unlikely) that is a pretty tiny population considering that with over thirty million Canadians now, we have plenty of space (latest figures are something like just over three people per square kilometre now) that I am sure no one has walked on. The history of my immediate area, even though relatively fertile, is of very small First Nations villages of the Neutral tribe who simply didn't have the population numbers to walk over much land. Again, speaking of Canada, the weather prohibits a lot of travel - more so fifty years ago when muddy roads were impassable in the spring and fall and winter was an easier time to travel but even now, less than an hour from downtown toronto my county closes roads due to the season.
I was recently in the UK and seeing so many people in such a small country (and yet there was still open countryside) made me appreciate Canada's wildness even more.
posted by saucysault at 9:24 AM on June 15, 2010
Estimates of how many First Nations and Inuit lived in what we now call Canada in the 1400s range from 200,000 to two million. Even if there were two million (highly unlikely) that is a pretty tiny population considering that with over thirty million Canadians now, we have plenty of space (latest figures are something like just over three people per square kilometre now) that I am sure no one has walked on. The history of my immediate area, even though relatively fertile, is of very small First Nations villages of the Neutral tribe who simply didn't have the population numbers to walk over much land. Again, speaking of Canada, the weather prohibits a lot of travel - more so fifty years ago when muddy roads were impassable in the spring and fall and winter was an easier time to travel but even now, less than an hour from downtown toronto my county closes roads due to the season.
I was recently in the UK and seeing so many people in such a small country (and yet there was still open countryside) made me appreciate Canada's wildness even more.
posted by saucysault at 9:24 AM on June 15, 2010
No way. There are some places people just don't want to walk.
posted by spakto at 11:10 AM on June 15, 2010
posted by spakto at 11:10 AM on June 15, 2010
And even with vastness of the earth and given populations aside, people follow the path or lest resistance when walking, and I would assume that to be particularly true for the vast majority of human history when calories where harder to come by.
Why don’t you climb the mountain?
Because it’s there!
posted by Widepath at 7:52 PM on June 15, 2010
Why don’t you climb the mountain?
Because it’s there!
posted by Widepath at 7:52 PM on June 15, 2010
I know of areas that are less than 10km away from main arterial highway in Canada that have never been trodden upon because the landscape makes the land useless for economic activity... And I'm currently looking at the North Shore mountains right next door to Vancouver (a city of 2 million people), where I'm sure there's areas up there that have never been walked upon falling within your criteria of a square meter.
I'd go with a definite no.
posted by sleslie at 8:54 AM on June 16, 2010
I'd go with a definite no.
posted by sleslie at 8:54 AM on June 16, 2010
This thread is closed to new comments.
For temperate countries with higher populations (i.e. the UK, the US, China) the likelihood is far higher (much denser concentrations of people over time) but there are still probably random square metres of ground all over the globe that have, in reality, never borne the weight of a human foot.
posted by Happy Dave at 2:16 AM on June 15, 2010