Your note on the Maya is incorrect. The Maya did not live as north as they could on the Yucatán peninsula.
The Maya had distinct phases. First, the classic Maya world developed primarily centered on the region of Peten, Guatemala, centered on the large lowland cities such as Tikal, Calakmul, and Palenque.
There were highland Maya but the civilization had its greatest prominence in the lowlands of northern Guatemala. The highlands were important as a source of obsidian, stone, and other resources.
Then the classic Maya collapse occurred, this center of civilization was reduced, and development began to shift.. not southward toward the Guatemalan highlands but northward. Cities such as Chichén Itzá were actually quite late in the span of Maya civilization but represent the location of the highest societal complexity of the Postclassic period.
There were different hypotheses about Maya population densities, with one end of the range holding that the lowland Maya world was among the most densely populated in the world at the time. Modern LiDAR research has found an astounding amount of infrastructure under the forest canopy, confirming the higher estimates as being more accurate.
Similarly, this technology is being applied in the Amazon and we are finding a surprising amount of lost cities and evidence of quite high population densities.
The Maya have been held as a great counter example to the idea that development to high population densities is impossible in tropical forest landscapes, and it does appear that much of the neotropics have these relict civilizations that provide similar challenges.
One might argue, well, they collapsed, however periodic collapse was more of a feature of all the civilizations in the American continent than an anomaly.
Overall I loved your posts on this topic and they’re very compelling. I’m somewhat considering doing a deep dive on this topic of rainforest civilizations as I have taken classes in Maya archaeology and this has long been one of my favorite subjects.
Human habitation does seem to follow the patterns you describe to a remarkable extent. But there are some quite significant counterexamples hiding below the forest canopy.
You are right. I made the map after writing that section and I forgot to update it. I will now.
When you look at that map, you notice that all three Mayan areas were the driest in the region. But you’re right that the original one was also the wettest.
It would be amazing to have much more detailed data on population densities in the past. It would help this type of endeavor tremendously.
My hypothesis is that the Maya were able to develop their civilisation on the tropical lowlands of the Yucatan due to a unique combination of geographical features.
The existence of a pronounced dry season being a major factor. The only part of the region that exhibits a true tropical rainforest climate with year long rains is in the far south. The rest of the peninsula has either a tropical wet and dry climate or a tropical savanna climate which both feature dry seasons of varying degrees. One of the apex cities of the Maya, Chichén Itzá, is located on the driest part of the peninsula. As it was dry for long periods of the year this would have acted as a defence against tropical disease.
I also think there are parallels with ancient Egypt (not just the penchant for pyramids 😉) but the availability of fresh water sources without the damaging effect of rains. In a way the Cenote were to the Maya what the Nile was to the Egyptians. They are more prevalent in the drier north as well which mirrors Egypt - hot climate, but dry with access to fresh water (obviously the Yucatan is still considerably wetter than Egypt).
The fact that the Maya didn’t have any major domesticated animals might have played a role as well as there were no vectors to encourage the spread of disease. Also malaria wasn’t present in the Americas pre 1492 (obviously there were other tropical diseases present).
EDIT: but as you so accurately put a lot of Mayan cities were located in the wetter part of the peninsula like Tikal so that does go against my hypothesis somewhat. Maybe the Little Ice Age played a role? It might have been drier overall at that time.
Interesting! How does your framework explain that the Mississippi basin (temperate, fertile, huge navigable rivers) didn’t produce a durable pre-European empire in North America, despite looking like a perfect “high-density core” in your model?
If its geography is the best, and has been so for centuries, how come it had to wait Europeans to emerge!?
It is, to me, one of the most understudied parts of the emergence of civilization. This region has been historically totally understudied. Maybe I should write an article about this...
The Mississippian culture, including the city of Cahokia, was durable for a while, until the Little Ice Age, followed by disease from European contact, took it down. https://en.wikipedia.org/wiki/Mississippian_culture
Without actually attempting to compare population numbers, my guess is that it was still less populated than other ancient civilizations with similarly good geography. Maybe malaria was always an issue? I'd be interested to hear others' thoughts.
From my understanding it was due to the absence of a 'civilization defining' crop for cultivation. Plants like goosefoot were cultivated but they didn't provide enough in the way of nutrients/energy like rice/wheat/corn. The Mississippi river basin only became a hive of human activity after the emergence of cold tolerant corn varieties (these took a long time to adapt and make their way north from Mesoamerica).
You keep outdoing yourself! Great article. I have one thought that perhaps the timefame is not large enough, but to take an example, Egypt was much greener 3-4,000 years ago and desertification throughout some temperate regions were very different than what we see today. To name a few, the Gobi, Sahara and many other land areas throughtout the world, were smaller and more temperate. We live on a constantly changing rock.
As a side note, unrelated to geography, the view today of the mainstream archeologists regarding the pyramids and Sphynx, there is mounting evidence that the pyramids are quite older than the current narrative.
I think it was a matter of time. Humans came much, much later there than in Eurasia. And it’s not just distance, it’s also the fact that they had to cross lots of different latitudes, adapting to each every time. That meant delay and lots of tech to develop and forget.
Fantastic summary. Worth noting that the peak in seasonality around 10 kya strongly incentivised the domestication of storable grain staples which made civilisation as we know it possible.
The exception seems to have been the pre-contact Brazilian civilisation, which we are only now finding evidence for after its total collapse upon introduction of old world diseases.
It is worth noting this culture seems to have domesticated cassava (did you get back to discussing it in the article?) which is a rare exception to the typical staple crops which require predictable cycles of warm/wet growing seasons and coo/dry storage conditions. You noted it was the key to the emergence of dense populations in the Niger Delta.
I suspect that tropical lowland civilisations are possible, but they would demand the domestication of a new package of crops and livestock which can endure the challenges, along with probable selection of the humans to endure the local diseases (if not sustainable technological solutions to the issue). Though it is possible without the bulk storage of grain it becomes impossible to build centralised states since tubers are difficult to tax and transport.
Lots of information to think about here. I appreciate the article. The only thing I’ll push back on is the Kalahari. This is the area where the San people live and they are likely the oldest continuously people in the world. They are highly adapted to the environment and while economically impoverished , culturally rich. The Tsodilo Hills area has cave artwork exceeding 4k paintings dating back 100,000 years. When seen by
European colonizers they were baffled by paintings of penguins. They didn’t understand that the San walked to the ocean and back to North West Botswana. In a world increasingly threatened by climate change climate adaptability is wealth.
I'd say it was this one: The Sahara, the Kalahari, and Somalia are empty.
Also, people who live at high altitudes are well adapted to the lower oxygen levels. They can exert themselves as well as anyone. The common factor across deserts and high mountains is the shallow and unproductive soil. The people who live there are mostly herders, with low stocking densities.
The main downside for people born at high altitude would be poverty, but that means they do not suffer from the chronic diseases of affluence. They also have better cardiovascular health.
Tour guides are an exception to the poverty and also get to travel between high and low altitudes. Anecdotally, they feel most comfortable back at altitude. Low altitudes make them feel restless. Their blood is thicker so they may have high blood pressure when travelling at low altitudes.
A sly nod as I’m Buddhist so I would dispute the claim about emptiness but that’s a different thing. I understand your point. Identity is not the same as quantity.
This reads like the ultimate 'Developer Notes' for Earth as a strategy game.
I love how you broke down the 'Nerfs' (Soil leaching, Tsetse fly, Malaria) and the 'Buffs' (Volcanic ash, Silt from floods, Gulf Stream).
As someone who analyzes fictional worlds (like Dragon Quest) through geography, this real-world analysis is incredibly validating. It proves that whether in fiction or reality, you cannot build a believable high-density civilization without solving the 'Food vs. Disease' equation set by the terrain.
The outlier of Java (Volcanoes overriding the tropical penalty) is a perfect plot twist!
El artículo de Tomás como siempre mueven al pensamiento profundo y la discusión, por lo cual valoro y sigo sus publicaciones. Pero, como casi siempre también, propone que variables como el calor, la topografía montañosa y la productividad agrícola ayudan a explicar patrones globales de pobreza. Estos factores ambientales, tal como el propio autor reconoce, influyen en los costos de transporte, en la acumulación de excedentes y en la densidad poblacional histórica. Sin embargo, desde un enfoque epistemológico, estas variables no operan de manera aislada ni determinista, sino en interacción con otras variables como procesos históricos, institucionales y geopolíticos.
El mismo texto muestra excepciones relevantes a su hipótesis central. Regiones con climas cálidos y montañosos como Singapur, Hong Kong o partes del sudeste asiático lograron altos niveles de desarrollo económico, mientras que países con climas templados y favorables, como Argentina o Ucrania, experimentaron estancamientos prolongados. Estos casos sugieren que las condiciones ambientales son condiciones habilitantes o restrictivas, pero no causas suficientes.
Otro elemento empírico que relativiza la explicación ambiental es que una proporción significativa de los países actualmente pobres fueron colonias de potencias europeas. El propio patrón geográfico que Tomas describe coincide en gran medida con la geografía del colonialismo histórico. Estudios comparativos muestran que las economías coloniales se estructuraron en torno a la extracción de recursos y monocultivos, configurando trayectorias institucionales distintas a las de los países que industrializaron tempranamente. Desde la complejidad, esto constituye una dependencia de trayectoria que interactúa con el ambiente, pero no se deriva de él.
Metodológicamente, el enfoque de Tomás es valioso como ejercicio de síntesis, pero tiende a priorizar un conjunto limitado de variables explicativas. Desde una perspectiva de complejidad la pobreza es un fenómeno emergente, resultado de interacciones no lineales entre ambiente, tecnología, instituciones y procesos históricos. En este marco, el clima y la geografía explican parte de la variabilidad observada, pero no permiten, por sí solos, comprender las divergencias de largo plazo entre países.
Como ecólogo no puedo dejar de refutar la caracterización de los suelos del Amazonas. La afirmación citada es incorrecta porque confunde fertilidad agrícola con funcionamiento ecológico, ignora el ciclo de nutrientes característico de las selvas lluviosas y contradice evidencia arqueológica, ecológica y socioeconómica ampliamente documentada. En la Amazonia, como en la mayoría de las selvas tropicales húmedas, la fertilidad no está en el suelo, ¡¡¡sino en el sistema vivo!!!. A diferencia de los sistemas templados, donde gran parte de los nutrientes se almacenan en el suelo, en la selva amazónica: los nutrientes están principalmente en la biomasa viva (árboles, lianas, epífitas, microorganismos). La hojarasca cae, se descompone rápidamente y los nutrientes son recapturados casi de inmediato por las raíces superficiales. Existe una red micorrícica altamente eficiente que minimiza las pérdidas por lixiviación, incluso bajo lluvias intensas. El sistema funciona como un ciclo cerrado y acelerado, no como un sistema empobrecido. Los suelos amazónicos (oxisoles y ultisoles) son antiguos y pobres en minerales, pero no son estériles: ¡¡¡¡¡son suelos funcionales dentro de un sistema ecológico complejo y estable!!!!!!. La erosión pluvial no destruye la selva porque la cobertura vegetal permanente protege el suelo. La degradación ocurre cuando esa cobertura se elimina. La idea de una Amazonia “vacía” ha sido refutada por múltiples líneas de evidencia como restos de paisajes antropogénicos (camellones, terrazas, canales, geoglifos), la existencia de terra preta de índio, suelos antrópicos extremadamente fértiles creados mediante manejo intencional de carbono y nutrientes, evidencias de poblaciones densas y redes de asentamientos a lo largo de los grandes ríos antes del colapso demográfico causado por la conquista europea.
La expansión agropecuaria no ocurre porque la Amazonia sea “naturalmente apta” para la agricultura, sino por razones económicas, tecnológicas y políticas. La deforestación libera un pulso breve de nutrientes (cenizas por "tala y roza"), que permite algunos años de producción agrícola o ganadera. Luego de pocos ciclos, los suelos pierden estructura, carbono y nutrientes, volviéndose improductivos sin insumos externos. Entonces los avances ses sostienen mediante subsidios estatales, infraestructura vial y energética, paquetes tecnológicos basados en fertilizantes, cal y agroquímicos.
El Programa de Aceleración del Crecimiento (PAC) de Brasil impulsó Rousef de carreteras, hidrovías, represas y corredores logísticos que reducen costos de transporte, facilitando la expansión de soja y ganadería hasta el propio eje fluvial del Amazonas, no se trata de una respuesta a una “vocación natural del suelo”, sino de una decisión de política territorial y económica (equivocada en mi opinión)
Por último, el corazón de la Amazonia no está protegido por infertilidad ni por erosión, sino por dificultad de acceso histórico (hoy en retroceso), altos costos energéticos y económicos para sostener la producción, fragilidad del sistema una vez removida la cobertura forestal como se demostró en el colapso de la producción ganadera impulsada por EEUU en Cista Rica. De hecho, donde llega la infraestructura, la deforestación avanza rápidamente, incluso en zonas con suelos muy pobres, lo que contradice la idea de una protección geográfica intrínseca.
La Amazonia no es “vacía”, ni “estéril”, ni incapaz de sostener poblaciones humanas. Es un sistema ecológico altamente productivo, pero basado en reciclaje biológico de nutrientes y cobertura permanente, no en agricultura extractiva. La afirmación analizada extrapola criterios de regiones templadas a un sistema tropical complejo, ignorando su ecología fundamental. La frontera agropecuaria avanza no porque la selva sea apta para la agricultura, sino porque la tecnología, el capital y las políticas públicas permiten explotar transitoriamente un sistema que colapsa cuando se lo simplifica.
" people living in the mountains have less oxygen, which might make it harder to exert yourself"
Ppl in the higher altitudes of the andes adapted to the local geography and climate by develping shorter and stronger legs and building huge lungs, cool air temps boosts productivity for most mortals.
Furthermore boosting hemoglobin and even modifying it is routine for high altitude creatures. Black hat geese routinely cruise at 30k' altitude whereas Rupell vultures can go to 37k' or possibly higher. 30k' is where homo sapien sapien expire if loitering too long.
Some athletes, not all, can do blood doping by saving a quart of blood following high altitude training, then during a critical need of a boost in a race or event, shed one quart of current blood and take on the "special" quart for extra performance.
A move i affectionately referr to as "oilchange".
Proper magnesium levels, whatever that may be, the national institute of hell refuses to be honest about it, equipps homos with the ability to live and fuction well in high temperatures.
Foods grown in leached soils are incapable of supplying much.
The oceans are of a few places where minerals as such are available!
Finally high humidity and ambient temps are very taxing on organs making geographies as such undesirable yet masses seem to flock there!
Great article, I liked that I was able to mentally short-cut through certain bits of this piece because I've read so many of your previous articles. I think that because of the Malthusian constraints prior to industrialization and Haber-Bosch, a good perspective is that since the Ice Age, more Eurasians have lived and died than Sub-Saharan Africans. With more people coming into existence, you get more potential for human invention and progress. Hence the patterns you see today where Eurasians dominate in terms of raw global power.
Also, when discussing India and SE Asia for your grand theory, it's important to note that the modern day populations there have significant ancestry from people who lived in more temperate zones during the Ice Age like Iran, Eastern Europe, Caucasus(for India) and China ( for SE Asians and some Eastern Indians). We know this for a fact now because of archaeogenetics!
Your note on the Maya is incorrect. The Maya did not live as north as they could on the Yucatán peninsula.
The Maya had distinct phases. First, the classic Maya world developed primarily centered on the region of Peten, Guatemala, centered on the large lowland cities such as Tikal, Calakmul, and Palenque.
There were highland Maya but the civilization had its greatest prominence in the lowlands of northern Guatemala. The highlands were important as a source of obsidian, stone, and other resources.
Then the classic Maya collapse occurred, this center of civilization was reduced, and development began to shift.. not southward toward the Guatemalan highlands but northward. Cities such as Chichén Itzá were actually quite late in the span of Maya civilization but represent the location of the highest societal complexity of the Postclassic period.
There were different hypotheses about Maya population densities, with one end of the range holding that the lowland Maya world was among the most densely populated in the world at the time. Modern LiDAR research has found an astounding amount of infrastructure under the forest canopy, confirming the higher estimates as being more accurate.
Similarly, this technology is being applied in the Amazon and we are finding a surprising amount of lost cities and evidence of quite high population densities.
The Maya have been held as a great counter example to the idea that development to high population densities is impossible in tropical forest landscapes, and it does appear that much of the neotropics have these relict civilizations that provide similar challenges.
One might argue, well, they collapsed, however periodic collapse was more of a feature of all the civilizations in the American continent than an anomaly.
Overall I loved your posts on this topic and they’re very compelling. I’m somewhat considering doing a deep dive on this topic of rainforest civilizations as I have taken classes in Maya archaeology and this has long been one of my favorite subjects.
Human habitation does seem to follow the patterns you describe to a remarkable extent. But there are some quite significant counterexamples hiding below the forest canopy.
You are right. I made the map after writing that section and I forgot to update it. I will now.
When you look at that map, you notice that all three Mayan areas were the driest in the region. But you’re right that the original one was also the wettest.
It would be amazing to have much more detailed data on population densities in the past. It would help this type of endeavor tremendously.
Great comment, I thoroughly enjoyed reading it!
My hypothesis is that the Maya were able to develop their civilisation on the tropical lowlands of the Yucatan due to a unique combination of geographical features.
The existence of a pronounced dry season being a major factor. The only part of the region that exhibits a true tropical rainforest climate with year long rains is in the far south. The rest of the peninsula has either a tropical wet and dry climate or a tropical savanna climate which both feature dry seasons of varying degrees. One of the apex cities of the Maya, Chichén Itzá, is located on the driest part of the peninsula. As it was dry for long periods of the year this would have acted as a defence against tropical disease.
I also think there are parallels with ancient Egypt (not just the penchant for pyramids 😉) but the availability of fresh water sources without the damaging effect of rains. In a way the Cenote were to the Maya what the Nile was to the Egyptians. They are more prevalent in the drier north as well which mirrors Egypt - hot climate, but dry with access to fresh water (obviously the Yucatan is still considerably wetter than Egypt).
The fact that the Maya didn’t have any major domesticated animals might have played a role as well as there were no vectors to encourage the spread of disease. Also malaria wasn’t present in the Americas pre 1492 (obviously there were other tropical diseases present).
EDIT: but as you so accurately put a lot of Mayan cities were located in the wetter part of the peninsula like Tikal so that does go against my hypothesis somewhat. Maybe the Little Ice Age played a role? It might have been drier overall at that time.
Great posting. Enjoyed reading it. This is a one-stop lesson in demographics . Should be recommended reading for each student.
Thanks!
Interesting! How does your framework explain that the Mississippi basin (temperate, fertile, huge navigable rivers) didn’t produce a durable pre-European empire in North America, despite looking like a perfect “high-density core” in your model?
If its geography is the best, and has been so for centuries, how come it had to wait Europeans to emerge!?
It is, to me, one of the most understudied parts of the emergence of civilization. This region has been historically totally understudied. Maybe I should write an article about this...
The Mississippian culture, including the city of Cahokia, was durable for a while, until the Little Ice Age, followed by disease from European contact, took it down. https://en.wikipedia.org/wiki/Mississippian_culture
Without actually attempting to compare population numbers, my guess is that it was still less populated than other ancient civilizations with similarly good geography. Maybe malaria was always an issue? I'd be interested to hear others' thoughts.
Cahokia and the rest of the Mississippian Culture fell well before the Europeans arrived
From my understanding it was due to the absence of a 'civilization defining' crop for cultivation. Plants like goosefoot were cultivated but they didn't provide enough in the way of nutrients/energy like rice/wheat/corn. The Mississippi river basin only became a hive of human activity after the emergence of cold tolerant corn varieties (these took a long time to adapt and make their way north from Mesoamerica).
You keep outdoing yourself! Great article. I have one thought that perhaps the timefame is not large enough, but to take an example, Egypt was much greener 3-4,000 years ago and desertification throughout some temperate regions were very different than what we see today. To name a few, the Gobi, Sahara and many other land areas throughtout the world, were smaller and more temperate. We live on a constantly changing rock.
As a side note, unrelated to geography, the view today of the mainstream archeologists regarding the pyramids and Sphynx, there is mounting evidence that the pyramids are quite older than the current narrative.
True! It does change.
The Sahara / Egypt were greener but earlier than that. Mostly during the last glaciation. By 3000 BC it was mostly as it is today.
I’ve read some on the debate about old civilizations. I’ll see what is discovered!
You might enjoy Gerald Pollack's newest book, where he talks about weather in different zones. Some interesting insights!
Charged : The Unexpected Role of Electricity in the Workings of Nature
This is gorgeous. Tomas, such a great leap forward! Do you want fan support in your research?
How so?
I could think researching certain sources, creating graphs, Challenge assumptions pre-publish.
But what would help you the most?
Depends on the person. What’s your best work?
A good read, thanks!
It may be interesting to dive into the recent work of Evert van de Vliert. He’s an emeritus professor in (latitudinal) psychology and wrote some interesting articles on behavior and latitudes: https://www.researchgate.net/scientific-contributions/Evert-Van-de-Vliert-57818622
Fascinating stuff. Thanks for sharing, I didn't know!
Any explanation why there were no large centers of population in Argentina before the Spanish?
I think it was a matter of time. Humans came much, much later there than in Eurasia. And it’s not just distance, it’s also the fact that they had to cross lots of different latitudes, adapting to each every time. That meant delay and lots of tech to develop and forget.
Fantastic summary. Worth noting that the peak in seasonality around 10 kya strongly incentivised the domestication of storable grain staples which made civilisation as we know it possible.
The exception seems to have been the pre-contact Brazilian civilisation, which we are only now finding evidence for after its total collapse upon introduction of old world diseases.
It is worth noting this culture seems to have domesticated cassava (did you get back to discussing it in the article?) which is a rare exception to the typical staple crops which require predictable cycles of warm/wet growing seasons and coo/dry storage conditions. You noted it was the key to the emergence of dense populations in the Niger Delta.
I suspect that tropical lowland civilisations are possible, but they would demand the domestication of a new package of crops and livestock which can endure the challenges, along with probable selection of the humans to endure the local diseases (if not sustainable technological solutions to the issue). Though it is possible without the bulk storage of grain it becomes impossible to build centralised states since tubers are difficult to tax and transport.
True!
I did mention cassava here!
I'm skeptical that Amazonian civilizations were very big and advanced but we'll see.
Agreed on your take on lowland tropical civilizations. It is theoretically possible, but it would have taken much longer.
Lots of information to think about here. I appreciate the article. The only thing I’ll push back on is the Kalahari. This is the area where the San people live and they are likely the oldest continuously people in the world. They are highly adapted to the environment and while economically impoverished , culturally rich. The Tsodilo Hills area has cave artwork exceeding 4k paintings dating back 100,000 years. When seen by
European colonizers they were baffled by paintings of penguins. They didn’t understand that the San walked to the ocean and back to North West Botswana. In a world increasingly threatened by climate change climate adaptability is wealth.
Thanks!
What claim are you pushing back on?
I'd say it was this one: The Sahara, the Kalahari, and Somalia are empty.
Also, people who live at high altitudes are well adapted to the lower oxygen levels. They can exert themselves as well as anyone. The common factor across deserts and high mountains is the shallow and unproductive soil. The people who live there are mostly herders, with low stocking densities.
Empty is not absolute. It’s relative. There is no such thing as emptiness anywhere in nature on Earth.
People on mountains live in plateaus.
Agreed on mountain people—for those who’ve evolved to adapt. But also, does that adaptation have no downside?
Thanks!
The main downside for people born at high altitude would be poverty, but that means they do not suffer from the chronic diseases of affluence. They also have better cardiovascular health.
Tour guides are an exception to the poverty and also get to travel between high and low altitudes. Anecdotally, they feel most comfortable back at altitude. Low altitudes make them feel restless. Their blood is thicker so they may have high blood pressure when travelling at low altitudes.
Interesting!
A sly nod as I’m Buddhist so I would dispute the claim about emptiness but that’s a different thing. I understand your point. Identity is not the same as quantity.
Yes, just as Sonya said.
This reads like the ultimate 'Developer Notes' for Earth as a strategy game.
I love how you broke down the 'Nerfs' (Soil leaching, Tsetse fly, Malaria) and the 'Buffs' (Volcanic ash, Silt from floods, Gulf Stream).
As someone who analyzes fictional worlds (like Dragon Quest) through geography, this real-world analysis is incredibly validating. It proves that whether in fiction or reality, you cannot build a believable high-density civilization without solving the 'Food vs. Disease' equation set by the terrain.
The outlier of Java (Volcanoes overriding the tropical penalty) is a perfect plot twist!
El artículo de Tomás como siempre mueven al pensamiento profundo y la discusión, por lo cual valoro y sigo sus publicaciones. Pero, como casi siempre también, propone que variables como el calor, la topografía montañosa y la productividad agrícola ayudan a explicar patrones globales de pobreza. Estos factores ambientales, tal como el propio autor reconoce, influyen en los costos de transporte, en la acumulación de excedentes y en la densidad poblacional histórica. Sin embargo, desde un enfoque epistemológico, estas variables no operan de manera aislada ni determinista, sino en interacción con otras variables como procesos históricos, institucionales y geopolíticos.
El mismo texto muestra excepciones relevantes a su hipótesis central. Regiones con climas cálidos y montañosos como Singapur, Hong Kong o partes del sudeste asiático lograron altos niveles de desarrollo económico, mientras que países con climas templados y favorables, como Argentina o Ucrania, experimentaron estancamientos prolongados. Estos casos sugieren que las condiciones ambientales son condiciones habilitantes o restrictivas, pero no causas suficientes.
Otro elemento empírico que relativiza la explicación ambiental es que una proporción significativa de los países actualmente pobres fueron colonias de potencias europeas. El propio patrón geográfico que Tomas describe coincide en gran medida con la geografía del colonialismo histórico. Estudios comparativos muestran que las economías coloniales se estructuraron en torno a la extracción de recursos y monocultivos, configurando trayectorias institucionales distintas a las de los países que industrializaron tempranamente. Desde la complejidad, esto constituye una dependencia de trayectoria que interactúa con el ambiente, pero no se deriva de él.
Metodológicamente, el enfoque de Tomás es valioso como ejercicio de síntesis, pero tiende a priorizar un conjunto limitado de variables explicativas. Desde una perspectiva de complejidad la pobreza es un fenómeno emergente, resultado de interacciones no lineales entre ambiente, tecnología, instituciones y procesos históricos. En este marco, el clima y la geografía explican parte de la variabilidad observada, pero no permiten, por sí solos, comprender las divergencias de largo plazo entre países.
Como ecólogo no puedo dejar de refutar la caracterización de los suelos del Amazonas. La afirmación citada es incorrecta porque confunde fertilidad agrícola con funcionamiento ecológico, ignora el ciclo de nutrientes característico de las selvas lluviosas y contradice evidencia arqueológica, ecológica y socioeconómica ampliamente documentada. En la Amazonia, como en la mayoría de las selvas tropicales húmedas, la fertilidad no está en el suelo, ¡¡¡sino en el sistema vivo!!!. A diferencia de los sistemas templados, donde gran parte de los nutrientes se almacenan en el suelo, en la selva amazónica: los nutrientes están principalmente en la biomasa viva (árboles, lianas, epífitas, microorganismos). La hojarasca cae, se descompone rápidamente y los nutrientes son recapturados casi de inmediato por las raíces superficiales. Existe una red micorrícica altamente eficiente que minimiza las pérdidas por lixiviación, incluso bajo lluvias intensas. El sistema funciona como un ciclo cerrado y acelerado, no como un sistema empobrecido. Los suelos amazónicos (oxisoles y ultisoles) son antiguos y pobres en minerales, pero no son estériles: ¡¡¡¡¡son suelos funcionales dentro de un sistema ecológico complejo y estable!!!!!!. La erosión pluvial no destruye la selva porque la cobertura vegetal permanente protege el suelo. La degradación ocurre cuando esa cobertura se elimina. La idea de una Amazonia “vacía” ha sido refutada por múltiples líneas de evidencia como restos de paisajes antropogénicos (camellones, terrazas, canales, geoglifos), la existencia de terra preta de índio, suelos antrópicos extremadamente fértiles creados mediante manejo intencional de carbono y nutrientes, evidencias de poblaciones densas y redes de asentamientos a lo largo de los grandes ríos antes del colapso demográfico causado por la conquista europea.
La expansión agropecuaria no ocurre porque la Amazonia sea “naturalmente apta” para la agricultura, sino por razones económicas, tecnológicas y políticas. La deforestación libera un pulso breve de nutrientes (cenizas por "tala y roza"), que permite algunos años de producción agrícola o ganadera. Luego de pocos ciclos, los suelos pierden estructura, carbono y nutrientes, volviéndose improductivos sin insumos externos. Entonces los avances ses sostienen mediante subsidios estatales, infraestructura vial y energética, paquetes tecnológicos basados en fertilizantes, cal y agroquímicos.
El Programa de Aceleración del Crecimiento (PAC) de Brasil impulsó Rousef de carreteras, hidrovías, represas y corredores logísticos que reducen costos de transporte, facilitando la expansión de soja y ganadería hasta el propio eje fluvial del Amazonas, no se trata de una respuesta a una “vocación natural del suelo”, sino de una decisión de política territorial y económica (equivocada en mi opinión)
Por último, el corazón de la Amazonia no está protegido por infertilidad ni por erosión, sino por dificultad de acceso histórico (hoy en retroceso), altos costos energéticos y económicos para sostener la producción, fragilidad del sistema una vez removida la cobertura forestal como se demostró en el colapso de la producción ganadera impulsada por EEUU en Cista Rica. De hecho, donde llega la infraestructura, la deforestación avanza rápidamente, incluso en zonas con suelos muy pobres, lo que contradice la idea de una protección geográfica intrínseca.
La Amazonia no es “vacía”, ni “estéril”, ni incapaz de sostener poblaciones humanas. Es un sistema ecológico altamente productivo, pero basado en reciclaje biológico de nutrientes y cobertura permanente, no en agricultura extractiva. La afirmación analizada extrapola criterios de regiones templadas a un sistema tropical complejo, ignorando su ecología fundamental. La frontera agropecuaria avanza no porque la selva sea apta para la agricultura, sino porque la tecnología, el capital y las políticas públicas permiten explotar transitoriamente un sistema que colapsa cuando se lo simplifica.
" people living in the mountains have less oxygen, which might make it harder to exert yourself"
Ppl in the higher altitudes of the andes adapted to the local geography and climate by develping shorter and stronger legs and building huge lungs, cool air temps boosts productivity for most mortals.
Furthermore boosting hemoglobin and even modifying it is routine for high altitude creatures. Black hat geese routinely cruise at 30k' altitude whereas Rupell vultures can go to 37k' or possibly higher. 30k' is where homo sapien sapien expire if loitering too long.
Some athletes, not all, can do blood doping by saving a quart of blood following high altitude training, then during a critical need of a boost in a race or event, shed one quart of current blood and take on the "special" quart for extra performance.
A move i affectionately referr to as "oilchange".
Proper magnesium levels, whatever that may be, the national institute of hell refuses to be honest about it, equipps homos with the ability to live and fuction well in high temperatures.
Foods grown in leached soils are incapable of supplying much.
The oceans are of a few places where minerals as such are available!
Finally high humidity and ambient temps are very taxing on organs making geographies as such undesirable yet masses seem to flock there!
Great article, I liked that I was able to mentally short-cut through certain bits of this piece because I've read so many of your previous articles. I think that because of the Malthusian constraints prior to industrialization and Haber-Bosch, a good perspective is that since the Ice Age, more Eurasians have lived and died than Sub-Saharan Africans. With more people coming into existence, you get more potential for human invention and progress. Hence the patterns you see today where Eurasians dominate in terms of raw global power.
Also, when discussing India and SE Asia for your grand theory, it's important to note that the modern day populations there have significant ancestry from people who lived in more temperate zones during the Ice Age like Iran, Eastern Europe, Caucasus(for India) and China ( for SE Asians and some Eastern Indians). We know this for a fact now because of archaeogenetics!
I felt like we were solving a puzzle! Fun article, kept my curiosity on point. What do you use to make the maps?