AP World History Unit 2: Networks of Exchange
Table of Contents
I. The Silk Roads (Topic 2.1)
  A. Routes and historical context
  B. Transportation and commercial improvements
  C. Demand, production, and trading cities
II. The Mongol Empire and the Making of the Modern World (Topic 2.2)
  A. Conquest and state formation
  B. Trade and communication under Mongol rule
  C. Cultural transfers, continuity, and decline
III. Exchange in the Indian Ocean (Topic 2.3)
  A. Geography, goods, and environmental knowledge
  B. Navigation, ships, and commercial practices
  C. Port cities and growing states
  D. Diasporic communities and cultural exchange
  E. Zheng He’s voyages
IV. Trans-Saharan Trade Routes (Topic 2.4)
  A. Geography and transportation
  B. Goods and commercial connections
  C. Mali, trade, and Islam
V. Cultural Consequences of Connectivity (Topic 2.5)
  A. Religious diffusion and adaptation
  B. Scientific, technological, literary, and artistic exchange
  C. Urban growth and decline
  D. Travelers and historical sources
VI. Environmental Consequences of Connectivity (Topic 2.6)
  A. Crop diffusion and changing land use
  B. Plague and exchange networks
VII. Comparison of Economic Exchange (Topic 2.7)
  A. Shared causes and effects
  B. Differences shaped by geography and transport
  C. Comparison, causation, and evidence
Free Unit Notes
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I. The Silk Roads (Topic 2.1)
A. Routes and historical context
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The Silk Roads were connected overland trade routes linking China, Central Asia, Southwest Asia, and Europe. Most goods passed through several merchants rather than one person traveling the entire route.
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These routes existed before 1200. Growing cities, demand for luxury goods, and stronger commercial connections expanded their use from c. 1200 to c. 1450.
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Deserts and mountains shaped routes around reliable water sources and mountain passes. Oasis cities supplied travelers and became centers of exchange.
B. Transportation and commercial improvements
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Caravans, groups traveling together, carried goods using pack animals. Camels and improved saddles made dry overland travel more practical.
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Caravanserai were roadside inns where merchants and animals could rest and goods could be protected. They reduced travel risks and encouraged trade and cultural contact.
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Credit let merchants obtain goods or money with an agreement to pay later. It allowed larger transactions without immediate payment in coins.
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Bills of exchange were written payment orders that helped merchants transfer funds between places without carrying large amounts of coin.
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Banking houses accepted deposits, lent money, and exchanged currencies. These services helped merchants finance trade across regions.
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Paper money, used in China, made payments easier to carry. A money economy relies on currency for transactions rather than mainly on barter.
C. Demand, production, and trading cities
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High transport costs favored luxury goods, valuable products worth carrying long distances, such as silk, fine textiles, porcelain, and precious stones.
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Chinese, Persian, and Indian producers increased textiles and other manufactured exports. China expanded porcelain production and the manufacture of iron and steel.
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Rising demand encouraged specialized production; increased production supplied more trade. Artisans, merchants, and states benefited from sales and taxes.
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Kashgar, near routes around the Taklamakan Desert, and Samarkand, in Central Asia, grew as merchants purchased supplies, exchanged goods, and paid taxes.
II. The Mongol Empire and the Making of the Modern World (Topic 2.2)
A. Conquest and state formation
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The Mongols were pastoral nomads, people who moved with grazing herds on the Eurasian steppe. Skilled riding and archery supported their military strength.
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Chinggis Khan, also called Genghis Khan, united Mongol groups in 1206. His armies and successors expanded through China, Central Asia, Persia, and the Russian lands.
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Disciplined cavalry, coordinated attacks, feigned retreats, and siege techniques borrowed from conquered peoples helped defeat larger settled societies.
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Conquest could destroy cities, irrigation systems, and populations. The sack of Baghdad in 1258 ended the Abbasid caliphate there; Mongol armies completed the conquest of Song China in 1279.
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Succession struggles divided the empire into khanates, territories governed by khans. These states remained connected through trade and ruling families but sometimes fought each other.
a. The Yuan dynasty, founded by Kublai Khan, governed China and Mongolia.
b. The Ilkhanate ruled Persia and neighboring Southwest Asian territories.
c. The Chagatai Khanate controlled much of Central Asia.
d. The Golden Horde dominated the western steppe and collected tribute from Russian princes.
B. Trade and communication under Mongol rule
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Pax Mongolica refers to the relative security that Mongol power provided across much of Eurasia during the thirteenth and fourteenth centuries. It did not mean that all warfare ended.
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Protected routes, support for merchants, and connections between khanates encouraged long-distance trade. Conquered regions entered wider systems of taxation, production, and exchange.
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The yam, a relay-station network, supplied fresh horses and provisions for official communications. Authorized travel documents helped officials and some travelers move across Mongol territories.
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Mongol rulers employed and relocated skilled workers, administrators, and scholars. Their movement spread knowledge, sometimes through forced migration.
C. Cultural transfers, continuity, and decline
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Mongols adapted the Uyghur script for writing Mongolian, allowing written orders and records. This shows conquerors borrowing from conquered or incorporated peoples.
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Religious tolerance under many Mongol rulers allowed merchants and religious specialists to travel, although treatment varied by ruler and period.
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Chinese gunpowder knowledge and other technologies moved west through Eurasian contacts. Persian and Chinese scholars also exchanged astronomical and medical knowledge.
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Wider connections carried Greco-Islamic medicine into western Europe through Arabic-to-Latin translations. Hindu-Arabic numerals, developed in India and transmitted through the Islamic world, simplified calculation and bookkeeping in Europe.
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Not every transfer depended on Mongol rule. Translation centers and Mediterranean trade connected societies before and during Mongol expansion.
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Mongol rule changed political leadership while retaining many local administrative practices. Yuan rulers used Chinese institutions; Ilkhanate rulers adopted Persian traditions and eventually Islam.
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Rivalries, financial pressures, disease, and rebellions weakened Mongol states. The Ming dynasty replaced the Yuan in 1368, but Eurasian trade and cultural exchange continued.
III. Exchange in the Indian Ocean (Topic 2.3)
A. Geography, goods, and environmental knowledge
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Indian Ocean routes connected East Africa, Arabia, Persia, India, Southeast Asia, and China through the Arabian Sea, Bay of Bengal, and nearby seas.
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Monsoon winds reverse direction seasonally. Sailors timed departures and return trips around these predictable patterns; ships often waited in ports for favorable winds.
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Maritime shipping carried more cargo at lower cost per unit than overland travel. Merchants transported luxury goods as well as bulkier products, including cotton textiles, timber, and grain.
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Important exchanges included Chinese silk and porcelain, Indian cotton cloth, Southeast Asian spices, and East African gold and ivory. Enslaved people also moved through the network.
B. Navigation, ships, and commercial practices
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The magnetic compass indicated direction, including when landmarks or stars were unavailable. The astrolabe used the positions of celestial bodies to help estimate latitude.
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Lateen sails, triangular sails, helped ships maneuver in different wind conditions. Stern-mounted rudders improved steering.
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Dhows, sailing vessels widely used in the western Indian Ocean, and larger Chinese junks carried merchants and cargo. Watertight compartments in Chinese ships helped limit flooding.
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Larger ships and improved navigation increased carrying capacity and made voyages more reliable. These developments worked together with knowledge of winds and currents.
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Credit, merchant partnerships, and shared commercial practices helped finance voyages. Muslim trading connections linked distant ports, although Hindu, Jain, Chinese, and other merchants also participated.
C. Port cities and growing states
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Rulers gained revenue by taxing cargo, protecting merchants, and maintaining ports. Trade wealth supported stronger states, which could then encourage more trade.
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The Swahili city-states, including Kilwa and Mombasa, linked the East African interior to overseas markets. Gold, ivory, and other exports paid for imported textiles and porcelain.
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Gujarat, in western India, prospered through cotton-textile exports and connections between East Africa, Arabia, and Southeast Asia. Customs revenue strengthened its rulers.
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The Sultanate of Malacca grew during the early fifteenth century near the strait connecting the Indian Ocean and South China Sea. Its location, port services, and Muslim commercial ties attracted merchants.
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Calicut, on India's southwestern coast, became a major meeting place for merchants exchanging Indian products and goods from other regions.
D. Diasporic communities and cultural exchange
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Diasporic communities are settlements of people living outside their ancestral homeland while maintaining cultural connections to it. Seasonal port stays encouraged permanent merchant settlements.
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Arab and Persian merchants settled in East Africa, spreading Islam and intermarrying with local families. They also adopted African languages and customs.
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Swahili remained a Bantu language while incorporating many Arabic words. Coastal mosques and imported goods reflected connections with the wider Islamic world.
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Chinese merchants established communities in Southeast Asian ports; Malay merchants and sailors formed communities across the Indian Ocean basin. Migrants retained some customs and adapted others locally.
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Cultural exchange worked in both directions: merchants influenced local societies, and local societies changed merchant communities.
E. Zheng He's voyages
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Ming admiral Zheng He led seven major expeditions from 1405 to 1433, reaching Southeast Asia, South Asia, Arabia, and East Africa.
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The fleets displayed Chinese power, built diplomatic and tribute relationships, and encouraged trade and cultural contact. Some expeditions also used military force.
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Ming rulers later ended these state-sponsored voyages as priorities and spending changed. Private merchants and established Indian Ocean trade continued.
IV. Trans-Saharan Trade Routes (Topic 2.4)
A. Geography and transportation
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Trans-Saharan trade crossed the Sahara, connecting West Africa with North Africa and Mediterranean markets. Routes linked oasis towns and the savanna south of the desert.
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Camels tolerated desert conditions better than many other pack animals. Improved camel saddles made carrying heavy cargo more efficient.
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Large caravans offered protection and moved substantial loads. Experienced guides used knowledge of oases, distances, and desert conditions to plan journeys.
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These technologies and practices expanded trade after 1200; camels and Saharan trade themselves were much older.
B. Goods and commercial connections
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West African gold moved north, while salt from Saharan mines moved south. Salt was valuable for diets and food preservation.
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Merchants also exchanged copper, textiles, horses, books, ivory, kola nuts, and enslaved people. Gold supplied North African and European monetary systems.
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Muslim commercial networks, Arabic literacy, and shared legal practices helped merchants arrange transactions and maintain contacts across regions.
C. Mali, trade, and Islam
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Sundiata established the Mali Empire in the thirteenth century. Mali expanded after the earlier power of Ghana weakened.
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Mali's rulers controlled important trading centers and access to gold-producing regions. Taxes on trade financed armies and government, helping protect and extend commercial networks.
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Imperial expansion drew more farmers, miners, and merchants into regional and trans-Saharan markets. Niger River connections linked inland production with desert routes.
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Mansa Musa's pilgrimage to Mecca in 1324–1325 displayed Mali's wealth and strengthened ties with the Islamic world. His spending and gifts of gold affected markets along the journey.
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Rulers supported mosques, scholars, and education. Timbuktu and Gao developed as centers of trade and Islamic learning.
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Islam spread especially among rulers, merchants, and urban residents. Many communities retained indigenous beliefs or combined them with Islamic practices.
V. Cultural Consequences of Connectivity (Topic 2.5)
A. Religious diffusion and adaptation
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Cultural diffusion is the spread of beliefs, practices, and knowledge between societies. Merchants, migrants, missionaries, pilgrims, and scholars carried traditions along trade routes.
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Buddhism continued to shape East Asian temples, art, literature, and religious life. Its spread began long before 1200 and continued through regional connections.
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Syncretism combines elements of different traditions. Chan Buddhism in China, later called Zen in Japan, reflected Buddhist interaction with Chinese traditions.
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Hinduism and Buddhism influenced Southeast Asian courts, architecture, and religious life. Khmer temples and Hindu-Buddhist traditions in Java illustrate these connections.
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Islam spread through West African trade networks, Swahili ports, and South and Southeast Asian connections. Merchants and Sufis, Muslims emphasizing spiritual devotion, helped carry it into new communities.
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Conversion did not require complete cultural replacement. Local languages, customs, and political traditions often continued alongside new religious practices.
B. Scientific, technological, literary, and artistic exchange
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Papermaking spread from China through Central Asia and the Islamic world to Europe. More available paper supported recordkeeping, scholarship, and the circulation of texts.
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Gunpowder, developed in China, spread across Eurasia and contributed to changes in weapons and siege warfare.
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Scholars translated and developed earlier Greek, Indian, Persian, and Chinese learning. Medical knowledge, mathematics, astronomy, and navigation circulated through connected intellectual centers.
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Persian literary traditions circulated across courts in Southwest and South Asia. Arabic connected scholarship and religious study across much of the Islamic world.
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Artistic exchange included Chinese motifs in Persian illustrations and Persian cobalt used in Chinese blue-and-white porcelain. These products joined materials, techniques, and tastes from different regions.
C. Urban growth and decline
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Trade supported urbanization, the growth of cities. Merchants, artisans, religious institutions, and governments concentrated around ports, markets, and caravan stops.
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Higher agricultural productivity supplied food for urban populations. Hangzhou, Calicut, and Timbuktu illustrate different links between production, trade, and city growth.
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Urban outcomes varied. Invasions destroyed some cities, epidemics reduced populations, and shifts in trade routes weakened older centers. Baghdad's destruction shows that greater regional connectivity did not make every city prosper.
D. Travelers and historical sources
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Expanding networks enabled more long-distance journeys and written accounts. These texts spread information about unfamiliar societies and reveal both connections and cultural differences.
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Ibn Battuta, a fourteenth-century Moroccan Muslim scholar, described journeys across Islamic societies and beyond. His legal training and religious expectations shaped his judgments of local customs.
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Marco Polo, a late-thirteenth-century Venetian traveler, described Yuan China and Asian trade. His account helped circulate knowledge of Asian wealth and institutions among European readers.
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Margery Kempe, an English Christian pilgrim in the early fifteenth century, described religious experiences and travel to places including Jerusalem and Rome. Her account offers evidence about pilgrimage and women's experiences.
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Identify an account's point of view, purpose, historical situation, and audience. A pilgrim's religious goals or a merchant's interests influence what the writer notices and emphasizes.
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Compare travel accounts with other evidence. A writer's perspective can explain cultural assumptions without making every reported event representative or fully reliable.
VI. Environmental Consequences of Connectivity (Topic 2.6)
A. Crop diffusion and changing land use
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Crops moved with migrants and merchants. New food sources could improve diets, support larger populations, and encourage cultivation of additional land.
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Champa rice, a quick-ripening, drought-resistant variety from present-day Vietnam, reached China before 1200. Its continued use supported multiple harvests where conditions allowed and helped sustain population and urban growth.
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Bananas, originating in Southeast Asia, spread to Africa through earlier Indian Ocean connections. Their cultivation provided an additional food source and supported settlement in suitable tropical areas.
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Citrus fruits spread through Islamic trade and agricultural networks into Mediterranean regions. Irrigation and suitable growing conditions helped farmers establish these crops.
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Expanded cultivation could increase deforestation, soil exhaustion, and erosion. Environmental effects depended on local farming practices and conditions; trade did not produce identical outcomes everywhere.
B. Plague and exchange networks
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Pathogens are disease-causing organisms. Trade routes moved infected people, animals, and disease carriers as well as goods.
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Bubonic plague, caused by the bacterium Yersinia pestis, commonly spread through infected fleas associated with rodents. Ships, caravans, and military movements helped carry plague across connected regions.
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The Black Death spread across parts of Eurasia and North Africa in the fourteenth century, reaching Mediterranean Europe in 1347. Its effects extended well beyond Europe, though regional evidence and mortality estimates vary.
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Severe population losses disrupted production, trade, and tax collection. Communities also experienced fear, religious responses, and persecution of falsely blamed groups, including Jews in parts of Europe.
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Labor shortages increased workers' bargaining power in parts of western Europe, contributing to higher wage demands and weaker serfdom. Elites sometimes resisted through wage restrictions and other controls.
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The same connections that spread useful crops and knowledge also increased exposure to disease. Population growth from agricultural improvements and population loss from epidemics could occur within the same broader period.
VII. Comparison of Economic Exchange (Topic 2.7)
A. Shared causes and effects
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The Silk Roads, Indian Ocean routes, and trans-Saharan routes all expanded through demand, improved transportation, commercial practices, and political support. Their relative importance varied by region.
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Trade and state power reinforced each other: rulers protected routes and collected taxes, while commercial revenue financed government and expansion.
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All three networks supported merchant settlements and trading cities. Their connections spread religions, technologies, and cultural practices alongside goods.
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Exchange increased specialized production for distant markets. It also moved enslaved people and exposed communities to disruption and disease.
B. Differences shaped by geography and transport
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Silk Roads: Overland routes crossed Eurasian deserts, steppes, and mountains. Pack-animal costs favored valuable, relatively light goods; caravanserai and oasis cities supported travel.
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Indian Ocean: Sea routes connected coastal societies across a wide basin. Monsoon knowledge and navigation technology supported ships carrying both luxury goods and heavier bulk cargo.
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Trans-Saharan routes: Desert caravans linked West Africa with North Africa. Camels, saddles, guides, and oases supported exchanges especially associated with gold and salt.
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Political organization differed. Mongol khanates dominated large parts of the Silk Roads, Mali influenced important trans-Saharan connections, and many competing states and ports shared Indian Ocean trade.
C. Comparison, causation, and evidence
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Compare the same feature across networks, such as transport, goods, state involvement, or cultural effects. Explain why a similarity or difference existed.
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A defensible comparison is that both Silk Road and Indian Ocean commerce benefited from transport improvements, but sea transport supported more bulk cargo because ships carried larger loads at lower cost per unit.
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Use specific evidence and explain its connection to the claim. Caravanserai reduced risks for overland merchants; larger junks increased maritime carrying capacity. Naming them alone does not explain their effects.
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Distinguish continuity from change: established routes, religious traditions, and geographic constraints continued, while trade volume, commercial services, and political control changed.
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Recognize multiple causes and uneven effects. Strong states could encourage trade, but merchants, technology, demand, and environmental knowledge also mattered; increased connectivity brought both opportunities and costs.
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