875: Jonathan Kennedy | How Pathogens Have Shaped Our World

Conquests & Diseases

The Roman and Spanish conquests were significantly influenced by the spread of diseases, which played a crucial role in shaping the outcomes of these historical events. Jonathan Kennedy highlights how the Spanish conquest of the Americas was facilitated by smallpox, which devastated indigenous populations, reducing their numbers from 60 million to 6 million over a century 1. This massive depopulation even affected global climate, contributing to the Little Ice Age 1.

The population of the Americas at the beginning of the century is something like 60 million, and at the end of the century, it's 6 million.

--- Jonathan Kennedy

In contrast, the Spanish were largely unaffected by the diseases that ravaged the Americas, due to differences in domesticated animals and urbanization levels, as explained by Kennedy 2.

   

Cultural Shifts

Diseases have also played a pivotal role in shaping cultural and linguistic landscapes. The Basque language, for instance, survived the spread of Indo-European languages due to the region's mountainous terrain, which acted as a barrier to invasions and cultural assimilation 3. Jonathan Kennedy notes that the resilience of certain populations in maintaining their language and culture can often be attributed to geographical advantages.

There's massive historical advantages to being a really big pain in the ass to either invade, conquer, or travel through.

--- Jordan Harbinger

Additionally, the spread of Indo-European languages is linked to the migration of Neolithic farmers, who brought diseases to hunter-gatherer populations, influencing linguistic evolution across Europe and Asia 4.