The rise of germs are linked to the rise of food production, particularly in the domestication of once wild animals. One of the major side effects of livestock are germs, that is human diseases of animal origins. Animals are so prevalent in human society in the form of livestock and companionship animals it is hard to imagine our lives without them. When one thinks about their beloved Dog, an ancestor the domesticated wolf, we rarely think about their nasty germs that they are passing along to us. “Some of us adults, and even more our children, pick up infectious diseases from our pets” (Diamond). Many of these germs, of animal origins, have become major killers of humanity throughout our recent history. These animals we have chosen to live with side-by-side have led to the spread of disease, a major consequence hand-in-hand with the domestication of animals. These microbes that once infected animals “transferred themselves from their original animal hosts” (Diamond) to humans. A characteristic of epidemic microbes is that they once lived in other animals and evolved to infect the human species. This evolution happened while humans were living in close proximity to animals giving the microbes a chance to adjust themselves to infect us. When living in dense populations humans are living among their own waste compared to hunter gathers who leave their waste behind as they move across the land. These conditions found in dense populations of people provided a breeding ground for these microbes. Animals that carried these microbes were mainly social animals living naturally in large populations “hence when we domesticated social animals, such as cows and pigs, they were already afflicted by epidemic diseases just waiting to be transferred to us” (Diamond). These diseases, such as the measles virus, which evolved from cattle, changed its properties to adapt to us. “Given our proximity to the animals we love, we must be getting constantly bombarded by their microbes” (Diamond). Animal microbes evolved into specialized human pathogens to the point where it can become transmitted directly between people causing epidemics. One of the most notorious human epidemic of animal origins is AIDS, a major killer of modern humanity, which derived from monkeys. These infectious diseases can be traced back to the diseases of our animal friends.
