The article explores the origins of major human infectious diseases, particularly those that emerged after the advent of agriculture. It highlights that many of these diseases originated from animal hosts and evolved to infect humans through a series of stages. The study identifies five stages in the evolutionary transformation of an animal pathogen into a human-specific pathogen. The research emphasizes the importance of understanding these origins to develop strategies for disease prevention and control. The study compares the origins of tropical and temperate diseases, noting that tropical diseases are more likely to have animal reservoirs, while temperate diseases often have human-to-human transmission. It also discusses the role of agriculture in the emergence of these diseases, as it led to the domestication of animals and increased human population density, creating conditions for pathogen transmission. The article proposes an "origins initiative" to trace the origins of major diseases and establish a global early warning system to monitor pathogens that could potentially infect humans. This initiative would involve systematic sampling and phylogeographic analysis of related pathogens in diverse animal species, focusing on those with potential contact with humans. The study also addresses the differences in the origins of temperate and tropical diseases, noting that temperate diseases are more likely to have human-to-human transmission, while tropical diseases often have animal reservoirs. The research highlights the importance of understanding these differences to better predict and prevent future disease outbreaks. The article concludes by emphasizing the need for further research into the origins of infectious diseases and the importance of monitoring pathogens that could emerge from animals to humans. It calls for a global effort to track and understand these pathogens to improve public health and prevent future disease outbreaks.The article explores the origins of major human infectious diseases, particularly those that emerged after the advent of agriculture. It highlights that many of these diseases originated from animal hosts and evolved to infect humans through a series of stages. The study identifies five stages in the evolutionary transformation of an animal pathogen into a human-specific pathogen. The research emphasizes the importance of understanding these origins to develop strategies for disease prevention and control. The study compares the origins of tropical and temperate diseases, noting that tropical diseases are more likely to have animal reservoirs, while temperate diseases often have human-to-human transmission. It also discusses the role of agriculture in the emergence of these diseases, as it led to the domestication of animals and increased human population density, creating conditions for pathogen transmission. The article proposes an "origins initiative" to trace the origins of major diseases and establish a global early warning system to monitor pathogens that could potentially infect humans. This initiative would involve systematic sampling and phylogeographic analysis of related pathogens in diverse animal species, focusing on those with potential contact with humans. The study also addresses the differences in the origins of temperate and tropical diseases, noting that temperate diseases are more likely to have human-to-human transmission, while tropical diseases often have animal reservoirs. The research highlights the importance of understanding these differences to better predict and prevent future disease outbreaks. The article concludes by emphasizing the need for further research into the origins of infectious diseases and the importance of monitoring pathogens that could emerge from animals to humans. It calls for a global effort to track and understand these pathogens to improve public health and prevent future disease outbreaks.