History of smallpox centuries, the WHO certified the global eradication of smallpox in December 1979. Smallpox is one of two infectious diseases to have been eradicated, the other being rinderpest, which was declared eradicated in 2011. It has been suggested that smallpox was a major component of the Plague of Athens that occurred in 430 BCE, during the Peloponnesian Wars, and was described by Thucydides. Galen's description of the Antonine Plague, which swept through the Roman Empire in 165–180, indicates that it was probably caused by smallpox. Returning soldiers brought the disease home with them to Syria and Italy, where it raged for
Human extinction genetic exchange between human populations will continue, it is highly unlikely that humans will split into multiple species through natural evolution. Some scenarios envision that humans could use genetic engineering or technological modifications to split into normal humans and a new species – posthumans. Such a species could be fundamentally different from any previous life form on Earth, e.g. by merging humans with technological systems. Such scenarios do harbor a risk of the extinction of the "old" human species by means of the new, posthuman entity. Humans are doing so well that there's no more survival of the fittest. This