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Viruses were expected to be small, but the range of sizes came as a surprise. Some were only a little smaller than the smallest known bacteria, and the smaller viruses were of similar sizes to complex organic molecules. [14] In 1935, Wendell Stanley examined the tobacco mosaic virus and found it was mostly made of protein. [15]
In the 20th century many diseases both old and new were found to be caused by viruses. There were epidemics of poliomyelitis that were only controlled following the development of a vaccine in the 1950s. HIV is one of the most pathogenic new viruses to have emerged in centuries. Although scientific interest in them arose because of the diseases ...
Western Hemisphere populations were ravaged mostly by smallpox, but also typhus, measles, influenza, bubonic plague, cholera, malaria, tuberculosis, mumps, yellow fever, and pertussis. The lack of written records in many places and the destruction of many native societies by disease, war, and colonization make estimates uncertain.
The proteome of a virus, the viral proteome, still contains traces of ancient evolutionary history that can be studied today. The study of protein FSFs suggests the existence of ancient cellular lineages common to both cells and viruses before the appearance of the 'last universal cellular ancestor' that gave rise to modern cells.
Paleovirology is the study of viruses that existed in the past but are now extinct. In general, viruses cannot leave behind physical fossils, [1] therefore indirect evidence is used to reconstruct the past. For example, viruses can cause evolution of their hosts, and the signatures of that evolution can be found and interpreted in the present ...
The history of coronaviruses is an account of the discovery of the diseases caused by coronaviruses and the diseases they cause. It starts with the first report of a new type of upper-respiratory tract disease among chickens in the U.S. state of North Dakota, in 1931.
“The research is a breakthrough: it challenges our perceptions and understanding of ancient England, showing how pivotal migration is to who we are and for the first time allows us to explore ...
Epidemics of the 19th century were faced without the medical advances that made 20th-century epidemics much rarer and less lethal. Micro-organisms (viruses and bacteria) had been discovered in the 18th century, but it was not until the late 19th century that the experiments of Lazzaro Spallanzani and Louis Pasteur disproved spontaneous generation conclusively, allowing germ theory and Robert ...