Crowding and Disease Virulence

This Element is an excerpt from Germs, Genes, & Civilization: How Epidemics Shaped Who We Are Today (9780137019960) by David P. Clark. Available in print and digital formats.

Why it's wishful thinking to believe that diseases will eventually evolve into milder forms-and what the hard truth means for humanity.

Earlier thinking held that, given time, all diseases would adapt, to become no worse than measles. Virulent diseases were newcomers, not yet adapted to biological détente with their human hosts. This wishful thinking has obvious marketing appeal-but it ignores the ugly side of both evolution and human history.

David P. Clark is Professor in the Microbiology Department at Southern Illinois University. He has published 70+ articles in scientific journals and is author of several college textbooks, including Brock Biology of Microorganisms, now in its 12th edition; Molecular Biology Made Simple and Fun, now in its 3rd edition; Molecular Biology: Understanding the Genetic Revolution; and Biotechnology: Applying the Genetic Revolution. Clark earned his Ph.D. from Bristol University in 1977. His research has focused on antibiotic resistance and the genetics and regulation of bacterial fermentation.