The Graham Lecture

The Royal Philosophical Society of Glasgow welcome Prof Dorothy H Crawford, Emeritus Professor of Medical Microbiology and Assistant Principal for Public Understanding of Medicine, University of Edinburgh.

Microbes have inhabited planet Earth for over 4 billion years and during this time they have adapted to occupy every available niche including the most inhospitable hot springs, deep ocean trenches, acid lakes and polar ice caps. In contrast modern man only evolved some 200,000 years ago and we are still learning to live in harmony with microbes; the invisible enemy.

By colonising our bodies microbes have profoundly influenced our evolution and by causing epidemics and pandemics they have helped to shape our history. But despite our detailed knowledge of their makeup, and an armament of weapons to fight them, microbes are still responsible for 14 million deaths a year. And presently they are emerging at an increasing rate.

In this talk I will explore the links between the emergence of microbes and the cultural evolution of the human race. I will contrast the infectious diseases suffered by our hunter gatherer, farmer and city-dwelling ancestors as man’s lifestyle has changed through the ages, and show how microbes have exploited every opportunity to infect and reproduce, thereby ensuring their own future. Finally we will take a look at modern times with our present problems, and I will pose the question: are we better off today than our ancient ancestors were?