New perspectives on evolutionary medicine: the relevance of microevolution for human health and disease

Abstract

Evolutionary medicine (EM) is a growing field focusing on the evolutionary basis of human diseases and their changes through time. To date, the majority of EM studies have used pure theories of hominin macroevolution to explain the present-day state of human health. Here, we propose a different approach by addressing more empirical and health-oriented research concerning past, current and future microevolutionary changes of human structure, functions and pathologies. Studying generation-to-generation changes of human morphology that occurred in historical times, and still occur in present-day populations under the forces of evolution, helps to explain medical conditions and warns clinicians that their current practices may influence future humans. Also, analyzing historic tissue specimens such as mummies is crucial in order to address the molecular evolution of pathogens, of the human genome, and their coadaptations.

An Evolutionary Medicine Approach to Understanding Factors That Contribute to Chronic Obstructive Pulmonary Disease

“…If the young individuals in the Stone Age had inhaled biomass smoke from fires and developed COPD in their early life, genetic predispositions to COPD would have been under strong negative selection pressure (fig. 2) [27]. Exertional dyspnea would have caused a decrease in physical activity, reducing the ability to survive circumstances, such as hunting and wars, thereby reducing the chances of reproduction.…”

“…d x = A fraction of dying people of age x; S x = reproductive value of a person of age x (for example, S65 = 0, while S15 = 1). This figure illustrates that in the Stone Age there was a very significant opportunity for the process of natural selection because of high levels of differential mortality that allowed less than half of the individuals born to pass on their genes to the next generation, eliminating the other half [27]. …”

“…Biological state index (Ibs) values over the past 15,000 years of human evolution (adapted from Ruhli and Henneberg [27]). The index value is a probability that an average person will be able to fully participate in reproduction of the next generation.…”

Evolutionary medicine – the quest for a better understanding of health, disease and prevention

“…In a similar vein, yet from a translational research perspective, Crispel et al describe in a rat model how the age at weaning from lactation regulates life history, growth, body composition and maturational tempo [19]. Rühli and Henneberg highlight the fact that humans continue to evolve and that microevolutionary changes can be observed over a few generations, including changes that are brought about by improved medical care [20]. …”

Evolution of prevention: Epidemiological transitions, evolutionary medicine, and clinical practice

“…The value of its discoveries for clinical medicine and medical research has been increasingly recognized (Alcock, 2012;Rühli and Henneberg, 2013). The field has revealed that humans are continuing to evolve in response to their environments and to shifts in the burden of disease over time.…”