Date on Master's Thesis/Doctoral Dissertation


Document Type

Doctoral Dissertation

Degree Name

Ph. D.



Committee Chair

Dugatkin, Lee Alan, 1962-

Author's Keywords

Chemical signals; Health status; Mate selection


Pheromones; Chemical senses; Mate selection


The objective of my dissertation research was to determine the role of chemical signals in conveying information regarding an individual's health status and suitability as a mate in humans and to examine the role that commensal microflora play in this system. Chemical signals in humans have been theorized to play a role in disassortative mating relative to the major histocompatibility complex (MHC) and in selection of mates based on fluctuating asymmetry. In addition, chemical signals have been shown to communicate health status in rodents. Commensal microflora are a necessary component of such chemical signaling systems since it is the microflora which ultimately create odor. Results from Chapter 2 and Chapter 3 revealed that, in humans, the axillary microflora are altered during periods of illness. Both a decrease in overall richness of microbes and an increased likelihood of possessing Micrococcus species during or following a period of illness was found. However, these alterations in axillary microflora were not found to result in an altered perception of the scent of men's body odor by women (Chapter 3). Results of Chapter 4 found that women in the follicular phase of their cycles prefer the scent of men's body odor whose axillary microflora is most dissimilar to their own. This finding has implications for mechanisms of MHCdisassortative mate selection through olfaction. Taken in total, this work provides evidence that health status can affect the composition of commensal microflora and furthermore that these commensal microflora may convey chemical signals which women could use in mate selection.