John Francois


 Ph. D. Candidate




Hormesis, the U-shaped dose response curve, was first described nearly 120 years ago. However, due to an unfortunate and erroneous association with homeopathy, hormesis is still struggling to prove itself as a valid biological hypothesis, even today. This, despite the fact that Calabrese and Baldwin (1997, 1999a, 1999b, 1999c, Calabrese 1999) have put together an impressive series of articles which clearly demonstrate that hormesis is an existing phenomenon.

    I propose a study which would allow to test the validity of Calabrese and Baldwin’s hypothesized mechanism (1999a), and to determine if stimulatory effects are truly an enhanced function rather than a trade-off within and among endpoints and in overall fitness, and what are the long-term effects of hormesis.

Using the annual invasive grass species Bromus rubens which will be treated with a series of varying doses of inhibitory compounds, I propose to determine the relative growth and growth rate of these plants compared to controls, with particular emphasis on doses around 100-fold and 100,000-fold below full dose. A delay in growth followed by growth exceeding that of the controls would provide reasonable evidence in support of the  suggested mechanism for hormesis. 


Calabrese EJ. 1999. Evidence That Hormesis Represents an “Overcompensation” Response to a Disruption in Homeostasis. Ecotoxicology and Environmental Safety 42: 135-137.

Calabrese EJ, Baldwin LA. 1997. A Quantitatively-Based Methodology for the Evaluation of Chemical Hormesis. Human and Ecological Risk Assessment 3: 545-554.

Calabrese EJ, Baldwin LA. 1999a. Reevaluation of the Fundamental Dose-Response Relationship. Bioscience 49: 725-732

Calabrese EJ, Baldwin LA. 1999b. The Marginalization of Hormesis. Toxicologic Pathology 27: 187-194.

Calabrese EJ, Baldwin LA. 1999c. Chemical Hormesis: Its Historical Foundations as a Biological Hypothesis. Toxicologic Pathology 27: 195-216.


two crabs on the beach (photo K. Plank)


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