Integrated Environmental Assessment and Management — Volume 8, Number 2—pp. 379–388 ß 2012 SETAC 379

Learned Discourses: Timely Scientific Opinions Timely Scientific Opinions In a Nutshell...

Intent. The intent of Learned Discourses is to provide a forum for open Ecotoxicology discussion. These articles reflect the professional opinions of the authors Evolution of the toxic response: How might ecotoxicology regarding scientific issues. They do not represent SETAC positions or benefit by considering evolution?, by Emily Monosson. policies. And, although they are subject to editorial review for clarity, Ecotoxicology will benefit by embracing both evolutionary consistency, and brevity, these articles are not peer reviewed. The Learned principles and the evolutionary histories of life’s defensive Discourses date from 1996 in the North America SETAC News and, systems. when that publication was replaced by the SETAC Globe, continued Debate there through 2005. The continued success of Learned Discourses depends Opinions Scientific Timely Discourses: Learned on our contributors. We encourage timely submissions that will inform and Response to Huebert et al. ‘‘Canada’s environmental effects stimulate discussion. We expect that many of the articles will address monitoring program: Areas for improvement’’ (IEAM 7:143–144), controversial topics, and promise to give dissenting opinions a chance to by Thijs Bosker, Timothy J Barrett, and Kelly R Munkittrick. be heard. The authors respond to 2 of the 3 areas recommended for Rules. All submissions must be succinct: no longer than 1000 words, improvement: pseudoreplication; and designation of alpha (a). no more than 6 references, and at most one table or figure. Reference Rebuttal to the response of Bosker et al. (2012) to ‘‘Canada’s format must follow the journal requirement found on the Internet at environmental effects monitoring program: Areas for improve- http://www.setacjournals.org. Topics must fall within IEAM’s sphere of ment’’ (IEAM 7:143–144), by Dave Hueber. interest. Without improvements, there will be unnecessary and Submissions. All manuscripts should be sent via email as Word unjustifiable requirements for increasingly intensive and extensive attachments to Peter M Chapman ([email protected]). monitoring. Risk Assessment Population level risk assessments—Science or fiction?,by Magnus Wang. Population modeling can produce a much clearer picture of Learned Discourses Editor the predicted risk and the involved uncertainty than standard Peter M. Chapman risk assessments. Golder Associates Ltd. 500-4260 Still Creek Drive Global Climate Change Burnaby, BC V5C 6C6, Canada Understanding interactive effects of climate change and [email protected] toxicants: Importance of evolutionary processes, by David A Kimberly and Christopher J Salice. Understanding how and whether populations respond will be critical in developing effective management strategies. Social Responsibility Incorporating chemical footprint reporting into social respon- SETAC’s Learned Discourses appearing in the first 7 volumes of the sibility reporting, by Kristen Hitchcock, Julie Panko, and Paul Scott. SETAC Globe Newsletter (1999–2005) are available to members online Chemical footprint analysis could be used for brand pro- at http://communities.setac.net. Members can log in with last name and tection, consumer education, and green marketing purposes. SETAC member number to access the Learned Discourse Archive. DOI: 10.1002/ieam.1300

Toxicology is a science with deep evolutionary roots. Yet EVOLUTION OF THE TOXIC RESPONSE: many toxicologists seldom pause to consider the evolutionary HOW MIGHT ECOTOXICOLOGY BENEFIT BY 1 origins of the responses they study. Evolution is both CONSIDERING EVOLUTION? accepted as the ‘‘organizing principle in all levels of life’’ Emily Monosson* and is taken for granted (Bull and Wichman 1998). More Montague, MA, USA recently, many fields from agriculture to conservation to *[email protected] medicine have begun to embrace evolutionary principles DOI: 10.1002/ieam.1285 to guide their practices (Hendry et al. 2011). Evolutionary toxicology as defined by Bickham (2011) is ‘‘the study of the effects of chemical pollutants on the genetics of natural 1Adapted from Evolution in a Toxic World, by Emily Monosson. Copyright ß populations,’’ and is born out through observations of contemporary evolution and altered gene flow in wild popu- 2012 Emily Monosson. Reproduced by permission of Island Press, Washington, lations. Yet writes Bickham (2011), ‘‘The fact that pollutants DC, USA. have population genetic impacts, and thus influence evolu- 380 Integr Environ Assess Manag 8, 2012—PM Chapman, Editor

tionary processes, is not yet widely appreciated among fine tuning of all aspects of toxic defenses from absorption, to ecotoxicologists, and certainly less so by toxicologists.’’ excretion, detoxification, and storage. Placing this process in an Evolutionary toxicology exemplifies how the application of evolutionary context may help us better understand a species’ evolutionary principles can benefit applied toxicology and response to common and essential chemicals and to chemicals ecotoxicology in particular. I propose that, in addition, that resemble closely these compounds—nutritional or hormo- ecotoxicologists consider the evolutionary history of life’s nal mimics—as well as to chemicals that are new to life and chemical defensive systems. Bringing the long-term history of chemical mixtures. All of which may be useful as green chemists these systems and their evolution in response to naturally work to design hazards out of chemicals. occurring chemicals to light, can provide ecotoxicology with a Chemical testing and regulation have greatly improved deeper and broader foundation. over the years. However, the more problematic chemicals Medical science, for example, has begun to embrace are those that cause subtle impacts at low doses. Although evolution. As a result, rather than viewing the human body improved sensitivity of analytical chemistry alerts us to as the ‘‘optimally functioning’’ outcome of evolution and smaller and smaller concentrations of chemicals in biological disease as an abnormal failure, some diseases might be and environmental matrices, molecular genetics allows us to considered as ‘‘expected and true responses to novel environ- observe altered genetic expression as hundreds or thousands mental challenges and conditions that were not present fifty of genes and gene networks respond to small amounts of thousand years ago or even fifty years ago’’ (Robins and Evans chemicals. Ecotoxicologists, managers, and regulators are now 2009). Medical researchers are now asking questions such as: faced with interpreting this avalanche of data. Would a deeper has modern day reduction in parasite infestation and intestinal understanding of the nature of these systems, provided worms in large segments of human populations led to through an evolutionary perspective help us make sense of increases in asthma, autoimmune diseases, and allergies? today’s data, identify responsive nodes, or subtle yet key How useful are responses like cough, fever, and diarrhea, and interspecies differences in responsiveness? when do they become a threat rather than a benefit? What is Additionally, as observations of contemporary evolution in the relationship between the physiology of starvation and response to chemical contaminants become more frequent we obesity and diabetes? must consider one of the most insidious consequences of our How might considering evolutionary history help guide activities: causing genetic changes, possibly on a large scale. modern-day ecotoxicology in assessing an organism’s response As Bickham (2011) writes, ‘‘Of fundamental importance, it to chemical stressors? The evolutionary origins of defensive must be emphasized that these genetic impacts are emergent responses may provide perspective on the breadth and effects not necessarily predictable by study of contaminant capacity of life’s ability to handle potentially toxic naturally exposures or even the understanding of the mechanisms of occurring and toxic synthetic chemicals. Some defenses, such toxicity, even though contaminant exposure is the root cause as DNA repair and antioxidants, likely appeared at the dawn of the effects.’’ of life and have been conserved (in most species) for over 3 Toxicology, and thus ecotoxicology, is ripe for a revolution. billion years, whereas other stressor defenses are unique to As Hartung (2009) writes regarding toxicology, ‘‘There is eukaryotic life, and still other protective measures came into almost no other scientific field in which the core experimental play only after terrestrial plant and animals made landfall. protocols have remained nearly unchanged for more than We might consider, for example, changes in the selective forty years.’’ Toxicology is at a crossroads. There may be pressures shaping these systems and their modern day many routes forward, but it seems that the revolution taking counterparts, or differences across species in retention or place in toxicology and thus in ecotoxicology can only benefit ‘‘blossoming’’ of specific genes and gene families. Such studies by embracing both evolutionary principles and the evolu- might also provide greater insight into the evolvability of tionary histories of life’s defensive systems and networks. some systems, which, in turn, may assist ecotoxicologists interested in genotoxic effects, and contemporary evolution. REFERENCES Revelations of early ligands for specific receptors, and the Bickham JW. 2011. The four cornerstones of evolutionary toxicology. Ecotoxicology subsequent evolutionary history of those receptors, might 20:497–502. provide insight into why some receptors are more promiscu- Bull J, Wichman H. 1998. A revolution in evolution. Science 281:1959. ous than others, and which chemicals are more likely to Gerber L, Williams G, Gray S. 1999. The nutrient-toxin dosage continuum in human substitute for physiological ligands. evolution and modern health. Q Rev Biol 74:273–289. Looking through an evolutionary lens, ecotoxicologists Hartung T. 2009. Toxicology for the twenty-first century. Nature 460:208– might consider the impact of industrial chemicals on the 212. development of the toxic response in individuals and in Hendry A, Kinnison M, Heino M, Day T, Smith TB, Fitt G, Bergstrom C, Oakeshott J, populations. Are there examples of comparable periods (for Jørgensen P, Zalucki M, et al. 2011. Evolutionary principles and their practical example, natural yet sudden shifts in the chemical environ- application. Evol Appl 4:159–183. ment) in the evolutionary record, and can we trace life’s Robins N, Evans J. 2009. Why physicians must understand evolution. Curr Opin response through phylogenetic study? Might this help us Pediatr 21:699–702. identify responses or physiological systems that are either sensitive or resistant to such changes? A focus on evolutionary history may also provide insights into the networked nature of life’s response to toxicants. Would this in turn allow us to make better use of ‘omics approaches to toxicology? Considering evolution also helps us think about optimization. The process of natural selection optimized life’s response to naturally occurring chemicals (Gerber et al. 1999), which in turn required