Precision medicine solves extinction from biodiversity collapse.

The time has come to develop and advance a new subdiscipline, precision ecotoxicology, if we are to address the biodiversity crisis. Advancing precision ecotoxicology, which includes comparative ecotoxicokinetics and ecotoxicodynamics from the laboratory and the field, is necessary to engage biodiversity loss because species, and even down to individual organisms for threatened and endangered species, represent the key environmental management or protection goal. For other taxa, the population level of biological organization is commonly identified as the protection goal during prospective and retrospective chemical assessments. However, mechanistic understanding from molecular initiation events to adverse outcomes at the individual level is critical to fully understand chemical, physical, and biological threats and to protect biodiversity. For biodiversity hot spots experiencing significant environmental stress, protection goals associated with chemicals and waste management may need to be modified to also protect the individual, if we are to reduce the impacts of pollution on biodiversity. Precision ecotoxicology will inherently leverage advances in mechanistic, computational, and evolutionary ecotoxicology, molecular ecology and systematics, and precision medicine and environmental health science. Precision medicine, which is sometimes called personalized medicine, aims to define genetic differences within and among individuals, in combination with environmental and social factors, leading to diseases, in an effort to tailor interventions accordingly to specific people. In contrast to traditional approaches in medicine, it is advancing diagnosis, treatment, and prevention of diseases for the individual patient. Researchers are similarly advancing precision environmental health science, which similarly aims to understand underlying individual level susceptibilities to environmental exposures that elicit adverse human health outcomes. Precision medicine and environmental health science have leveraged completion of the human genome in 2003, and subsequent advances in pharmaco- and toxicogenomics. Such precision health efforts are important to environmental management of chemicals and waste because the individual level of biological organization represents the key protection goal during human health risk assessment, a practice that is thus analogous to protection goals for threatened and endangered species. Since completion of the human genome, genomes of thousands of other species have been assembled, and many more have been sequenced as costs of sequencing and annotation have precipitously decreased along with increased workforce capacity and throughput in bioinformatics. Such information is already supporting cross species extrapolation approaches (https://www.epa.gov/chemical-research/sequence-alignment-predict-across-species-susceptibility; http://ecodrug.org/), which are increasingly important for assessing and managing chemicals and waste. Precision ecotoxicology promises reciprocal benefits to human health as development of non-animal alternatives, alternative animal models (i.e., zebrafish), adverse outcome pathways, high-throughput chemical screening, and other new approach methodologies are progressing. This progress is necessary, in part, due to the U.S. Environmental Protection Agency’s recent decision to eliminate mammalian studies by 2035 (https://www.epa.gov/newsreleases/administrator-wheeler-signs-memo-reduce-animal-testing-awards-425-million-advance). In addition, when coupled with diverse green chemistry and engineering efforts, precision ecotoxicology will support innovation, including sustainable molecular design of less hazardous chemicals and technologies. But as precision ecotoxicology is developed to understand individual and subpopulation susceptibilities within a species, we need to continue to connect mechanistic pursuits to the population level of biological organization. In fact, precision ecotoxicology promises to advance an understanding of the often variable population level responses to chemical, physical, and biological stressors.