August 2021

There is a lot in the media these days about how protecting biodiversity reduces the risk of zoonotic disease spillover, and hence the risk of epidemics and pandemics. There seems to be a lot of good evidence for this in published studies on the topic, but how universal is such a conclusion? What is the science behind it? What about context? Are there exceptions to the rule?
Dan Salkeld is a disease ecologist, and professor at Colorado State University. He has been addressing this topic in the literature for years, and shares some of his conclusions with us. We also talk a little more broadly about the trend, in the literature, towards making generic causal links, when the sum of the data show correlations of varying strength, and include exceptions.
Resources:
Ecological Fallacy and Aggregated Data: A Case Study of Fried Chicken Restaurants, Obesity and Lyme Disease - A 2020 paper by Dan, and Michael Antolin, about how easily correlations can be drawn from data
Conservation of biodiversity as a strategy for improving human health and well-being - A 2017 paper by Dan and colleagues summarizing current knowledge on biodiversity–zoonotic disease relationships and outlining a research plan to address the gaps in our understanding
Interacting effects of land use and climate on rodent-borne pathogens in central Kenya - A 2017 paper to which Dan contributed, which expresses the complexity of the roles of different drivers of spillover risk
Public health perspective on patterns of biodiversity and zoonotic disease - A 2015 letter to PNAS in which Dan responds to an article by Civitello et al. (2015), and warns against hasty conclusions
Biodiversity inhibits parasites: Broad evidence for the dilution effect - The article in PNAS to which Dan responded
Parasite biodiversity faces extinction and redistribution in a changing climate - A paper I mentioned in the discussion, about how parasite diversity is expected to decrease more than the diversity of hosts, if habitat changes as a result of climate change.