All organisms in an ecosystem are interconnected, and any imbalance in this complex relationship can have irreversible consequences for both humans and nonhumans. Numerous examples illustrate how the destruction of one species can lead to unforeseen and devastating impacts on others.

“Biodiversity and ecosystem functioning do matter to human beings. … And it’s not always the charismatic and fuzzy species,” said Eyal Frank, an environmental scientist and economist at the University of Chicago, in a New York Times interview in July 2024. Frank is one of the authors of the study “The Social Costs of Keystone Species Collapse: Evidence from the Decline of Vultures in India,” published in the American Economic Review in October 2024.

Various studies have shown how this lack of natural harmony has affected biodiversity and human health. For instance, the loss of trees in the United States due to the invasive emerald ash borer increased human deaths related to cardiovascular and respiratory illnesses, according to a 2013 article in the American Journal of Preventive Medicine. The study, conducted in 15 U.S. states from 1990 to 2007, examined the effects of this imbalance on biodiversity and human health.