'Stickiness' of rarity and the universal dance of dominance

Intriguingly, this principle is not confined to grand ecosystems like the Amazon but resonates across the spectrum of life, encompassing birds, fish, plankton, and more. Marten Scheffer, professor Aquatic Ecology, explains, "We show that a few percent of all species make up the majority of all biomass. This is true not only for the trees in the Amazon but also for the bacteria in our guts, the mushrooms in the forest, birds, fish, plankton, you name it."

The research challenges conventional wisdom, debunking the notion that the remaining 95 percent of species, though very rare, are redundant. These rare species can step in and take over the functions of dominant species. The study unveils a dynamic ecosystem where rarity is not synonymous with insignificance.

Universal principles and the 'stickiness' of rarity

Beyond mere observation, the study delves into the mathematics behind this unequal distribution. The scientists introduce the concept of the 'stickiness' of rarity. This term is used to indicate that rarity, once achieved, is difficult to change. This is similar to how something can be 'sticky' and difficult to release.

It is difficult for species to escape rarity. This mathematically fundamental 'stickiness' is a universal principle that extends across ecosystems. Professor Scheffer explains: "On an abstract level, this 'stickiness' also applies to poverty. As we showed earlier, inequality in nature is mathematically similar to inequality in society, where a few percent of people also have most of the wealth."

Scheffer comments: “Our findings reveal a dance of dominance and rarity that spans from the microscopic to the majestic. The 'stickiness' of rarity is a fundamental force shaping our ecosystems and, surprisingly, mirrors societal inequalities. Understanding these universal principles opens doors to new perspectives on biodiversity and its role in our interconnected world."

More information

• Article A tiny fraction of all species forms most of nature: Rarity as a sticky state, published in the scientific journal PNAS.

Text: Wageningen University & Research
Photo: Jeff Krause, CC BY-NC-ND 2.0 DEED (lead photo: snowy-headed robin-chat)