Israeli study finds ecosystems can collapse, just like coalitions

An Israeli study recently found evidence of an old theory: in nature, ecosystems either have few species with strong bonds or many species with weak bonds – just like in government coalitions.

Researchers from Israel’s Bar-Ilan University calculated the level of connectivity in the ecosystems of bacterial communities to better understand how to preserve human health and the environment. 

For comparison, government coalitions often dissolve when too many parties disagree on too many issues. Even if a coalition seems stable, a small crisis can cause a chain reaction that eventually causes the system to collapse. 

The same rings true in ecosystems, particularly bacterial ones, according to the study published in the Nature Ecology and Evolution journal.

In an ecosystem, different species can have a negative effect on one another. The cheetah, for example, preys on the zebra, and trees in the jungle compete with one another for sunlight.

Conversely, species can also affect one another positively, like when bees pollinate flowers.

In the 1970s, biologist Robert May theorized that an ecosystem can become unstable and collapse if it has too many species. He also proposed that small ecosystems in nature are characterized by strong bonds, while large systems have weak ones.

The latest study, headed by Yogev Yonatan and Guy Amit from the research group of Dr. Amir Bashan, demonstrated the first evidence of May’s theory in microbial ecosystems.

According to the researchers, the microbiome is of great importance to one's health – such as digestion and absorption of nutrients and training of the immune system. Outside the human body, bacteria play a vital role in creating the living conditions of larger organisms.