Israeli study finds ecosystems can collapse, just like coalitions

Researchers study connectivity in ecosystems to better understand human health and the environment

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

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

By comparison, governing 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.

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The same is true in ecosystems, particularly bacteria, according to the study published in the Nature ecology and evolution log.

In an ecosystem, different species can have a negative effect on each other. The cheetah, for example, preys on zebras, and jungle trees compete for sunlight.

Conversely, species can also influence each other positively, as when bees pollinate flowers.

JACK GUEZ / AFPA bee collects honey from an orange blossom in the Israeli Mediterranean coastal city of Netanya on March 13, 2016.

In the 1970s, biologist Robert May hypothesized 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 connections, while large systems have weak ones.

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

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