The Interspecies Relationships that Evolved in Nature

BBC, February 14, 2024

Periphytons are formed from a cross-species coupling of algae and fungi, together with plant detritus, microbes and bacteria (Credit: Getty Images)

From bats and carnivorous plants to crocodiles and birds, nature is full of remarkable pairings that depend on each other to survive.

A green-brown spongy sludge congregates en masse across the surface of the Everglades' shallow marshes in southern Florida. At first glance, it may look like a harmful algal bloom that sucks oxygen from the water, suffocating the surrounding ecosystem and releasing toxins. But it is in fact a beautifully productive coupling of algae, fungi and a few other third, fourth and fifth wheels, such as plant detritus, microbes and bacteria.

This cluster of beings forms a perfectly matched relationship, known as a periphyton, and provides the cornerstone of the Everglades' highly biodiverse ecosystem explains Meenakshi Chabba, a scientist with the non-profit Florida's Everglades Foundation. "It's incredible because you have this community of organisms coming together and they form this matter which is the basis of the entire food chain here."

A periphyton is an example of mutualism; an unexpectedly close cross-species relationship. As with any relationship, mutualism involves various, complex types of codependency and benefits – yet it roughly breaks down into two types: species that are highly dependent on each other, known as obligate mutualism; and species that have a friends-with-benefits approach, known as facultative mutualism. This latter type gets something out of the relationship, but they'd survive without each other just fine.

In this sense, while periphyton's slimy mixing of algae and fungal matter perhaps isn't nature's most glamourous pairing, it has resulted in a symbiotic romance which has lasted for "probably hundreds of millions of years" says Chabba.

So as many of us dwell on the ingredients of a good relationship, we explore some other unusual – yet wildly successful – couples of the animal and plant kingdom that could give humanity some romantic inspiration.

Read full article: https://www.bbc.com/future/article/20240213-valentines-day-the-interspecies-relationships-that-evolved-in-nature?ocid=global_future_rss%5d