News | 02 November 2021

When we learned that competition was not the only driver of evolution

Share

It was the American biologist Lynn Margulis who, in the middle of the 20th century, placed cooperation and, in particular, symbiosis, in a privileged place amongst the mechanisms that enable evolution.

That of coral and clownfish is one of the best known examples of symbiosis in the sea / annaroik.org
That of coral and clownfish is one of the best known examples of symbiosis in the sea / annaroik.org

At the end of the 19th century, the idea that competition and the law of the strongest were the main drivers of evolution began to take hold. In the mid-20th century, with the discovery of the structure and functioning of DNA, random genetic mutations complemented Darwin's theory of natural selection to explain how species evolve. However, in the 1960s, American biologist Lynn Margulis shook up these theories.

In particular, Margulis incorporated symbiosis as an evolutionary force by developing another theory, that of serial endosymbiosis or symbiogenesis, which had already been proposed a century ago by some voices without much success. This theory took up Darwin's natural selection and defended that cooperation and association also allow life to make evolutionary leaps. Most of Margulis' postulates proved to be true at the end of the 1970s, but the theory of endosymbiosis is still largely unknown to most people.

A groundbreaking concept

The idea that evolution does not only involve competition, but that cooperation is also an evolutionary force, was then, and still is now, groundbreaking, and serves as an inspiration to rethink social values and models, placing cooperation as the central driver of change and improvement.

While developing the theory of serial endosymbiosis, Lynn Margulis demonstrated that the origin of eukaryotic cells -that is, those of animals, plants, fungi, protozoa and algae- occurred through the association of bacteria of different types that, together, generated more complex forms of life.

The biologist explained that a sulfur- and heat-loving bacterium merged with another bacterium that could swim. Then another oxygen-breathing bacterium joined them, and finally, they all merged with photosynthesizing bacteria. This fusion of four types of bacteria generated an evolutionary leap since they could do together what they could not separately.

The foundations of Lynn's contribution to the theory of evolution appeared in 1967 with the publication of a research work conducted at the University of Chicago that revealed that eukaryotic cells also have DNA outside the nucleus and that it is a different DNA. This discovery already pointed to symbiosis between bacteria that at some point began to live together.

Symbiosis and the human species

Possibly, at present, the most well-known form of mutualistic or positive symbiosis is found in the human species: the close cooperation we have with millions of microbes that inhabit our body, whether in the stomach, in the mouth or on the skin, and that carry out tasks essential to our health.

The key role of symbiosis with microbes in ensuring the proper functioning of the vast majority of living beings invites us to think that, more than an individual, each of us is a community, an ecosystem that works and self-regulates like other systems as complex as the Earth itself. For this reason, Lynn's theory and work also contributed to the development of knowledge about the functioning of the planet we live on.

Cooperation and resilience

At ICM we are very interested in this idea since we also understand the ocean as a complex and self-regulating system that some expert has referred to as the Earth's 'circulatory system'. Over the last few decades, this ecosystem has come under pressure from human activity and, on many occasions, has recovered resiliently, in part, thanks to the wealth of variants of symbiosis, interdependence, and cooperation that exist between the organisms in marine ecosystems.

The study of ecosystems inspires us towards the discovery and implementation of forms of cooperation such as co-creation, co-governance, cooperative or mutual aid, which provide solutions to the climate crisis and global change. Many experts assure that only in this way we will be resilient and capable enough to make the necessary evolutionary leaps to overcome the dynamics that are leading us to destabilize the system that keeps us alive.