I recently finished Togetherness: Symbiosis and the Hidden Story of Life’s Greatest Collaborations by Rowan Hooper, and found the book fascinating and a wonderful deep dive into the importance of symbiosis in the natural world, not just for individual species that are involved in partnerships, but for life itself on this planet.

Hooper’s central aim in Togetherness seems to be to challenge the view that competition is the primary driver of evolution—a perspective often associated with capitalism and the phrase “survival of the fittest.” Hooper suggests that Darwin emphasized this idea partly to make his book more marketable. In Hooper’s account, the idea has since been embraced too enthusiastically, contributing to an overemphasis on competition and individuality in science, politics, and finance. The book instead presents symbiosis and cooperation as common features of life, not exceptions.

Part I explores symbiotic relationships around the world and shows how species can co-evolve toward dependence on one another. Hooper begins with figs and wasps in Brazil. Across the regions where figs grow, fig species have evolved relationships with wasps specific to those regions. He describes how both partners have become dependent on one another for reproduction.

Hooper also describes oak-associated fungi in Britain. These mycorrhizal partners help oaks obtain water and nutrients. The relationship beween oaks and their fungal parters are described as the “wood wide web” discussed elsewhere, most notably in Suzanne Simard’s research on trees in Canada.

In the chapter on coral, Hooper describes the relationship between corals and their algal partners. Corals are cnidarian animals that live in colonies, and photosynthetic algae living in their cells produce energy for them. Hooper discusses how rising ocean temperatures can cause corals to expel their algal partners—a process known as coral bleaching—leaving them without this source of energy. He returns to human impacts, including climate change and pollution, in greater detail in Part III.

The book also includes a chapter on lichens, an essential subject for any book about symbiosis. Lichens are complex partnerships that often involve several organisms, including fungi, algae, and cyanobacteria. They play important ecological roles in extreme environments: they can colonize bare rock and help weather stone into proto-soil for terrestrial plants. Lichens also challenge a narrow reading of “survival of the fittest,” showing the importance of cooperation and interdependence among species.

In Part II, Hooper traces the history of ecology and the development of symbiosis as a theory. He discusses Lynn Margulis’ theory of symbiogenesis, which proposes that complex eukaryotic cells evolved through the cooperative merger of free-living prokaryotic cells. He points to mitochondria, which he describes as oxygen-using alpha-proteobacteria, and chloroplasts, which are photosynthetic cyanobacteria. Margulis published this theory in a 1967 paper that was met with criticism at the time and became more widely accepted in later decades.

Hooper also emphasizes how much cooperation underlies human life. He notes that much of our DNA comes from bacteria and that humans have been in relationship with bacteria over a very long timescale.

In Part III, Hooper considers the balance in nature and how human activity threatens it. Climate change is one significant impact he discusses, with coral bleaching as one example.

He also describes the symbiosis between nitrogen-fixing legumes and rhizobia bacteria to illustrate how human activity is affecting essential symbiotic partnerships. Legumes form nodules that house the bacteria and supply them with nutrients; the bacteria fix nitrogen from the air and make it available to plants and soil. This relationship is foundational to agriculture. Applying chemical nitrogen fertilizer can have many harmful effects, including nutrient runoff that contaminates waterways and contributes to algal blooms and dead zones, groundwater contamination, air pollution, and climate change. But beyond these environmental effects, Hooper also considers how added nitrogen can affect the legume–rhizobia relationship: when nitrogen is readily available in the soil, plants have less need to invest energy in nourishing their bacterial partners and take the easier path, neglecting or abandoning their partnership.

Taken together, these examples support Hooper’s central case: life is shaped not only by competition, but also by cooperation and interdependence. The book connects that evolutionary perspective to present-day ecological pressures, asking readers to consider how human activity can disrupt relationships on which living systems depend.

A couple of final notes – I listened to the Audible audiobook, and this book was narrated by the author himself. It was a delightful listen and I certainly recommend. However, this is a book that I want to go back through and so will be adding a hard copy to my collection as well.

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Table of Contents

Part I: Partners for Life

1. Figs: Wasps and the Forbidden Fruit
2. Lichens: The poor trash that formed the world
3. Orchids: Close and more close their writhing limbs surround
4. Ants: History’s first farmers
5. Fungi: The world turned upside down
6. Corals: The end of the individual

Part II: The Bridge Between Worlds

7. A woman, a computer, and the Garden of Eden
8. A neighbor from another world
9. The symbiotic origin of life
10. Digital ecology
11. The roots of ecology
12. The Flowering of the biosphere
13. In which we find we are all from Asgard
14. From slime to eternity
15. The path to holistic Darwinism

Part III: Casting the Spell

16. The industrial food complex
17. Upsetting the balance
18. Engineering superpowers
19. Planetary restoration
20. The world bank of carbon
21. Rewilding the human
22. Our symbiotic future

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