Sweet in Tooth and Claw by Kristen Ohlson review - The author reveals a beautiful and complex picture of how the world natural world is interconnected

Tennyson's famous line "Tho' Nature red in tooth and claw' from In Memoriam A.H.H, which pits God against Nature - to simplify the profound exploration of grief at the centre of the poem - fits well with the widespread notion of evolution being based primarily on competition. (The poem was written about a decade before On the Origin of Species.) Sweet in Tooth and Claw examines how the fittest also means those biological entities most able to cooperate with members of other species, as well as their own.

Ohlson examines the way plants and fungus cooperate to ensure that both survive. The vast underground network of "fungus roots" in forests goes further than this, allowing different species of tree to share carbon fuel. For example, "when the birch had no leaves and could not photosynthesise, some of the growing fir's carbon flowed to the birch". It isn't clear whether the fungus or the tree calls for this action, but it happens.

The author goes on to detail how agricultural practices that minimise disturbance of the soil allow for the development of seeds suited for specific areas, and those which don't rely on the mass application of insecticide and artificial fertiliser, may result in greater productivity. In other words, using the way that plants, fungus, bacteria and insects work together, rather than seeking to eliminate diversity, makes sense.

It is fascinating to read that the carcasses of salmon, discarded by fussy bears during the glut caused by the fishes' migration to spawn, have a profound effect on forests even some distance from streams. The feast of nitrogen is transported deeper into the forests by "mycorrhizal connections", causing a "salmon shadow". Disrupting the migration of salmon has consequences not only for that species and the carnivores who eat them, but for the forest itself.

The chapter "We Need Better Metaphors" deals with the way that evolution has often been talked about in terms of fighting and even a "gladiators' show" (Thomas Huxley). Alongside the many modern scientists mentioned throughout Sweet in Tooth and Claw, such as ecologist Suzanne Simard, a most interesting thinker she mentions is Peter Kropotkin, better known for his anarchist writings than those on evolution. In 1902, he wrote a book called Mutual Aid: A Factor of Evolution. Kropotkin was focusing on aid within species, rather than between different species, but it is interesting to trace the way economic and social factors enter the discourse of science, a bit like those pesky interconnecting fungi.

One of the welcome photographs shows a pod of whales working together to catch fish; Kropotkin's book asked the question, "Who are the fittest: those who are continually at war with each other, or those who support each other?" It's hard not to think of climate change in the light of this quotation. Richard Dawkins's 1976 book The Selfish Gene used a different set of metaphors; we are "robot vehicles blindly programmed to preserve the selfish molecules known as genes", which is, as anthropologist David Graeber notes, "bleak". To this reviewer, the Dawkins quote also sounds like a weird hymn to capitalism.

Speaking of metaphor, the title of the book, Sweet in Tooth and Claw, is certainly distinctive, but whether "sweet" is quite the right word is open to debate. It seems a little bland when put beside the complex relationships the author describes. However, "Cooperative in Tooth and Claw" sounds terrible, and would lose the easy connection to the well-known Tennyson phrase.

The section of the book "We Are Ecosystems" deals with the way each of us is "hosting a whirl of organisms busily interacting with us and with each other in a complex web of connection". Just thinking about the fact that "even our microbiota have a microbiota" can bring on a state like vertigo. Ohlson also gives yet another reason why having a dog is good for us. Dogs' tendency to "pad and shed some of...wilder nature back inside..." has a positive effect on the microbes we need to be healthy.

The author examines the way cities can incorporate green spaces, not only for aesthetic reasons, but also to ensure diversity of species in even the most urban of environments. Singapore is cited as a success here. American researchers have also examined disparities as to "who has access to nature and who is invited into the ranks of science".

This is a great book for the non-scientist interested in how we humans live, how we produce our food, and our relationship with the rest of the natural world, from forests to coral to the microbiota of our guts. Clear and entertaining, Kristin Ohslon bridges the wide gap between current researchers and the curious.