IT IS old news to say that life on Earth constitutes an intricate web of mutual relationships so crucial to each of its many partners that disruption to one can be catastrophic to others. This is the basic concept of ecology, and especially of (the ecology of communities of species living together).
Nevertheless, it is useful to be reminded that there is no place on Earth for which we know everything about all its inhabitant species 鈥� from its largest plants and animals to its microbes and viruses 鈥� and about the relationships that exist between them. Such an understanding of the whole biosphere, then, is beyond our reach.
We have discovered some remarkable synecological facts, however, such as the relationship between Africa鈥檚 whistling thorn tree and the fierce biting ant that lives upon it. In return for growing additional nesting sites and providing nectar, the ants defend the tree against grazing mammals by swarming to the attack when one approaches. Fieldworkers have found that if they simulate the extinction of grazing mammals, the ant-tree relationship ends 鈥� the trees terminate their now unnecessary contract with their bodyguards.
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Another remarkable mutuality, recently reported in 快猫短视频 (23 August, p 33), is that between domesticated dogs and humans. At the in July this year, discussion of canine psychology revealed that what we often dismiss as merely anthropomorphic attributions of human-like mental states to dogs 鈥� a sense of guilt, of fairness, a grasp of social complexities in relations with humans 鈥� might actually be accurate representations of what goes on in dog minds. The suggestion is that this is a canine evolutionary adaptation caused by 10,000 years of close human-dog cohabitation and selective breeding.
Whereas the ant-tree relationship is by now the kind of thing one expects to find in an ecosystem, the dog psychology suggestion is more fertile ground for speculation. Mutuality is a two-way street: has the evolution of humans been influenced psychologically and physically by their relationship with dogs? Humans have relations of various closeness with a number of other animals, such as cats, horses and cattle 鈥� what are the evolutionary reciprocities there? For millennia, humans and domesticated animals have shared the same habitations, breathed each other鈥檚 breath all night long, exchanged viruses and bacteria 鈥� influenza is an annual gift to humankind from China鈥檚 pigs 鈥� and eaten each other鈥檚 body products in different forms (we their flesh, they our excrement: this latter a delicacy for pigs, for instance).
The net might be cast wider. Humans are what they are in important part because of the vegetation and climate of the last few hundred thousand years. A glance at the landscape of Europe, for example, shows how hugely and quickly humans have transformed its ecology, and by extension their own place in its synecology. We are discovering how unsustainable this is 鈥� for humans. Nature itself does not lack such robustness.
The planet bears the scars of past catastrophes that annihilated many species, reshaped the land and changed its vegetation 鈥� but life adapts, continues, and flourishes: it is not life itself that fails, only particular versions of it. Humans are busy endangering themselves and many other species in their suicidal plunge, but life itself has all the time in the world, and it will reassert itself in new forms when it is ready.
鈥淟ife itself has all the time in the world, and will assert itself in new forms鈥�
This contrast, between the fragility of aspects of the present and the robustness of life overall, is a hopeful one. But if we value any present life forms, ourselves included, perhaps we need to study synecology more carefully: those unexpected mutual relationships might offer some survival tips.