GILLIAN BURKE
“Life thrives on alliances and partnerships”
It’s not fair!” Back in the day, that was the standard protest and cry of frustration when I wasn’t allowed to do something my older brother was allowed to do. In return, all my Dad would offer was “No black man is fair” as he casually walked away, clearly quite pleased with himself for having left me bewildered and out of words. It took a while for the penny to drop but I realised this was his very own Dad joke (as in to be fair-skinned). I can laugh now, mainly because I miss him, but four decades on I still can’t shake off that ‘it’s not fair’ feeling.
The world just doesn’t seem fair, does it? It’s tempting to give in to the idea that unfairness is the very nature of life itself. If viewed through the lens of competition, ‘selfish genes’ and survival of the fittest, it’s hard to disagree. Life is harsh. But, at least in some quarters, this worldview is getting a little pushback.
In the East African savannah, ol-kine lo luia, the iconic whistling thorn trees, are guarded by tiny acacia ants. Browsing giraffes and even elephants stand no chance against these swarming and biting insects. The trees in return offer food and shelter, housing the ants in swollen plant galls at the base of the thorns, while a sugary treat is delivered by specialised leaf glands.
More mutualistic partnerships, this time riding the backs of zebra and buffalo, appear in the shape of oxpeckers that feast on ticks and flies that would otherwise parasitise these grazing herbivores. The mammalian hosts are grateful even when, on occasion, the birds take it a little too far and peck open wounds to drink blood.
So oxpeckers might be letting the side down a bit, but there are still plenty of examples of mutualism, where a charming and happy deal is struck not just between species, but even between entire groups of organisms. Insects and flowering plants have been locked in a co-evolutionary embrace that spans geological time. The adaptive force behind the dazzling variety of form, colour and scent of insect-pollinated flowers is the need to attract the unwitting flying vectors that move pollen from flower to flower. For their efforts, the insects are richly rewarded with nectar.
Alliances can reach right across kingdoms to produce partnerships greater than the sum of their parts. Lichens, the exemplars of low-key beauty, are the perfect marriage between the plant and fungal kingdoms. The algal-fungal union has created this group of organisms that are able to eke out a living in some of most inhospitable places on earth – bare rock and bone if need be.
It seems everywhere we look complex partnerships are being revealed. Our own bodies play host to ‘friendly bacteria’, which are vital to our health. It turns out these microbial partnerships are found in almost every niche on earth – even within the humble barnacle. The host-microbiome relationship can be so entangled that it’s hard to discern where one species ends and another begins.
I was raised on the standard issue image of the evolutionary tree of life, with a single trunk branching out to give rise to new and evermore complex life forms, but we are now being invited to reimagine this tree as one where partnerships and mutualism cause the branches to meet again, and eventually fuse.
This notion of life thriving on alliances and partnerships is deeply appealing to me. I might be clutching at straws but I’m hanging on to the idea that life is as much, if not more, about cooperation and partnerships as competition. I’d like to think of it as nature’s cue that a fairer world is possible.
Gillian will be back next month with more thoughts on our natural world