During a discussion over a meal the topic changed to cicadas. This has been a bumper year for them in the Blue Mountains. The ground is pockmarked with the holes from which they have emerged after 7 years of sap-sucking underground; the husks left after molting are scattered along the fences; they fly recklessly across the garden and the air is full of their sounds broadcast in looking for a mate. I have rescued dozens from being run over on the road, or tormented by our dog.

One participant in the lunch discussion, knowing the rigours of a cicada life cycle, asked: But what’s it all for? This has to be the main existential question – why is Nature what it is? Why are there millions of forms of life, large and small, each with its own way of propagating offspring and ensuring their survival. The answer lies in the process of evolution whereby organisms change to adapt to new environments and opportunities. Homo sapiens was no different, having evolved from earlier hominim species, which had ape-like ancestors. We are as much the product of evolution as cicadas. But this is the ‘how’ and not the answer to the ‘why’ in the question.

If you are religious, you can ascribe the whole process of evolution to a god – she or he created the diverse wonders of Nature, and who are we, mere mortals, to question why. But if a god created the present diversity of life on earth, why would she or he use the lengthy and often wasteful process of evolution to do so. Many more species have gone extinct over the previous millions of years than exist now. And even the religious still can’t answer the question – What is it all for?

The best answer we have is that it is what it is. We, the only fully aware species, can benefit from knowing and wondering at the many and diverse forms of plants and animals, accept that evolution has occurred, that the result is magnificent, and that we are also one result of the process. The inevitable and more important question then is: What are we for?