HAVE you sat and watched ocean waves tumble to shore, each wave unique: its rise, its height, its break, the way it throws the light around …never exactly the same as the wave before. And waves have been breaking on earthly shores since shores first rose from the sea.
In the sea: that’s where life began, about 3.8 billion years ago, so “they” say, back when mere hints of land broke the waters’ surface. To this day, the oceans are spectacularly alive with the effusion of plants and animals that have evolved to inhabit them. The “bathypelagic” zone — the waters lying a kilometre or more below the surface — is still the world’s biggest biosphere.
In concert with the sun, the oceans also help to shape our climates and atmosphere, and drive global-scale processes that sustain life on that 28 per cent of the planet’s surface that has risen in long, slow contortions above sea level. If you could trace the history of a drop of water from your kitchen tap, you’d learn the history of the planet and every living thing on it… and no other known planet possesses anything like our oceans.
Have you sat and stared into the night sky? Our parents have. Our great grandparents did, and their great grandparents before them. People around the world have, for as long as there have been people. And, when you look at the star we call Rigel, you are seeing energy that, more than 800 years ago, was launched from a sun 60,000 times brighter than ours. On the other hand, the light from Proxima Centauri, our solar system’s nearest star neighbour, reaches us in a little over four years. On 19 March 2008, light visible to the naked eye reached Earth from an exploding star in a previously unknown galaxy 7.5 billion light years away.
As well as looking into a local corner of the Universe when we look at the stars, we are gazing into visions from the past. In fact, we are seeing many pasts and, in our still-expanding universe, the sources of all of those tiny points of light are speeding away from us and from each other.
People are peculiar too. We’re all members of a relatively new species — Homo sapiens sapiens (wise-wise guys) — that, until around 70 thousand years ago, was unique to Africa.
Before that — for our species’ first 180,000 or so years, or about three fifths of human existence — Africa was our shared homeland. Then people started adventuring out into the rest of the world in a succession of migrations, following coastlines for the most part where food was most to hand and fusing their bloodlines with those of other waves of migration, including Neanderthals.
When, as a child in New Zealand, I snacked on raw shellfish pulled from the sand or knocked like ripe berries from a rock, it just seemed “normal”. I did it without a thought that those same creatures had for so long fed my ancient ancestors.
When we have what we need, we take a lot for granted. We’re here, it seems, because we’re here because we’re here…
