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One afternoon recently, I was sitting in the upstairs lounge, watching the clouds slowly drift westward over Loch Sunart. They crept across the sky, swallowing ever-shrinking patches of blue, darkening the landscape as they went. As the world outside dimmed, something bright caught my eye — a flash of yellow on a solitary boulder in the grass, just above the high tide line. Could it be treasure? Intrigued, I headed down to the shore. Once there, I ran my fingers across the splash of colour. Not gold, but lichen – a living mosaic of yellows and oranges, glowing against the greying world around it. Something that I was to later learn has long prepared our planet for life.  Sunburst Rock - Loch Sunart, Resipole, Sunart Intrigued by the vivid bursts of colour clinging to the rock, I was curious to know more. So, with a little research, I discovered the lichen is called maritime sunburst – a name so perfect it felt as if the lichen itself had chosen it. Even beneath the deepening grey of the sky, it seemed to shout, bold and defiant, “IT’S STILL SUMMER”. I learnt that this lichen, like all lichens, is a remarkable partnership between two very different organisms: fungi and algae. They live together in close cooperation. The fungi provide the algae with protection, moisture, and, in the case of maritime sunburst lichen, even a kind of sunscreen. This sunscreen is what gives the lichen its bright golden colour. Tucked safely within the fungi, the algae use sunlight to make sugars through photosynthesis. These sugars then feed the fungi in return. This partnership is incredibly ancient, with the oldest known lichen dating back around four hundred million years. Even more remarkably, it hasn’t happened just once. It has evolved independently at least three different times in the history of life on Earth – an extraordinary example of what is known as convergent evolution. The reason? Well, this alliance is perfectly suited to tough environments. Together, the fungi and the algae are more resilient than either could be alone. The fungi absorb water and nutrients; the algae guard against drying out and shield them from the sun. Time and again, through different evolutionary paths, these two have found each other, forging one of nature’s most successful relationships. How lichen reproduce is equally fascinating, if not a little bit unusual. Because lichen isn’t a single organism but a partnership, it does not usually reproduce as one. Instead, the fungus part of the lichen releases spores, which can only grow if they land near the species of algae that they can bond with. When they do, the fungal spores send out tiny filaments, like arms, that reach out and grab the algae. And from that moment, a new lichen begins. Lichens are also among the first living things to appear in places where life seems impossible. Their secret lies in the powerful teamwork between fungi and algae that allows them to draw energy from sunlight and extract nutrients from nothing more than air, rain, and stone. After a wildfire, when the ground is still blackened and lifeless, lichens are often the first to return. When glaciers melt and expose raw rock, lichens quietly begin to grow. Even on the barren flanks of a newborn volcanic island, they are among the earliest signs of life. And as they spread, they help create the conditions needed for others to follow – mosses, grasses, trees, insects, birds, mammals. Whole ecosystems begin with this humble alliance. This was an astounding discovery. A discovery that reminded me of the wonders of the workings of the natural world. A discovery of a flash of gold on the shore of Loch Sunart that was not treasure, but instead an ancient partnership that can prepare the earth for life itself.  Maritime Sunburst – Sàilean Dubh, Ardtoe, Ardnamurchan
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