Before the First Hawaiians
The life forms that originally colonized these islands may have been neither plant nor animal. And they’re still here.
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The candle-flame lichen (Candelaria concolor) is a frequent urban dweller, found growing on roadside trees.
Seventy million years ago, the first Hawaiian Islands emerged from the Pacific Ocean. Then as now, Hawai‘i was the world’s most isolated archipelago. For the earliest life forms to arrive and gain a foothold as the lava cooled, it had to have been a remarkable journey.
Those first living things were probably tiny spores that drifted down from high in the atmosphere and set into motion the process that transformed a lifeless landscape into a lush island ecosystem.
Neither plant nor animal, the first Hawaiian may have been a species of lichen.
“There are approximately 2,000 species of lichens in Hawai‘i,” says Robert Lucking, a lichenologist at Chicago’s Field Museum of Natural History, home to one of the largest research collections of lichens in the world. “Of these, about 1,200 are found nowhere else.”
That so many lichens are endemic to the Islands wasn’t known until Lucking and his team started sequencing the DNA about a year ago.
Although they have done fieldwork all over the world, Lucking and his colleagues are paying special attention to Hawai‘i and other islands in the Pacific because they are Earth’s unique evolutionary laboratories. “Even more than the Galapagos Islands, in Hawai‘i we have been able to observe evolution on the spot.”
Lichens are symbiotic organisms that form when a fungus combines with an alga or cyanobacterium (also known as a photobiont), the photosynthesizing partner of the pair. It’s the fungus’s job to provide a nurturing environment for the photobiont to grow in. The photobiont returns the favor by transforming sunlight into carbohydrates for the fungus. Together, they are able to live in environments that, apart, neither fungus nor alga would survive.