Founder effect: Combination of genetic drift and natural selection resulting in a new genetic direction for a small population or individual in a new environment. (Dictionary of Biology, E. Martin 1986)
My first lesson in Hawaii was about dirt. Soil development to be more precise. Like many who experience Hawaii for the first time, from an airplane approach onto the Huehue lava flow at Keahole Airport, I saw barren, black rock. No swaying coconut trees, no Polynesian hula girls, just a two hundred year old lava flow with a few tufts of grass here and there. Unlike many tourists who at this point ask, “What have we gotten ourselves into?”, I asked the naturalist’s question, “What’s going on here?”
My belongings loaded into the red, subcompact rental car, I drove south towards a place called Hoopuloa. Moments after merging onto the main road, Queen Kaahumanu, a new and splendid bird hopped across my lane. With the determination and poor driving etiquette often displayed by birdwatchers, I flipped a U-turn and skid off the gravel shoulder. Binoculars and bird book close at hand, my first myna was observed and identified. Not hawaiian, I read, but a native to India. As the drive continued south, the sparse rock land gave way to lush urban landscape, dense agricultural plantings, and the lush Kona forests. And still, with the image of heat waves rising off the black rock of the airport in my head, I wondered, “What’s going on here?”
All of Hawaii’s native species derived from colonizers that got here either through the air like the Pacific Golden Plover who is an anuual visitor. Or by sea like the Monk Seal.
What’s going on here is colonization. Colonization by a malihini portagee from California, colonization by an invasive fountain grass from Africa, colonization by a bio-control Myna from India. Colonization of the most isolated archipelago in the middle of the world’s greatest ocean.
A couple days later upon settling in to my new niche in South Kona, I happened along a flow of ants with a peculiarly crazy procession. After a brief enjoyment of the chaotically synchronized dance of the ants, I began, as a proper Western man, to take inventory. What are they called? Are they hawaiian ants? If not, where are they from? Did they arrive by the United Flight 40 San Francisco to Kona direct? (Soon enough, I found out these answers: Crazy Ant, Paratrechina longicornis, native to New Guinea.) With my gaze focused on the minute, I noticed the dirt. It was a small pocket of debris nestled in a depression of chunky rock. Down on my knees, I bowed forward for an ant’s perspective. In the small area at arms length around me was a rocky substrate pockmarked with little islands of soil. Some the size of my thumb, others as large as my head. Probing, flicking and scooping, I discovered a micro-archipelago in my front yard on the slope of Mauna Loa. The “dirt” I caressed wasn’t really dirt at all. It was a cornucopia of organic stuff: tiny live creatures, their discarded exoskeletons, their tiny little turds of digested materials, earthworms, sowbugs, other little microfauna plus sand-sized pieces of lava. The rock that held these islands of soil was basalt lava, a piece of clinker from an a’a flow that pushed it’s way out of the southwest rift zone of Mauna Loa in 1926—a thick vein of lava erupted down the mountainside like toothpaste squeezed out of its tube.
Kupaoa is a native Dubautia that is a lava colonizing plant as is the resplendant Amau fern.
Knees aching from the sharp rock, I stood and inhaled an expansive view. Life was all around me. On the young Hoopuloa flow before me, every inch of rock was covered with growth: lichens, ohia-lehua trees, kukaenene, ohelo, kupaoa. Farther off was the jungly growth of guava and christmas berry broken by the cultivated gardens of housesites and macadamia nut orchards. All of it, I realized, grew from barren lava like that at Huehue. The grayish, sunbleached trunks of the eighty-foot high ohia-lehua trees, which formed a long mauka-makai line on undeveloped state land in the distance, began in the little pockets of debris from colonizers—these founders of the flow at my feet.
In a view from my toes to the not too distant tree tops, a lesson lay about me. Life took hold in a place where magma gases once occupied. The little burst pockets of vapor in the lava provided a niche for organisms to colonize, grow, devour, defecate, die and decompose. The debris of these colonizations together make soil, so that one day a forest, an orchard, a taro patch, may occupy the hard rock of the volcano. As this lesson sifted into the cracks and crannies of my mind, I wondered what life would sprout from the debris of my colonization on Hawaii? What will be my founder effect?