Editor’s Note :
Travel is more than movement—it is a way of reading the world.
Cultural Express launches Hidden Pattern, a new column by USC professor Cheng-Ming Chuong and Violet Shen, former Director of Clinical Research at Children’s Hospital of Orange County.
Through words and images, they explore landscape, culture, nature, and science—revealing the traces of time, the path of evolution, and the hidden order of the world.
Introduction:
Born of fire and sea, the Galápagos reveals evolution in motion:Giant tortoises’ shells record drought and rain, finch beaks answer hunger, marine iguanas brave cold waters, and blue-footed boobies dance for love.
In this three-part journey, the authors follow Darwin’s footsteps through volcanoes, oceans, and astonishing diversity of life—revealing how evolution transforms chance into wonder.(Part 2 of 3)
We arrived in the Galápagos with no palms or white sand—only blazing sun, crashing waves, and black lava that seemed freshly cooled.
Among the rocks, miniature “Godzillas” basked in the sun. Clad in rough scales and spiny crests, they occasionally raised their heads and snorted white mist from their nostrils. The surreal scene felt like a lost prehistoric world.
Lava Beasts, Salt Mist
In 1835, 26-year-old Charles Darwin witnessed the same strange sight when he arrived aboard HMS Beagle. Repelled by their appearance, he called the creatures “imps of darkness.”
They were Galápagos marine iguanas. Their irritated-looking snorts are not signs of anger.
Marine iguanas grip rocks and swim with flat tails
Marine iguanas dive into the Pacific to graze on algae, swallowing large amounts of salt.
Specialized glands near their eyes concentrate the excess salt and expel it through their nostrils.
What looks like a comical sneeze is actually an ingenious adaptation to life at sea.
Stone Rain, History Begins
Three centuries before Darwin, Tomás de Berlanga, the bishop of Panama, drifted upon the islands after his ship veered off course en route to Peru.
He found a dry, desolate volcanic landscape inhabited by monstrous iguanas and giant tortoises.
In a letter to Spain’s King Charles V, Berlanga described the islands as covered in worthless volcanic rock, as though “God had rained stones,” and marveled at tortoises large enough to carry a man.
Written in 1535, his letter became one of the earliest Western accounts of the Galápagos.The “islands of monsters” would, three centuries later, transform humanity’s understanding of life.
Volcanoes Rise, Life Adapts
Straddling the equator about 600 miles west of Ecuador, the Galápagos did not break away from an ancient continent.
Every island rose from undersea volcanoes.
A volcanic hotspot continues to feed the western islands, while the Nazca Plate slowly carries older islands eastward like a conveyor belt.
This created today’s pattern: younger islands in the west, about one million years old, and older islands in the east, roughly four million years old.
On western Fernandina and Isabela, we saw active volcanoes and vast fields of exposed lava.
The older eastern islands have endured far more erosion, developing forests, valleys, grasslands, and desert terrain.
Warm and cold currents also converge around the archipelago, shifting water temperature and nutrients with the seasons and sustaining extraordinary marine life.
Volcanoes built the stage; the ocean raised the barriers. But how did life first arrive?
Rafts Drift, Species Split
A newly emerged volcanic island has no soil, forests, or land animals. Its earliest arrivals may have been windblown microbes, spores, and seeds.
Birds crossed the ocean, insects rode the wind, and seeds traveled on feathers or floating debris.
Reptiles made an even more astonishing crossing. Storms may have swept their ancestors from South America on natural rafts of vegetation.
After drifting hundreds—even thousands—of miles, one chance landfall could reshape a species for millions of years.
The ocean severed these pioneers from their South American ancestors, while the islands imposed a second layer of isolation.
Confronted by different environments, life found new paths and gradually adapted. Each young island became a natural stage for evolution in miniature.
Land Ancestors, Marine Marvels
Marine iguanas descended from a South American lineage and share a common ancestor with land iguanas. But the world they reached was no lush paradise.
It was a dry, exposed volcanic wilderness where food was scarce.
Land iguanas remained ashore, drawing food and moisture from cactus flowers, fruit, and tender stems. Marine iguanas entered the ocean to graze on algae.
From similar ancestry, different environments and diets led them down sharply different evolutionary paths.
Galápagos land iguanas sport sturdy limbs, blunt snouts, and low spines.
Over time, natural selection reshaped the marine iguana. A powerful, flattened tail propels it like a paddle. Long, sharp claws grip wave-battered lava.
A short, blunt snout scrapes algae from rock. Specialized glands remove excess salt, while dark skin absorbs sunlight and restores body heat lost in cold water.
Its black skin, flattened tail, sharp claws, and fearsome face are not flaws. They are chapters of evolutionary history written upon the body.
Darwin found no answers—only mysteries. Today, the salt-spouting marine iguana is no “imp of darkness,” but a living wonder shaped by fire, sea, isolation, and natural selection. (Part I of III)
Next Week｜How the Galápagos reshaped tortoise shells and finch beaks—another evolution story awaits.