On the Galapagos Islands, one has the exciting opportunity to walk in the footsteps of Charles Darwin on this primeval archipelago seemingly isolated from the destructive encroachment of human civilization and the ravages of time. This isolated archipelago consists of 15 major islands, along with numerous islets, uplifts, and reefs, located on the equator about 600 miles west of Ecuador in the Pacific Ocean. The “enchanted islands” reveal disturbing facts about this allegedly forgotten world of rock and life, often erroneously depicted as lost in time and enduring beyond the forces of change: The Galapagos flora and fauna struggle in the shadows of active volcanoes to survive against the increasing menaces of recently introduced species, particularly the human animal itself.
Darwin’s eerie “cradle of life” appears as an inhospitable world of lava flows and desolate vistas: a cluster of igneous islands looking like a group of enormous chunks of lunar landscape haphazardly floating upon the swift Humboldt Current. When surrounded by mists and low clouds, these deceptively foreboding islands present a vivid scene reminiscent of our reconstruction of prehistoric times. In fact, this archipelago actually represents a delightful anachronism: present-day life forms eking out an existence in a pristine environment. Fortunately, the inhabitants enjoy a subtropical climate, which is cool, due to fresh trade winds and several capricious ocean currents.
The static first appearance of the Galapagos Islands is an illusion. An extremely strange but special place on the earth, this slowly changing archipelago testifies to the pervasive influences of evolutionary forces. This area of our planet is a geological hot spot of frequent and intensive volcanic eruptions, reflecting the restless and convulsive entrails of the earth: One sees craters, collapsed cliffs, and calderas everywhere. Within this century, wind erosion may finally cause the famous and official geological sentinel of these islands (Pinnacle Rock of Bartolome Bay, which rises 200 feet above sea level) to topple back into the ocean, which waits to once again reclaim its own.
The ages of these islands range from 600,000 years to at least 9 million years. (The discovery of fossil invertebrates and fishes in uplifted marine limestone layers between lava flows allows geologists to date the ancient strata of these rocks.) In fact, this entire archipelago is almost imperceptively drifting eastward on the Nazca Plate due to tectonic movement. The eastern uplift islands are oldest and may sink back into the sea, while the western volcanic islands may suddenly explode. Yet further geological building is likely to result in the eventual formation of new islands.
On the summit of a volcano on Bartolome Island, 364 feet above the ocean, one experiences the breathtaking panoramic view of a moonlike landscape of craters and spatter cones against the blue ocean. Populations of surface colonizer plants and lava cacti need only soil, moisture, and oxygen to survive in this rugged and demanding volcanic environment.
The Galapagos Islands were the catalyst that inspired Charles Darwin to formulate his theory of biological evolution. When he arrived here in 1835, animals displayed little fear of humans. Over time, the creatures have learned to fear our species. As a national park belonging to Ecuador, this ever-changing archipelago remains a refuge for numerous vulnerable species (especially a wide variety of birds), some found nowhere else on this planet. Winds and waters continue to bring living things to these islands where, as in organic evolution, survival is the exception and extinction is the rule.
Tower Island is a veritable ornithologist’s paradise. This isolated area supports a rich bird population that includes the mockingbird, great and magnificent frigate birds, yellow warbler, red-footed crowned night heron, and the world’s only nocturnal swallow-tailed gull (which is now found throughout this archipelago). On the other islands, one finds the penguin, pelican, waved albatross, and vermillion flycatcher, as well as the flightless cormorant, red-billed tropicbird, and even the flamingo. The Galapagos also has its own hawk and two species of owl.
Yet the most beloved birds are the masked, red-footed, and blue-footed boobies. The comical appearance along with the humorous sounds and behavior patterns of the blue-footed booby have endeared this particular bird to every visitor of these islands. Like other animals, the boobies often seemed to be deliberately posing for their pictures to be taken.
Throughout this archipelago, the traditionally recognized 14 species of Galapagos finches actually represent a far more complex situation of about 52 distinct overlapping types, with genetic, physical, and behavioral similarities and differences attributed to adaptive radiation, natural selection, and extinction. These enigmatic “Darwin’s finches,” as they are now called, remain a puzzle to evolutionists, particularly taxono-mists and geneticists, because certain populations prematurely defined as species are in fact capable of interbreeding. However, other groups of finches are reproductively indifferent, and still others even display altruistic behavior. (The iguanas and tortoises do exhibit clear biological variations to the point of speciation.)
Until recently, all the wild birds and animals had few if any predators and, as a result, were at first unafraid even of humans. As a sad demonstration of their capacity to learn and thereby acquire a new instinct, some finches and iguanas now exhibit a fear of our species (as do other animals among these islands).
The struggle of life on the Galapagos Islands demonstrates both the creative and destructive forces always at work in nature. The fragile ecosystems and precarious niches of this changing archipelago have been drastically altered by recently introduced plants and animals that are harmful to the endemic botanical and zoological specimens; such harmful feral animals include Norway rats, mice, pigs, goats, dogs, cats, horses, cattle, and burros. There have been over 200,000 wild goats on James Island. Of course, the most dangerous animal is the human species, and around 8,000 people now inhabit the Galapagos Islands.
About 600,000 years ago, violent eruptions formed the impressive Alcedo Volcano of Isabela Island, and Charles Darwin himself was the first to describe the resultant double crater. (Strangely, Captain FitzRoy’s own stone engraving marking the historic visit of HMS Beagle to this island has never been found.) A population of giant tortoises now lives among streaming fumaroles in this volcano’s wet and grassy caldera valley 1 mile above sea level. In fact, it is possible that a tortoise still survives that was living when the young geologist explored this captivating area in the 19th century. Here, on these lava flows at the base of this shield volcano, one comes close to experiencing the beginning of our earth.
The world’s only seagoing iguana is found at the Galapagos and may even inhabit the same island with the land iguana. The black-red marine iguanas are found in seething colonies camouflaged against lava rocks while basking in the warm equatorial sun. These “imps of darkness” represent an evolutionary shift from land to water adaptation, and they feed on seaweed and marine algae to a depth of 36 feet. They can remain underwater for up to one hour. Retaining a land reptile metabolism, the marine iguanas eject salt water from their systems. The larger brown-yellow land iguanas feed primarily upon the buds and spiny pancake pads that fall from the giant prickly-pear Opuntia cactus. They live in colonies, dig burrows, and spend much time basking in the sun.
The Charles Darwin Research Station was established in 1964 at Academy Bay on Santa Cruz Island. Despite its status as a legally protected national park and wildlife preserve since 1959, the ongoing conservation efforts of this scientific station have not prevented the archipelago from being exploited for personal gain and profit. Unfortunately, international scientists are more destructive than tourists in upsetting the normal natural conditions of the delicately balanced ecosystems and fragile niches throughout these renowned islands. In touching and banding rare birds, as well as netting and branding land iguanas, scientists have altered the total behavior of these life forms and even contributed to many needless deaths.
Fortunately, the Charles Darwin Research Station is successfully taking steps to restore the populations of giant tortoises. These huge reptiles seem like antediluvian animals reminiscent of the age of dinosaurs. One may weight up to 1,000 pounds and live to be 200 years old. In the past, they were killed by the thousands for their meat and the fresh water from their stomachs. Today, there may be less than 15,000 wild tortoises living on these islands.
At the research station, tortoise eggs of this endangered species are incubated and hatched, and the young are raised until they are from 5 to 10 years old, and then released only when they are capable of protecting themselves from predators in their appropriate natural habitats. This scientific station also helps eradicate the introduced pests, conserve other unique species and the differing natural environments of these islands, and maintain Beagle III for essential patrolling and communication throughout the archipelago.
The clear Galapagos waters are inhabited by fur seals, sea lions, and green turtles. There are even rays, sharks, dolphins, and whales further out at sea. Coastlines are usually spotted with red Sally Lightfoot crabs. At Tagus Cove (Isabela Island), one finds soft-colored sponges, beautiful cup corals, and brown sea anemones.
Under the Southern Cross, life has been evolving on these islands for millions of years. One may even speak of the evolution of the Galapagos Islands themselves. Yet if incisive measures are not continuously taken, this unique archipelago (as Darwin once knew it) will soon no longer exist. The loss would be irreplaceable. To paraphrase the words of the great naturalist: At the Galapagos Islands, both in space and time, one seems to have been brought somewhat nearer to those first appearances of new beings on this earth.
References:
- Darwin, C. (2000). The voyage of the Beagle. Amherst, NY: Prometheus Books.
- De Roy, T. (2000). Galapagos: Islands born of fire. London: Warwick House.
- Jackson, M. H. (1993). Galapagos: A natural history. East Lansing: Michigan State University Press.
- Moorehead, A. (1969). Darwin and the Beagle. New York: Harper & Row.
- Weiner, J. (1995). The beak of the finch: A story of evolution in our time. London: Vintage.
