Wildlife of the Galapagos Islands The Galapagos finches evolved from one common ancestor, the Grassquit, which was blown by strong winds to the islands an estimated 3 million years ago. There are now 13 different species. A unique aspect of the land birds of this island is how they managed to travel the distance from the mainland to the islands and settle there. Each species seems to occupy its own niche in the environment as their beak sizes and shapes vary to suit them. Of the species of sea turtles around the Galapagos, only the Pacific green sea turtle returns to nest there. Sea turtles have a very short neck and fins while the giant tortoises have a long neck and legs. Sea turtles only come to land to nest and the giant tortoises never go in water but are able to float if they fall in due to a large space between the body and shell. The giant tortoise's ancestor is suspected to come from the Brazilian jungle which may have floated to the Galapagos millions of years ago. There are both land and marine iguanas in the Galapagos. The ancestor, iguana-iguana, is believed to have come from mainland Ecuador on rafts by currents including the Panama Flow. Some stayed on the coast and others moved inland for food and adapted colors to suit their environments and predation. They are the only lizards in the world that tolerate and dive in salt water. The marine iguanas have tails longer than their bodies and sharp claws for aquatic lifestyles. The waved albatross is endemic to the islands and flew to the Galapagos and most likely stayed due to food and minimal predators. The flightless cormorant has no land predators and are expert divers and exploit aquatic food sources. Large webbed feet allow for this and therefore does not require flight in the species. They still have wings because they offer balance and maneuvering skills. There are no seals but two types of sea lions, Galapagos sea lions and fur seals (sea lions). The ancestor of the sea lion came from California. The ancestor of the fur seal came from Chile. Both females are smaller than males and have small litters of 1-2 with 9 months gestation but can also undergo delayed implantation if food sources require it. Galapagos penguins came as a result of ocean currents from southern South America. They evolved to be smaller and they utilize lava tubes and crevices for incubation of their nests. The diverse and isolated nature of the Galapagos makes it a unique treasure. There is a large range of wildlife that is not found anywhere else in the world. It is incredible to learn of the specific and seemingly accidental events that needed to occur for such a diverse group of species to find and settle on these islands. Because of these chance events, the Galapagos are a rare, complex, and awe-inspiring location on the planet that are irreplaceable.
Galapagos: Conserving the Last Eden Juan Jose Alava of the Ocean Pollution Research Program has done research involving the Galapagos Islands. The thirteen islands vary in age with a history of high primary productivity, oceanographic features, and variable sea surface temperatures. The Panama Current, Peru Current, and Equatorial Undercurrent all influence the sea temperatures of the islands. The Peru Current and Panama Current form the south equatorial current which flows from east to west. Even higher biodiversity is seen on the west where more nutrients are deposited. El Niño and la Nina influence the temperatures of the water. The diverse species of the Galapagos offer plenty of research opportunities. Charles Darwin’s famous finches of the Galapagos are an example of adaptive radiation. The Galapagos Penguin occupies a unique location on the equator. A variety of other unique bird species live here, many endemic. The only marine lizard is found in the Galapagos. Land iguanas have developed the special characteristic of nasal glands that excrete salt. The unique giant tortoise can live up to 150 years and the largest biomass of sharks in the world is found in the northern islands of Darwin and Wolf. The Galapagos was named a national park in 1959 and is a world heritage site and has several reserves and sanctuaries to protect it but threats remain. Invasive species, increased human presence, tourism and pollution plague the islands. Movement from mainland to the Galapagos is restricted now to manage population growth. “Continentalization” of the islands has been occurring as more resources are needed to support human populations which contributes to pollution and species presence. Solid waste including nylons hooks and plastics affect sea lions and other life. The Jessica oil spill affected the marine iguanas and reduced their populations. Ships traveling to the islands contribute to physical and auditory pollution and increased collisions. Galapagos fisheries affect the predator populations near the shore. Conservation efforts have included education efforts, ranger training, and capture and rescue operations. Animals were also captured to biopsy and measure pollutants and sea lions were found to be in contact with DDT which is very harmful to organisms. Pesticides used in tropical areas to treat malaria as well as PCPs and DDT used in other areas can be spread through ocean currents. The US Navy Base on the Island used DDT to kill rats on the island during its time there and the chemical lingers today. Education is a very important aspect of conservation and preserving the purity of the Galapagos and surrounding waters. Human influence has brought destruction and altered the health and populations of species in the Galapagos as has occurred worldwide. It emphasizes that no area is truly pure and undisturbed and is one of the many predictors that humans as a species will continue to exploit any resource or environment that offers a profit, ultimately to our self-destruction. Stricter enforcement and restrictions may help the Galapagos but effects of human-related issues including pollution, overpopulation, and overfishing will see ramifications well into the future.
Submarine Morphology Volcanic morphology of the younger, western Galapagos Islands of Fernandina, Isabela, and Santiago and several outside flanks was studied using sonar and water depth data of submarine rift zones to understand the growth of the islands. Rift zones, volcanic cones, and deep-water lava flows reveal a great deal about geological activity. Rift zones are shorter in the Galapagos than some other islands due to a lower supply rate of magma due to less activity. Active volcanic areas occur along rift zones and volcanic flanks. Rift zones above the water’s surface tend to be more spread out while those underwater are more developed. Submarine rift zones of Fernandina are lined up with those rift zones above the water, except in the western zone of Fernandina or northwestern zone of Ecuador. The rift zone in Fernandina is the longest in the western region and shows more volcanic activity as seen in its volcanic cones and progressively irregular rifts. Volcanic cones vary in shape and size at different depths due to different pressures affecting the gas of the magma and how erupted materials compile. Their presence on rifts, along with deep craters, indicates activity. Deep lava flows are often correlated with vents and cones on rift zones, and indicate the foundational building of volcanoes on which new islands form. The correlations between rift zones, lava flows, and volcanic cones offer insight into volcanic activity and the formation of the Galapagos Islands. Further, more intensive research using these technologies and new understandings can help piece together the origins of the islands and their future.
Galapagos Population Growth and Tourism The Galapagos has become a hotspot for tourism and immigration from Ecuador. Tourism has increased greatly in the Galapagos Islands and continues to as the years progress. In order to address this and keep up, services and development have been increased as well as management of the islands. As more money was being brought in through the Galapagos and interior conflicts and economic crises occurred in Ecuador, more people began moving onto the islands to escape. As ecotourism has grown in popularity, the Galapagos has become one of the most popular destinations. At the same time that revenue has grown and helped improve local development, the pristine island is becoming urbanized to accommodate the growing number of tourists, many of which are from foreign countries including the U.S., U.K., and Germany. Tourist fleets and their capacities have grown in size considerably. Overall, tours and tourist fleets contributed considerably to the Ecuadorian economy from 1991-2006. Hotels also grew in number during this time, however it did so more successfully on Santa Cruz as it became a tourist hotspot. This allowed for increased employment opportunities. The growth of tourism in Ecuador’s economy overall falls behind that of other Latin American countries and makes it apparent that it is not reaching its full potential. The influx of tourism for the Galapagos though, does in fact benefit the mainland and encourages others to visit the country itself and even other countries, signifying the importance of the islands' tourism. Threats to conservation on the island are extensive. Population growth has contributed to the threat of invasive species, pollution, and construction. It has been found that though the economy is growing, per capita income is stable if not declining due to immigration. More stress is placed on resources, including fisheries, to combat the growing population and in the 1990s, restrictions on fishing resulted in unrest and anger among the citizens, and could occur again under different conditions and threaten conservation. Many immigrants from Ecuador lack respect for the conservationist goals of the islands. Finally, basic human services including education fall behind as the population increases so rapidly. To regulate these factors, education, management of ecosystems, increased fees, sites and zones with restrictions, resource rent to regulate exploitation, and the regulation of vessels are being pushed. Donations also aid conservation of the Galapagos. These are essential to protect the biodiversity and economic benefits that the islands give and many rely on. As the population will continue to grow in the future, these risks will become even more imminent and will require more substantial restrictions which will be necessary to protect this biological treasure from overexploitation.
Galapagos Sustainable Ecotourism Conservation became a popular topic in the 60s and 70s and to this day the number of organizations and new, innovative, and more sustainable alternatives for daily living continue to grow. Nature tourism or ecotourism has grown in popularity as a result and created an environment where unique and threatened biodiversity is the desire of many travelers. This has allowed traveling to become an even deeper learning experience and has even pushed companies involved to become more “eco-friendly.” Reserved areas became encouraged and in the case of the Galapagos Islands, other than it becoming a national park in the mid 1900s, it more recently became a center for research. Education is a main goal of this research station in order to preserve and protect the precious ecosystem. International connections and influence has also resulted from the ecotourism industry. Ecuador makes substantial profit from these ventures but also sees lasting effects. The tourists that visit the Galapagos have greatly increased in number which contributes to degradation of the land and sea including erosion and pollution. Introduced species and increased population on the island are other major issues that have led to the destruction and exploitation of native flora and fauna. The fishing industry has become a major cause for concern as it threatens populations of a variety of species and consequently the food web. More development on the island as a result of increased human presence further interrupts habitats and threatens species. Efforts by the Park and Darwin Conservation have helped to minimize this and continue to try to maintain sustainable development on the islands. Preserving the islands is the main focus as conservation battles with development to protect and limit resource use and human presence.
Evolution in the Galapagos Darwin initiated the revolutionary idea of evolution as a result of his visit to and research on the Galapagos Islands and its diverse wildlife. Mockingbirds, of Espanola, are larger and have longer, curved beaks to dig and have speckled breast feathers. Two other islands have their own species and a fourth species is found across many islands. On Genovesa, the mockingbirds have a purer white breast. Birds and their appearances vary significantly between islands, similar to the tortoises. Darwin witnessed “aboriginal creations”, which today is termed endemic species, across the Galapagos. On Floreana, he found 21 endemic plants, and again noticed differences between the species on various islands. In addition, Darwin noticed the similar appearances of Galapagos species to those of South America. The finches of the Galapagos were Darwin’s most well-known discovery of evolution through varying adaptations that suit particular environments and their conditions. Varying beak sizes suit different seed sizes. On Daphne Major, an island Darwin didn’t visit, researchers found that depending on the seed size that is available, the next generation of finches born will have either smaller or larger beaks to favor the food source. This demonstrates the principle of natural selection, as smaller-beaked birds are selected for in the presence of smaller seeds and result in birds with these beaks in the next generation. The same occurs when conditions change and large seeds are present. This is an example of evolution occurring in a shorter time frame and was the study that led Darwin to this concept. Understanding and visualizing how fast adaptations can occur and evolution can occur before our eyes is truly fascinating. Evolution was always understood to be a long, tedious process but in fact it can be seen on a smaller scale in these finches and this has revolutionized the future of research.
Galapagos Finch Evolution Experiments on the Galapagos finches today continue to reveal new information on how new species form. The diversity of habitats has allowed for varying features of the finches. DNA has shown that all of the finches are more closely related to one another than to any mainland species, therefore indicating one species arrived on the island from the mainland and evolved into the species seen today. This proves that there is a single common ancestor of these finches. Research conducted by biologists Rosemary and Peter Grant included tagging, beak size and shape, and weight. Extensive data on the birds was collected. A severe drought occurred in 1977 that affected the seed availability. After the smaller seeds were depleted, only birds with larger beaks were able to take advantage of the larger seeds. This resulted in 80% of the population dying as those with smaller beaks were unable to exploit the larger seeds. The next generation brought offspring with slightly larger beak depths as a result of natural selection. When an El Nino brought heavy rains in 1983, the vegetation was altered and a future drought resulted in large beaks being unfavorable and the following generation showing smaller beak depths. Speciation of these finches occurred most likely due to populations being separated and changing to fit their environment. These new species do not mate as a result of differing mating calls that only attract that particular species and the differentiation of different species among potential mates. Variations in location and environments allowed for new species to form and flourish in their own niches. These finches truly demonstrate how nature responds to environmental variability and how natural selection occurs, allowing for more understanding of how we came to have the multitude of unique species we see today.
The Origin of Birds The evolution of birds was a rather nonlinear and diverse array of evolutionary paths. This area of research was opened up around 150 years ago in Germany when the archaeopteryx fossil was uncovered dating back 150 million years ago. This fossil revealed wing and tail feathers as seen today in birds, but also was found to have teeth, claws in the hand, three digits, and a bony tail. Another species uncovered, Pterosaur, was found to have three digits and a fourth long digit with a membrane attached to it for flying. The differences among the pterosaur and archaeopteryx demonstrate different evolutionary tracks begging the question of how birds arose. The discovery by Thomas Huxley that archaeopteryx and another terrestrial dinosaur shared similar features progressed the idea that birds are related to dinosaurs. This idea wasn’t easily believed by most. Then in 1963, a fossil was discovered in Montana of a claw of a two-legged smaller dinosaur called Deinonychus that was used for slashing and not walking. This proposed the idea that dinosaurs could be quicker, more agile, and lighter. The archaeopteryx and deinonychus share hollow bones, long arms, and similar hips and shoulder bones and drew the connection between birds and theropods, two-legged dinosaurs. Theropods were also found to have wishbones, just as birds do. Further evidence, including dinosaur nests, furthered the confirmation of the descent of birds from dinosaurs. China in the mid 90s brought forth many fossils including fossils revealing primitive feathers on the body most likely used for warmth, communication, or social interactions. These feathers evolved to be used in flight and when the mass extinction of the dinosaurs occurred a small group of birds survived and brought forth the array of bird species we see today. Understanding the ancestry of birds to dinosaurs demonstrates the resilience of nature and the intricate and often times confusing process that evolution is. It also demonstrates how technology and science have advanced to more accurately map out the history of our planet and help make connections in the large evolutionary tree of life.
Charles Darwin and the Origin of Species Charles Darwin was born in 1809 in England and upon graduating from Cambridge, he left to sail on the HMS Beagle and arrived in the Galapagos in 1835. His trip to the Galapagos brought forth research that showed what he thought were mutations among species that were exposed to different environmental conditions to help them better adapt and compete. He called this idea natural selection, as those that were favored survived and the others that did not adapt didn’t. At the time of his research Darwin was not the only one that was questioning and studying the origin of life, and the work of other scientists is noted throughout his book. He published the first book on the evolution of species, On the Origin of Species, in 1859 and through his observations of natural selection, brought forth the new and soon to be life-changing concept of evolution. It altered scientific thought as previously it was generally accepted, though often questioned, that species were fixed and did not change in the thousands of years since their “creation”. His other book, The Descent of Man, used common ancestry to imply that humans descended from a simple organism and were not created. His naturalistic explanation challenged religious justification for the formation and continuation of life and helped initiate the scientific explanation of evolution.