Galapagos
The Galapagos are home to many animal species; in addition to its high number of endemic species, the wide-ranging communities of the Galapagos are also unique. Tropical fish, penguins, sea lions, and iguanas, for example, all live together- this doesn’t happen anywhere else on Earth. The effects of natural selection can also be easily seen in Galapagos wildlife. Feeding techniques, physical characteristics, and other behaviors are all perfectly specialized for efficiency in different environments.
(See Guayaquil assignments for more info on individual species) |
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The Galapagos Islands contain many endemic species, such as the Galapagos Penguin, lava gull, flightless cormorants, and blue-footed booby. As such, the islands were made a national park in 1959, and declared a world natural heritage site in 1979. More recently, laws such as the “Special Law of Galapagos” have been put into place to conserve Galapagos biodiversity. However, invasive species, growing permanent and tourist populations, and pollution threaten many Galapagos species. Solid waste, oil spills, and illegal overfishing are among the most threatening human impacts on marine life. Also impacting wildlife is decades-old DDT, used by American soldiers during the second world war at the Galapagos base; DDT takes an extremely long time to degrade, and accumulates in organisms (especially those in higher trophic levels), disrupting their biological processes. Education is key if the Galapagos Islands are to be conserved for future generations.
Mapping the submarine morphology of the Galapagos Islands can give researchers a better understanding of the processes that cause island growth and evolution. Some of the structures found using bathymetric and sonar techniques include rift zones, volcanic cones, and lava flows. Recently, geologists have learned that these lava flows (which are at great depth) are originating from submarine rift volcanism, and that volcanic activity in the northwestern Fernandina rift has been focused at the shallow end of the rift.
Although volcanism may be my least favorite subdiscipline of geology, its complexities still amaze me. Completely understanding the process of island formation might be a lofty goal, but studies like this one certainly help, and may help us better predict what will happen to the Galapagos in the future. |
Invasive mammals such as pigs, donkeys, goats, and rats have been an ecological disaster for fragile environments like the Galapagos since they were introduced by humans during the past few hundred years. They’ve destroyed endemic species both directly and indirectly, by ravaging vegetation and eating tortoise and sea turtle eggs/hatchlings, among other things. Many of these introduced animals have now been eradicated, despite opposition from some locals.
The methods of eradicating these invasive species range from ground hunting to aerial hunting to even poisoning. Pigs were eradicated on Santiago Island through a combined effort of ground hunting and poisoning during a campaign that stretched 30 years. Donkeys and goats have also been eliminated on Santiago, as well as other islands, using techniques such as aerial hunting and “Judas goats”. Ground hunters were often assisted by dogs, and poisoning was usually accomplished by injecting bait with substances like 1080 (sodium fluoroacetate). Aerial hunting proved to be very effective for donkeys and goats; however, goats eventually began to associate the sound of a helicopter with death. The remaining goats would hide from hunters; they were very difficult to find. To combat this issue, hunters took advantage of goats’ herding instinct by catching and releasing “Judas goats” which they tagged with tracking collars. Once released, these goats would seek out others, and lead the hunters right to them. The Judas goats would be recaptured for re-use while their newly-found herd was slaughtered. Rats, unfortunately, are harder to eliminate- that process is ongoing. Some of these methods of eradication, such as poison and Judas goats, are obviously controversial. Personally, however, I believe the end justifies the means. The results of invasive species eradication have been immediate and significant- areas that were completely destroyed are seeing new life. With the help of seed banks, extinct species are being re-introduced, and habitats are well-suited for endemic species once again. Hopefully, as time goes on, Ecuadorian citizens living in the Galapagos will be educated on the importance of eradicating invasive species, and the last remaining populations will also be removed. |
The Galapagos tourism industry began in the late 1960s with around 2,000 visitors per year. Since then, it has grown to accommodate nearly 3,500 guests per night. The growth of the industry has brought both good and bad to the islands; Santa Cruz’s economy and living conditions have improved drastically, but the other islands haven’t shared in their prosperity. In fact, unstable population growth, socioeconomic divide, civil unrest, and the number of introduced species have all been observed increasing alongside the growth of the tourism industry. In addition, tourists have become increasingly dissatisfied with Galapagos nature and wildlife, and have generally been unaware of ecotourism opportunities in mainland Ecuador.
It’s a shame that tourists aren’t appreciating the Galapagos as much as they used to, especially with all the damage tourism has done to the islands (and their human and nonhuman inhabitants). Hopefully, in the future, Ecuador will be able to properly advertise mainland ecotourism activities that can both draw visitors away from the islands as well as potentially replace natural resource extraction as a driving economic force.
It’s a shame that tourists aren’t appreciating the Galapagos as much as they used to, especially with all the damage tourism has done to the islands (and their human and nonhuman inhabitants). Hopefully, in the future, Ecuador will be able to properly advertise mainland ecotourism activities that can both draw visitors away from the islands as well as potentially replace natural resource extraction as a driving economic force.
Ecotourism has expanded rapidly and globally over the past few decades. While a huge influx of ecotourists may be good for a host country’s economy, large numbers of tourists (despite their good intentions) have a negative effect on the environment. In the Galapagos, the goals of conservation and expanding ecotourism clash on a regular basis. Trash from tour boats has been found to kill marine life, exotic species accidentally introduced by tourists/the tourism industry are devastating native wildlife, and the growth of the Galapagos’ permanent human population to support tourism is causing habitat fragmentation and the destruction of geologic structures- and the list continues. A proper balance between development and conservation is hard to sustain, but can be achieved through education and management of tourism growth.
As I’ve been reading more and more about the negative effects of tourism on the Galapagos, I’ve been feeling increasingly guilty about our visit. Fortunately, with our extensive preparation, we should have less of an impact on the islands than most. In the future, I hope Ecuador will be able to market mainland opportunities for ecotourism more effectively, and possibly draw away tourists from the Galapagos.
As I’ve been reading more and more about the negative effects of tourism on the Galapagos, I’ve been feeling increasingly guilty about our visit. Fortunately, with our extensive preparation, we should have less of an impact on the islands than most. In the future, I hope Ecuador will be able to market mainland opportunities for ecotourism more effectively, and possibly draw away tourists from the Galapagos.
The Galapagos Islands are one of the easiest places in the world to see the effects of evolution. Mockingbirds, for example, can vary in size, beak length and shape, feather coloration depending on which island they inhabit. On Española Island, the mockingbirds’ beaks are long and curved to allow for more efficient digging. Darwin noticed these slight differences in species between islands on his 1831 voyage; he also noticed the similarities between species found on the South American mainland and those in the Galapagos. His observations eventually led to the theory of evolution, which ironically can be easily observed in a short period of time on one of the Galapagos Islands that Darwin never visited- Daphne Major. Plants’ seed size varies with the amount of rainfall received each year; the beak size of ground finches on the island changes as well. When small seeds are more prevalent, the next generation has a smaller average beak size, and the opposite is true when large seeds are dominant.
I was very surprised to learn that evolution could be observed in such a short period of time with macroscopic organisms like the ground finches on Daphne Major. Before watching this video (and before learning about the ground finch study in Ecological Principles), I assumed that evolution was a much slower process (if you exclude bacteria, etc.), requiring thousands if not millions of years to occur. This video did an excellent job explaining the ground finch study and evolution as it relates to the Galapgos.
I was very surprised to learn that evolution could be observed in such a short period of time with macroscopic organisms like the ground finches on Daphne Major. Before watching this video (and before learning about the ground finch study in Ecological Principles), I assumed that evolution was a much slower process (if you exclude bacteria, etc.), requiring thousands if not millions of years to occur. This video did an excellent job explaining the ground finch study and evolution as it relates to the Galapgos.
Princeton researchers Peter and Mary Grant have been studying the evolution of Darwin’s finches for over 40 years, with a concentration on the island of Daphne Major. The 13 finch species found in the Galapagos are spread across the islands, and have all adapted to fill various ecological niches created by differences in island size, height, and topography. DNA analysis of the finches has shown that they are more closely related to each other than they are to any mainland species, which means that they must have all diversified from one single ancestral species that colonized the Galapagos.
Although not always seen, the finches continue to evolve. On Daphne Major, changes in food supply (due to lack or overabundance of rainfall) have led to the evolution of the ground finch population. When smaller seeds are more readily available, the birds with smaller beaks have a higher chance of survival, and the next generation’s beaks are smaller. When larger seeds are dominant, the finches with larger beaks have a higher chance of survival, and the next generation will have larger beaks. As the first finches in the Galapagos began to colonize different islands, the varying conditions they encountered led to changes more extreme than those observed on Daphne Major. Eventually, these changes led to the inability of the finches to breed with other populations, and they became a new species. It’s really incredible that evolution can be observed in such a short time period on Daphne Major. The Galapagos’ unique environment makes it a perfect location for studies like the Grants’; this is one of the many reasons why it’s critical to protect the islands. |
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The Earth is home to over 10,000 species of birds. To understand their origins, researchers have explored the fossil record and traced their evolution over time. In 1861, the first intermediate organism connecting reptiles and birds was discovered in Germany- Archaeopteryx. It had feathered wings and a feathered tail like modern birds, but other features such as a long boney tail and a toothed beak more commonly associated with reptilians. While some believed that Archaeopteryx may have evolved from pterosaurs, this idea was eventually discounted due to the lack of similarities in wing structure. In the mid-20th century, the idea that birds evolved from dinosaurs began to gain traction, due to John Ostrom’s proposition that some dinosaurs were small and agile. By the 1980s, there was a consensus that birds evolved from therapods, a group of dinosaurs characterized by hollow bones and three-toed limbs. Although it was originally believed that feathers were evolved for flight, the discovery of wingless, feathered therapods showed that feathers pre-date flight, and must have evolved for other purposes, such as insulation or mating displays. Over time, true birds evolved, and a small group of them survived the KT extinction; these diversified into the birds we see today.
Following the evolution of birds through geologic time is a fascinating experience. New discoveries are being made constantly, and as we explore more of the fossil record, we will likely learn much more about the evolution of not only birds, but other animals as well. Examining the evolution of birds on a long time scale like this gives me much more of an appreciation for the small changes we learned about taking place in the Galapagos and elsewhere around the world; given enough time, small adaptations can lead to a whole new group of organisms. |
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