Land Iguana Expert
The Untold Truth of Human Involvement: My Week in the Galápagos
My arrival to the Galápagos Islands was like landing on Mars but with gravity to keep me balanced. The anticipation that had blood oozing in my veins and heart racing was enough to overwhelm the average person. However, I embraced this slight discomfort knowing that as the plane drew closer to the Galápagos I would encounter a new culture different from my own. Finally, the plane decides to land. Unprepared for the hot sun that had sweat crawling down my back, I was eager to explore the lands that made Charles Darwin famous. An inner city kid with little experience of nature, I was happy to explore a world not too damaged by humans and board the rocket ship out of Ithaca’s deadly winters. Tall buildings that made it impossible to see the skyline were absent. This is what I needed—a moment to appreciate nature and the inspiration to preserve natural habitats.
The notion that all is perfect in paradise becomes debunked when one learns how invasive species can decimate a population in the Galápagos. Philornis downsi, a blood-sucking parasitic fly brought to the archipelago by humans is just one example in which humans have created threats to the survival of native populations (1). The fly’s name (phil=loves; ornis=birds) is a huge misnomer as the fly larvae not only consumes the blood and tissue of nestling birds but also leaves its host either dead or deformed. Studies of the native mangrove finches have found that the prevalence of P. downsi is linked to the decline of reproductive success, one explanation for why the population of Darwin’s finches has dwindled since the 1960s (2). Therefore, developing effective defenses against these parasites becomes crucial for the various hosts. In order to visualize this, picture a soccer net as a host and a soccer ball as the parasitic fly. A soccer match with poor defensive schemes allows for numerous goals to be scored; however, if effective defenses are put in place, the chances in which an opponent can score is limited. This analogy highlights what ought to be done to limit the chances invasive species have to threaten a population. While increasing habitat size counteracts the human destruction of habitats, another threat to the finches, it does not address the prevalence of the parasitic fly. In fact, increasing habitat size simply gives the parasitic fly more fruit punch on a hot day.
The imbalance between the interests of people and the welfare of animals makes it extremely difficult to preserve native populations. As a result, animals unable to escape the dangers of human involvement are the ones at risk for extinction. Because an inverse relationship exists between the total present diversity and the extinction rate, Earth’s biodiversity decreases when human behaviors like habitat destruction increase the extinction rate. The deviation from the background extinction rate, the standard rate of extinction before humans became a primary contributor to extinctions, is primarily due to the need to accommodate the interest of the growing population (3). This explains why we are currently in the midst of a sixth mass extinction. One of the main evolutionary consequences of mass extinctions is that the event occurs relatively quickly and there are fewer opportunities to adapt (4). Despite how scary this might sound, the harsh realities of extinction become insignificant if people are unwilling to understand their own environmental impact. Going to the Galápagos made the issues facing many endemic species a personal matter. A professor who accompanied me on this trip, Dr. Toews explains the future implications of human involvement:
The effects of this invasive species are doubly bad. Even from someone who doesn’t work on Darwin’s finches, the loss [of] biodiversity is second only to the loss of our ability to understand the process of evolution.
Many scientists including Dr. Toews share the same sentiment that one’s ability to understand evolutionary processes becomes hindered when native animals no longer exist. Picture yourself having to solve a complex mathematical equation filled with foreign symbols. Without the guidance of an individual except the outdated textbooks sitting in your local library, you might have a headache trying to solve this equation. This analogy mimics how firsthand accounts of native species can make it easier and at times necessary to explain evolutionary processes.
The Galápagos made a teenager aware of the issues that face many endangered species. This teenager was me. Coming from the air conditioned plane that took me from Guayaquil International Airport to Seymour Airport, constant gazes met my long body covered in sweat. Standing at a height of 6’4" with Nigerian roots, I have grown accustomed to these looks but the Galápagos made me a noticeable foreigner. Uncomfortable, I leave my tour group and wander along the coast of Baltra Island. The blue waters that made my legs shrivel were so cold that thoughts of death constantly swirled in my mind. Trying to make sense of how any animal could live in such waters and avoid death was like solving a jigsaw puzzle with missing pieces. Due to the lack of efforts to repair a human mistake that introduced the Galápagos to a parasitic fly, Darwin’s finches must endure the violent blows to their survival. I jump out of the cold water to sit in the hot sand. As my legs are gradually brought to life, I take out my notebook and sketch the colorful marine iguana before it disappears:
Understanding why certain conservations methods are ineffective and not feasible creates the need to develop alternative approaches to reduce the population of these deadly parasites (5). For example, the introduction of native species to control the P. downsi offer a viable solution in preserving Darwin’s finches, but when other species are harmed, this option can do more harm than good. Therefore, the release of an “effective, ecologically safe parasite of P. downsi in the Galápagos” (6) requires a utilitarian approach that takes into account the benefit of all species, not just one.
The introduction of the Philornis downsi has had an impact on native populations unable to evolve fast enough to limit the effects of the parasitic fly. Limited exposure to pathogens makes one vulnerable to blood-borne diseases because there isn’t a need for a strong immune system. Darwin’s finches find themselves in this predicament. Because the fitness of a pathogen is determined by the internal environment of its host, it becomes necessary to have defense responses that prohibit a pathogen to multiply, develop, and transmit itself from host to host. So far, the P. downsi parasite has been winning the evolutionary arms race against the finches due to its ability to change within a single host (7).
The initial high virulence of the pathogen explains the early deaths of Darwin’s finches. However, pathogens are more than capable of making sure their host does not die before they can be transmitted to a new host, highlighting how the selection for within-host replication and between-host transmission determines the virulence of the P. downsi parasite (8). Effective modes of transmission and survival require the pathogen to maintain low virulence, which not only makes the deadly parasite invincible but also explains the horrid and ugly pictures you might see of Darwin’s finches infected with P. downsi. This parasite has unlocked the Da Vinci code of added life.
As I sit on a yacht and enjoy the Galápagos sunrays penetrating my chill body, I strike up a conservation with Scott, another professor who accompanied me on this trip. As we discuss the deaths of two sea lions we saw earlier that afternoon on South Plaza, talks of extinction were inevitable. Although the sea lions might have died due to different circumstances facing Darwin’s finches, I soon was aware that human actions, perhaps even mine, can threaten the survival of any species. Trying to escape the bite from a fat mosquito, I abandon my conversation with Scott and race across the Fragata yacht in hopes of evading the blood-thirsty insect. My track years serve me well as I dash to my room. Heart racing, I sit in bed and pretend to scratch myself off the mosquito’s death list.
Weaving my way on the jagged streets of Puerto Ayora with Sofia, a friend who obsesses about the vibrancy of Ecuadorian’s culture, I can’t help notice the bustling community that was invested in their culture. This observation is rarely seen in the United States, a country too consumed with technological advances and social media. The social addiction of Twitter and Facebook has made almost irrelevant the threats to biodiversity. While the new drug includes a tweet or Facebook post, its side effects have caused the depreciation for both unique environments and species. As the average U.S. citizen is thinking about the next iPhone or his next tweet, much deeper issues face Ecuadorians. Philip, a native to Ecuador who I had met in Puerto Ayora, expresses his concerns that the Galápagos is being exploited due to its unique environments and organisms. In addition, these concerns extend to the local governments who are unwilling to help its own residents despite the enormous generated income that comes from tourism.
My week in the Galápagos provided me with deeper insights of not only the threats mosquitos pose to their host, in particular, Darwin’s finches, but also how local residents are being mistreated by its own government. The issues that face many Galápagos residents drew my attention to the unspoken issues back home: the inequalities of wealth between those who have power and those who don’t. For most, the summer season provides the opportunity to take a mental break from yearlong careers by visiting tourist attractions. While the Galápagos might be on everyone's bucket list due to its history and beautiful scenery, not enough thought is given to the animals or residents, thereby putting lives in danger. The growing interests of tourists have made it difficult for Darwin's finches to survive in their natural habitat while perpetuating the tension local residents already have with their government. The next time you head off to your summer destination, think about the role you might have in one’s environment and the potential lives you can save.
A Galápagos journey that took me away from Ithaca’s harsh winters made the survival threats of many animals important to me. While a classroom setting can be useful in learning evolutionary concepts, I believe that first-hand accounts create lasting and meaningful memories. As noted by the famous poet, Cesare Pavese, “we do not remember days, we remember moments.” My week in the Galápagos will certainly evoke moments that I will never forget.
(1) Fessl, B. et al. (2006) The life-cycle of Philornis downsi (Diptera: Muscidae) parasitizing Darwin’s finches and its impacts on nestling survival. Annals of the Entomological Society of America 108.3, 242-250.
(2) Kleindorfer, S. et at. (2014) Changes in Philornis infestation behavior threaten Darwin’s finch survival. Current Zoology 60.4, 542-550.
(3) Willy Bemis, BioEE 1780 lecture, April 21, 2016.
(4) Willy Bemis, BioEE 1780 lecture, April 21, 2016.
(5) Koop, J. et al. (2016) An introduced parasitic fly may lead to local extinction of Darwin’s finch populations. Journal of Applied Ecology 53.2, 511-518.
(6) Fessl, B. et al. (2002) Philornis downsi – a recently discovered parasite on the Galápagos archipelago – a threat for Darwin’s finches? Ibis 144.3, 445–451.
(7) Kleindorfer, S. et al. (2006) Effects of the parasitic flies of the genus Philornis (Diptera: Muscidae) on birds. Emu 106.1, 13-20.
(8) Baba, T. et al. (2002) Genome and virulence determinants of high virulence community-acquired MRSA. The Lancet 359.9320, 1819-1827.