Monday, July 4, 2022

The ghost of Darwin is everywhere here: LSU in the Galápagos

 

 

 

From June 7th to the 24th this year, I was able to travel to Ecuador and the Galápagos Islands as an instructor for two LSU Study Abroad classes, including
Evolution. I have wanted to teach evolution in the Galápagos for some time, in fact this Study Abroad course was first planned for 2020 but cancelled twice due to COVID. It was therefore quite the relief to finally get to go this summer; and it was an absolute delight. This was the thirty-sixth country that I’ve visited (most of them for research) and the Galápagos Islands will be among my favorites for many reasons that I will get to shortly. I’m grateful that Dr. Dan Holstein, from the LSU College of the Coast & Environment, who has worked there several times, was there to show me the ropes. Dan and I brought seven LSU undergraduate students with us, and as an added bonus - my family joined us for the first part of the trip in San Cristóbal.

            Dan is a marine biologist, and an incredible swimmer, so many of the activities he arranged were snorkeling fish surveys – something right up my alley. Despite their tropical location, the Galápagos Islands actually have rather cool marine waters surrounding it, something Dan studies for his research; we learned from him how the many continuingly changing currents impact the marine life. That includes the famous Humboldt Current bringing cold Southern Ocean waters up to equatorial South America. The Galápagos are of course famous for Darwin’s time there on his Voyage of the Beagle, but Dan who taught his Ecology course here also benefitted from Alexander Von Humboldt’s legacy in this region too. Humboldt, was the most famous person besides Napoleon in early19th century Europe (read ‘The Invention of Nature’ by Andrea Wulf), and is often credited with founding the discipline of ecology. We were not all that far from Chimborazo, the great mountain in the Ecuadorean Andes that Humboldt made famous by being the first European to climb it and to study how its fauna and flora changes with increasing elevation. That mountain reaching just above 20,000 feet was thought at the time of Humboldt to be the tallest in the world and is about 200km south of Ecuador’s capital Quito which itself can reach over 10,000 feet in parts. All of us on the trip, as Louisianans, are used to living below sea level, so we felt the altitude of Quito. It was my first time experiencing the impacts of high altitude; I had hoped I had inherited more genes from my extinct Denisovan ancestors who apparently provide Nepalese and Indian sherpas on the Himalaya with adaptations for living and working in high altitudes (Simonson et al. 20151).

            After a few days in Quito visiting our host institute, the beautiful Universidad San Francisco de Quito (USFQ), the class headed to the Galápagos Islands. We would visit eight of these islands that can be found 600 miles off the coast of mainland South America. Their famous remoteness, and value for evolution research from Charles Darwin to Peter and Rosemary Grant, was never lost on us. Dan I would lecture every afternoon and it was amazing to infuse our lessons with the observations we had made out in the field (or vice versa). There was one day where I discussed the adaptations of hawk moths to block predatory bat sonar with their genitalia (see Barber et al. 2022 for more) and the very next day a curator at the Darwin Research Station in Santa Cruz was showing us these very moths and slides of their funky genitalia.
 

            We began our Galápagos adventures in Isla de San Cristóbal, one of the few inhabited islands, which together have a total population of only about 20,000 people, all concentrated in just a few urban centers; 97% of the islands are reserved within national parks. You can do little outside of these population centers without a guide, so local park rangers escorted us on all of our excursions. We were glad to have these knowledgeable and friendly locals with us. We spent a week in San Cristóbal, which gave the students a great perspective on the variation that exists even within one island. This island on the edge of the Galápagos undersea volcanic hotspot that created these landmasses, is one of the oldest of the islands at 4 million years old; but it also has sections that are much younger – and you can see the transition clearly as you move from soil rich highlands which also has a large freshwater lake - (El Junco; which is devoid of fish, sadly for me), to white sand beaches formed from the poop of parrotfishes and other coral munching critters (who chewed ancient reefs that don’t even exist anymore). The youngest part of the island (near Cerro Brujo) in the northwestern section and it is full of lava rocks and a few short stubby plants and lichen. Much of the highlands on these islands include farmland, and the oldest established farms in all of the islands are in San Cristóbal. This farmed area is called ‘El Progresso’ and was founded in the late 1800s. Despite clear evidence of human impacts, including converted natural land like these farms and pastures, the Galápagos islands are one the cleanest most eco-conscious places I’ve ever been. We would visit places I would call absolute paradise, with long stretches of soft sand and a view of a perfect turquoise ocean where we had only the ever-present Galápagos sea lions as our company. These spots had no bar, no bathroom, no infrastructure whatsoever reminding you of the impact of humans. Still even in these pristine areas, if you dig a little bit, you will see our legacy on the planet. Dan had students doing microplastic surveys using sieves and regular spaced plot areas, and just below the top layer of sand they found enough plastic (mostly objects carried by the currents from elsewhere) in a few short minutes to fill a small garbage bag. The Galapagueños all seemed to be on board with keeping the ecotourism model a relatively small operation; leaving most of the islands uninhabited and untouched (although also somewhat vulnerable to illegal foreign fishing vessels and other poachers – see Bonaccorso et al. 2021). We were in Ecuador during a period of unrest particularly in Quito. Indigenous mainlanders and others were fighting for their rights in the mainland, and even the Galápagos fishers were protesting expanded no-fishing seasons meant to protect the wildlife. Dan and I asked the students to come up with ways they would try to explain to the local fishers, whose livelihoods were at stake, how they would approach discussing these added restrictions. I was proud that these students recognized their privilege but also came up with some brilliant ways of discussing long term sustainability as discussion points for explaining the need for shorter fishing seasons (with an understanding that in the end the fishers may be right).

(Top Row) Green Sea Turtle, San Cristóbal Giant-Tortoise, Bravo Clinid, (Bottom Row) Waved Albatross, Marine Iguana, The author with a Galapagos Penguin 
 

            

The nearly daily snorkels could be exhausting. As part of earning research credits students would do multiple surveys (in cool, if not frigid, water) identifying and counting the local fish fauna. We saw pufferfish, sharks, damselfish, wrasses, eels, mullet, sea horses, giant mobula rays and much more. The sea lions which were typically lazily lying around the shore line and sometimes the sidewalks and park benches, were playful underwater often circling us like curious puppies. The sea turtles too paid us no mind as we approached (minding the 6-foot limits imposed by the national parks). And that was one of the oddest things about the Galápagos, the animals often ignore you or even come up to you. On Española island I was shocked to be so close to albatross nests and blue-footed boobies and the many thousands of marine iguanas that you sometimes had to almost step over in order to continue on the trail. The mockingbirds (that Darwin studied intently) and the famous Darwin’s finches (which Darwin hardly mentions in any of his books) would land on your feet. The finches, mockingbirds, lava lizards, and of course giant tortoises varied enough by islands that even the students noticed without much prompting that they were distinct species. It was easy to see how Darwin could come here (he visited five islands over five weeks) and come to his conclusions about natural selection and the common origin of life on Earth. For me the lava lizards were the most conspicuously different on the various islands we visited. The marine fauna on the other hand was beautiful and abundant but not as diverse as you might expect – we saw about 35 species on our surveys, far fewer than we would see in some place like Indonesia or many other tropical island regions. This unique but depauperate assemblage was a frequent topic in our ecology and evolution classes.

            Española island had perhaps my favorite Galápagos species on it, you may be surprised to learn that this ichthyologist was enamored with a bird, the Waved Albatross (Phoebastria irrorata). Its strong features, dark eyes set on snow white feathers and yellow bill was simply stunning, that such a creature exists makes me wonder about all of life on Earth. On Española we saw several nesting pairs ready to continue their long-term (sometimes decades long) partnerships rearing the next generation.

We visited several areas with Galápagos tortoises and these giants too left us in awe. There tank like frames, varied shell shapes (the islands are named after the saddle shape of the tortoises’ carapace). They also make hilarious noises (although not as belch-y and comical as the female sea lions which sounded like a raucous slumber party every night). We went to a rearing facility – La Galapaguera that had newly hatched tortoises too. One of my favorite moments at this hatchery was the entire LSU class cheering on one baby tortoise that had fallen onto its back, it righting itself after a few long minutes made us cheer like we had just seen Joe Burrow had throw a touchdown pass against Alabama. The ‘Baby Yoda’ like slow growth meant that you would see individuals not much larger than the box turtles you encounter in the woods in Louisiana except that they would be only six years old. The giants of the giants were closer to one hundred or more. In our snorkels we’d run into sea turtles that seemed as big or even bigger than the tortoises on land. It is no wonder why whalers and other early travelers would come here to refuel and take away these giants for food and profit. There are estimates that over 200,000 such giants were taken from land, and perhaps even more from the seas.  

We also stayed on the more heavily populated Santa Cruz and the young but massive Isla Isabela which still has an active volcano which we climbed (Sierra Negra). We swam through channels on other islands like Kicker Rock, which I think is named that because of how much you have to kick to get through the rocks. I didn’t like Kicker Rock as much as some of our easier snorkels but we did see massive porcupinefish and a surgeonfish, Prionurus laticlavius, which my former PhD student, Dr. Bill Ludt (now Curator at the Los Angeles Natural History Museum) studied for his dissertation. He studied that species and another that was thought to be a different species but for which he did some very good ecological, genomic and natural history sleuthing to discover that they were indeed the same. The one place Bill had trouble getting samples of this species from was the Galápagos, so it was nice to see that the characters he described were indeed mixed and variable in these islands as he predicted. My biggest disappointment was not being able to collect any samples from the islands as my permits did not come in on time. I did leave some tissuing tools behind in case they do become available soon. Perhaps unsurprisingly, collecting permits in the Galápagos are not easy to obtain. We were pleasantly surprised to be able to work on some finch research being done by the lab of Jaime Chavez (an Ecuadorian researcher who is based at San Francisco St. University in California). Using mistnets we caught finches near population centers and weighed and measured them for the Chavez lab’s long term impact study. Apparently, these finches that were famously adapted for different seed sizes, and other specific niches, are learning that they like French fries too. We passed the island of Daphne Major a few times, which was made famous by Peter and Rosemary Grant in one of the greatest natural history evolution experiments of all time. They have studied every individual finch on that island for decades to see how the changing role of climate impacts survival of the different morphs/species that live there (read the Pulitzer Prize winning ‘Beak of the Finch’ by Jonathan Weiner for more). Luckily the island remains uninhabited or we might get French Fry Finches there too (read Kurt Vonnegat’s ‘Galápagos’ if you want to see what might really happen in isolation, even to humans).

Isabela truly was otherworldly – not just because of the volcanic landscape, but surely the best snorkel of the more than a dozen we did was in Los Tunnels where we swam thorough rocky natural archways and with baby Blacktip Reef Sharks (Carcharhinus melanopterus)

in mangroves and saw adult Oceanic Whitetips (Carcharhinus longimanus) resting in their undersea caverns. In spots the water was as clear as a swimming pool, in others there were areas so dense with salps it seemed the entire ocean must be filled with them. 

 Perhaps like Darwin the greatest insights about the Galápagos will come to the students once they return home. Several of them had never traveled abroad before and for their final group project one said, ‘every moment has been a learning experience.’ Who could ask for a better summary of a trip than that?

 

 

Barber, J.R., Plotkin, D., Rubin, J.J., Homziak, N.T., Leavell, B.C., Houlihan, P.R., Miner, K.A., Breinholt, J.W., Quirk-Royal, B., Padrón, P.S. and Nunez, M., 2022. Anti-bat ultrasound production in moths is globally and phylogenetically widespread. Proceedings of the National Academy of Sciences, 119(25), p.e2117485119.

 

Bonaccorso, E., Ordóñez-Garza, N., Pazmiño, D.A. et al. International fisheries threaten globally endangered sharks in the Eastern Tropical Pacific Ocean: the case of the Fu Yuan Yu Leng 999 reefer vessel seized within the Galápagos Marine Reserve. Sci Rep 11, 14959 (2021). https://doi.org/10.1038/s41598-021-94126-3

 

Simonson, T.S., Huff, C.D., Witherspoon, D.J., Prchal, J.T. and Jorde, L.B., 2015. Adaptive genetic changes related to haemoglobin concentration in native high‐altitude Tibetans. Experimental Physiology, 100(11), pp.1263-1268.

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