by Jerold Last
The biologist-guide, a young man with an academic look and a pleasant slight French accent, took the microphone to explain what made the Galapagos Islands so special. “On each of the islands we visit, you’ll see clear evidence of the volcanic origin of these islands: volcanoes, rocks, lava flows, cinders and scattered volcanic rocks, vents, and calderas. The guides will point out these features as you come to them, and we’ll show you some typical formations in the slide shows. The island chain is young in geological time, 2-3 million years old. We believe all of the native species of living plants and animals on the islands arrived here by swimming or floating on trees or rafts from coastal South America. In the last couple of hundred years non-native species originating from ships that visited here have also become established.
“You’ll notice that none of the animals seem to be afraid of humans. They’ll let you come close and study them. That’s because they’ve lived here so long without their normal predators they have no fear of being eaten. The guides will talk about a few exceptions to that like tortoise poaching by humans for food and their shells and illegal fishing as they discuss the different species you’ll see.”
The biologist paused briefly to take a drink of water from a small bottle on the podium. “The weather here isn’t what you’d expect from an island archipelago in the middle of the Pacific Ocean sitting right on the Equator. Our weather originates from the two strong ocean currents that dominate here. From May to December the South Equatorial Current, which flows south to north, brings cold water to the area, which makes for cold air, fog, and a windy drizzle. Think about San Francisco in the summer months, when the marine layer comes on shore. The rest of the year, from January to April, is the “rainy season”, when the south-flowing current called the “El Niño” dominates. This time it’s warm water from the Gulf of Panama, which warms the air and brings bright sunshine and enough humidity with it to cause occasional heavy rain. The islands are deserts except during the “El Niño” periods, which only happen in certain years.
“The vegetation on the islands has to be drought resistant and hardy to survive. The animals here have to be able to feed on this sparse vegetation, fish, or other marine life. The native animals that were able to get here originally to populate the islands, 600 miles off the coast, are strong swimmers or fliers if they eat fish, or are reptiles, which can handle the small amount of water available most of the time and aren’t damaged by floating a long time in salt water. There’s only one terrestrial mammal species native to the islands, the rice rat. There aren’t any native amphibians or freshwater fish.”
He raised a paperback copy of Darwin’s “The Origin of Species” over his head. “How many of you have read this book?”
A sprinkling of hands went up in the audience.
The biologist lowered his copy of the classic book and put it down on the lectern in front of him. “Good,” he said, “This evening I’d like to briefly talk about a few of the things that are in this book and a couple of other things that aren’t. There are a lot of misconceptions about Darwin---what his theories are all about and what he himself thought. I’ll be brief, but I think you’ll all get more out of seeing the Galapagos Islands if you have a little context about what Darwin saw when he was here and how his views about nature changed as a result of his visits.”
He paused for a dramatic moment or two to let what he had just said to us sink in before continuing. “Darwin’s job as a naturalist on HMS Beagle was to count the different species of plants and animals on the islands as part of creating an inventory of what lived in the Southern Hemisphere. Let’s start with a few facts that Darwin studied and learned. Here in the Galapagos there are a lot of birds, reptiles, and marine animals living together in a relatively stable environment. While the various populations fluctuate over time, the actual numbers of each species here remain roughly the same size unless human intervention threatens a species. Resources, especially food, are limited, and are also relatively stable over time. Each of the different species on the islands is fertile and produces more than enough offspring to maintain the population.”
He paused again for a moment to let this additional information sink in. “What did Darwin conclude from these facts? As he thought about what he saw, he inferred that there must be an ongoing struggle for survival between the individuals within a species and between the different species sharing the space here. Many of the species ate similar foods, so they competed for the fish, the plants, and the habitat they needed to survive. And that thought process got him into asking the question of who wins and loses in this struggle for survival? Are there rules that determine who will win and lose?”
There was another dramatic pause before he asked his big question for the evening. “What do you folks think he suggested was the most important rule for picking which individuals and which species would win and which would lose?”
He looked out over his audience. The group responded with dead silence. People were afraid to answer for fear of being wrong and looking foolish, just like students anywhere.
“Come on, somebody suggest something,” requested our biologist.
A small, quiet voice from somewhere in the back of the room very tentatively suggested, ever so cautiously, “Bigger and stronger individuals took the food because the smaller ones couldn’t compete with them.”
“Good,” replied the biologist. “Does anyone else have any ideas to share?”
The first answer opened the floodgates and everyone tried to answer at once. After a minute or two things settled down. The biologist continued, “Look around you carefully at the plants, birds and animals tomorrow as you explore the islands. You’ll see there’s a lot of difference between the individuals in any of the species you look at, and between the different species. There are a lot more differences between the blue-footed boobies and the ones with red feet than just the color of their feet. Look at the families of birds and marine mammals you see. Do they look more alike than unrelated birds of the same species? Is the natural variation within the species inheritable?
“Darwin’s major contribution to science was the Theory of Natural Selection, which he published in 1858, simultaneously with another English scientist named Alfred Wallace, who independently developed a similar theory. Darwin first worked on developing these ideas between 1837 and 1838, just after the Beagle returned him to England after his 5-year voyage in South America. He was the first to suggest that individuals less suited to a specific environment were less likely to survive and less likely to reproduce. Conversely, individuals more suited to a specific environment were more likely to survive and more likely to reproduce, and to leave the inheritable traits that made them better suited to the specific environment to their future generations. He called this process natural selection.”
The biologist paused again to sip some water from his bottle on the podium. “He also suggested that as populations changed to adapt to their environments, the variations accumulated over time to create new species. Thus he had a theoretical explanation for evolution, which hadn’t been explained before his ideas. Limited resources lead to an individual struggle for existence, either against other individuals of the same species or against the environment, or most commonly against both.”
A hand went up in back. “I thought Darwin was the first scientist to suggest the idea of evolution. Before him didn’t everyone believe in the literal truth of the bible?”
“Actually, no,” replied the biologist. “Aristotle tells us that the early Greek philosophers like Empedocles had suggested that living species evolved on Earth. The early Christian church and medieval western scholars interpreted Genesis as an allegory rather than literal fact. It wasn’t until the Protestant reformation that the Christian church started teaching the literal truth of the bible. Charles Darwin’s grandfather Erasmus Darwin suggested in the 1790s that transmutation of species occurred by spontaneous generation. Jean-Baptiste Lamarck actually thought acquired characteristics could be in
herited, and in 1809 he published his theories, which have been influential ever since. And, parenthetically, partially correct, as the modern science of epigenetics seems to be telling us.”
He paused to take a long drink of water from his bottle before handing the microphone to Juana.
Juana took her turn at the microphone, “Tomorrow we’ll visit Bartholomew Island, which contains the highest point in the Galapagos Islands, Pinnacle Rock. You’re all going to have to do some climbing to get there but I promise you a spectacular view of sunrise over the ocean and a great view of the islands. Those of you who enjoy snorkeling will have a good opportunity to see fish and marine animals just off the beach.
“In the afternoon we’ll be visiting James Island, also called Isla Santiago. If you’re lucky you may get to see some of the famous Galapagos Tortoises, which are mostly found on the largest island in the Galapagos, Isabela, right across the channel from Santiago. The wild tortoise population is protected---no touching, no hunting, no removing from the area. Despite all of our precautions, we’re still losing the wild Galapagos Tortoises, which are land tortoises, and several of the other marine tortoise species to poachers and other predators. The park is totally dependent on the tortoise-breeding center, a breeding and release facility on Santa Cruz Island, to maintain the population of large tortoises in the wild areas of the park. The center, operated by the Darwin Research Station and the Ecuadorian National Park Service, is the largest scientific facility in the park.”
After the presentation several of the Frigate Birds group gathered over dessert and coffee in the back of the room. The conversation centered on what we’d just seen and heard this afternoon. Barbara Kaufman started things off with a comment about the boobie birds. “Have you ever seen a funnier looking bird than the blue-footed boobies, especially when they’re landing?”
“They may look funny,” replied Inge Schultz, “But keep in mind that Charles Darwin would argue they are present here in such large numbers because they’re better adapted to this local environment than any of the other species that could have colonized the niche they occupy.”
“Does anyone know where they got their name?” asked Barbara. “It’s kinda weird.”
Dieter chuckled at that. “Not so weird perhaps. More descriptive, I’d say. ‘Blue-footed’ because that’s the color of their feet, of course. The usual explanation of where ‘boobie’ comes from is from a corruption of ‘bobo’, the Spanish word for a clown. Blue-footed clowns are a good description, wouldn’t you agree?”
Barbara nodded her thanks. She, her sister Gretchen, and Suzanne began a private conversation I couldn’t help but listen to, as I was standing right beside my wife.
Suzanne asked, “Of all the things you expected to see in the Galapagos, Gretchen, what was at the top of your list before you got here?”
“That’s easy,” she replied. “Barbara and I have been very active in several of the big conservation groups. Since we were in high school, we’ve given donations to and raised money for The Sierra Club, The World Wildlife Foundation, Save the Tortoises, the Nature Conservancy, and a few other organizations that try to maintain native habitat and animals in their normal state in the wild. This trip is Item #1 on both of our bucket lists, seeing the animals in their native habitat as they’ve lived for thousands of years with minimal impact from human hunting and development. I’d say the birds and tortoises were at the head of the list for both of us. How about you?”
Suzanne had been thinking about this, so her answer was ready. “I read Darwin the first time when I was in high school, and again in a few college courses. I’ve always wanted to see the real thing so I could better understand what inspired him to make one of the greatest intuitive leaps in the history of biology. I’m looking forward to picking up some of the same vibes Darwin might have experienced 175 years ago. And maybe I’m fantasizing that Robert could be influenced by the same vibes and start falling in love with biological science as it washes over him, even if he’s still much too young to understand any of it.”
The Australian couple, the Weavers, wandered over and joined the conversation. “Did you folks ‘ear what Juana said aboot the Galapagos Tortoises? How they’re poached and threatened with extinction? We can tell you all aboot that. Emily and I live in a part of the world with a lot of traditional Chinese medicine all ‘round us. We visited Singapore and ‘ong Kong last year on a tour. Closer to ’ome there’s a big Chinese population in Darwin up in Queensland. They all believe that ground-up Tortoise shells can cure a lot of different sicknesses. You can find tiny packets of ground tortoise shells for sale in the specialty markets for thousands of dollars an ounce. Those poachers make a lot of money if they can get away from ‘ere with a tortoise. Ain’t that right, Wifey?”
Emily Weaver beamed at her husband. “Righto. Poaching wild animals is big business if you can sell the pieces on the black market. Traditional Chinese remedies like rhinoceros horns, tiger bones, bear bile, tortoise shells, and seahorses sell for huge sums of money, and there’s a population of more than a billion potential customers to sell the stuff to. It’s easy for us to criticize the people who buy this stuff, but lots of other cultures hunted species almost to extinction for even worse reasons. A century ago in the USA, for example, they killed millions of birds in Florida for their feathers, and killed most of the native beavers in the country to make stupid hats that were considered fashionable.”
Victor Weaver got that look you get when you remember something you want to mention but don’t remember the details. “Oi, Emily. Wasn’t there some kinda big deal about one of them tortoises a few years back at ‘ome?”
Emily Weaver turned out to have a better memory than Victor. She seemed to defer to her husband to speak for the couple unless she felt she had something important or topical to add to the conversation. Now she did. “Let me tell you a bit more about those Galapagos Tortoises the biologist spoke on. We actually met one named Harriet back home in Queensland, at the Australia Zoo, Steve Irwin’s big reptile park and zoo north of Brisbane. You all know Steve from TV. He was the famous Crocodile Hunter before he drowned a few years back.
“Harriet lived to be about 175 years old, so she had a history almost as long as Australia’s. Harriet was actually collected by Charles Darwin when he was here in the Galapagos Islands in 1835 and brought back to England with him. After that, Harriet came to Australia in 1841 with John Wickham, the captain of the Beagle, when he retired from that ship’s command. Captain Wickham came to Brisbane as a British Government official with all his belongings, including three Galapagos Tortoises, named Tom, Dick, and Harry. Eventually Wickham left Australia to move back to Europe, and all three of his Galapagos Tortoises were moved to the Brisbane Botanical Gardens.”
“Righto,” replied Victor.
Emily continued, “Tom died during World War II. He was preserved and put in the Queensland Museum where Tom’s remains were studied by biologists. They discovered he was a she. It turned out that Harry was also a female, so she became Harriet about 60 years ago. After World War II, Harriet became a national heroine in Australia because she was so old. She was moved to an animal sanctuary outside of Brisbane where they had better facilities for her in the 1950s, and to the Australia Zoo in the 1980s. The whole country celebrated her 175th birthday a year or so before she died of old age and heart failure. Just about everybody in Australia knows a bit about Galapagos Tortoises because of Harriet.
“There’s one thing in particular I remember from all those stories about Harriet. It’s very hard to breed these animals in captivity so she was never able to have baby tortoises. The Honolulu Zoo in Hawaii is the only place in the world other than the Galapagos Islands where they’ve been able to breed substantial numbers of the tortoises. That’s why they’re so rare and why their shells are so valuable for the game poachers, like the biologist told us.”
With that fascinating addition to our conversation the party broke up to go back to their cabins to prepare
for dinner. When we were alone I turned to Suzanne and asked, “Have you noticed one family of birds here in the Galapagos having trouble finding their niche?”
Suzanne grimaced as she replied, “I sense a bad pun coming on, Roger. What family of birds is that?”
“I was wondering if you’d noticed the trio of lovebirds, Barbara and Gretchen Kaufman and Raul Vonhorst, seem to have split up? The Kaufman sisters are with us in The Frigate Birds, while Raul is in a Spanish-speaking group. Do you think their hormones weren’t up to the task of counteracting the hangovers? Or do you think maybe there wasn’t much going on between them in Quito?”
Suzanne looked thoughtful. “It’s funny you asked me the question now, Roger. I’ve been thinking about them all day, along much the same lines. In retrospect I’ve been wondering if all three of them spent the day together at the museum and city tour for reasons other than romance. They really don’t seem to have anything in common except liking to party late at night. It’s almost like all three of them were trying to size each other up.”
I’m always fascinated by a mystery, no matter how trivial. “We should have plenty of chances to chat with the girls on this tour. Maybe you can solve this little mystery if you encourage them to confide in you, Suzanne.”