In yesterday’s post, we mentioned we’d be sharing information about Charles Darwin and his impact on The Galapagos Islands, emblazoned in the public’s minds for past and future generations. After reviewing the description of his life from many sources, I found this source to be most informative. I have edited it in part to fit the size and nature of our posts.

“Charles Darwin: History’s most famous biologist…

By Kerry Lotzof

Charles Robert Darwin (1809-1882) transformed the way we understand the natural world with ideas that, in his day, were nothing short of revolutionary. He and his fellow pioneers in the field of biology gave us insight into the fantastic diversity of life on Earth and its origins, including our own as a species.

Data has revealed that they can dive down to 200 meters and hold their breath for more than 20 minutes. Their natural predators are sharks and orcas; whales very rarely fish sea lions in the Galapagos. The biggest colony of sea lions in the archipelago is in Puerto Baquerizo Moreno and San Cristobal.

Charles Darwin is celebrated as one of the greatest British scientists who ever lived, but in his time, his radical theories brought him into conflict with members of the Church of England.

Young Charles Darwin

Born in 1809 in Shrewsbury, Shropshire, Darwin was fascinated by the natural world from a young age. Growing up, he was an avid reader of nature books and devoted his spare time to exploring the fields and woodlands around his home, collecting plants and insects. In 1825 Darwin enrolled in medical school at the University of Edinburgh, where he witnessed surgery on a child.

Seals and sea lions are marine mammals called ‘pinnipeds’ that differ in physical characteristics and adaptations. Sea lions (left) are brown, bark loudly, “walk” on land using their large flippers, and have visible ear flaps. Seals have small flippers, wriggle on their bellies on land, and lack visible ear flaps.

Surgeries at the time would have been carried out without the use of anesthetic or antiseptics, and fatalities were common. Watching this procedure left Darwin so traumatized that he gave up his studies without completing the course.

During his time in Edinburgh, Darwin also paid for lessons in taxidermy from John Edmonstone, a former enslaved man from Guyana. The skills Edmonstone taught Darwin became crucial just a few years further into his career. After his time in Scotland, Darwin went to Cambridge University to study theology.

These sea lions have gone without many predators because of their isolated location. The only predators they have are sharks, killer whales, and dogs. So, like most Galapagos animals, they have no reason to fear people.

The voyage of HMS Beagle

In no rush to take holy orders in 1831, Darwin accepted an offer to embark on a five-year voyage aboard HMS Beagle. One of his Cambridge professors recommended him for the role of naturalist and companion to the ship’s captain, Robert FitzRoy.The journey would change both his life and the trajectory of Western scientific thinking.

Most other marine mammals in the Galapagos cannot be considered residents because they are migratory. There are only two species of seals (including the Galapagos sea lion), two whales, and two dolphins that are true Galapagos residents.

Darwin explored remote regions and marveled at a world so different from the one he knew. He encountered birds with bright blue feet, sharks with T-shaped heads, and giant tortoises. Darwin collected plants, animals, and fossils on his travels and took copious field notes. These collections and records provided the evidence he needed to develop his remarkable theory.

The Galápagos mockingbird (Mimus parvulus) is a species of bird in the family Mimidae. It is endemic to the Galápagos Islands, Ecuador. This bird had no fear of Tom, standing quite close to him.

Darwin returned to England in 1836. A highly methodical scholar, constantly collecting and observing, he spent many years comparing and analyzing specimens before finally declaring that evolution occurs by a process of natural selection.

What is the theory of natural selection?

To this day, the theory of evolution by natural selection is accepted by the scientific community as the best evidence-based explanation for the diversity and complexity of life on Earth. The theory proposes that the ‘fittest’ individual organisms – those with the characteristics best suited to their environment – are more likely to survive and reproduce. They pass on these desirable characteristics to their offspring.

There were many other boats in the area.

Gradually, these features may become more common in a population, so species change over time. If the changes are great enough, they could produce a new species altogether. On his travels, Darwin had collected finches from many of the Galápagos Islands – off the coast of Ecuador – which helped him to formulate his idea.

The waved albatross, also known as The Galapagos albatross, is one of three species of the family Diomedeidae that occur in the tropics. When they forage, they follow a straight path to a single site off the coast of Peru, about 1,000 km to the east.

Some of these finches had stout beaks for eating seeds, and others were insect specialists. But Darwin realized that they were all descendants of a single ancestor. As they dispersed to different islands, the birds adapted to eat the various foods available. Natural selection has produced 13 different species of finch.

Darwin’s pigeons

From his travels on HMS Beagle, Darwin suspected that the environment might naturally manipulate species, causing them to change over time – but he couldn’t find a means to explore this effectively in the wild. Experimenting with artificial selection in pigeons gave him a way to study how far a species could change. By artificially selecting features – crossing birds with particular characteristics to generate different offspring – he gathered valuable evidence for evolution by natural selection.

These sea lions may look like the California sea lion (Zalophus californianus) but are different. They are smaller and breed primarily on the Galapagos Islands.

To illustrate his theory, Darwin bred the birds to have exaggerated features. The similarity between artificial selection and natural selection is at the heart of his explanation of evolution in his revolutionary book On the Origin of Species. After completing his experiments, he gave all 120 of his pigeon specimens to the Museum. They are currently part of our bird collections kept at Tring, Hertfordshire.

The adult males are larger than the females. When dry, they are usually dark brown or varying shades of gray. The adult males have a pronounced bump on their foreheads. Adult females are light brown or tan with a smaller forehead. All sea lion pups are dark brown when born, and as they mature, they change to light brown or tan. Young Galapagos sea lions have a nearly flat head.

A shared discovery

Darwin knew his radical ideas would be met with stiff opposition. Even after 20 years of research, he worried about how his theory of evolution would be received as it challenged widely held religious beliefs of the time.

He delayed publishing on the topic for a great number of years while he assembled a mountain of evidence. Darwin volunteered to send Wallace’s ideas to a journal for immediate publication when he learned that the young naturalist Alfred Russel Wallace had developed similar ideas.

While larger animals in the Galapagos (like cows, goats, and horses) exist, sea lions are the largest endemic land animal. These islands are 1000 kilometers (600 miles) from the mainland – that’s a long swim for a land animal.

On advice from friends, the two scientists organized a joint announcement. Their theory of evolution by natural selection was presented at the Linnean Society in London. Both had studied the natural world extensively and made several observations critical to the development of the theory. The following year, Darwin published the contentious but now-celebrated book, ‘On the Origin of Species.’

The American Oystercatcher is found in the intertidal zone of most Galapagos Islands. Their population is small; around 400 birds live in the archipelago.

On the Origin of Species

Published in 1859, On the Origin of Species provoked outrage from some members of the Church of England as it implicitly contradicted the belief in divine creation. Despite accusations of blasphemy, the book quickly became a bestseller.

Great apes

The Descent of Man and Selection in Relation to Sex – which Darwin published in 1871 – fuelled even greater debate as it suggested that humans descended from apes. The Bishop of Oxford famously asked Thomas Huxley, one of Darwin’s most enthusiastic supporters, whether it was through his grandfather or grandmother that he claimed descent from a monkey.

This is something many people want to experience when they visit the Galapagos, and it’s definitely a thrill. The young pups stay in shallow waters until they are around five months old. During that time, they don’t even fish for themselves. They have no reason to be territorial or aggressive. Even at 12 to 24 months, they are only partially independent; they will continue to nurse until their mother has another pup. And even then, she may continue to nurse the older pup. They don’t mature until they are around 4 to 5 years old.

Despite the attacks, Darwin’s conviction in the scientific explanation that best fits the available evidence remained unshaken. He was keen for his ideas to reach as many people as possible and for his books to be read in many different languages. Part of his success has been attributed to his conversational and approachable writing style.

Since Galapagos sea lions don’t migrate outside the archipelago, their breeding season isn’t dependent on migration patterns. And while their breeding season may vary from year to year, it normally lasts 16 to 40 weeks between the months of May through January. For that reason, you might see pups throughout the year.

The Origin of Species was so influential that within a year, it had been published in German. In Darwin’s lifetime, his book was translated into German, Danish, Dutch, French, Hungarian, Italian, Polish, Russian, Serbian, Spanish and Swedish. Our Library has 478 editions of On the Origin of Species in 38 languages and in Braille.

Darwin and the Tree of Life

Charles Darwin used the concept of a Tree of Life in the context of the theory of evolution to illustrate that all species on Earth are related and evolved from a common ancestor.

The tips of the branches show the species that are still alive today. The tree also shows those that are now extinct. Darwin explained:

‘From the first growth of the tree, many a limb and branch has decayed and dropped off; and these fallen branches of various sizes may represent those whole orders, families, and genera which have now no living representatives, and which are known to us only in a fossil state.’

Orders, families, and genera are all groups that can be used to classify organisms. The lines on the tree show evolutionary relationships between species. For example, a recent version of the Tree of Life would show a line between some types of dinosaurs and the earliest birds, as scientists reason that birds evolved from a particular lineage of dinosaurs.

This means that closely related species are found close together, stemming from the same branch. For example, humans, chimpanzees, gorillas, and orangutans are all great apes, so they all belong to the same branch of the tree of life.

Darwin’s legacy

Although Darwin’s theory of evolution has been modified over time, it remains fundamental to the study of the natural world. Darwin changed not only how we see all organisms but also how we see ourselves.”

Darwin was, without a doubt, a pioneer in his time. Some may not believe the extent of his theory, but if you are interested in learning more, you can read his book and many other publications written about his life and theory. How exciting for us to be in this magical place in our lives.

We are grateful for this experience, however, limited it may be for me right now since I am learning so much from the daily talks by the two naturalists, Juan Carlos and Orlando, the wonderful photos Tom is taking on each excursion, and my research in the process of it all. I am not disappointed at all.

Now, on to another topic…Last night, I received a private email from a reader (one of many we receive each day) whose name I won’t disclose to protect his privacy that read as follows:

“Hi,

I have been reading your blog for years and was sorry to read you could not accompany Tom on the excursions. I would appreciate it, and I believe many of your readers would too if you could describe in detail with pictures the environment and obstacles one might encounter on these types of excursions. I have a bad knee and can not walk long distances so I would like to know the details. Things include getting in and out of the zodiacs, terrain encountered, wet/dry conditions, etc.

Thank you so much, and I wish you continued enjoyment in your travels.”

I wish we had thought of taking photos of the walking and hiking environment sooner. Unfortunately, we were so focused on the wildlife and scenery that we didn’t center our attention on the terrain specifically. However, I borrowed the following three photos from other passengers, as shown below.

Shipmates Karin and Stephen took this photo of the rocks to navigate at another location.

Tom says, “There are times when paths consist of small pebbles and other times when there are large lava rocks and boulders that are hard to navigate. Sometimes, it’s just a walk on a smooth sandy beach.”

A photo of a lot easier trail shipmates Karin and Stephen took on a walk.

Each evening, either of the two naturalists at a nightly briefing session describes in detail the excursion for the next day, including some photos of the terrain and any potential walking hazards. Many of the walks were shorter, but some were as long as 1½ hours. At times, there were options to embark on the long or short walk, which could be beneficial in your case.

It’s hard for us to determine if you’d be able to tackle these excursions based on the severity of your knee condition. Even getting on and off the panga boat (the Zodiac boat) was too difficult for me to participate in any of the activities. The boat ride may be smooth or choppy, during which one has to use one’s legs to support oneself since there are no specific seats on these boats. One must use their legs to hold themselves up while sitting on the inflated rubber sides of the boat.

Shipmate John took this photo of the rocks the passengers have to navigate on an excursion. It’s not too easy for those with walking disabilities.

We probably wouldn’t have booked this cruise if we knew how difficult these excursions would be based on my unsteadiness. However, as it turns out, we made the best of it and have enjoyed ourselves and learned a lot. Only you can decide if this would work for you.

That’s it for today, folks.

Be well.

Photo from ten years ago today, October 19, 2013:

Tag: Tree of Life

Day 6…Celebrity Xploration…The Galapagos Islands…Charles Darwin’s influence on The Galapagos Islands…A reader writes, asking a valid question…