When on board H.M.S. ‘Beagle,’ as naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past inhabitants of that continent. These facts seemed to me to throw some light on the origin of species—that mystery of mysteries, as it has been called by one of our greatest philosophers. 
-Charles Darwin, “On the Origin of Species by Means of Natural Selection

Galapagos, Ecuador (WHTM) — On Feb. 12, 1809, Charles Robert Darwin was born in England. He is well known for developing the scientific theory of evolution by natural selection after visiting the Galapagos Islands in the mid-1800s, where researchers continue to explore the natural environment that has seen little interference from humans.

As a child, Darwin was interested in plants and nature, and he didn’t quite fit into the typical school system, explained Vanessa Gallo, expedition leader aboard Lindblad Expedition’s National Geographic Islander, which takes guests around the Galapagos Islands and educates them about the area’s geography, wildlife, and history.

Darwin studied medicine at Edinburgh University beginning in 1825, following in the footsteps of his father and grandfather. But after seeing some of the gruesome work that he would be doing as a doctor, he left the school and returned home, Gallo said.

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At the behest of his father, Darwin switched to Christ’s College in Cambridge in 1828, where he began studying theology and humanities and where he was educated as an Anglican gentleman. Here, he also learned more about botany and geology, making important connections with teachers such as Reverend John Henslow, as explained by the Encyclopedia Britannica.

After finishing school, 22-year-old Darwin wanted to travel rather than join the clergy, so he was happy to take the opportunity, suggested by Henslow, to travel aboard the HMS Beagle as a companion to the ship’s 26-year-old captain Robert Fitzroy, who wanted company in his travels to Tierra del Fuego at the southern end of South America.

Darwin suffered from seasickness aboard the Beagle after it set sail in 1831, but that didn’t stop him from working. Although he was just supposed to be a companion to Fitzroy, Darwin acted like a naturalist, avidly collecting specimens — plants, fossils, insects, animals — from the places where the Beagle stopped, Gallo explained.

Darwin’s boxes of samples crowded the already cramped ship, so he began sending them back to family and friends whenever the Beagle reached larger ports, said Gallo. He began to develop a reputation among scientists back home with his extensive collections.

In 1835, the Beagle reached the Galapagos archipelago. Darwin’s first impression of Galapagos was not the most flattering, but the islands separated by ocean but located close to one another created an interesting environment for study.

Nothing could be less inviting than the first appearance. A broken field of black basaltic lava is every where covered by astunted brushwood, which shows little signs of life. The dry and parched surface, having been heated by the noonday sun, gave the air a close and sultry feeling, like that from a stove: we fancied even the bushes smelt unpleasantly. 
Charles Darwin, “Voyages of the Adventure and Beagle

Isabela island, Galapagos (Photo: Avery Van Etten)

In Galapagos, Darwin encountered iguanas, tortoises, and birds that Darwin wrote were “So tame and unsuspecting…that they did not even understand what was meant by stones being thrown at them; and quite regardless of us, they approached so close that any number might have been killed with a stick.”

Their limbs and strong claws are admirably adapted for crawling over the rugged and fissured masses of lava, which every where form the coast. In such situations, a group of six or seven of these hideous reptiles may oftentimes be seen on the black rocks, a few feet above the surf, basking in the sun with outstretched legs.
Charles Darwin on marine iguanas in “Voyages of the Adventure and Beagle

I was always amused, when overtaking one of these great monsters as it was quietly pacing along, to see how suddenly, the instant I passed, it would draw in its head and legs, and uttering a deep hiss fall to the ground with a heavy sound, as if struck dead. I frequently got on their backs, and then, upon giving a few raps on the hinder part of the shell, they would rise up and walk away;—but I found it very difficult to keep my balance.
Charles Darwin on tortoises in Voyages of the Adventure and Beagle

In my collections from these islands, Mr. Gould considers that there are twenty-six different species of land birds. With the exception of one, all probably are undescribed kinds, which inhabit this archipelago, and no other part of the world.
Charles Darwin, Voyages of the Adventure and Beagle

Darwin’s voyage aboard the Beagle ultimately took him for many stops around the southern tip of South America to a few stops in Australia and Africa before he returned home to Europe. His travels inspired many questions, which he continued to ponder after returning home.

Darwin connected with Charles Lyell to discuss geological realizations he had had on his trip. And he worked with other experts to catalog the specimens he and his companions collected, which showed that some of the specimens he had thought were different types of birds actually belonged to the same family, just differently adapted to their environments, according to the Encyclopedia Britannica. Probably the most popular example of this is the group of birds known as Darwin’s finches, but he also had a similar realization with the islands’ mockingbirds.

Finches observed by Charles Darwin (Credit: Getty Images)

In a society that was predominantly religious and creationist, Darwin’s ideas were heretical, so he developed them furtively. Even his wife Emma Wedgewood was not supportive of his ideas, Gallo noted.

Building on Thomas Malthus’ concept of overpopulation, Darwin started to think that competition among organisms in a crowded environment would cause less “fit” organisms to die out — a concept he called “natural selection.” Organisms’ offspring develop random variations, he theorized, and if those variations help them outcompete others to survive and reproduce, they will pass them onto their offspring, and eventually those changes will become more widespread in a population.

Darwin received the Royal Society’s Royal Medal in 1853 for his work with barnacles, and he published books on geology, but he continued to keep his evolution theory secret, Encyclopedia Britannica describes.

In 1858, Darwin got a letter from Alfred Wallace, who had, separately from Darwin, developed a theory very similar to Darwin’s concept of evolution. To avoid being beaten to publication, Darwin allowed some of his colleagues to present his ideas along with Wallace’s to the Linnean Society. Then Darwin began writing an abstract detailing his theory, which turned into “On the Origin of Species by Means of Natural Selection.”

“On the Origin of Species” was published in 1859. Darwin’s contemporary and friend Thomas Huxley defended the theory publicly, stepping into the role the more cautious Darwin was hesitant to take. And while Darwin had avoided directly linking humans with apes, others rapidly made the connection after his work was published, according to the Encyclopedia Britannica.

Darwin continued to write after “On the Origin of Species,” even though he suffered from periods of illness. He wrote several updated editions of “On the Origin of Species.” He studied pollination of orchids and published “The Various Contrivances by which British and Foreign Orchids are Fertilised by Insects” in 1862, and after further studying the effects of cross-pollination, he published “The Effects of Cross and Self Fertilization in the Vegetable Kingdom” in 1876. He also published “Variation of Aminals and Plants under Domestication” in 1868 after investigating variation and selection of traits in domesticated breeds. And he published other works on similar veins of research, as well.

In 1871, Darwin published his two-volume work, “The Descent of Man, and Selection in Relation to Sex,” in which he delved into the evolution of humans and civilization and addressed some common criticisms of his theories, according to Encyclopedia Britannica. Between 1876 and 1881, Darwin wrote an autobiography, which he intended to be for his grandchildren.

Darwin died from a heart attack on April 19, 1882, and was buried at Westminster Abbey.

In a late edition of “On the Origin of Species,” Darwin added some notes about Galapagos, “and with these pages, he is changing the Galapagos forever,” Gallo, who lives on the island of Santa Cruz, said. Darwin told people that if they visited the Galapagos Islands, they “would be able to see evolution in action,” said Gallo.

That excited scientists, and it led to conservation efforts in the archipelago, Gallo said. The Galapagos National Park was created in 1959, 100 years after Darwin published “On the Origin of Species,” to recognize and protect the islands’ unique species and geology as well as the location’s role as “a living laboratory of evolutionary processes still underway,” according to the Galapagos National Park website.

Isabela island, Galapagos (Photo: Avery Van Etten)

The park’s website states that 97% of the land of the islands is protected. A recently expanded marine reserve also helps protect the aquatic life of Galapagos.

Research in Galapagos continues today with organizations like the Charles Darwin Foundation in Puerto Ayora on the island of Santa Cruz, which maintains an extensive and carefully preserved natural history collection.

“I’m very happy with what [Darwin] did because without that, without what he published in the last edition of ‘On the Origin of Species,’ Galapagos would not be here as it is. Without this protection, without this conservation, it would have been gone — people fishing, there’d be hotels — all gone. So we’re very happy with what he started and what all the scientists continue even nowadays; they haven’t stopped,” said Gallo.