In 1831, not long after Charles Darwin finished his university studies, he was recommended by one of his mentors (John Henslow) for a position on Her Majesty’s Ship (HMS) Beagle, a Royal Navy vessel that was preparing for a survey voyage around the world. Darwin accepted the job of naturalist, and whenever possible during the five-year voyage, he went ashore to study rocks and to observe and collect plants and animals. Overall, Darwin spent three years and three months on land and 18 months at sea. Darwin's observations during this voyage helped him formulate his theory of evolution by natural selection.
December 27, 1831
With Charles Darwin as the ship’s naturalist and Robert FitzRoy as captain, the HMS Beagle sailed from Plymouth, England.
January 6, 1832
The Beagle reached Tenerife Island, the largest of the Canary Islands, which Darwin had dreamt of visiting. Darwin was delighted to see the Peak of Teneriffe from the ship, but was disappointed when the crew of the Beagle was not allowed to go ashore. They would have had to perform a 12-day quarantine period to avoid bringing cholera from England to the islands. Captain FitzRoy decided, instead, to sail onward to the Cape Verde Islands.
January 16–February 7, 1832
The Beagle anchored at Porto Praya (now Porto Praia) on the island of St. Jago (now Santiago), the largest island in the Cape Verde archipelago. Darwin spent 23 pleasant days collecting and exploring on this island. The island was a study in contrasts: the coast presented scorching heat, lava plains, and soil unfit for vegetation in most places, while the valleys were lush.
Darwin spent time contemplating the geology of the volcanic island. He observed a layer of seashells embedded 45 feet above water on an upraised coast and wondered how long ago they had existed on the sea floor. Darwin also observed the habits of marine animals, including sea slugs (Aplysia) that emit a purplish-red fluid when disturbed and cuttlefish that can change their color to escape detection.
February 29–March 18, 1932
After several weeks at sea, the Beagle arrived on the coast of Brazil at the city of Salvador. Darwin described this first day in South America in his published journal of the trip (The Voyage of the Beagle),
“Delight… is a weak term to express the feelings of a naturalist who, for the first time, has wandered by himself in a Brazilian forest. The elegance of the grasses, the novelty of the parasitical plants, the beauty of the flowers, the glossy green of the foliage, but above all the general luxuriance of the vegetation, filled me with admiration.”
April 4–July 5, 1832
After a few weeks of survey work, the Beagle arrived in Rio de Janeiro. In Rio, Darwin met and accompanied an English merchant and several others on a journey to the man's estate, 300 miles round trip by horseback. They stayed in small villages and estates along the way. Darwin saw firsthand the cruel treatment of slaves on this trip. Darwin was vehemently against slavery and vowed at the end of his voyage never to visit a slave country again. Darwin spent the remainder of his stay in Rio in a cottage at Botafogo Bay. He found it idyllic and wrote,
“In England, any person fond of natural history enjoys in his walks a great advantage, by always having something to attract his attention; but in these fertile climates, teeming with life, the attractions are so numerous, that he is scarcely able to walk.”
July 26, 1832
The Beagle anchored at Montevideo. For the next two years, the Beagle surveyed the southeastern coast of South America, as well as the Falkland Islands. Darwin spent much of this time exploring on land and collecting specimens to send back to his mentor, John Henslow, in England. In the town of Maldonado alone Darwin collected several quadrupeds, eighty kinds of birds, and many reptiles, including nine species of snakes. He noticed striking differences between the species he saw in South America and those of Europe. Darwin was also pleased to find the teeth and fragments of large extinct animals.
As part of these two years, the Beagle surveyed the coast of Tierra del Fuego, where Darwin first encountered the living conditions and culture of the indigenous people. In a letter to one of his sisters he wrote,
“…the difference between a domesticated & wild animal is far more strikingly marked in man.”
He thought the native Fuegians lived in a miserable state, naked in inclement weather and living in temporary houses made from boughs of trees. For Captain FitzRoy, one reason to anchor at Tierra del Fuego was to repatriate a few native Fuegians who were taken years earlier from their native land to England for religious instruction. The repatriated Fuegians were to serve as missionaries to their people in Tierra del Fuego.
June 11, 1834
The Beagle sailed into the Pacific Ocean. In July, the Beagle let Darwin off at Valparaiso, Chile, where he began his first inland excursion into the Andes. He became quite ill during that trip and ended up staying with a friend in Valparaiso for a month to recuperate. After he had recovered, the Beagle picked him up to continue surveying the coast of Chile.
March 11, 1835
The Beagle again anchored at Valparaiso, Chile. Darwin began another inland expedition that took him into the Andes. At a number of points along the voyage of the Beagle, Darwin had already noticed the unusual location of fossil shells significantly above sea level. In the Andes he found fossil shells at nearly 14,000 feet. He wrote,
“Daily it is forced home on the mind of the geologist, that nothing, not even the wind that blows, is so unstable as the level of the crust of this earth.”
Darwin deeply enjoyed his 24-day excursion, after which he returned to Valparaiso.
April 27–July 5, 1835
Darwin set out on a 420-mile journey northward from Valparaiso to a port near Copiapó, Chile, where he met the Beagle. In this two-month journey, he studied the geology of the landscape as he traveled along the coast, into the Andes, and on desert plains. He explored copper, silver, and gold mines, and observed Indian ruins. In a letter to one of his sisters he wrote,
The country is very miserable; so burnt up & dry, that the mountains are as bare as turn-pike roads, with the exception of the great Cacti, covered with spines.”
July 19, 1835
The Beagle anchored at Callao, the seaport of Lima, Peru, where the ship and Darwin stayed for six weeks. Darwin didn’t enjoy the cloudy weather. He also didn’t explore as much as he would have liked, because Peru was in a state of political anarchy at the time. For security reasons Darwin kept his excursions within the town’s limits. He was anxious to get to the Galápagos Islands, which he believed would be interesting in both geology and zoology. He was particularly interested in having a look at an active volcano.
September 15–October 20, 1835
The Beagle arrived at the Galápagos Islands (west of Ecuador), and Darwin took the opportunity to study the unusual flora and fauna of the islands. Darwin noted that most of the animals were endemic (found nowhere else) to the islands, although they were similar to animals found on the mainland of South America. Darwin also observed that the fauna of the Galápagos differed from island to island. He postulated that in earlier times some animals from mainland South America had arrived on the archipelago and had subsequently undergone different and distinctive changes on each of the islands. He wondered what might account for these changes.
Darwin's Finches
Of the land birds, Darwin noted 13 species of finches, which varied in beak size. Darwin wrote,
“Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends.”
November 15–December 26, 1835
After an ocean voyage of 3200 miles, the Beagle reached Tahiti and stayed for more than a month. The people and landscape of Tahiti charmed Darwin. Darwin ate well and enjoyed the excursions to the interior of the island, which had extensive groves of wild banana. FitzRoy, Darwin, and others met with the Queen of Tahiti to discuss a debt she owed the British government, a debt that she agreed to pay back.
December 21–December 30, 1835
Having crossed the Pacific Ocean, they arrived at New Zealand. In comparison to Tahiti, Darwin found New Zealand an unpleasant place. He described the natives in their persons and houses as filthily dirty and offensive. He found that walking excursions were difficult because land was thickly covered with ferns and otherwise interrupted by creeks and deep brooks.
January 12–January 30, 1836
The Beagle anchored within Sydney Cove. Darwin admired Sydney, which had broad, clean streets and reminded him of the London suburbs. He noted the aborigines wandering homeless in the town and wrote that their numbers were rapidly decreasing, in part due to disease brought from ships. To see some of the country, Darwin hired a man and two horses to take him to a village 120 miles in the interior. On one morning he was taken out kangaroo hunting, but never saw a kangaroo, an animal that he described as becoming scarce in part due to the destructiveness of the English greyhound.
February 5, 1836
The Beagle anchored at a cove on the shores of Hobart, Tasmania. During a stay of 10 days, Darwin made several excursions to identify geological structures in the region.
March 6–March 14, 1836
The Beagle reached King George's Sound. Darwin wrote,
“We stayed there eight days; and we did not during our voyage pass a more dull and uninteresting time.”
Again, Darwin was unable to see a kangaroo hunt, but he walked many miles in the effort.
April 1–April 12, 1836
The Beagle arrived at the Keeling (or Cocos) Islands, which are lagoon-islands formed of coral. Darwin noted just five or six types of tree, including coconut. The islands also had very few land animals. Darwin found only 13 species of insect. The organisms of the surrounding water, in contrast, were multitudinous.
April 29–May 9, 1836
The Beagle arrived at Port Louis on the island of Mauritius. Darwin walked around town and explored the seacoast to the north, describing the scenery as intermediate in character between that of the Galápagos and of Tahiti. Darwin and the rest of the crew were all utterly homesick as the voyage was coming to a close. Darwin wrote to one of his sisters,
“There is nothing, which I so much long for, as to see any spot & any object, which I have seen before & can say I will see again.”
May 31–June 18, 1836
The Beagle arrived at the Cape of Good Hope at the southern tip of Africa. Darwin traveled to Cape Town, where he continued his collections of rocks, animals, and plants.
July 19, 1836
The Beagle reached Ascension, a volcanic island in the middle of the Atlantic Ocean. Darwin walked to the highest point on the island, Green Hill. He found the geology of the island interesting. He discovered numerous “volcanic bombs,” which are masses of lava that were ejected during an eruption and that cool into solid fragments in the air before reaching the ground.
August 1–August 6, 1836
The Beagle sailed again to Bahia, on the coast of Brazil, to complete the chronometrical measurement of the world. Darwin took several long walks and once again enjoyed the tropical forests.
August 31, 1836–September 5, 1836
The Beagle again reached Porto Praya on the Cape Verde Islands, staying five days.
September 20, 1836
The Beagle arrived at the Azores and stayed six days.
October 2, 1836
The Beagle arrived back in England. A few days later he wrote to Captain FitzRoy,
“I do assure you that I am a very great man at home—the five years voyage has certainly raised me a hundred per cent. I fear such greatness must experience a fall—”
Little did Darwin know that his experiences would help him unravel one of the biggest mysteries of life—the mechanism by which life on Earth evolves.
When Darwin returned to England, he continued to ponder his observations. His ruminations were strongly influenced by the geologist Charles Lyell, who a few years earlier had popularized the idea that Earth had been shaped by slow-acting forces that were still at work. Darwin reasoned that similar thinking could be applied to the living world. Over the next decade, he developed the framework of an explanatory theory for evolutionary change based on three major propositions:
- Species are not immutable; they change over time.
- Divergent species share a common ancestor and have diverged from one another gradually through time (a concept Darwin termed descent with modification).
- Changes in species over time can be explained by natural selection: the differential survival and reproduction of individuals based on variation in their traits.