Charles Darwin's five-year voyage aboard the HMS Beagle stimulated his curiosity and set him on the path to great discovery. Darwin's keen powers of observation, exhaustive collections, and new findings provided a wealth of evidence on the origin of species. Darwin was puzzled because many of his observations could not be explained by his previously held beliefs. Darwin would devote much of his life to developing a theory that could account for his many observations.
Introduction
In December 1831, Charles Darwin set sail on the HMS Beagle and began a five-year voyage of discovery. The young Darwin, age 22, had been recommended for the voyage by his former professor, John Henslow, who considered Darwin an exceptional naturalist.
The primary mission of the Beagle was to survey and map the coastal waters of South America for the British Navy. Darwin was to observe, record, and collect specimens of rocks, minerals, plants, and animals. His supplies included specimen jars and preservative, a microscope, binoculars, notebooks, a rifle, and a book given to him by Henslow—the first volume of Lyell's Principles of Geology.
What Darwin Saw
As the crew of the Beagle was conducting surveys along the east and west coasts of South America, Darwin hired guides and travelled inland to explore, often for weeks at a time (Figure 1). Darwin was impressed by the diversity of life he encountered, the grandeur of the rich tropical rainforests, and the geographic features of the landscape. He was keen to document everything he saw. Darwin was a meticulous observer and painstaking collector. During the voyage he gathered thousands of specimens and filled notebooks with more than 4000 pages of detailed observations.
Figure 1 Darwin spent five years on the HMS Beagle. The ship was 27.5 m long and carried 74 people. Darwin's cabin was so small that he had to remove a drawer from the end of his bunk to make room for his feet when he lay down.
Image: A picture of a ship and a map of tracing the route the ship took. The ship began in Australia traveling across the Indian Ocean, past Africa to Europe. Turning around at Europe, the ship then made its way around the bottom of South America to the Galapagos Islands, then across the South Pacific Ocean.
While in Patagonia, Darwin made some important discoveries including fossils of giant Glyptodon (Figure 2) and Megatherium. Darwin would later find out that these specimens resembled the much smaller modern armadillos and sloths, respectively. Darwin noted that modern and extinct animals that resemble each other seemed to share similar geographical distributions. In this case, like their fossil relatives, modern-day armadillos and sloths are both found in South America.
Figure 2 (a) The fossil Glyptodon resembled (b) the present-day armadillo, except that the Glyptodon was almost 200 kg heavier.
Print Page 295
Darwin also discovered fossils of marine organisms high in the Andes Mountains. Later, following a severe earthquake, he was informed that a section of coastline had risen 3 m out of the water. This evidence supported Lyell's theory that such events could, over millions of years, account for large-scale changes like the formation of mountain ranges. By the time Darwin left South America, he was becoming increasingly convinced that Earth was dynamic and changing.
The Galapagos Islands
The most famous of Darwin's observations were on the Galapagos Islands, lying approximately 1000 km off the west coast of South America. This small isolated archipelago is made up of 18 islands that were formed from volcanoes that rose up from the ocean floor.
Upon his arrival Darwin was immediately struck by the unusual and unique flora and fauna that inhabited the islands. Among the most unusual species were birds such as the nesting boobies, with no fear of humans, iguanas that could dive underwater to feed on seaweed, and giant land tortoises (Figure 3). Oddly, many species bore a striking resemblance to species he had observed on the continent of South America, even though they lived in entirely different habitats.
Figure 3 (a) The Galapagos marine iguana and (b) a species of Galapagos tortoise
As he went about collecting specimens, it did not occur to Darwin that neighbouring islands, often within sight of each other, might be home to entirely different species. Only later would he learn from experts that many of the specimens he had assumed were just varieties of a single species were different species entirely, including the 13 species of Darwin's finches that are now famous.
Perhaps as surprising were the species that were absent from the Galapagos. There was not a single native species of amphibian or large land mammal in the entire Galapagos, even though some of these islands were over 100 km in length. Darwin realized that only species that could have arrived by air or water lived in the Galapagos. Insects, birds, plants, and reptiles could have arrived by air or water. Amphibians perish in salt water, and no large terrestrial mammal can survive for long without fresh water. It seemed the islands had been populated by species that had arrived from elsewhere. However, most of these species only resembled species in mainland South America; they did not live there.
Darwin's Return
Darwin left England believing that species were immutable, but he returned five years later with many doubts. Darwin was an individual of extraordinary determination. He would spend the next 20 years of his life formulating his theory of evolution and unravelling what he referred to as "that mystery of mysteries:' The influence of the Beagle voyage is captured in Darwin's own journal entry of 1837: "Had been greatly struck . . . on character of S. American fossils—& species on Galapagos Archipelago. — These facts origin (especially latter) of all my views:'
Further Reading
Darwin, Charles. (1839). Voyage of the "Beagle." Available online at The Complete Work of Charles Darwin Online.
Darwin, Charles. (1835). Galapagos notebook. Available online at The Complete Work of Charles Darwin Online.
Stewart, P.D. (2007). Galapagos: The islands that changed the world. New Haven: Yale University Press.
7.3 Questions
Key
K/U: Knowledge and Understanding T/I: Thinking and Investigation C: Communication A: Application
1. What qualities of a good scientist did Darwin display on the voyage? K/U
2. Describe Darwin's key observations regarding the distribution of fossils. K/U
3. What did the change in coastline following an earthquake lead Darwin to believe?
4. Darwin was surprised by the species he found on the Galapagos Islands. K/U T/I A (a) What other species did they remind him of? (b) What is the connection between the types of native animals on the Galapagos and their ability to cross the open ocean?
5. Use the Internet and other sources to research the following: [GO TO NELSON SCIENCE] T/I A C (a) Examine Darwin's childhood and formal education. (b) Find out what circumstances led to Darwin's selection for participation in the voyage and his acceptance. (c) Describe the life history of at least one species of Galapagos wildlife. (d) Outline some of Darwin's other scientific findings from the voyage, including his investigation of coral reefs. (e) Describe Darwin's work ethic and approach to science. Did Darwin conduct any experiments of his own? Did he rely on the opinions of others?
Voyage of the HMS Beagle
ABSTRACT
Charles Darwin's five-year voyage aboard the HMS Beagle stimulated his curiosity and set him on the path to great discovery. Darwin's keen powers of observation, exhaustive collections, and new findings provided a wealth of evidence on the origin of species. Darwin was puzzled because many of his observations could not be explained by his previously held beliefs. Darwin would devote much of his life to developing a theory that could account for his many observations.
Introduction
In December 1831, Charles Darwin set sail on the HMS Beagle and began a five-year voyage of discovery. The young Darwin, age 22, had been recommended for the voyage by his former professor, John Henslow, who considered Darwin an exceptional naturalist.
The primary mission of the Beagle was to survey and map the coastal waters of South America for the British Navy. Darwin was to observe, record, and collect specimens of rocks, minerals, plants, and animals. His supplies included specimen jars and preservative, a microscope, binoculars, notebooks, a rifle, and a book given to him by Henslow—the first volume of Lyell's Principles of Geology.
What Darwin Saw
As the crew of the Beagle was conducting surveys along the east and west coasts of South America, Darwin hired guides and travelled inland to explore, often for weeks at a time (Figure 1). Darwin was impressed by the diversity of life he encountered, the grandeur of the rich tropical rainforests, and the geographic features of the landscape. He was keen to document everything he saw. Darwin was a meticulous observer and painstaking collector. During the voyage he gathered thousands of specimens and filled notebooks with more than 4000 pages of detailed observations.
Figure 1 Darwin spent five years on the HMS Beagle. The ship was 27.5 m long and carried 74 people. Darwin's cabin was so small that he had to remove a drawer from the end of his bunk to make room for his feet when he lay down.
Image: A picture of a ship and a map of tracing the route the ship took. The ship began in Australia traveling across the Indian Ocean, past Africa to Europe. Turning around at Europe, the ship then made its way around the bottom of South America to the Galapagos Islands, then across the South Pacific Ocean.
While in Patagonia, Darwin made some important discoveries including fossils of giant Glyptodon (Figure 2) and Megatherium. Darwin would later find out that these specimens resembled the much smaller modern armadillos and sloths, respectively. Darwin noted that modern and extinct animals that resemble each other seemed to share similar geographical distributions. In this case, like their fossil relatives, modern-day armadillos and sloths are both found in South America.
Figure 2 (a) The fossil Glyptodon resembled (b) the present-day armadillo, except that the Glyptodon was almost 200 kg heavier.
Print Page 295
Darwin also discovered fossils of marine organisms high in the Andes Mountains. Later, following a severe earthquake, he was informed that a section of coastline had risen 3 m out of the water. This evidence supported Lyell's theory that such events could, over millions of years, account for large-scale changes like the formation of mountain ranges. By the time Darwin left South America, he was becoming increasingly convinced that Earth was dynamic and changing.
The Galapagos Islands
The most famous of Darwin's observations were on the Galapagos Islands, lying approximately 1000 km off the west coast of South America. This small isolated archipelago is made up of 18 islands that were formed from volcanoes that rose up from the ocean floor.
Upon his arrival Darwin was immediately struck by the unusual and unique flora and fauna that inhabited the islands. Among the most unusual species were birds such as the nesting boobies, with no fear of humans, iguanas that could dive underwater to feed on seaweed, and giant land tortoises (Figure 3). Oddly, many species bore a striking resemblance to species he had observed on the continent of South America, even though they lived in entirely different habitats.
Figure 3 (a) The Galapagos marine iguana and (b) a species of Galapagos tortoise
As he went about collecting specimens, it did not occur to Darwin that neighbouring islands, often within sight of each other, might be home to entirely different species. Only later would he learn from experts that many of the specimens he had assumed were just varieties of a single species were different species entirely, including the 13 species of Darwin's finches that are now famous.
Perhaps as surprising were the species that were absent from the Galapagos. There was not a single native species of amphibian or large land mammal in the entire Galapagos, even though some of these islands were over 100 km in length. Darwin realized that only species that could have arrived by air or water lived in the Galapagos. Insects, birds, plants, and reptiles could have arrived by air or water. Amphibians perish in salt water, and no large terrestrial mammal can survive for long without fresh water. It seemed the islands had been populated by species that had arrived from elsewhere. However, most of these species only resembled species in mainland South America; they did not live there.
Darwin's Return
Darwin left England believing that species were immutable, but he returned five years later with many doubts. Darwin was an individual of extraordinary determination. He would spend the next 20 years of his life formulating his theory of evolution and unravelling what he referred to as "that mystery of mysteries:' The influence of the Beagle voyage is captured in Darwin's own journal entry of 1837: "Had been greatly struck . . . on character of S. American fossils—& species on Galapagos Archipelago. — These facts origin (especially latter) of all my views:'
Further Reading
Darwin, Charles. (1839). Voyage of the "Beagle." Available online at The Complete Work of Charles Darwin Online.
Darwin, Charles. (1835). Galapagos notebook. Available online at The Complete Work of Charles Darwin Online.
Stewart, P.D. (2007). Galapagos: The islands that changed the world.
New Haven: Yale University Press.
7.3 Questions
Key
K/U: Knowledge and Understanding
T/I: Thinking and Investigation
C: Communication
A: Application
1. What qualities of a good scientist did Darwin display on the voyage? K/U
2. Describe Darwin's key observations regarding the distribution of fossils. K/U
3. What did the change in coastline following an earthquake lead Darwin to believe?
4. Darwin was surprised by the species he found on the Galapagos Islands. K/U T/I A
(a) What other species did they remind him of?
(b) What is the connection between the types of native animals on the Galapagos and their ability to cross the open ocean?
5. Use the Internet and other sources to research the following: [GO TO NELSON SCIENCE] T/I A C
(a) Examine Darwin's childhood and formal education.
(b) Find out what circumstances led to Darwin's selection for participation in the voyage and his acceptance.
(c) Describe the life history of at least one species of Galapagos wildlife.
(d) Outline some of Darwin's other scientific findings from the voyage, including his investigation of coral reefs.
(e) Describe Darwin's work ethic and approach to science. Did Darwin conduct any experiments of his own? Did he rely on the opinions of others?