My Research Story: Charles

Darwin

Early Life• Date of Birth: February 12, 1809

• Interests: nature, books, fishing, hunting and collecting insects

• Education:• Medical School in Edinburgh• Cambridge University

Captain Robert FitzRoy• Although I enrolled at Cambridge to become a

clergyman, I became the protégé of John Henslow, a Botany professor.

• Henslow recommended me to Captain Robert FitzRoy, who was preparing the survey ship HMS Beagle for a voyage around the world.• FitzRoy accepted me because I was a skilled

naturalist and because we were of similar age and social class.• When I was 22 years old, I embarked on the

Beagle.

HMS Beagle at sea

The Voyage of the Beagle

• The five-year around-the-world voyage on the Beagle departed in December 1831.

• The primary mission of the voyage was to chart poorly known stretches of the South American coastline, but I spent most of my time on shore, observing and collecting thousands of plants and animals.

• I observed that the plants and animals in temperate regions of South America more closely resembled species living in the South American tropics than species living in the temperate regions in Europe.

• The fossils I found, though clearly different from living species, distinctly resembled the organisms of South America.

• While on the voyage, I read Lyell’s Principles of Geology.

• While in Chile, there was a violent earthquake.• I observed the rocks along the coast

that had been thrust upward by several feet.

• I also found fossils of ocean organisms high in the Andes, so I inferred that the rocks containing fossils must have been raised by similar earthquakes.

• These observations reinforced what I learned from reading Lyell’s work.

• My interest in geographic distribution of species was kindled by a stop at the Galápagos Islands west of South America.

• Although the animals on the Galápagos resembled species living on the South American continent, most of the species of the Galápagos were not known from anywhere in the world.

• I hypothesized that species from South America had colonized the Galápagos and speciated on the islands.

Seed-eater

Cactus-eater Insect-eater

Adaptation• Adaptations: inherited characteristics of organisms that enhance their

survival and reproduction.• I began to perceive adaptations to the environment and the origin of new

species as closely related processes.• From studies made years after my voyage, biologists have concluded that this

is what happened to the Galápagos finches.

Seed-eater

Cactus-eater Insect-eater

The finches on the Galápagos were different species because of an accumulation of adaptations. A striking different among them is their beaks, which are adapted to specific diets.

Natural Selection

• In 1844, I wrote an essay on natural selection as the mechanism of descent with modification but did not introduce his theory publicly• Natural selection is a process in which

individuals with favorable inherited traits are more likely to survive and reproduce.

• In June 1858, I received a manuscript from Alfred Russell Wallace, who had developed a theory of natural selection similar to mine.• I quickly finished The Origin of Species and

published it the next year.