The Theory of Evolution
Year of Discovery: 1858
What Is It? Species evolve over time to best take advantage of their surrounding
environment, and those species most fit for their environment survive best.
Who Discovered It? Charles Darwin
Why Is This One of the 100 Greatest?
Darwin’s theory of evolution and its concept of survival of the fittest is the most fundamental and important discovery of modern biology and ecology. Darwin’s discoveries are
150 years old and are still the foundation of our understanding of the history and evolution
of plant and animal life.
Darwin’s discovery answered countless mysteries for anthropology and paleontology.
It made sense out of the wide distribution and special design of species and subspecies on
Earth. While it has always stirred controversy and opposition, Darwin’s theory has been
verified and supported by mountains of careful scientific data over the past 150 years. His
books were best sellers in his day and they are still widely read today.
How Was It Discovered?
Charles Darwin entered Cambridge University in 1827 to become a priest, but
switched to geology and botany. He graduated in 1831 and, at age 22, took a position as naturalist aboard the HMS Beagle bound from England for South America and the Pacific.
The Beagle’s three-year voyage stretched into five. Darwin forever marveled at the
unending variety of species in each place the ship visited. But it was their extended stop at
the Pacific Ocean Galapagos Islands that focused Darwin’s wonder into a new discovery.
On the first island in the chain he visited (Chatham Island), Darwin found two distinct
species of tortoise—one with long necks that ate leaves from trees, and one with short necks
that ate ground plants. He also found four new species of finches (small, yellow birds common across much of Europe). But these had differently shaped beaks from their European
cousins.
The Beagle reached the third Galapagos Island (James Island) in October 1835. Here,
right on the equator, no day or season seemed any different than any other.
As he did every day on shore, Darwin hoisted his backpack with jars and bags for collecting samples, a notebook for recording and sketching, and his nets and traps and set off
across the frightful landscape through twisted fields of crunchy black lava thrown up into
giant, ragged waves. Gaping fissures from which dense steam and noxious yellow vapors
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