Charles Darwin

On December 27, 1831, Charles Darwin set sail from Devenport, England aboard HMS (His Magesty's Ship) Beagle.  During that time Darwin studied the plants, animals, landforms, and fossils of the many countries and islands he visited during the five-year voyage.  He dissected animals and plants, kept a journal, sent fossils and specimens back to England, and wrote letters to friends and colleagues describing his observations.

DARWIN, CHARLES ROBERT was born into a welathy family at Shrewsbury on the 12th of February 1809. He was the younger of the two sons and the fourth child of Dr Robert Waring Darwin, son of Dr Erasmus Darwin. His mother, a daughter of Josiah Wedgwood (1730—1795), died when Charles Darwin was eight’ years old.  He was an average student who loved to hunt and collect plants and animals.  He spent two years in medical school at Edinburgh but he did not enjot the experience of seeing and hearing his first operation.  He then trained as a clergyman at Cambridge University for three years. He was mostly bored by his studies but while at college he became friends with some of the most respected scientists of the time.

Through a college contact he accepted an unpaid post as naturalist aboard the HMS Beagle which sailed around the world for 5 years from 1831 to 1836.  Darwin took along Lyell's just published Principles of Geology which challenged belief that the earth was created only 6,000 years ago. He was impressed by Lyell's idea that the rocks on Earth were millions of years old.  He gradually began to think that if the characteristics of plants and animals could change over time then the Earth itself could change the way it also looked.

Darwin got off the ship wherever possible and he collected specimens and  took notes on virtually every fossil and living organism he encountered. These observations sowed the seeds of his theory of evolution.  Darwin was amazed by the variety of organisms he encountered during his voyage. Everywhere he looked, he saw new and oddly shaped trees, exotically colored flowers and birds, and beetles and other insects.  Darwin quickly realized that the diversity of living organisms was only part of the mystery of life.

  VOYAGE OF THE BEAGLE
Darwin writes in his journal:

December 27, 1831, Devenport, England  #1
Heavy winds blew our ship back to port two times.  Under the command Captain Fitz Roy the Beagle finally set sil on December 27, 1831. The object of the expedition was to complete the survey of Patagonia and Tierra del Fuego, commenced under Captain King in 1826 to 1830 -- to survey the shores of Chile, Peru, and of some islands in the Pacific -- and to carry a chain of chronometrical measurements round the World.

January 16, 1832 Porto Praya  #2
Porto Praya is a desolate place. Volcanic fires of past ages and the scorching heat have made the soil unfit for vegetation.  A single green leaf is hard to find, but flocks of sheep and cows survive there. It rains very seldom but when it does it rains in torrents, and immediately small plants grow out of every crack and crevice.

July 5th, 1832, Rio de Janerio, Brazil  #3
One dark night we were surrounded by numerous seals and penguins, which made strange noises. On a second night we witnessed a splendid scene of natural fireworks; the mast-head and yard-arm-ends shone with St. Elmo's light; and the form of the vane could almost be traced as if it had been rubbed with phosphorus.

July 24, 1833, Maldonado, Uruguay  #4
About fifty years ago, under the old Spanish government, a small colony was\par established here; and it is still the most southern position (lat. 41) on this eastern coast America, inhabited by civilized people.

August 24, 1833, Buenos Aires, Argentina  #5
I discovered fossil armadillos, giant ground sloths, peculiar horses, and creatures that reminded me of the hippopotamus.
 They look like their modern relatives except that they were a lot larger.  The bones were found embedded on the beach, within the space of about 200 yards square.  I saw so many fossils that I am convinced that there are more extinct species than living species.  I also realize that living species have ancestors

January 9, 1834, Port St. Julian, Argentina  #6
The whole southern part of the continent, a distance of 1200 miles had been uplifted. Here I observed beds of fossil ocean organisms (sea shells) thousands of feet above sea level.

December 17, 1834, Tierra del Fuego, Argentina  #7
A group of Fuegians partly concealed by trees, were perched on a wild point overhanging the sea; and as we passed by, they sprang up and waving their tattered cloaks sent forth a loud and sonorous shout. The savages followed the ship, and just before dark we saw their fire, and again heard their wild cry.

January 15, 1835, Bay of S.Carlos, Chile  #8
On the night of the 19th the volcano of Orsono was in action.  Large masses of molten lava could be seen being cast out of the crater.  

February 20, 1835 Valdivia, Chile  #9
I was on shore and lying down when an earthquake came on suddenly and lasted two minutes.  It lifted beds of marine mussels twenty feet above the high water mark.

March 4, 1835, Concepci'on, Chile  #10
The mayor of the Concepci'on told me the terrible news of the great earthquake of the 20th: -- "That not a house in Concepcion or Talcahuano (the port) was standing; that seventy villages were destroyed; and that a great wave had almost washed away the ruins of Talcahuano."


September 15, 1835, Galapagos Islands, Ecuador  #11

The Galapagos Islands are a cluster of 18 rugged volcanic islands.  We explored the islands for five weeks and we landed on six of the islands.  The climate was far from being excessively hot, due to the low temperature of the surrounding water, brought by the great southern Polar current.  These islands are inhabited by large numbers of bizzare and often beautiful plant and animal species.  Of the 26 species of land birds, 23 are found nowhere else in the world. Of the 436 species of plants, 223 are found nowhere else.  

I have observed species of birds, lizards, and tortoises and have found that the different species are only found on certain islands.  I think that an ancestral stock had migrated to the islands where they underwent profound changes under the different conditions of the individual islands. Apparently a single ancestral group could give rise to several different varieties or species.  

Finches
I observed finches that were probably descended from one type of ancestor and then, due to isolation and through chance, different climates and natural forces such as food availability and type, they evolved into thirteen different types of finches identified by the different beak shapes and sizes. Some of the finches were found in the treetops and others lived in the lower shrubs of a neighboring islans.  Some finchs had heavy, short beaks used for pecking trees, while others had small, thin beaks used for capturing insects.

During a drought season when no new seeds were produced for an island's finches to eat, the finches were forced to hunt for remaining seeds on the ground. Soon all the visible seeds had been devoured.  It so happened that those with slightly thicker bills than average could turn over stones a little bit better than the rest to find the remaining seeds and so they managed to survive the famine. The others perished.  When the drought ended and the birds again had young, this new generation had slightly thicker bills.  Survival of the fittest.

Lizards
The rocks on the coast abounded with great black lizards, between three and four feet long; and on the hills, an ugly yellowish-brown species was equally common. We saw many of this latter kind, some clumsily running out of the way, and others shuffling into their burrows.

Tortoises
I observed several types of land tortoises on the islands.  Tortoises with short necks were living in damp areas with lots of plant life that grew short to the ground.  Longer-necked tortoises were living in dry areas with cacti.  I wonder whether the length of their necks made it possible for the tortoises to live in different environments.

November 15, 1835, Tahiti Island, French Polynesia  #12
The luxuriant vegetation of the lower part could not yet be seen, and as the clouds rolled past, the wildest and most precipitous mountain peaks showed themselves towards the centre of the island. As soon as we anchored we were surrounded by canoes.

January 12, 1836, Sydney, Australia  #13
Having entered the harbor, it appears fine and spacious, with cliff-formed shores of horizontally stratified sandstone. The nearly level country is covered with thin scrubby trees.  Proceeding further inland, the country improves: beautiful villas and nice cottages are here and there scattered along the beach.  In the distance stone houses, two and three stories high, and windmills standing on the edge of a bank, pointed out to us the neighborhood of the capital of Australia.  I saw the ostrich, rhea, emu, and wonder why these large flightless birds are found only in Australia.  Organisms on one continent are different from those on another continent.

April 1, 1836 Cocos Islands  #14
We arrived in view of the Keeling or Cocos Islands, situated in the Indian Ocean, and about six hundred miles distant from the coast of Sumatra. This is one of the lagoon-islands of coral formation, similar to those in the Low Archipelago which we passed near.

May 19, 1836, Port Louis, Mauritius  #15
This island, the forbidding aspect of which has been so often described, rises abruptly like a huge black castle from the ocean. Near the town, as if to complete nature's defence, small forts and guns fill up every gap in the rugged rocks. The town runs up a flat and narrow valley; the houses look respectable, and are interspersed with a very few green trees.

July 19, 1836, Ascension  #16
On the 19th of July we reached Ascension. Those who have beheld a volcanic island, situated under an arid climate, will at once be able to picture to themselves the appearance of Ascencion. They will imagine smooth conical hills of a bright red colour, with their summits generally truncated, rising separately out of a level surface of black rugged lava. A principal mound in the center of the island, seems the father of the lesser cones. It is called Green Hill its name being taken from the faintest tinge of that color, which at this time of the year is barely perceptible from the anchorage. To complete the desolate scene, the black rocks on the coast are lashed by a wild and turbulent sea.

October 2, 1836, Falmouth, England  #17
On the 2nd of October we made the shore, of England; and at Falmouth I left the Beagle, having lived on board the good little vessel nearly five years.

BACK HOME
On Darwin's return to England in 1836 he was convinced of the idea that all organisms, including humans, are modified descendents of previously existing forms of life.  Darwin thoughts developed in two stages: the realization that organisms are not fixed and unchangeable and to provide an explanation of the process of evolutionary change.  

In 1838 Darwin read "An essay on the principle of population, as it affects the future improvement of society" by a mathematician named Malthus.  Malthus claimed that sometime in the future human population growth would exceed resources and there would be intense competition causing war, misery and famine.  From this Darwin concluded that competition exists among all living things and a "struggle for existence" might be the means by which well adapted individuals survive and the ill adjusted are eliminated.

Darwin married his cousin Emma Wedgwood in 1839 and continued to study and publish on a variety of scientific subjects achieving a great reputation as a naturalist and traveller.

His eight years grueling work on barnacles, published 1851-4 established Darwin's reputation as an authority on taxonomy as well as geology and the distribution of flora and fauna as in his earlier works.
Darwin spent the next 20 years formulating his theory while also working on a number of other scientific projects.  Darwin became interested in the domestication of plants and animals and how breeders artificially select different varieties of dogs, horses, fowl and crop and ornamental plants from one species.

  In 1858, while Darwin was working on his manuscript outlining his theory of evolution, he received a manuscript for review by a young English naturalist named Wallace.  The title was "On the tendencies of varieties to depart indefinitely from the original type".  To Darwin's surprise Wallace had independently come up with the same theory of natural selection!  Wallace was a naturalist working mostly in the Malay Archipelago.  He had also read Essay on the principle of population by Malthus and it came into his mind during a malarial fever.  He wrote..."suddenly there flashed upon me the idea of survival of the fittest"

Darwin wanted to let Wallace publish first but Lyell convinced him that they should jointly present their work. Papers by both Darwin and Wallace were read before the Linnaean Society of London on July 1, 1858.   Lyell urged Darwin to publish his full theory of evolution as soon as possible. "On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life" was published and sold out on Nov. 24, 1859.  The complete text of Darwin's "Origin of Species" is available on the web here.

Both Darwin and Wallace share credit for the theory of natural selection, however there is much more to the theory of evolution than this. Over more than 20 years Darwin amassed massive amounts of meticulously documented evidence to support his theory of "descent with modification" which can be summarized as follows:

  1. all species reproduce in excess of the numbers that can survive
  2. yet adult populations remain relatively constant
  3. therefore there must be a severe struggle for survival
  4. all species vary in many characteristics and some of the variants confer an advantage or disadvantage in the struggle for life
  5. the result is a natural selection favoring survival and reproduction of the more advantageous variants and elimination of the less advantageous variants

In his final book published the year before his death, The formation of vegetable mould through the action of worms (1881) Darwin again made an important contribution which, as was characteristic of Darwin, revealed the amazing complexity and importance of a natural process of gradual accumulation, which no one seemed to have grasped before, and that had all along been under our feet.

 Charles Darwin was a mild, kind, pleasant man, unassuming and sincerely modest. He suffered from an unexplained illness much of his adult life (perhaps picked up during the Beagle voyage). He nevertheless remained driven and ambitious to explore nature and examine it candidly and to remain part of the elite scientific world he respected and admired. Darwin died in 1882 and he is buried in Westminster Abbey.