I planned and booked my Galapagos trip back three years ago just prior to breaking my leg and was unable to go.  Finally, three years later I made it to this unique volcanic archipelago 1000 km off the coast of Ecuador in the Pacific Ocean.   The name Galapagos comes from the giant tortoises shell that they thought looked like horse saddles and Galapagos comes from the spanish word for saddle.  The tortoises are one of the most well known inhabitants of the islands. 

Charles Darwin born February 12th 1809 in Shrewsbury, England sailed in his early twenties around the world on the HMS beagle from 1831 to 1836 with Robert Fitzroy.   Darwin's grandfather was Joshua Wedgwood of the pottery fame. His mother died when he was eight. His father was a physician. He was not a good student but he tried first medicine then law then finally managed by default to acquired degree in Divinity from Cambridge. By chance, Robert Fitzroy asked him to travel with him on the HMS beagle as he was assigned to chart coastal Waters. Fitzroy's hobby, or passion was to seek out evidence for literal biblical interpretation of creation and since Darwin was trained for the ministry, he was central to Fitzroy's decision to have him aboard. Darwin was 27 when he returned home to England with many specimens he collected on his travels. Darwin was not the one that came up with the concept of evolution because by this time the idea was decades old.  What Darwin saw was that organisms competed for the same resources and some would do better than others and then pass on this ability to their offspring. Darwin never used the phrase 'survival of the fittest' in any of his work. It was an expression coined many years after the publication of Darwin's book the "origin of the species". It seems his conclusions were not inspired by him noticing the diversity in the beaks of finches on the Galapagos Islands. Although this is the common narrative. The ornithologist John Gould was the one that realized the Darwin had found finches with different talents, thus their beaks differed.

Alfred Wallace came up with the same ideas as Darwin. Just a couple of decades later. Their ideas were presented together as the Darwin-Wallace presentation.  Another naturalist name Patrick Matthew said that he came up with principles of natural selection the year Darwin set sail on the Beagle and had his paper published in the "naval timber and aboriculture journal".

Somehow the theory became Darwin's alone, and called Darwinism.  The others didn't get much credit.

Even though it's called "the origin of species", he never actually spoke about the origin of species, just on changes and survival of the animals with the better changes for the environment they lived in over time, or natural selection. Darwin with a background in divinity was tormented by his ideas and referred to himself as" the devil's chaplain" and said that revealing the theory felt like confessing to a murder. He knew that his theories had no support of fossil evidence and tried to justify his theory without evidence.

Saltationists, those that believe evolutionary changes happen suddenly not gradually ( The word comes from the Latin for leap), disagreed with Darwin.

William Paley, a theologian, in the early 1800s, contended that if you found a pocket watch on the ground and you had never seen one before, you would instantly believe it was made by some intelligent entity because of its complexity. Therefore, he stated that the complexity of Nature was proof of it having a designer.  This gave Darwin food for thought which he stated in letters to friends. Darwin never ever stated how the species might have originated just how it might become stronger or faster or how we tend to say, fitter. It wasn't until Mendel's pea plant experiments (mid 1800's) where he determined there were dominant and recessive traits that helped Darwin's theory make more sense. Mendel's work was widely ignored but certainly laid the groundwork for life sciences today.  

Darwin eventually made his belief in our kinship with apes in his book. The descent of Man in 1871 , again with no supporting evidence.

Much of what Darwin wrote, his theories, did not really gain any acceptance until the mid 1900s.