Sunday, November 24, 2019

A Voyage, a Book and the Scientist that Changed the World

The 1869 first edition of Charles Darwin's The Origin of the Species.

170 years ago today on November 24, 1859 On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life by Charles Darwin was published in London.  It has been called the most influential book of the last two hundred years.  Its competition?  Only Das Kapital by Karl Marx.  Both books shook the world to its foundation and both are still despised by many of the same people.

Contrary to myth, Darwin’s book was not the first to advance a theory of evolution.  Darwin himself pointed out many antecedents stretching back to classical Greek philosophers.  Indeed transmutation of species over time had been a common notion and not particularly controversial until the Protestant Restoration ushered in a new tendency to view Bible stories as not just allegorical, but was absolute, undeniable fact.  Even in the face of this new insistence that God had flawlessly created the world and all of its creatures and that they were immutable, mounting fossil and other evidence had been pointing to evolutionary change for more than a hundred years.  

Darwin’s own grandfather, Erasmus Darwin had postulated evolutionary development.  Jean-Baptiste Lamarck had expanded on that work in his 1809 book, which has been called the presentation the first truly cohesive theory of evolution.

By the early decades of the 19th Century some sort of evolutionary change was accepted by most leaned Europeans.  Opposition continued to come from conservative religious circles, who regarded any evolution as a challenge to Biblical inerrancy.  But many other religious figures were searching for ways of reconciling Biblical faith with emerging science.  Indeed in Britain many, if not most, of the important naturalists of the late 18th Century and later were also Anglican clergymen.  

William Paley advanced the idea of a Natural Theology which accepted evolutionary change as evidence of God’s design.  But this theory held that God had used evolution to develop the now immutable species which were the perfection of his creation.  Also, Man, said by the Bible to have been created in the image of God, was created outside the development of the “lower species.

Darwin, who was born the same year a Lamarck published his book, grew up in this era and was influenced by it.  His family was Unitarian.  His father was a free thinker who had quietly abandoned religion but allowed his son to be baptized in the Church of England largely because of social advantages it might give him.  His mother, the daughter of Josiah Wedgewood, wealthy the ceramic and porcelain manufacturer, however made sure that her son attended Unitarian chapel.

Darwin, the young scientist adventurer.
Drawn to the study of nature as a child, Darwin apprenticed as a medical doctor serving the rural poor of Shropshire before going on to study medicine at the University of Edinburgh.  He preferred the study of natural history to his medical courses and was soon involved in field research on marine invertebrates.  His father, still hoping to secure a career for his son, had the young man transfer to Christ College, Cambridge from which he might become an Anglican parson with the leisure to pursue his interests in natural science.  He graduated with a bachelor’s degree and a firm basis in natural science as it was known and practiced at the time.  Indeed, inadvertently he had become one of the first generation of University trained scientists—a dramatic change from the era of the gentleman investigator

Before his father could obtain ordination and an appointment for his son, Charles was offered an appointment as a naturalist and companion to Captain Robert FitzRoy of the H.M.S. Beagle who was about to embark on a lengthy voyage to explore and chart the coasts of South America.

The Beagle, with Darwin on board, set sail on December 27, 1831 on what proved to be a five year voyage.  Darwin spent much time on land investigating fossils, noting geographic upheavals, and the proliferation of local species.  At each stop evidence piled up for him that massive geological changes had taken place that elevated sea beds, and that extinctions of species had commonly occurred.  

HMS Beagle in the Straights of Magellan.  The Patagonian natives in the canoes and others who had earlier been captured, educated in England and made sailors caused Darwin to make in important observation. 

Perhaps most shocking he observed that natives of Tierra del Fuego taken captive on the first voyage of the Beagle and subsequently educated in England were as agreeable and accomplished as any English sailors.  When he compared them to the “savage and degraded” condition of the natives on the island, Darwin concluded that there was not racial inferiority, but that exposure to a “higher culture” elevated the human.

Famously, on the Galápagos Islands off the western coast of South America, Darwin observed in mocking birds and tortoise shells local variations on different islands that seemed to show rapid evolutionary divergence from a common ancestor.  By the time Darwin returned to England, he had grave doubts about the commonly accepted theory of immutability of species.  

Galapagos finch specimens collected by Darwin are still preserved by the Natural History Museum in London.  Local variations in bills  were a key to unlocking natural selection.
When he returned to England he found that he was already a scientific celebrity based on the publication of letters he had sent home.  Darwin went to work finding depositories for the huge volume of specimens—geologic, fossil, and animal and plant remains—that he had brought home.  When experts got a hold of these finds they quickly helped identify, for instance, several distinct species of Galápagos finches.  He was soon presenting highly praised scholarly papers proving that the South American continent was still rising from the sea, describing the formation of atolls, and the distribution of overlapping species of South American Rheas as he worked furiously on assembling his notes for publication.

As his reputation soared, he took his cousin Emma Wedgewood as his wife.  Continued overwork brought a succession of health crises, but Darwin continued to prepare his notes, which were published originally in conjunction with Captain FitzRoy’s logs.  In 1839 his Journal and Remarks was successfully published independently of FitzRoy’s logs.

Darwin continued publications based on his Beagle trip and on new research, like his definitive work on barnacles.  But all the while he struggled to find a suitable explanation of how evolutionary change operated.  Then in 1839 he read An Essay on the Principle of Population by Thomas Malthus.  Although appalled by the application of Malthus theory of population—that unmolested it would expand geometrically until controlled by famine—to public policy, Darwin saw how “in the struggle for existence…favourable variations would tend to be preserved and unfavourable ones to be destroyed. The result of this would be the formation of new species.”  On the basis of this breakthrough insight, Darwin began formulating his new theory.

Beetle browed and balding--Darwin in 1842 when his notes on Vestiges of the Natural History of Creation was published anonymously.
He would work on it for years.  Fearing for his ill health, Darwin completed a 230 page Essay on the subject to guide further research based on his notes should he die.  This was published in 1842 anonymously as Vestiges of the Natural History of Creation. It was the public’s first glimpse at Darwin’s emerging thought.  It became both a best seller and the target of withering criticism from both Biblical literalists and scientists invested in the immutability of species.  Darwin adapted his arguments in light of these criticisms.

In 1856 Alfred Russell Wallace published a paper independently postulating processes of evolution close the idea of natural selection that Darwin was developing.  As a generous scientist, he felt no jealousy, though friends urged him to speed work on his definitive treatment of the subject.  Rather than rush to publication, Darwin was determined to go deeper and expand his paper into “my big book.”  Meanwhile he and Wallace agreed to make a joint presentation On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection to Linnean Society in London on July 1, 1858.  A scarlet fever epidemic, however, took the life of Darwin’s youngest son and he was unable to be present to personally read his paper.  The following year On the Origin of Species was finally published.

In the book Darwin struggled to avoid the word “evolution” because it was already fraught with controversy. Instead he preferred to write about common descent.   He avoided, on the whole, implications of to humans, suggesting only briefly that, “light will be thrown on the origin of man and his history.”  The book was an instant best seller.  The initial press run of 1,200 quickly sold out and new editions had to be rushed out. 
Despite Darwin’s cautious approach early reviews by critics tagged him as promoting “the descent of man from apes,” which became an enduring public image of his work.  The controversy would rage for decades. 
Darwin was mocked as an ape in the 1871 attack on the Theory of Evolution.
Despite continuing ill health Darwin pressed ahead with more original research and with new books expanding on his theories.  In 1871 he published The Descent of Man, and Selection in Relation to Sex in which he definitively asserted that humans were animals and subject to the same condition of natural selection as any other.
Darwin’s scientific investigations had robbed him of any vestige of conventional Christian faith, even his wife’s continued fervent Unitarianism.  He did not necessarily disbelieve in any Creator or Creative Force, but admitted to becoming agnostic on the subject.  He was friendly with his local Anglican vicar and participated in social charity of the parish although he avoided worship services and refused communion.  His beloved children, under his wife’s eye, were raised Unitarian.
When Charles Darwin died on April 19, 1882 he was a revered public hero.  At the request of the President of the Royal Society, he was given a state funeral and interred at Westminster Abbey near the final resting place of Isaac Newton.

Despite his well known agnosticism, Darwin was honored with burial at Westminster Abby next to John Herschel the mathematician  and astronomer and near Sir Isaak Newton.
Ironically, not long after his death, alternative theories to natural selection became the vogue in explaining evolution.  This period has been called “the eclipse of Darwinism.”  But one after another the alternative theories failed.  Beginning in the 1930’s the understanding of modern genetics began to explain just how traits could be passed on by natural selection.  Within a decade Darwin’s original theory had been largely confirmed.  
Today, neo-Lamarkianism is making a bit of a struggling comeback, but recent research has shown that species in environmental crisis may simply accelerate the rate of random mutation so that adaptive mutations might succeed. 
On the other hand a Biblical fundamentalism unknown in Darwin’s time has taken hold on the right of Protestant Christianity which has made public denial of evolution a hot button political issue.  More sophisticated opponents now accept some sort of evolution guided by so-called Intelligent Design rather than natural selection.  Some even claim that there is a science of intelligent design.  But then simply claiming something is science does not make it so.  

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