Charles Darwin



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Charles Darwin


  • Darwinian revolution removed man from the center of creation, as the Copernican revolution had removed the Earth from the center of the universe

  • Man was just another organism, evolved through gradual change from lower animals


  • Darwin eliminated the Argument from Design as a scientific theory

  • Darwin eliminated the Chain of Being - man was just another branch on the tree of life

  • He was a very unlikely and very unwilling revolutionary


  • Born in Shrewsbury, England, fifth child of a wealthy family


  • Maternal grandfather was Josiah Wedgewood (Wedgewood pottery)

  • Paternal grandfather was Erasmus Darwin, who had written a book on evolution (Zoonomia) from a Lamarckian viewpoint



  • Local school in Shrewsbury was one of the best schools in England, with Samuel Butler as Headmaster


  • Charles was an indifferent student, “too much rote learning”

  • Went to medical school at Edinburgh, but soon dropped out, couldn’t stand the sight of blood


  • Transferred to Christ’s College, Cambridge, to prepare for the Anglican ministry

  • Spent most of his time partying, even gambled away his semester’s tuition!


  • Father was pretty disgusted with him:




“You care for nothing but shooting, dogs, and rat-catching, and you will be a disgrace to yourself and all your family”


  • Finally got his B.A., looked like he would settle down at 22 as a minister…but something very unexpected happened

  • The H.M.S. Beagle was about to set sail for South America, and the captain was advertising for a gentleman naturalist

  • ROAD TRIP !!

  • The Captain of the Beagle was a 26 year-old gentleman named Robert Fitzroy

  • Fitzroy had advertised for a gentleman’s companion, preferably a naturalist



  • Fitzroy’s favorite uncle had slit his throat - did madness run in his family?

  • He needed someone to keep him company

  • Fitzroy’s predecessor had blown his brains out in his cabin on the previous voyage


  • Darwin’s father objected, but Charles won him over

  • His uncle Jos helped him out by writing Dad a letter, inventing the “top ten list”, reasons why Charles should not be allowed to go, together with a rebuttal of each point


  • Beagle set sail for South America in December 1831

  • Beagle was to map the southern coast of South America, explore the interior, visit tropical islands and native tribes along the way


  • Voyage would expose Darwin to an incredible wealth of exotic plants and animals

  • Would visit jungles, deserts, coral islands, make several expeditions inland

  • Brought along many books, including Charles Lyell’s Geology


  • Unfortunately, Darwin and Fitzroy did not get along

  • Fitzroy was moody, contentious, intensely devout


  • Beagle finally reached the Galápagos Islands in September of 1835

  • Isolated group of volcanic islands off the coast of Peru, far from the mainland


  • Classic tale of scientific discovery

  • Each island had one or more species of finches

  • Each species of finch was adapted to the environment of each individual island


  • Ancestral finch must have reached the islands from South America, gradually spread out over the archipelago

  • Different local conditions caused them to diverge into a closely related group of species


  • Unfortunately, almost none of it is true…


  • Darwin didn’t even know that the birds he was observing were finches, much less related species

  • Found out they were finches long after he had returned home, identified by the British ornithologist John Gould


  • It was tortoises, not finches, that started him thinking about evolution

  • Galápagos tortoises are large, long-lived

  • Natives could tell by looking at them which island they came from


  • How could these species of tortoise have such a precise distribution?

  • What natural force had caused them to diverge from one another?

  • Crew had eaten them all and thrown the shells overboard!



  • He recognized the mockingbirds, and observed that they were very similar to species he had seen on the mainland


  • Their ancestors must have arrived from the mainland, and evolved in geographical isolation, in response to local conditions

  • It was not until 1838, two years after returning home, that Darwin finally realized how this must have occurred


  • He knew that animals could pass particular traits on to their descendants

  • Farmers could even breed animals for specific characteristics

  • They did so by selecting individuals with particular desirable traits to breed together


  • But what force in nature could substitute for the hand of the farmer?

  • In 1838, Darwin read An Essay on the Principle of Population, published in 1798 by Thomas Malthus


  • Thomas Robert Malthus - born in 1766 near Guilford England (Albury Parish, Surrey)

  • Second son of seven children

  • Godfathers were Jean Jacques Rousseau, David Hume - dad was a bit radical…


  • Borne with a speech impediment - hare lip and cleft palate

  • Lived a quiet life, with his parents, who called him Bob…


  • Bob may have gotten his inspiration from his father, arguing over social philosophy

  • Utopian schemes were all the rage

  • Utopian philosophers felt that nature had much to teach us


  • Social evolution followed natural evolution, nations could evolve into utopias

  • Dad was a “free thinker”, believed that the utopians were correct

  • Malthus disagreed…


  • Home schooled, later taught by radical social philosopher Gilbert Wakefield, at a school called the Dissenting Academy

  • Very liberal education…

  • Teacher jailed for seditious libel in 1799


  • Malthus studied theology at Cambridge 1776 to 1782 , was ordained into the Church of England in 1788

  • Was a good student, popular with his peers, "often a source of infinite delight and pleasantry to his companions…wont to set the table in a roar."


  • Eventually moved a few miles down the road from his parents, as curate of Okewood Chapel

  • 1804, age of 39, married his first cousin Harriet (age 28…hmmm), had 3 children (moderate for the times)



  • Malthus published his Essay on the Principle of Population in 1798

  • It was a runaway bestseller

  • He was on Letterman twice


  • Everyone read the Essay or talked about it

  • Malthus wrote to counteract arguments that social progress could be achieved through a better understanding of nature



  • Nature demonstrates that progress is only possible with enormous suffering and sacrifice of life

  • Wars, famines, plagues…these were nature’s way of balancing the books on the excess human population


  • Malthus thought that the “passion between the sexes” was too instinctual to be reasonably controlled or restrained

  • Besides, sex was supposed to feel good!

  • Sexual passion was part of the divine plan behind nature, “be fruitful and multiply”



  • Malthus did not object to the exercise of passion, but to the lack of sexual moderation among the lower classes

  • We were just too damned fruitful…


  • Was a 32 year old bachelor, still living with his parents when he wrote his famous essay

  • Basic argument was entirely mathematical


  • Population would increase geometrically, but resources could only increase arithmetically

  • Over time, this would lead to a growing gap between too many people and too few resources


  • Out of this gap came what Malthus called “the struggle for existence”

  • Ideas were a major influence on Darwin, who reasoned that what was true of humanity must also apply to other animals as well - a struggle for existence


  • In any struggle, there would be winners and losers

  • The winners must be those individuals better equipped to survive, what Herbert Spencer was to later call survival of the fittest


  • Darwin realized that evolution must be tied to variation

  • Species were really just local groups of individuals, all of whom varied from one another in certain ways

  • This focus on species as groups of populations was very revolutionary


  • Just as farmers selected the best varieties to breed, nature must somehow select those individuals best fit to survive

  • In every natural population, some varieties must be better equipped to prevail in the struggle for existence

  • Those well adapted individuals would have more offspring than others, passing on their variation to the next generation

  • Darwin realized that evolution was a selective process, what he called natural selection


  • Lacked any mechanism for heredity

  • Realized he’d be branded a heretic or worse, his family would also suffer


  • Darwin experimented with a variety of plants for several years, trying to discover the secrets of heredity

  • Even fooled around with the common garden pea, used by Mendel

  • Unlike Mendel, couldn’t figure it out…


  • Ironically, the answer was literally at hand, in his own library

  • Loaned a book called Plant Hybridisation to an acquaintance (J.G. Romanes) who was preparing an article for the 1881 edition of the Encyclopedia Brittanica


  • The book included a chapter which outlined Mendel’s experiments on garden peas

  • Neither Darwin nor Romanes ever read it, though Romanes includes Mendel in his list of plant hybridists’

  • Book was later found in Darwin’s library with the pages of the chapter uncut!


  • Darwin also delayed because he was shocked at the philosophical implications of this idea

  • The selective process must be utterly ruthless, with much suffering and death

  • Paley’s happy garden of nature became Tennyson’s “nature red in tooth and claw”


  • This argued against a benevolent plan behind nature, and man’s supreme place in nature

  • He writes in his notebook:

  • “It is difficult to believe in the dreadful but quiet war of organic beings, going on the peaceful woods and smiling fields.”


  • Darwin’s health continued to deteriorate, as he worried about his discovery and its implications

  • Many forensic historians have attempted to diagnose Darwin’s chronic disease

  • Most common answer is Chagas disease, tropical disease caused by a trypanosome


  • May have been panic attacks, due to his inner conflicts

“I have awakened in the night being slightly unwell and felt so much afraid though my reason was laughing and told me there was nothing and tried to seize hold of objects to be frightened of.”


  • Symptoms included shortness of breath, palpitations, dizziness, attacks of fear, lightheadedness, trembling, uncontrolled crying, intestinal problems

  • Classic symptoms of panic attacks, with a little agoraphobia thrown in…


  • His family suffered a series of misfortunes, including the death of his eldest daughter, Anne, at the age of ten

  • Tried various quack remedies like hydrotherapy, the water cure, but nothing worked


  • Finally published the Origin of Species in 1859, revealing his theory of Evolution by Natural Selection

  • Heard through a colleague that the naturalist Alfred Russel Wallace was about to publish the same theory, even hitting on the same name!


  • Darwin was invited to present a short excerpt from his earlier work, at the same meeting, thus establishing his priority for his theory


  • Darwin’s Theory of Evolution:

  • Growth with reproduction, inheritance

  • Variation in populations

  • Struggle for existence


  • Darwin’s Theory of Evolution:

  • Natural selection of certain varieties

  • Change in proportion of those varieties in the next generation

  • Extinction of poorly adapted forms




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