Lyell, Darwin and Wallace (3)

The final installment in my study of three great scientists of the nineteenth century, united by their collegiality, friendship, and their contributions to "the greatest* idea anyone has every had": natural selection.  You may wish to read the earlier installments about Charles Lyell and Charles Darwin.

In Singapore, 1862, aged 39.

Statue outside Natural History Museum, London, unveiled in 2013.

Alfred Russel Wallace was the youngest of the three, so that he was inspired by both Lyell's Principles of Geology and Darwin's Voyage of the Beagle while still in his formative years, and began his fieldwork prepared to believe in "the transmutation of species."  He also lived the most interesting and varied life, first becoming known as the co-discoverer of Natural Selection, then one of its chief defenders, an originator of biogeography as a discipline, and then a proponent of directed evolution, of spiritualism, and of social and economic justice.  He made substantial and original contributions to the Theory of Natural Selection, and  collaborated fruitfully with Darwin for some time.  He wrote widely and well on all of these concerns--depending on his writings for much of his income later in life.  Though attacked at the time for some of this, he stuck to his guns--even as the science of his time evolved away from allowing supernatural** hypotheses, and away from anthropocentrism, away from a belief that the universe is somehow directed to some goal.  Had he not been thus left behind by modern science, Wallace would be much more highly regarded today. 

Early life
Wallace began life in straightened circumstances, the seventh of nine children of a father who made unlucky investments, and was victim of unscrupulous men, so that Wallace did not attend school after the age of thirteen.  He was introduced to geology through apprenticeship with an older brother to surveying, and learned the rudiments of botany from inexpensive pamphlets produced by the Society for the Diffusion of Useful Knowledge.  An enthusiasm for insects came from his relationship with young entomologist Henry Bates, and insects would become both the chief source of Wallace's income, and the means he would use to unravel Natural Selection. 

On the Tendency of Varieties to Depart from the Original Type
Wallace's arrival on the world stage when, during his eight years in the Malay archipelago, Wallace's wrote in May 1858 to Darwin to ask him to send along an essay to Lyell, if he thought it worthwhile.  Wallace's theory was essentially the same as Darwin's, though Wallace emphasized changes in "conditions of existence" rather than competition among organisms as the motive force of natural selection.  In his accompanying letter to Lyell, Darwin declared of Wallace's essay that he "could not have made a better short abstract" of Darwin's own theory.  After that, Darwin, mourning the death of his youngest son,*** largely stayed out of the decision-making.  Lyell and close friend botanist Joseph Hooker, in a somewhat high-handed**** but honorable resolution of the problem, had Wallace's essay, On the Tendency of Varieties to Depart from the Original Type, presented together with excerpts from Darwin's much earlier (but unpublished) paper, and a letter from the previous year that proved Darwin's priority, at the Linnean Society of London on July 1, 1858.  (Though these made no noticeable ripple in the scientific community of the day, Darwin's publication the following year of The Origin of Species surely did.)

Further contributions to evolutionary theory
Beyond "natural selection," Wallace's most important contributions to evolutionary theory were that animals' striking coloration may arise by natural selection that warns predators of its poisonous nature; and that different varieties of the same species may, by natural selection, develop barriers to hybridization that increase reproductive fitness: this phenomenon--still an active area of research--is called the Wallace Effect. 

Disagreement with Darwin over "directed" natural selection
Wallace did not believe in traditional religion, but had strong convictions about the centrality of Man in the universe, and that the development of humanity was the universe's highest purpose.  Darwin fought him in later years as Wallace began to advocate for divine interference into natural selection at least three times: he believed that the origin of life itself (still a puzzle today) required divine intervention, as did the development of a human mind that (it seemed to Wallace) exceeded that which could be explained by natural selection, and then again to promote the high level of culture in the West that again seemed scientifically inexplicable.  This wasn't necessarily a crazy position at the time, since the nineteenth century was a period of gradual movement of the natural sciences away from considering supernatural explanations--because of the intractability of the "species problem,"***** the last of the sciences to do so.  Wallace was on the wrong side of history, but not because he was crazy.  (This is not the place for a full-throated defense of science's disregard of the supernatural, but if you want to learn a bit, Neil DeGrasse Tyson has a nice lecture illustrated with cautionary tales from science history.)

Further contributions to science
Beyond evolutionary theory, Wallace's work in Brazil and the Malay archipelago (modern day Malaysia, Singapore and Indonesia) and the publication of his "Geographic Distribution of Animals" and "Island Life" make him a central figure in the development of biogeography.  He documented a line among the islands that separated different groups of species, linked it to the depth of ocean separating them, and explained it by ancient connections among the islands; it is called the Wallace Line.  In his mid-fifties, Wallace went on a ten-month lecture and scientific tour of North America beginning in 1887.  A week of work with American botanist Alice Eastwood in the Rocky Mountains during this time provided the data to explain commonalities between British and American mountain flora by means of glaciation.  He published this in the paper, "English and American flowers."  These lectures and investigations became his 1889 book, "Darwinism."  His discovery that decades of smallpox vaccination data showed little or no improved survival led him to undertake an anti-vaccination campaign that made him unpopular with the medical establishment, despite using their own data.  He argued that deliberately introducing disease (cowpox) into children without clear evidence of positive outcomes was immoral. 

Proving a round earth
In an episode you could hardly make up, in 1870 Wallace accepted a five-hundred-pound wager publicized by a flat-earth proponent named John Hampden: to prove that Earth's surface is curved by showing curvature in the surface of an inland body of water.  In an elegant demonstration on a straight, six-mile long stretch of canal mutually agreed on, he put targets at fixed heights above the water on two bridges, and mounted a good telescope at the same height on a third.  In the telescope witnesses could clearly see that the marks were vertically out of line, with the nearer mark showing above the farther.  For good measure, a precise level on the telescope showed that it aimed higher than both distant marks.  The degree of curvature shown by this simple experiment over the little six-mile span of water even agreed fairly well with the known curvature of the earth.  Unfortunately, Hampden was a rabid biblical literalist, unscrupulous and with a mean streak: not only was the plain evidence denied and the wager not paid, but the man attacked Wallace, slandered him publicly, and continued his attacks even after twice found guilty of libel, fined and even imprisoned.  To add insult to injury, Wallace had to take a significant loss in lawyer's fees when Hampden transferred his assets to his family and declared bankruptcy to avoid the fines!  

Controversial beliefs
Wallace's scientific interests included Mesmerism, phrenology and spiritualism.  Mesmerism (hypnosis) was an interest that Wallace validated experimented in a variety of ways.  Phrenology--the hypothesis that features of a person's character were reflected in the detailed shape of the head (reflecting the structure of the brain)--was a popular idea at the time, gaining traction probably by a combination of fuzzy definitions and confirmation bias.  Many were take in.  Wallace's conviction that spiritualism was real has puzzled historians trying to reconcile it with his undeniably good scientific work.  Lately, it has been suggested that Wallace was more willing to buck convention than his colleagues--perhaps less invested in the status quo--as reflected in his early conviction of transmutation of species (which Darwin, by contrast, wrestled with for decades), an abandonment of traditional religion, and his adoption of non-mainstream social and economic ideas, as well as his spiritualist beliefs.  

His autobiography makes clear, though, that Wallace saw spiritualism as phenomena well-documented by a good many careful scientists, himself among them.  He did not see it as supernatural, insisting that our idea of the "natural" needed expanding.  John Nevil Maskelyne's debunking of a spiritualist did not convince Wallace, however.  Even today, we see paranormal investigators misled: most scientists are not used to investigating phenomena that are actively trying to deceive them!  Professional magicians, such as Harry Houdini in the 1920s and James Randi today, have worked to debunk spiritualism and other pseudosciences.  Deception is a magician's stock in trade, making them familiar with techniques and better at spotting it than conventional scientists.  These factors taken together make Wallace's convictions seem less strange to me.  Wallace's deep conviction that humanity and the human soul was at the center of the universe connect his belief in directed human evolution, social and political activism, and and the our continuation beyond death that underlies spiritualism.  In the same vein, Wallace found support in the the apparent centrality of our solar system in the universe.  He also deftly destroyed Percival Lowell's canals (therefore life) on Mars--on good evidential terms, but mainly from the conviction that there could be no intelligent life elsewhere.  

A late statement of Wallace's religion & philosophy from the end Darwinism contrasts his own  with the prevailing mechanistic and purposeless scientific view: "As contrasted with this hopeless and soul-deadening belief, we, who accept the existence of a spiritual world, can look upon the universe as a grand consistent whole adapted in all its parts to the development of spiritual beings capable of indefinite life and perfectibility. To us, the whole purpose, the only raison d'être of the world—with all its complexities of physical structure, with its grand geological progress, the slow evolution of the vegetable and animal kingdoms, and the ultimate appearance of man—was the development of the human spirit in association with the human body."
Yet he goes on to say, "that the Darwinian theory, even when carried out to its extreme logical conclusion, not only does not oppose, but lends a decided support to, a belief in the spiritual nature of man," because natural selection accounts only for the evolution of the human body, but not the spirit.

Economic and social justice and the environment
Wallace's economic and social justice concerns were wide and deep.  He had much to say in opposition to the enclosing of commons that gave him some of his early surveying work.  He endorsed "equal opportunity" for all, extending this superficially popular idea to an opposition to inherited wealth--since that makes opportunity inherently unequal.  He was the first president of the Land Nationalisation Society; favoring nationalization of rural lands, with land being allotted to those who would make best use of it for the public good.  He was critical of the effects of free trade on the working poor.  He lauded the work of Robert Owen, a social reformer who took a Scottish mill and mill town and remade it in the interests of the workers, reforming the "company store," introducing childhood education to ten years of age, raising standards of health and living, and earning the love of his workforce. He opposed eugenics--which was becoming popular at the time--on the sensible grounds that no one was in any position to determine just who was and was not fit to have their genes passed on.  Wallace advocated pure paper currency not backed by gold or silver.  He supported women's suffrage; he opposed militarism and believed air warfare should be banned internationally.  He was concerned about Man's effects on the environment, and was one of the first, in his 1911 book "World of Life", to say that the ice age megafauna mass extinction was "due to man's agency."

Last years
Wallace never got a permanent job and continued (partly due to risky investments) to struggle financially until given a government pension at Darwin's behest.  Characteristically, Wallace insisted in his autobiography that want of money had a good effect, since he was pushed to discover and write and lecture more.  Wallace continued his science, social activism and writing til late in life, finally dying at home on December 7, 1913 at ninety.

I enjoy comparing and contrasting Wallace with the fourteen years-older Darwin.

Family origin

Though both men technically had origins in the professional class and "new money," Darwin's life was comfortable (especially after marrying his cousin Emma Wedgewood), while Wallace and his family often struggled for financial stability.  Wallace was first a surveyor, briefly a teacher, then a collector of exotic animals, an unsuccessful investor, then an author.  (Partly by experience, Wallace had far more awareness of and sympathy for the lower classes, and his economic and social justice orientation was partly a result.)

Nascent natural history interests
Darwin honed his natural history interests partly in competitive beetle collecting as a student, but thought of himself chiefly as a geologist during his travels, experimented with pigeon breeding to gather evidence for evolution and selection, and amidst this became a barnacle expert after a chance encounter with an unusual specimen.  Wallace's first encounter with natural history involved an inexpensive little pamphlet on plants, but his friendship with young entomologist Henry Bates led him to insects, and these remained his chief scientific focus ever after, providing both an income and evidence of evolution.

Education
Darwin had a college degree, while Wallace left school at thirteen, and thereafter educated himself; in a sense, though, both men were self-educated, since Darwin was never much interested in the subjects he was supposed to be studying. 

Influences
Both men were inspired by Alexander von Humboldt's travels and learned some of their theoretical geology from Lyell; and Wallace was inspired to travel by (among others) Darwin's own "Voyage of the Beagle."  Both credited Thomas Malthus' "Essay on the Principle of Population" for the  "struggle for existence" that became a key part of Natural Selection.

Travels
Darwin's presence aboard the little ten-gun brig HMS Beagle almost didn't happen: the captain wanted a companion (Charles wasn't technically the ship's naturalist), one of Darwin's teachers recommended him for the post, Darwin's father opposed it, and only the intervention of a beloved uncle saved the day.  (At the same time, Darwin was a rather bold adventurer, spending much time ashore and climbing, walking or traveling long distances on horseback--sometimes through regions at war with each other.  Wallace was deliberate in his travels, first in the Brazilian Amazon, and then in the Malay Archipelago.  (While Darwin's trip was funded by his father, Wallace had a living to make.)  Wallace was able to spend much longer in each place than Darwin, who had to adjust his travels to that of the ship.

Conversion to "transmutation of species"
Darwin left port on his five-year circumnavigation an admirer of creationist William Paley and a fairly convinced creationist himself; only entertaining his first doubts when confronted with the distribution of animal species in the different places he visited.  He was twenty-two years old.  Wallace had the advantage of reading "Vestiges of the Natural History of Creation, a popular and controversial evolutionary hypothesis widely panned by scientists (including Darwin, who thought it devoid of evidence), but a spur to Wallace's imagination.  Wallace went to Brazil at age twenty partly for the express purpose of looking for evidence of "the transmutation of species."

Iconoclasm
While Darwin wrestled first with his theory, then the consequences of his theory for religion and society and for his own reputation, Wallace dove straight in.  Darwin might never have published****** if not spurred by Wallace's independent discovery.  In future years, while Darwin's case was largely argued by others, Wallace--besides being very active in those battles--also adopted socialism, land reform, and other causes that made him unpopular in many circles.

Field work
Darwin's field work was confined largely to his 5-year circumnavigation.  Thereafter, he was a homebody, doing lab and garden and greenhouse work at Downe House for the rest of his life.  Wallace spend four years in Brazil and another eight in the Malay Archipelago seeking to make a living collecting insects and other animals to send home to well-heeled collectors.  He also wrote constantly, using his writings as another source of income.  A lecture tour in the US (which Darwin never visited) also added to his income and funded further field work.

Fame
Darwin was widely known and had an enormous correspondence, received popular acclaim for his Voyage of the Beagle, and enormous scientific respect for his multi-volume monograph on barnacles.  Wallace wrote much and widely, becoming best known for his travel narrative, The Malay Archipelago.  Although many of Wallace's ideas were controversial, neither man lived to see their theory of natural selection accepted by the scientific establishment.  (The fact of "descent by modification" (evolution) immediately took science by storm, but the means by which species arose was argued for over half a century.)


Residence
Wallace lived many places (both before and after marrying rather late in life) even in late years, while Darwin settled into Downe House after marriage and remained there for good.  As a result of Darwin's illness and inclination, he seldom left it.


Family life
Darwin married his first cousin, Emma Wedgewood, when thirty years old, only a couple of years after the Beagle's return.  They had ten children, of whom seven survived to adulthood.  Wallace was forty-two when he married Annie Mitten, daughter of a friend who was a moss specialist.  (She was likely younger than Wallace, but I couldn't find out by how much.)  They had three children of whom two lived to adulthood.  Both men lost young children: for the Darwins an infant and a baby, while their beloved Annie died of consumption at age 10 in the midst of his barnacle work (strengthening Charles' turn to agnosticism) while Wallace lost his first born son at the age of 7 in 1874.  (I can find no reference to the event in his autobiography, which does not treat of his family.)  Both wives survived their husbands. 
  Health
From soon after his return, Darwin suffered debilitating illness that sapped his strength and often interrupted his work.  Despite "hydrotherapy" treatments, the illnesses were lifelong.  He died in 1882 at the age of seventy-three.  Wallace, despite years in the tropics, lived to a ripe old ninety, surviving well into the twentieth century.

About 1895. aged about 72.

Frontispiece to his 1889 book, Darwinism.

*In the words of the modern philosopher Daniel Dennett.
**Really teleological or "purpose-driven" hypotheses--things are meant by some higher purpose to work out as they have: Wallace himself would not have called them supernatural.
***Charles Waring Darwin, 18 months, died of scarlet fever on June 18th, the very day Darwin sent Wallace's essay along to Lyell.   In a June 29th letter to Hooker, he dumps the decision-making in their laps. 
****In publishing without Wallace's approval, the men probably broke copyright law of the time, but Wallace never expressed any opposition after the fact.  The delay involved in communicating with Wallace back in the Malay archipelago might itself have opened the men to suspicion.  And, indeed, associating his work with Darwin's established reputation probably benefited Wallace.  Darwin later wrote Hooker in appreciation of Wallace's attitude: "I enclose letters to you and me from Wallace.  I admire extremely the spirit in which they are written.  He must be an amiable man."
*****The species problem: how do all the species of life arise--each one exquisitely adapted to its place in nature???  --before Darwin & Wallace, no one was able to come up with a convincing non-supernatural explanation.
******Darwin left a sealed essay of his theory with instructions to Emma to publish it upon his death; meanwhile, he continued to build an unassailable case, but never quite looked like he would ever finish.


Sources: 
Wikipedia and its links are well-written & probably have as much info as you want.
The Malay Archipelago.  Wallace.  1869.
My Life.  Wallace. 1905.
The Life and Letters of Charles Darwin.  1887.  Francis Darwin

  

Lyell, Darwin and Wallace (2)

Charles Darwin grew up in a Victorian upper-middle class family.  Dad was a doctor.  Mother was often sick, and died when he was eight.  His older sisters looked after him.  Young Charles loved to collect beetles, shells, birds' eggs and the like.   Going to university for a medical education (Dad wanting him to follow in footsteps) was derailed by Charles' dislike of blood, and positive horror at seeing surgery in the days before anesthesia.  Instead, he joined the dedicated amateur scientist Robert Edmond Grant in his study of sea sponges.  Grant was an atheist and "transmutationist" (both of these very troubling and heretical beliefs) and thought the sponge might be a kind of bridge between the animal and plant worlds.  Darwin also learned geology from the lectures of Professors Robert Jameson and Thomas Charles Hope, who sparred over whether igneous rocks like granite and basalt were precipitated out of water (Jameson) or cooled from a melt (Hope).  Museum and field trips taught him to interpret sedimentary rock layers.

After a year and a half at Edinburgh, Darwin's rather frustrated father moved him to Cambridge University and changed his program of studies to prepare for the ministry--another appropriate career track for one of his station.  He continued to be a mediocre student at best--preferring riding, shooting, and competitive beetle-collecting.  But Charles also found he had some doubts about the beliefs he would have had to subscribe to to become a an Anglican cleric, and put off a decision for the Church.  At the same time, though, he studied and came to love the work of William Paley, who had made an eloquent case for the existence of a Creator by pointing out the unmistakable signs of creation all around, and particularly in the incredible complexity and clear "design" of living creatures -- each one intricately adapted to its place in the economy of nature.  Paley it was who extolled the sophistication of the eye in all its permutations, discussing those of mammals and birds in detail.  (Explaining the evolution of the eye would later become one of Darwin's touchstones when he developed his theory.)  Paley it was who made a generation of minister/naturalists: what better pairing of vocations for appreciating the Creator and His creation?  Meanwhile, true to form, Charles learned botany from Professor John Stevens Henslow and became acquainted with geologist Rev'd Adam Sedgewick and mineralogist Rev'd William Whewell.  At about that time Charles realized that, given his father's wealth, he needn't pursue a lucrative career.

Watercolor of Charles in the 30's, after his return to England aboard Beagle.  He will first make his name by writing a readable and insightful account of the voyage, published as an appendix to the captain's report until its popularity justifies its separate publication.

After graduating with his BA, Charles was persuaded to look into signing on for a voyage aboard the little ten-gun brig, Beagle (Robert Fitz Roy, RN), which would be charting parts of South American waters.  A naval captain in the rigid British society of that time led a lonely life, and Fitz Roy wanted someone of the same social class he could talk to.  With a little persuasion from Charles' uncle, Dad agreed to fund Charles' voyage.

Darwin had come to think of himself as a geologist.  And stepping aboard the Beagle, Charles' captain--an amateur geologist in his own right--presented him with the first volume of Charles Lyell's Principles of Geology.  This, along with the two remaining volumes that Darwin had sent to him during his adventures--was to be Darwin's geology theory textbook for the next five years.

Darwin turned out to suffer debilitating seasickness, and apparently never got over it.  His journal, full of tales of new cultures, dangers, adventures, and exploration as he rides or tramps in South America for weeks and months at a time, falls altogether silent when the Beagle weighs anchor, and takes up the story again only in the new port--silence on weeks, sometimes months, at sea.

Filled by Lyell with the vision of lands constantly eroding into the sea and shoreline and ocean floor just as constantly being raised up into plateaus and mountain ranges, Darwin ever interprets the landscapes he sees in these terms.  He finds flood plains raised far above the sea, abandoned by their former rivers; he collects shells from deposits only a few yards above sea level, and also high in the mountains, judging each deposit by the degree to which the species reflect those still present in the ocean nearby.  (He cannot "date" these deposits as we can today, but concludes that, if the species in a deposit are largely extinct, that deposit is very old.)  He experiences the severe earthquake in Concepcion, Chile on Feb 20, 1835; soon after he notices with satisfaction that large stretches of the coast were concurrently uplifted by many feet.

Though primarily a geologist in his own mind, Darwin does not neglect flora and fauna.  He collects specimens constantly: some he shoots, others--tame from limited exposure to man--he simply knocks on the head with a stick.  He is keenly aware of the distribution of plants in the various islands visited.  He notes the changes in that distribution--even extinctions--caused by alien plants and animals introduced by Europeans, and by the land-use decisions the colonists have made.

Returning at last to England, Darwin fills notebooks with ideas that lean more and more toward the theory of evolution by natural selection he will eventually arrive at.  He marries his first cousin, Emma Wedgewood, and settles into domestic life at Down House in Kent.  He is fond of his children and welcomes them into his study.  He writes, he researches, he does many experiments, he raises fancy pigeons to study variation first-hand, but for decades it seems he will never finish the multi-volume work on "my theory."  Probably he worries about the reception it will receive.  Probably he knows he will need overwhelmingly convincing evidence.  And the whole idea that the appearance of new species can be explained by physical causes always in action pains his devoted and devout wife; she fears he may not accompany her to heaven.  In 1846, a two-hundred-plus page essay on his theory is sealed up with specific instructions for publication in the event of his death, and there Darwin would leave it as he considered the fallout from the publication of an anonymously-written book: Vestiges of the Natural History of Creation.  This author had proposed an evolutionary hypothesis that had all the people talking, but scientists treated it with contempt, as the work of one with an inadequate science background, and little evidence, and Darwin finds it riddled with errors.

Instead of continuing work on the theory, Darwin turns his attention to a strange barnacle he had collected years before in South America.  In the end, he spends eight years developing expertise in the classification of barnacles--a large and difficult group of arthropods--and becomes renowned for this work.  "No one," his good friend the botanist Thomas Hooker observes, "has the right to talk about species who has not minutely observed and classified many."  His final, exhaustive, multi-volume barnacle monograph wins Darwin the Royal Society Medal, and establishes him as a bona fide scientist with a world-wide web of correspondents with whom he has consulted or who have provided the thousands of specimens that had arrived at Down House. 

In 1857 Darwin was 48 and had finished his barnacle work as having become the foremost expert on them; the following year he would open the fateful letter from the younger Alfred Russel Wallace.

Finished at last with barnacles, Darwin resumes work on his theory beginning with biogeography: conducting experiments to see how different species could survive passage to distant islands so as to colonize them.

Just two years later in 1858, Darwin receives an essay from the young naturalist Alfred Russel Wallace, who wants Darwin's help in recommending it to his friend Lyell.  They were already acquainted: Wallace had consulted the elder and established scientist before.  The essay was a bombshell: Wallace has arrived at the same conclusions as Darwin on the origin of species by descent with modification, and the same mechanism: the survival of those endowed with favorable variations in the struggle for existence.  Lyell and others pressed Darwin to present a chapter of his own together with Wallace's essay at a scientific meeting.  Then Darwin gets to work at last on a "brief summary" of his argument, and publishes it the next year: The Origin of Species.

He will do more science, showing that, in temperate regions at least, earthworms are the engineers of the soil.  He will extend his curiosity about human origins (cautiously only hinted at in the Origin) into another whole book along with his novel theory about sexual selection.  (Which posits that an important element of adaptation involves being able to attract a mate--leading to all sorts of "decorative" features in the "chosen" sex that lead in turn to reproductive success.)  Some elements of Darwin's theories are still being tested: only quite recently did researchers show that peacocks shorn of the irredescent "eyes" on the tail feathers do not father as many chicks.

And he will, in his own antisocial and retiring way, continue to battle against those who deny his theories.  (Wallace himself eventually decides that the evolution of humans cannot be explained by natural selection, and supports a supernatural "exception to the rule.")  Indeed, although "common descent" catches on pretty quickly due partly to ground prepared by others and partly due to the evidence he marshals, Darwin's most important contribution--evolution by natural selection--will battle all the way into the 20th century (long after Charles' death) before the dust has finally settled and Natural Selection stands alone in triumph: the only theory ever to successfully explain the amazing adaptations that give living things that "designed" look.

Although Darwin was wrong about many details (he had no real notion of genetics or population biology, for examples) it is remarkable that he got so much right; researchers continue to mine some of his more neglected ideas for new insights.

Darwin will die in April 1882 at home, after telling Emma, 

"I am not the least afraid of death – Remember what a good wife you have been to me

 – Tell all my children to remember how good they have been to me." 

The Origin of Species ends with some of Darwin's most famous lines.  "There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved."  


I've learned much from these books: Darwin: Discovering the Tree of Life by Niles Eldridge, and Darwin and the Barnacle byRebecca Stott; The Voyage of the Beagle, The Origin of Species, and The Autobiography of Charles Darwin, all by Himself.
Wikipedia has great articles for pursuing aspects of Darwin's life, among them Charles Darwin's Education.

Lyell, Darwin and Wallace (I)

This will NOT be my usual post of observations in suburban natural history.  But it IS a post I'm itching to write!  


Owing to my "discovery" of FREE electronic books after receiving an e-reader for my birthday, I have been immersed of late in the world of Charles Darwin.  I hadn't read his Origin of Species, and the journals of his round-the-world voyage since I was an undergrad, so I downloaded both and started in on the Journal.  I emerged a month later with a new appreciation for Darwin the Geologist (which is how he thought of himself) and quickly turned to Charles Lyell, the author of the three-volume Principles of Geology that came out around the time of Darwin's voyage and became both a major resource for Darwin, and a classic of the science in its own right.  (The Beagle's captain, Robert Fitz Roy, presented Darwin with the first volume* as a gift, and Darwin had the remaining volumes shipped to him during the five-year voyage.) 

I plowed through Principles of Geology over Christmas break, learning much about the state of science in the middle of the nineteenth century.  Lyell included a good deal of history and biology in his book, and--despite a scientific open-mindedness that sometimes surprised me--revealed some of the attitudes and biases of Victorians in his writing. 

Thinking about these two, their friendship, the encouragement Lyell gave Darwin on publishing his theory of species evolution, and yet Lyell's disbelief in Darwin's theory, I turned for the first time to the "other evolutionist": Alfred Russel Wallace.  Wallace is credited with arriving at very much the same theory as Darwin, and spurring Darwin to finally publish his "little book"--after decades of dithering--so that he wouldn't lose his priority of discovery.  In my scanty memory of science history, Wallace isn't credited with much else, but he certainly deserves to be. 

I will take these men in roughly chronological order, devoting this post to Charles Lyell.

Lyell was a lawyer, but also a man of means able to travel freely.  He was both a scientist** in his own right, and a great theorist and compiler of information.  His Principles is comprehensive, but is not a field manual.  (Darwin learned his rocks, strata, and the like as a college student--though almost entirely unofficially.)  The picture of 19th century science I get from reading Lyell ranges from science's attitudes toward religion, to white supremacist notions of Victorians, to the details of physical geography and stratigraphy. 

I will take the science first.  Lyell was a chief proponent of Uniformitarianism: the idea that the earth's surface was formed by ordinary processes that had occurred over long periods of time.  ("Deep time"--uncertain in extent, but probably measured in millions of years--was a break from the biblical timeline of 6000-odd years made popular by Bishop Usher.)  Uniformitarianism is often summarized: "the present is the key to the past."  The opposing camp believed that vast catastrophes had shaped the earth in olden times (often equated with biblical events such as Noah's flood), leaving us a landscape that could not be explained by present experience.  It was the consensus opinion that many species of ancient life were now extinct, and Lyell was one who believed extinction to be a normal part of earth history, rather than resulting from catastrophes.  Uniformitarianism was on the ascendancy, and modern geology traces its understandings mainly to it, though acknowledging that catastrophes DO sometimes happen: enormous volcanic eruptions and asteroid strikes, for example. 

Geologists, aware of the power of erosion to wear down the landscape, was very much concerned with understanding how there could still be mountains on an old earth.  At the same time, commonplace knowledge of strata bearing sea shells found high in the mountains begged explanation. Much of Lyell's second volume is reports of land that have risen or sunk in historical, or recent prehistorical, times.  Much of this work is very ingenious.  For example, a Greek ruin included pillars that showed evidence of damage by marine life, and historical reports of their being sometimes on dry land, other times in shallow water; Lyell interprets this as evidence that that landscape had fallen deep enough for the pillars to be completely submerged since they were built, and risen and fallen several times more recently.  He discusses many instances of coast that has sunk and been destroyed by the sea, including loss of whole villages in Great Britain.  He finds strata with marine fossils elevated above sea level, interpreting the age in which the land rose according to how many of the fossils matched creatures still living: the more that matched, the more recent the uplift.  (Geologists knew that lower rock strata in a series were older than higher strata, but had no way to know just how old any strata were.)  What causes the rising and falling of the earth's surface?  Lyell describes several hypotheses, some laughable until you realize that no one had any idea what lay below earth's surface beyond evidence that it was hot and molten in places.  He does not pretend an answer, but finds it pretty clear that earthquakes and volcanoes are somehow related to each other, and intermediate causes for some of the motion. (Not until just fifty years ago did we really begin forming a comprehensive picture, the theory of plate tectonics.)

Lyell's entire third volume is devoted to living species, what they are, their geographic distribution, and the question of their origin.  His understanding of ecology is very respectable.  He has clear notions of how species grow, decline and change their distribution in response to their physiological requirements, changes in conditions, and the influences of other species--whether competitors or predator/prey.  Except for terminology, Lyell could almost have taught the introductory ecology class I took in college.  He spends a good deal of time and ink first explaining Jean Baptiste Lamarck's evolutionary theory (now remembered as the first, but flawed, truly evolutionary theory) and then takes him apart with a very sharp scalpel.  He got my full attention when he turned his gaze on variation: the raw material of Darwin's Evolution by Natural Selection that would burst upon the world only a few years after this particular edition of Principles came off the presses.  Lyell showed evidence that variation was not the bottomless well Darwin needed, but had built-in limits.  He gave instance after instance of animals brought under domestication, bred in various direction, and then hitting a wall after they ran out of variation.  I wondered how Darwin would answer this.*** 

Of course, genetics was a black hole until the 20th century.  Many observations showed that offspring had characteristics of their parents and sometimes other ancestors, and that individuals varied.  But there was no clear mechanism to explain this.  (Gregor Mendel, hard at work crossing peas in his monastery garden, would publish in an obscure journal no one would read for decades.  He it was who discovered genes.)  So ideas like "inheritance of acquired characteristics" (Lamarck) were far from dead letters; Darwin entertained some unlikely theories of inheritance himself, and considered Lamarkian ideas possibly valid in late editions of his Origin.  

Science in Lyell's day was in the middle of a slow evolution.  Physics and chemistry had long since stopped invoking the "God hypothesis" to explain their observations.  The other natural sciences were following, but biology was lagging behind--in part because no one could come up with a plausible way to explain how living things could be so closely adapted to their situations without being designed so.  (Of course, even today there are those who can't accept it, but it's no longer a scientific problem, just one of human nature.)  Lyell himself looks hard for natural explanations for things, but still occasionally reaches for a teleological**** explanation.  "It seems, also, reasonable to conclude, that the power bestowed on the horse, the dog, the ox, the sheep, the cat, and many species of domesticated fowls, of supporting almost every climate, was given expressly to enable them to follow man throughout all parts of the globe, in order that we might obtain their services, and they our protection."  And the last few paragraphs of his Principles is a kind of credo.  "But in whatever direction we pursue our researches, whether in time or space, we discover everywhere the clear proofs of a Creative Intelligence, and of His foresight, wisdom, and power."  Not until the dawn of the 20th century would science finally refuse to settle for supernatural answers.  





The Victorian Lyell displays what I think a remarkable open-mindedness.  At one point he muses upon the future of humanity; he expects that humanity, as one among many species that have come and gone, will eventually become extinct as they have.  Later, in the realm of ecology, he points out that a natural landscape brought into cultivation--increasing its productivity for us--might very well be less productive for wildlife, making it at best a mixed blessing in the whole scheme of things.  "It admits of reasonable doubt whether, upon the whole, we fertilize or impoverish the lands we occupy," he writes.  Though he is aware of human-caused extinction, on the other hand, he seems to believe that it is our destiny--like that of many successful species before us-- to dominate and modify the face of nature.  (Of course, he could have little way of knowing what a hash we would make of it.)


I will leave discussion of Lyell's attitude toward imperialism and other races for another post, since it was one shared by other protagonists.

*This first volume was devoted to a history of geological ideas, going all the way back.  I suspected it would be a snoozefest.  It wasn't.

**Science at that time was not a profession; so most scientists had day jobs.  Many were clergyman, since the study of natural history was encouraged with the idea of learning about God from His creation.  Darwin came from a landed upper-middle-class family (at one point preparing for the ministry himself) and married his first cousin Emma Wedgewood (yes, that Wedgewood family), making him a man of leisure.  --though to his everlasting credit he worked very hard his whole adult life at his chosen vocation, making many discoveries which were eclipsed by his theory of evolution.

***Today we know that we inherit genes from our parents in the form of molecules of DNA that encode information, and that this DNA accumulates code variations randomly over time as chemical changes called mutations.  So although a particular population of domesticated animals really can "run out" of variation in the short term, mutation will continue to add more variation to the gene pool in the long term.

****Teleological explanations are about purpose; things are the way they are because they are means to some end.  For example, dogs have so much variation because that enables them to be bred to many different uses.  This is simply another way of saying it was "designed" that way.  (Lyell himself discusses a much more reasonable alternative hypothesis: that domestication didn't "work" on any animal that didn't start with enough variation to make useful breeds--such attempts were early abandoned and not recorded.)