Origin of Species: new online variorum

Yesterday, the world celebrated the sesquicentennial of the publication of The Origin of Species. But it is worth stressing that there was not one "Origin of Species", but six different editions produced in Britain alone during Darwin's lifetime. Fifty years ago, in time for the hundredth anniversary of the first publication, Morse Peckham produced a variorum text, which showed the variant readings between the six editions. However, Peckham's variorum has always been difficult to follow and is decidedly old-fashioned with its literal use of cut and paste.

To celebrate the 150th anniversary, my colleague at the University of Birmingham, Barbara Bordalejo, working with John van Wyhe at Darwin Online, has produced a fantastic new digital online variorum, which is much more flexible and user-friendly than Peckham's. Take a look at it here: http://darwin-online.org.uk/Variorum/index.html

For more details, see the editor's introduction: http://darwin-online.org.uk/Variorum/Introduction.html

At last, all of us can follow the evolution of The Origin!

First thoughts on "Creation"

Yesterday afternoon, I went to see "Creation", the new film out centred on Charles Darwin's relationships with his wife and his daughter, Annie. I guess I am in a unique position in writing this as I am sitting about two hundred yards from Montreal House in Malvern, where Annie died in 1851 and I live on land that was once part of the estate of the Lodge, the house in which Darwin and his family (including Annie) stayed for a few months in 1849.

But geographical proximity is not the real issue here--I have been far too close psychologically and intellectually to Darwin and his life, and Annie's role in it, for far too long to ever approach the movie as most viewers will. With that in mind, I was preparing to be disappointed, but in fact for the most part I enjoyed the movie, as did my children, because I remembered to tell myself that it was a work of imagination not historical biography.

There are lots of minor historical inaccuracies in the film, but as Eugenie Scott has pointed out, "Creation" will bring many aspects of Darwin's life, particularly his family life, to a wider audience, including the tragic loss of his daughter here in Malvern and the misery of his chronic illness. The acting is great, particularly Martha West as Annie and real husband and wife team Paul Bettany and Jennifer Connelly as Charles and Emma. And the lavish cinematography is a treat.

There were two things in the film I did not like. One was the way in which it flitted from one part of Darwin's life to another, back and forth across the decades. I would have preferred a simpler narrative. But more problematic was the way in which the film inter-linked Darwin's various struggles, intellectual and emotional, when as far as I am aware they were never linked. For example, there is no evidence that the death of Annie Darwin had any effect whatsoever on Darwin's work on the Origin of Species. And it is unclear to me whether differences in attitude to religion between Charles and Emma Darwin, which were clearly raised as an issue around the time of their marriage, persisted as a problem in their relationship as late as the film suggests, i.e. into the late 1850s. I may be wrong and will have to look into this, but the level of emotional intensity on Darwin's part in the film on this issue strikes me as off-kilter.

But all-in-all, a good film which I advise you to go and see! At the very least, it will banish the tired icon of Darwin as merely an old man with a bushy beard!

The evolution of the Origin revisualised

A few years back, Peter Robinson and Barbara Bordalejo, both textual scholars, came to work here in Birmingham. They, along with local New Testament scholar David Parker, have been at the forefront of efforts to exploit computers in textual scholarship and use the kind of phylogenetic approaches used on biological sequences to unravel the patterns of evolutionary branching among manuscripts. Peter and Barbara had worked extensively on Chaucer's Canterbury Tales, but shortly after her arrival here, Barbara was searching for a fresh project. David Parker, perhaps rather provocatively for a Reverend Professor, suggested that Barbara, Peter and I work together on the evolution of Darwin's Origin of Species, treating Darwin's publications as "textual genomes". We did some preliminary work on this and submitted a proposal to the Arts and Humanities Research Council, but alas it was not funded...

But the best proof that one is working on something worthwhile is when someone else comes up with the same idea quite independently (cf Wallace on Ternate!). So it is gratifying to see two examples of people doing the kind of analyses and developing the same kind of visualisation tools that we envisaged:

• The (En)tangled Word Bank is the work of computer scientist Greg McInerny and London-based visual artist Stefanie Posavec (see Science Blog Post) and is certainly pretty, although whether it can be used by scholars to unravel Darwin's thinking is unclear.
• Ben Fry's The Preservation of Favoured Traces looks more useful and provides a more intuitive view of changes, but sadly appears to lack a zoom tool, so that one can only gain a "God's eye" view of the whole text, without been able to look closely at individual sections.

But both projects provide a fascinating proof of concept and it would be great to see them integrated more fully into a project like Darwin Online, where they could make a real contribution to Darwin scholarship!

And now a request please! Can either or both projects now incorporate the two forerunners of the Origin: Darwin's 1842 Pencil Sketch and his 1844 essay (both transcribed here), so we can see quite how much of the Origin was written over ten years before Darwin started on his "big book"  Natural Selection (which should also be included). It always amazes me how much of the structure of Darwin's argument was laid out in those two manuscripts from the 1840s, but it would be nice to see visually how many of the words are in common too.

I have outsold my advance!

Just a brief note to report the good news that I have outsold the advance against royalties that I was given for my book, The Rough Guide to Evolution and have just had an additional payment. I think only about half of Rough Guides do this at all and I was quietly hoping to do so within the first year of publication. But the fact that I have done so in the first six months is good news indeed (as is the fact that a French translation courtesy of Edition Tournon is in the offing!). 

Thanks to all of you who bought the book and/or recommended it!

The Darwin Song Project

I have to confess that there is not much folk music in my iTunes library, but last week my copy of the Darwin Song Project CD arrived. And I am impressed!

The Darwin Song Project is the fruit of a frenetic collaboration between eight of the world's top folk artists, who composed the 17 songs of the album during a week-long retreat in a Shropshire farmhouse and then performed them in the new Theatre Severn in Darwin's home town Shrewsbury in March this year.

Even though it incorporates the Annie hypothesis, my favourite song on the album is the Dylanesque "Kingdom Come", which investigates how differences in religious belief divided Charles from his wife Emma. It opens with what must be a unique first line--an account of the life cycle of ichneumonid wasps, parasitic wasps that lay their eggs in the flesh of living caterpillars and which troubled Darwin!

Another delight is this mock-Country number, "We'll him down". I dedicate this YouTube link to all my friends from Dover, Pennsylvania (Lauri, Cyndi, Tammy and Nick)! Let's hope their Creationist compatriots realise that the song is ironic!

Videos for three other songs from the project are also available on YouTube. You can find out more about the project from its website and from this BBC Radio 4 show. And you can place your order for the CD here.

[Review of the album from The Guardian.]

Lamarck, Darwin and the Tree of Life

There has been some interesting discussion in the blogosphere as to whether Lamarck beat Darwin to the Tree of Life metaphor:

• http://scienceblogs.com/geneticfuture/2009/08/lamarck_beat_darwin_to_the_tre.php
  
• http://www.genetic-inference.co.uk/blog/?p=505
  

I am due to speak on this subject at the upcoming Society for General Microbiology meeting in Edinburgh, so I was intrigued to read these posts.

Here is my own quick-fire rather disorganised contribution to the argument, quickly cribbed off my Powerpoint slides, with a shameless inattention to sources:

It seems that Pallas did indeed come up with this metaphor in words before Lamarck and Darwin, even though he didn't draw a tree. This is what he wrote in 

Elenchus Zoophytorum (1766):

At omnium optime Arboris imagine adumbraretur Corporum organicorum Systema, quae a radice statim, e simplicissimis plantis atque ani- malibus duplicem, varie contiguum proferat truncum, Animalem & Vegetabilem; Quorum prior, per Mollusca pergat ad Pisces, emisso magno inter haec Insectorum laterali ramo, hinc ad Amphibia; & extremo cacumine Quadrupedia sustineret, Aves vero pro laterali pariter magno ramo infra Quadrupedia exsereret.

“But the system of organic bodies is best of all represented by an image of a tree which immediately from the root would lead forth out of the most simple plants and animals a double, variously contiguous animal and vegetable trunk; the first of which would proceed from molluscs to fishes, with a large side branch of insects sent out between these, hence to amphibians and at the farthest tip it would sustain the quadrupeds, but below the quadrupeds it would put forth birds as an equally large side branch.”

Augustin Augier in 1801 deserves credit for this description of a phylogenetic tree:

‘‘A figure like a genealogical tree appears to be the most proper to grasp the order and gradation of the series or branches which form classes or families. This figure, which I call a botanical tree, shows the agreements which the different series of plants maintain amongst each other, although detaching themselves from the trunk; just as a genealogical tree shows the order in which different branches of the same family came from the stem to which they owe their origin.’

see http://www.bio.sdsu.edu/faculty/archibald/Archibald08JHBonline.pdf for a depiction of Augier's tree. In fact, this article in general is an excellent source of information on the whole issue of evolutionary trees and in particular draws attention to a paleontological chart from 1840 that looks a lot like an evolutionary tree.

Chambers in his Vestiges of the Natural History of Creation has something that looks a bit like an evolutionary tree, although it is probably best described as a developmental tree. Follow this link: http://darwin-online.org.uk/content/frameset?viewtype=text&itemID=A2&pageseq=215

Note that Darwin's first depiction of an evolutionary tree is arguably not the oft-quoted "I think" figure, but these "coral of life" depiction that appears a few pages earlier in his notebook.

http://darwin-online.org.uk/content/frameset?viewtype=side&itemID=CUL-DAR121.-&pageseq=27

And finally, Wallace hit on the metaphor independently. One can dispute whether his tree-like diagrams on the classification of birds really count as evolutionary trees, but his verbal description in the article he published in 1855 clearly pre-date Darwin's published descriptions of the tree of life and add the appealing analogy of the human vascular system:

On the law which has regulated the Introduction of New Species. Annals and Magazine of Natural History, including Zoology, Botany, and Geology 16: (September): 184-196.
“We are also made aware of the difficulty of arriving at a true classification, even in a small and perfect group;—in the actual state of nature it is almost impossible, the species being so numerous and the modifications of form and structure so varied, arising probably from the immense number of species which have served as antitypes for the existing species, and thus produced a complicated branching of the lines of affinity, as intricate as the twigs of a gnarled oak or the vascular system of the human body. Again, if we consider that we have only fragments of this vast system, the stem and main branches being represented by extinct species of which we have no knowledge, while a vast mass of limbs and boughs and minute twigs and scattered leaves is what we have to place in order, and determine the true position each originally occupied with regard to the others, the whole difficulty of the true Natural System of classification becomes apparent to us.”

Interestingly, Wallace is now buried under a huge fossilised tree:

 [NB we all know it is really a huge fossil phallus ;-) ]

But the last word goes to Darwin, with his melodic prose:

The affinities of all the beings of the same class have sometimes been represented by a great tree. I believe this simile largely speaks the truth... As buds give rise by growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications. 

And for those of you who like reggae, try those "beautifiul ramifactions" Jamaican-styleee...

Happy Birthday to this Blog! And hello to a new blog on bacterial pathogenomics

Last week, while I was away on vacation in France, this blog had its first birthday. During this last year, the blog has plotted the completion, publication and reception of my book The Rough Guide to Evolution, but has covered much more besides in its 193 postings—from evolutionary tourism to flagellar biology. According to Google Analytics, the blog has received over 23,000 visits from 137 countries! 

It is unclear quite how well the book is selling, as I am still awaiting accurate figures for the first half of the year, but I have been told that worldwide sales so far are likely to be around 10,000-10,500, which means that there is a good chance I will have just outsold my advance against royalties in the first six months of the book's life!

But now I must confess that a change is at hand. I have to re-focus my efforts on my "day job" as a microbiologist, so, although I won't be closing this blog, I will be posting less often here. Instead, I will be using the insights into blogging that I have gained from this blog to drive forward a new blog Pathogens: Genes and Genomes, which will convey the excitement generated by the collision of high-throughput sequencing and clinical and environmental bacteriology. Feel free to join us there and to raise a glass to The Rough Guide to Evolution, book and blog!

Rough Guide to Evolution in Nature again this week

The Rough Guide to Evolution features again in the prestigious scientific journal Nature this week, thanks to Eugenie Scott (executive director of the US National Center for Science Education), who recommends it as Summer reading:

"The 200th anniversary of Charles Darwin's birth, plus the 150th anniversary of the publication of his best-known book, On the Origin of Species, make 2009 the year to learn about evolution. Mark Pallen's The Rough Guide to Evolution provides a concise summary of what you need to know: a brief history of the idea that all living things share common ancestry, a complete survey of the mechanisms of evolution and a solid summary of how life originated and then adapted through time to a changing planet. He livens up the story with literary, musical and cultural references so that you never feel you are being told to eat your vegetables. Alas, it is not only non-specialists who don't have a firm grasp of the strength of theory and data supporting the modern understanding of evolution — many scientists outside the field of evolutionary biology struggle too. This entertaining handbook will bring anyone up to date."

Thanks Genie!

Baba Brinkman's Rap Guide to Evolution now available in MP3

Canadian Lit Hop artist Baba Brinkman has just released his new album, The Rap Guide to Evolution, and as a special promotion, the album can be downloaded for free during the month of August in MP3 format. Follow the links from Baba's web page to get your copy: http://www.babasword.com/

Although Baba is not charging for downloads, he would appreciate donations to cover production costs.

The Rap Guide to Evolution is a hip-hop exploration of modern Evolutionary Biology. The album is based on the stage show of the same name, which appears at the Edinburgh Fringe Festival this August. Follow Baba's progress at the Fringe via his own blog for the event (Darwin on the Fringe) and be sure to go see the show if you are visiting the Fringe.

From Digbeth watesland to darwin-inspired arts space

Just picked this up from the Behind Closer Doors project website:

Two artists from Birmingham are part of an unusual project which has transformed a Digbeth waste-ground into a darwin-inspired exhibition space.

In the wake of the revered scientist’s bicentenary, Helen Grundy and Anne Guest are set to launch Unnatural Selection on 30th July at the Rea garden in Floodgate Street. The project is supported by Arts Council funding and the artists’ collective Behind Closed Doors.

Unnatural Selection aims to replicate Darwin’s methods of using his garden as a laboratory to observe nature, collect samples and carry out experiments.

There is a related workshop on saturday 1st August from 12-3pm.

Hat tip: Lewis Bingle.

PCR in song and video!

The polymerase chain reaction revolutionised molecular biology twenty years ago, opened up the study of ancient DNA from extinct organisms, and similar DNA amplification methods underpin the current revolution in high-throughput sequencing, so it is great to see molecular biology company BioRad celebrating this wonderful technique with a couple of hilarious catchy tongue-in-cheek songs.

Baba Brinkman at the Cambridge Darwin festival

I ducked out of the Cambridge Darwin festival for a variety of reasons, including severe cash flow problems after renovating my house. But Baba Brinkman went and from various sources I hear he had a great time there.

Here he is rapping to David Attenborough in King's College.

Another stray link between Darwin and the Wire...

Perhaps my earlier attempts to draw up links between the Darwins and the cult TV show The Wire were rather fanciful... 

But how about this for a more tangible link (left): Darwin's daughter Annie in the forthcoming film Creation is played by 10-year-old Martha West, daughter of Dominic West, who played Jimmy McNulty in The Wire! 

Everything connects...

I was suckered too...

In case anyone is thinking I have been too rough in publicising quite how many people have fallen for the Annie myth, let me confess, I was suckered by this story too and that is why I am quite so cross to see reality not match up to mythos. 

Here am I, in that piece of whimsy, the Origin of Species in Dub, falling for the myth that Annie's death influenced Darwin's evolutionary writings: 

http://www.infection.bham.ac.uk/BPAG/Dub/Videos/Track8.html

The spread of the Annie myth: it's worse than I thought

My posting on the spread of the Annie hypothesis has elicited this interesting posting on "the Angry Bitter Atheist myth"--the idea that a dismissal of religion purely on intellectual grounds isn't enough; instead atheists must also be angry at God for some tragedy or other. In fact, I have tried to avoid calling the "Annie hypothesis" (the claim that Annie's death triggered Darwin's final loss of faith in Christianity), the "Annie myth", for fear of drawing legal action (c.f. the bogus legal action against Simon Singh's use of the term "bogus"). 

But it is hard to avoid the conclusion that this story has been propagated so widely because it appeals to some human need for an emotional narrative, and so in that sense the term "myth" is appropriate. Plus, those who want to persuade Christians and other religious believers that Darwin was a thoroughly good chap for his work on evolution will wish to avoid the idea that his ideas on evolution had anything to do with his own loss of faith (even though they didn't have much to do with it)--far safer to blame it on a personal tragedy! 

Anyhow, on further investigation, I have found a few more examples of the uncritical acceptance of the Annie myth:

• Larry Moran and Niles Eldredge netted as uncritical devotees of the Annie myth in a single posting! Eldredge may be good on science, but he swallows both the "removed what little was left of his religious faith" myth and states as fact rather than wild guess that Annie died from tuberculosis.
• This article and podcast on Annie Darwin from the Oxford Dictionary of National Biography: "Darwin's experience of his daughter's life and his bereavement had a double significance for his thinking. Recent scholarship (Moore) has shown that it was probably the final factor in his gradual rejection of Christian faith"
• Plus this article from the same source on Darwin himself: "Moore reassessed Darwin's religious faith, showing that while he remained a pillar of his rural parish, the deaths of his father in 1848 and daughter Annie in 1851 finally led him to give up Christianity."
• Evolution 101 by Randy Moore
• More proof that even Carl Zimmer isn't infallible.
• The Mini Oxford Handbook of Clinical Medicine, which ascribes Annie's death to typhoid fever rather than the usual tuberculosis.
• Dinesh D'Souza's blog entry linking Annie's death and Darwin's loss of faith with the problem of evil
• Telegraph columnist George Pitcher in his article "Charles Darwin was not the father of atheism" 
• David Livingstone in a chapter in Where Science and Christianity meet lends credence to Moore's account of the Annie myth, but with more balance than most commentators, and he also goes for "typhoid fever" as cause of death.
• Even creationists are suckered in! http://www.evolutionthelie.com/history-of-science/evolutions-fatal-fruit-nurturing-charles-darwin/

It seems I really do need to get this paper finished and published to prevent this nonsense spreading further!

The surprising spread of the Annie hypothesis

As I have pointed out in previous posts, I have been working on a paper on the unsubstantiated claim that his daughter Annie's death led to Darwin's abandonment of Christianity. Once the paper is press, I will present my analysis of just what flimsy evidence the "Annie hypothesis" was based on by its originator, James Moore. But for now, let's just take a look at how far this modern "Darwin myth" has spread and how many people have suckered by it (even Carl Zimmer has been taken in!). 

Note, I use the term "myth" not so much in the sense of "false story" although I do think it is false, or at least unfalsifiable, but more because so many people wish to draw moral lessons from it. Most people seem far more comfortable with the idea that Darwin gave up Christianity only after something as traumatic as the death of a daughter, rather for the mostly dry intellectual reasons he cites in his Autobiography.

Anyhow, here is a draft of a table from the paper, showing quite how far the "Annie hypothesis" has spread. If you know of any additional striking examples of its presentation in print or on screen, please let us know by adding comments.

Table 1 Selected examples of the Annie Hypothesis in print, on screen and online

	Year	Quotations and context
In Print
1859 and All That: Remaking the Story of Evolution-and-Religion James R. Moore	1982	"Perhaps it was the "bitter and cruel" death in 1851 of ten-year-old Annie, his favourite child, just a month after he had read the moral challenge to that doctrine in Francis Newman's "excellent" spiritual Autobiography Faith, that prompted Darwin, as he later said, to give up Christianity once and for all."
Of Love and Death: Why Darwin 'gave up Christianity', James Moore	1989	See text of paper for discussion (in preparation).
Darwin, Desmond and Moore	1991	Account of Annie’s illness and death interspersed with interpolations about Darwin’s loss of faith.
Charles Darwin, Voyaging. Janet Browne.	1995	“His sense of God had virtually disappeared along with his daughter Anne.”
Rebecca Stetoff, , Charles Darwin And The Evolution Revolution	1996	"Darwin's own Christianity, never very deeply held, gradually eroded as he worked out his theory of natural selection; the remnants of his faith were wiped out entirely by the suffering and death of his daughter Annie in 1851. Later in life he described himself as an Agnostic--one who questions but does not flatly deny the existence of God. ... [Annie's] death destroyed the last lingering remnants of Darwin's Christianity."
Evolution, The Triumph of an Idea, Carl Zimmer	2001	“He could no longer believe that Anne’s soul was in heaven, that her soul had survived her unjustified death. It was then, 13 years after Darwin discovered natural selection, that he gave up Christianity”
Annie's Box Randal Keynes	2001	"After Annie's death, Charles set the Christian faith firmly behind him."
Emma Darwin, Edna Healey	2001	“The death of Annie confirmed Charles’s loss of faith”
Darwin and the Barnacle, Rebecca Stott	2003	“Perhaps he [Darwin] wanted to say what he was beginning to feel himself… that after death there was nothing—no God waiting to scour Annie’s record book…”
Darwin’s Origin of Species, A Biography, Janet Browne	2006	“Annie’s death may have finally tipped Darwin into disbelief”
The Reluctant Mr. Darwin, David Quammen	2006	“The death of Annie in 1851, following the death of his father three years ealier, marks an important point in Darwin’s long, quiet disengagement from religious belief and spirituality”
Darwin Loves You: Natural Selection and the Re-enchantment of the World, George Levine	2008	“But the hard experience of Annie’s death certainly had larger implications for his attitude toward religion, as James Moore has argued in his essay on this subject.” “That Anna [sic] died on Shakespeare’s birthday is a coincidence (is “intelligent design” an option?) of which I wish to take advantage, as I return to Darwin’s comment that Shakespeare had come to nauseate him.”
Rebel Giants, David Contosta	2008	“ For Charles, the death of this beautiful, kind, and beloved child was the last blow to any faith he had in God.”
“Call the Black Horses” from The Darwin Poems by Emily Ballou	2009	"You can safely put God to bed now/the way you can’t your daughter anymore./Tuck the sheets so tight he cannot move/and lock the bedroom door."
On Screen
The Voyage of Charles Darwin, BBC series	1978	Darwin voiceover on religion over funeral scene
The Devil's Chaplain, BBC documentary	1991	Moore stands over Annie's grave proclaiming that it was here that Darwin lost his Christian faith
Darwin's Dangerous Idea, PBS documentary	2001	Darwin family in black attends church, Darwin stays outside; Moore claims Annie's death destroyed Darwin's Christianity; claim repeated on PBS website
Darwin's Struggle: The Evolution of the Origin of Species BBC documentary	2009	Narrator states that after Annie's death "With his own belief in a Christian God already shaken, Darwin now severed his ties with traditional faith"; Moore links Darwin's statements in the Autobiography about the doctrine of damnation to anger at Annie's death. Moore claims links between Annie's death and "face of Nature" statements in Chapter III of Origin of Species, culminating in declaration "she suffered at Easter that others may live"
Did Darwin kill God? BBC Documentary	2009	Conor Cunningham bizarrely claims Annie died from cholera. Nick Spencer claims Annie's death once and for all finishes Darwin's Christian faith.
Creation (movie)	2009	Director's Statement: "The Darwin we meet in CREATION is a young, vibrant father, husband and friend whose mental and physical health gradually buckles under the weight of guilt and grief for a lost child. Ultimately it is the ghost of Annie, his adored 10 year-old daughter who leads him out of darkness and helps him reconnect with his wife and family."
Online
Wikipedia (accessed in 2009)		http://en.wikipedia.org/wiki/Development_of_Darwin "With Annie's death Darwin lost all faith in a beneficent God and saw Christianity as futile. "

 

David Hume's influence on Charles Darwin

As a result of helping my son Charlie with his homework, I have just (re-)read David Hume's Dialogues Concerning Natural Religion, which is a superb examination of the arguments for and against the existence of God. 

I was surprised to see how similar some parts of the Dialogues are to some parts of Darwin's own writings. I spent a bit of time Googling away to see if anyone else had noticed this, but can't find much evidence that anyone has. I found this one paper:

• David Hume and Charles Darwin, William B. Huntley, Journal of the History of Ideas, Vol. 33, No. 3, Festschrift for Philip P. Wiener (Jul. - Sep., 1972), pp. 457-470 http://www.jstor.org/stable/2709046
  

But this is concerned with the influence on Darwin of Hume's Treatise of Human Nature and An Enquiry Concerning Human Understanding and does not even mention Dialogues Concerning Natural Religion!

Daniel Dennett in Darwin's Dangerous Idea: Evolution and the Meanings of Life does describe some connections between Hume's thinking in the Dialogues and Darwin's evolution by natural selection. But in a chapter is entitled "Hume's Close Encounter", Dennett's point is "look how close Hume got to Darwin". Interpreting Hume in the light of Darwin strikes me as a cart-before-horse argument, reminiscent of David Lodge's fictional thesis on the influence of T. S. Eliot on Shakespeare. Instead, we should be looking for Hume's influence on Darwin!

So, is there any evidence that Darwin was familiar with Hume? The answer is yes, in abundance! Darwin kept a list of books to be read and Hume's works feature several times:

• Hume's Essay on Human understanding {(Sometime)}
  
• Hume's Essay
  
• Life of David Hume — (new Edit) by Bell recommended by Erasmus
  
• Hume's life of himself with corres: with Rousseau
• Humes dialogues & Nat. Hist of Religion
  
• Hume Hist. Engl. Vol 5 & 6. 
• 7th & 8th Vol of Hume's England — Admirable
  
• Hume's Essays. 2 Vol.
  
• 2. vols of Hume's History
  
• Hume's Hist of England. to end of the beginning of Elizabeth.
  

Plus Darwin lists Burton's Life of David Hume twice in his list, the second time with the verdict "poor". In fact, although I haven't totted up all of the books Darwin read, it seems likely that Hume is among the most common authors, if not the most common author, in Darwin's list!

So it is clear that Darwin read Hume's Dialogues, but was his later writing influenced by them? Well Dennett is right to point out how close Hume got to some of Darwin's key ideas:

Hume on the Struggle for Existence and War of Nature

"And why should man, added he, pretend to an exemption from the lot of all other animals? The whole earth, believe me, PHILO, is cursed and polluted. A perpetual war is kindled amongst all living creatures. Necessity, hunger, want, stimulate the strong and courageous: Fear, anxiety, terror, agitate the weak and infirm. The first entrance into life gives anguish to the new-born infant and to its wretched parent: Weakness, impotence, distress, attend each stage of that life: and it is at last finished in agony and horror."

"Observe too, says PHILO, the curious artifices of Nature, in order to embitter the life of every living being. The stronger prey upon the weaker, and keep them in perpetual terror and anxiety. The weaker too, in their turn, often prey upon the stronger, and vex and molest them without relaxation. Consider that innumerable race of insects, which either are bred on the body of each animal, or, flying about, infix their stings in him. These insects have others still less than themselves, which torment them. And thus on each hand, before and behind, above and below, every animal is surrounded with enemies, which incessantly seek his misery and destruction. "

And Hume gets close to Natural Selection: 

"And this very consideration too, continued PHILO, which we have stumbled on in the course of the argument, suggests a new hypothesis of cosmogony, that is not absolutely absurd and improbable. Is there a system, an order, an economy of things, by which matter can preserve that perpetual agitation which seems essential to it, and yet maintain a constancy in the forms which it produces? There certainly is such an economy; for this is actually the case with the present world. The continual motion of matter, therefore, in less than infinite transpositions, must produce this economy or order; and by its very nature, that order, when once established, supports itself, for many ages, if not to eternity. But wherever matter is so poised, arranged, and adjusted, as to continue in perpetual motion, and yet preserve a constancy in the forms, its situation must, of necessity, have all the same appearance of art and contrivance which we observe at present. All the parts of each form must have a relation to each other, and to the whole; and the whole itself must have a relation to the other parts of the universe; to the element in which the form subsists; to the materials with which it repairs its waste and decay; and to every other form which is hostile or friendly. A defect in any of these particulars destroys the form; and the matter of which it is composed is again set loose, and is thrown into irregular motions and fermentations, till it unite itself to some other regular form."

"It is in vain, therefore, to insist upon the uses of the parts in animals or vegetables, and their curious adjustment to each other. I would fain know, how an animal could subsist, unless its parts were so adjusted? Do we not find, that it immediately perishes whenever this adjustment ceases, and that its matter corrupting tries some new form?"

And here are a few parallel passages that suggest to me that Darwin might have been influenced by the Dialogues.

The ship and botched trials analogy

Hume in the Dialogues: "But were this world ever so perfect a production, it must still remain uncertain, whether all the excellences of the work can justly be ascribed to the workman. If we survey a ship, what an exalted idea must we form of the ingenuity of the carpenter who framed so complicated, useful, and beautiful a machine? And what surprise must we feel, when we find him a stupid mechanic, who imitated others, and copied an art, which, through a long succession of ages, after multiplied trials, mistakes, corrections, deliberations, and controversies, had been gradually improving? Many worlds might have been botched and bungled, throughout an eternity, ere this system was struck out; much labour lost, many fruitless trials made; and a slow, but continued improvement carried on during infinite ages in the art of world-making."

Darwin in the Origin of Species: "When we no longer look at an organic being as a savage looks at a ship, as at something wholly beyond his comprehension; when we regard every production of nature as one which has had a history; when we contemplate every complex structure and instinct as the summing up of many contrivances, each useful to the possessor, nearly in the same way as when we look at any great mechanical invention as the summing up of the labour, the experience, the reason, and even the blunders of numerous workmen; when we thus view each organic being, how far more interesting, I speak from experience, will the study of natural history become!"

The house/architect analogy

Hume: "If we see a house, CLEANTHES, we conclude, with the greatest certainty, that it had an architect or builder; because this is precisely that species of effect which we have experienced to proceed from that species of cause."

Darwin: "Throughout this chapter and elsewhere I have spoken of selection as the paramount power, yet its action absolutely depends on what we in our ignorance call spontaneous or accidental variability. Let an architect be compelled to build an edifice with uncut stones, fallen from a precipice. The shape of each fragment may be called accidental; yet the shape of each has been determined by the force of gravity, the nature of the rock, and the slope of the precipice,—events and circumstances, all of which depend on natural laws; but there is no relation between these laws and the purpose for which each fragment is used by the builder. In the same manner the variations of each creature are determined by fixed and immutable laws; but these bear no relation to the living structure which is slowly built up through the power of selection, whether this be natural or artificial selection."

The observation that introduced species thrive in new environments, even though they have not originated there.

Hume in the Dialogues: "LUCULLUS was the first that brought cherry-trees from ASIA to EUROPE; though that tree thrives so well in many EUROPEAN climates, that it grows in the woods without any culture. Is it possible, that throughout a whole eternity, no EUROPEAN had ever passed into ASIA, and thought of transplanting so delicious a fruit into his own country? Or if the tree was once transplanted and propagated, how could it ever afterwards perish? Empires may rise and fall, liberty and slavery succeed alternately, ignorance and knowledge give place to each other; but the cherry-tree will still remain in the woods of GREECE, SPAIN, and ITALY, and will never be affected by the revolutions of human society. It is not two thousand years since vines were transplanted into FRANCE, though there is no climate in the world more favourable to them.

It is not three centuries since horses, cows, sheep, swine, dogs, corn, were known in AMERICA. Is it possible, that during the revolutions of a whole eternity, there never arose a COLUMBUS, who might open the communication between EUROPE and that continent?... Nothing less than a total convulsion of the elements will ever destroy all the EUROPEAN animals and vegetables which are now to be found in the Western world."

Darwin in the Origin of Species: "Still more striking is the evidence from our domestic animals of many kinds which have run wild in several parts of the world: if the statements of the rate of increase of slow-breeding cattle and horses in South-America, and latterly in Australia, had not been well authenticated, they would have been quite incredible. So it is with plants: cases could be given of introduced plants which have become common throughout whole islands in a period of less than ten years. Several of the plants now most numerous over the wide plains of La Plata, clothing square leagues of surface almost to the exclusion of all other plants, have been introduced from Europe; and there are plants which now range in India, as I hear from Dr. Falconer, from Cape Comorin to the Himalaya, which have been imported from America since its discovery."

Superiority of the contrivances of nature to those of art

Hume: "Look round the world: contemplate the whole and every part of it: You will find it to be nothing but one great machine, subdivided into an infinite number of lesser machines, which again admit of subdivisions to a degree beyond what human senses and faculties can trace and explain. All these various machines, and even their most minute parts, are adjusted to each other with an accuracy which ravishes into admiration all men who have ever contemplated them. The curious adapting of means to ends, throughout all nature, resembles exactly, though it much exceeds, the productions of human contrivance; of human designs, thought, wisdom, and intelligence. Since, therefore, the effects resemble each other, we are led to infer, by all the rules of analogy, that the causes also resemble; and that the Author of Nature is somewhat similar to the mind of man, though possessed of much larger faculties, proportioned to the grandeur of the work which he has executed."

Darwin in the Origin: "We have seen that man by selection can certainly produce great results, and can adapt organic beings to his own uses, through the accumulation of slight but useful variations, given to him by the hand of Nature. But Natural Selection, as we shall hereafter see, is a power incessantly ready for action, and is as immeasurably superior to man's feeble efforts, as the works of Nature are to those of Art."

On the inability of finite minds to grasp an infinite deity

Hume in the Dialogues: "The question is not concerning the being, but the nature of God. This, I affirm, from the infirmities of human understanding, to be altogether incomprehensible and unknown to us. The essence of that supreme Mind, his attributes, the manner of his existence, the very nature of his duration; these, and every particular which regards so divine a Being, are mysterious to men. Finite, weak, and blind creatures, we ought to humble ourselves in his august presence; and, conscious of our frailties, adore in silence his infinite perfections, which eye hath not seen, ear hath not heard, neither hath it entered into the heart of man to conceive."

Darwin in his Autobiography:"But then arises the doubt—can the mind of man, which has, as I fully believe, been developed from a mind as low as that possessed by the lowest animal, be trusted when it draws such grand conclusions*? May not these be the result of the connection between cause and effect which strikes us as a necessary one, but probably depends merely on inherited experience? Nor must we overlook the probability of the constant inculcation in a belief in God on the minds of children producing so strong and perhaps an inherited effect on their brains not yet fully developed, that it would be as difficult for them to throw off their belief in God, as for a monkey to throw off its instinctive fear and hatred of a snake."

*Note the nice evolutionary twist added by Darwin here!

The balance of happiness/misery and pain/pleasure

Hume: "The only method of supporting Divine benevolence, and it is what I willingly embrace, is to deny absolutely the misery and wickedness of man. Your representations are exaggerated; your melancholy views mostly fictitious; your inferences contrary to fact and experience. Health is more common than sickness; pleasure than pain; happiness than misery. And for one vexation which we meet with, we attain, upon computation, a hundred enjoyments."

Darwin:"if we look to all sentient beings, whether there is more of misery or of happiness;—whether the world as a whole is a good or a bad one. According to my judgment happiness decidedly prevails, though this would be very difficult to prove. If the truth of this conclusion be granted, it harmonises well with the effects which we might expect from natural selection. If all the individuals of any species were habitually to suffer to an extreme degree they would neglect to propagate their kind; but we have no reason to believe that this has ever or at least often occurred. Some other considerations, moreover, lead to the belief that all sentient beings have been formed so as to enjoy, as a general rule, happiness."

Hume: "Admitting your position, replied PHILO, which yet is extremely doubtful, you must at the same time allow, that if pain be less frequent than pleasure, it is infinitely more violent and durable. One hour of it is often able to outweigh a day, a week, a month of our common insipid enjoyments; and how many days, weeks, and months, are passed by several in the most acute torments? Pleasure, scarcely in one instance, is ever able to reach ecstasy and rapture; and in no one instance can it continue for any time at its highest pitch and altitude. The spirits evaporate, the nerves relax, the fabric is disordered, and the enjoyment quickly degenerates into fatigue and uneasiness. But pain often, good God, how often! rises to torture and agony; and the longer it continues, it becomes still more genuine agony and torture. Patience is exhausted, courage languishes, melancholy seizes us, and nothing terminates our misery but the removal of its cause, or another event, which is the sole cure of all evil, but which, from our natural folly, we regard with still greater horror and consternation."

Darwin: "Now an animal may be led to pursue that course of action which is the most beneficial to the species by suffering, such as pain, hunger, thirst, and fear,—or by pleasure, as in eating and drinking and in the propagation of the species, &c. or by both means combined, as in the search for food. But pain or suffering of any kind, if long continued, causes depression and lessens the power of action; yet is well adapted to make a creature guard itself against any great or sudden evil. Pleasurable sensations, on the other hand, may be long continued without any depressing effect; on the contrary they stimulate the whole system to increased action. Hence it has come to pass that most or all sentient beings have been developed in such a manner through natural selection, that pleasurable sensations serve as their habitual guides. We see this in the pleasure from exertion, even occasionally from great exertion of the body or mind,—in the pleasure of our daily meals, and especially in the pleasure derived from sociability and from loving our families. The sum of such pleasures as these, which are habitual or frequently recurrent, give, as I can hardly doubt, to most sentient beings an excess of happiness over misery, although many occasionally suffer much."

Well, what does all this mean? It is uncertain to me whether these parallels reflect a direct influence of Hume's Dialogues on Darwin and if so, if there was a conscious or unconscious decision on Darwin's behalf to exploit them. 

Alternatively, Darwin may have encountered these arguments in a third source that used, or was used by, Hume (e.g. Paley). 

Or the resemblance could be purely coincidental. 

But, in conclusion, it is intriguing to see how far great minds think alike!