Processed meat? Really? How to process epidemiological news

So this week's Big Story in health is that processed meat is a risk for breast cancer.  A study has been published that finds it so.....so it must be true, right?  After all, it's on CNN and in some research report.  Well, read even CNN's headliner story and you'll see the caveats, the admissions, softened of course, that the excess risk isn't that great, but, at least, that the past studies have been 'inconsistent'.

Yummy poison!!  source: from the web, at Static.zoonar.com

Of course, with this sort of 'research' the weak associations with some named risk factors can easily be correlated with who knows how many other behavioral or other factors, and even if researchers tried to winnow them out, it is obvious that it's a guessing game.  Too many aspects of our lives are unreported, unknown, or correlated.  This is why week after week, it seems, do-this or don't-do-that stories hit the headlines.  If you believe them, well, I guess you should stop eating bacon.....until next week when some story will say that bacon prevents some disease or other.

Why breast cancer, by the way?  Why not intestinal or many other cancers?  Why, if even the current story refers to past results as being 'inconsistent' do we assume this one's right and they, or some of them, were wrong?  Could it be that this is because investigators want attention, journalists need news stories, and so on?

Why, by the way, is it always things that are actually pleasurable to eat that end up in these stories?  Why is it never cauliflower, or rhubarb, or squash?  Why coffee and not hibiscus tea?  Could western notions of sin have anything to do with the design of the studies themselves?

But what about, say, protective effects?
Of course, the headlines are always about the  nasty diseases to which anything fun, like a juicy bacon sandwich, not to mention alcohol, coffee, cookies, and so on seems to condemn us.  This makes for 'news', even if the past studies have been 'inconsistent' and therefore (it seems) we can believe this new one.

However, maybe eating bacon sandwiches has beneficial effects that don't make the headlines.  Maybe they protect us from hives, antisocial or even criminal behavior, raise our IQ, or get fewer toothaches.  Who could look for all those things, when they're busy trying to find bad things that bacon sandwiches cause?  Have investigators of this sort of behavioral exposure asked whether bacon and, say, beer raise job performance, add to longevity, or (heavens!) improve one's sex life?  Are these studies, essentially, about bad outcomes from things we enjoy?  Is that, in fact, a subtle, indirect effect of the Protestant ethic or something like that?  Of the urge to find bad things in these studies because they're paid for by NIH and done by people in medical schools?

The serious question
There are the pragmatic, self-interested aspects to these stories, and indeed even to the publication of the papers in proper journals.  If they disagree with previous work on the purportedly same subject, they get new headlines, when they should perhaps not be published without explicitly addressing the disagreement in real detail, as the main point of the work--rather than the subtle implication that now, finally, these new authors have got it right.  Or at least, they should not headline their findings.  Or something!

Instead, news sells, and thus we build a legacy of yes/yes/no/maybe/no/yes! studies.  These may generally be ignored by our baconophilic society, or they could make lots of people switch to spinach sandwiches, or many other kinds of effects.  This latter is somewhat akin to the quantum mechanical notion that measurement gives only incomplete information but affects what's being measured.

Epidemiological studies of this sort have been funded, at large expense, for decades now, and if there is anything consistent about them, it's that they are not consistent.  There must be a reason!  Is it really that the previous studies weren't well done?  Is it that if you fish for enough items, you'll catch something--big questionnaire studies looking at too many things?  Is it changing behaviors in ways not being identified by the studies?

Or, perchance, is it that these investigators need projects to get funded?  This sort of yo-yo result is very, very common.  There must be some explanation, and that inconsistency itself is likely as fundamental and important as any given study's findings.  Maybe bacon-burgers only are bad for you in some cultural environments, and these change in unmeasured ways, and that varying results are not 'inconsistent' at all--maybe it's the expectation that there's one relevant truth, so that inconsistency suggests problems in study design.  Maybe the problem is in simplistic thinking about risks.

Where do cynical possibilities meet serious epistemological ones, and how do we tell?

In order to be recognized, you have to be read: an impish truth?

Edgar Allan Poe was an American short story writer, a master of macabre horror--the 3 G's, one might say: Grim, Gruesome, and Ghastly.  Eeeeek!! If you don't know Poe, a BBC World Service podcast in the series The Forum (Sept 15, 2018) discusses his life and work.  If you haven't yet, you should read him (but not too late at night or in too dark a room!).  The Tell-tale Heart, The Murders in the Rue Morgue, The Pit and the Pendulum, and The Cask of Amontillado should be enough to scare the wits out of you! Eeeeek!!

Edgar Allan Poe (1809-49)

Ah, scare tactics--what a ploy for attention!  At a time when not many people were supporting themselves with writing alone, Poe apparently wrote that this going over the top was justified or even necessary if you wanted to make a living as a writer.  If you have to sell stories, somebody has to know about them, be intrigued by what they promise, go out and buy them.

Is science also a fantasy horror?
Poe was referring to his use of extreme shock value in literature, stories of the unreal.  But a colleague in genetics once boasted that "anything worth saying is worth exaggerating, and worth repeating", and drum-beating essentially the same idea over and over is a common science publishing policy.   This attitude seems schemingly antithetical to the ideals of science which should, at least, be incompatible with showmanship for many reasons.

Explaining science and advocating one's view in responsible ways is part of education, and of course the public whose taxes support science has a right to know what scientists do with the money.  New ideas may need to be stressed against a recalcitrant public, or even scientific, community.  Nonetheless, pandering science to the public as a ploy to get attention or money from them, is unworthy.  At the very least, it temps exaggeration or other misrepresentations of what's actually known.  We regularly see the evidence of this in terms of outright fraud that is discovered, and also yes-no-yes-again results (does coffee help or hurt you?).

This, I think, reflects a gradual, subtle, but for someone paying attention, a substantial dumbing-down of science reporting, by even the mainstream news media--even the covers and news 'n views headlines of the major science journals approach checkout-counter magazines in this, in my view.  Is this only crass but superficial pandering for reader and viewership--for subscription sales, or could it reflect a serious, degeneration in the quality of education itself, on which our society so heavily relies?   Eeeeek!!

In fact, showman scientists aren't new.  In a way, Hippocrates (whoever he was, if any single individual) once wrote a defensive article (On the Sacred Disease) in explicit competition for 'control' of the business of treating epilepsy, an effort to maintain that territory for medicine against competition from religion.  Centuries later, Galen was apparently well-known for public demonstrations of vivisection and so on, to garner attention and presumably wealth.

Robert Boyle gave traveling demonstrations of his famous air-pump, doing cruel things to animals to show that he created a vacuum.  Gall hustled his phrenology theory about skull shape and mental traits.  In the age of sail, people returning from expeditions to the far unknown gave lurid reports (thrills for paying audiences) and brought back exotica (dead and stuffed).  The captain of the Beagle, the ship on which Darwin sailed, brought live, unstuffed Fuegians back to England for display, among other such examples.

Yes, showman science isn't new.  And perhaps because of the various facets of the profit motive (now perhaps especially attending biomedical research) we see what seems to be increasingly common reports of corruption even among prominent senior (not just desperate junior) academic scientists.  This presumably results from the irresistible lure of lucre or pressure for attention and prominence.  Getting funded and attention mean having a career, when promotion, salaries, tenure, and prestige depend on how much rather than on what.  Ah, well, human fallibility!

The daily press feeds on, perpetuates (and profits from) simplistic claims of discovery along with breathless announcements that are often basically and culpably exaggerated promises.  Universities, hungry for grants, overhead, and attention, are fully in the game.  Showboat science isn't new, but I think has palpably ballooned in recent decades.  Among other things, scientists intentionally, with self-interest, routinely sow a sense of urgency.  Eeeeek!!

So should there be pressure on scientists to quiet down and stop relentless lobbying in every conceivable way?  My personal (probably reactionary!) view is a definite 'yes!':  we should discourage, or even somehow penalize showmanship of this sort.  The public has a right to know what they're paying for, but we should fund science without forcing it to be such a competitive and entrepreneurial system that must be manipulated by 'going public', by advertising.  If we want science to be done--and we should--then we should support it properly.

In a more balanced world, if you're hired as a science professor, the university owes you a salary, a lab, and resources to do what they hired you to do.  A professor's job should not depend on being a sales agent for oneself and the university, as it very often is, sometimes rather explicitly today.  Eeeeek!!

The imp of the perverse--in science today
One of Poe's stories was The Imp of the Perverse.  The narrator remarks upon our apparent perverse drive to do just the opposite of what we think--or know--that we should do.

The Imp of the Perverse.  Drawing by Arthur Rackham (source: Wiki entry on the story)

I won't give any spoilers, since you can enjoy it for yourself.  (Eeeeek!!)  But I think it has relevance to today's attitudes in science.  Science should be--our self-mythology is that it is--a dispassionate search for the truth about Nature.  Self-interest, biased perspectives, and other subjective aspects of our nature are to be avoided as much as possible.  But the imp of our perverse is that it has become (quoth the raven) ever-more important that science be personally self-serving.  It is hard to prevent ourselves, our imp, from blurting out that truth (though it is often acknowledged quietly, in private).

On the good side, careers in science have become more accessible to those not from the societal elite.  The down side is that therefore we have to sing for our supper.  Darwin and most others of science lore were basically of independent means.  They didn't do science as a career, but as a calling.

Of course, as science has become more bureaucratic, bourgeois, and routine, Nature yields where mythology--lore, dogma, and religion--had held forth in the past.  So, it is not clear whose interest that imp is serving.  That's more than a bit unnerving!  Eeeeek!!

Science 'ethics': can they be mainly fictional, too?
Each human society does things in some way, and things do get done.  Indeed, having been trained as an anthropologist, perhaps I shouldn't be disturbed or surprised by the crass aspects of science--nor that this predictably includes increasingly frequent actual fraud egged on by the imp of the pressure of self-interest.  Eeeeek!!

Our mythology of 'science' is the dispassionate attempt to understand Nature.  But maybe that's really what it is: a myth.  It is our way of pursuing knowledge, which science, of course, does.  And in the process, as predecessors such as those I named above show, gaming science is not new.  So isn't this just how human societies are, imperfect because we're imperfect beings?  Is there reason to try, at least, to resist the accelerating self-promotion, and to put more resources not just to careers but to the substance of real problems that we ought to try to solve?

Or should we just admire how our scientists have learned to work the system--that we let costly projects become entrenched, train excess research personnel, scare the public about disease, or make glowing false promises to get them to put money in the plate every tax year?  In the process, perhaps real solutions to problems are delayed, and we produce many more scientists than there are jobs, because one criterion for a successful lab is its size.

Were he alive and a witness to this situation, Poe might have fun dramatizing how science has become, though wonderful for some, for many, a horrible nightmare: Eeeeek!!

Flirting with old-tyme racism. Is anyone paying attention?

The ability to extract DNA from archeological bone specimens has opened a new area for research to reconstruct the past, but in some senses, this is allowing the field of anthropology to recapitulate its sometimes questionable history.  Anthropology has always been the study of groups of people, often characterized categorically, that is, as if their members were all alike, and were quite different from other groups.

There's a fine line between this kind of typological thinking and the hierarchical ranking of groups, often been aided and abetted by the technologies of the day, from phrenology in the 19th century, which could be used to show, for example, that Africans were born to be slaves, and in need of masters, to the use of DNA markers today, which have been interpreted by some to confirm the existence of biological races, and the primacy of genes over environment in the determination of who we are.  In a time when social policy is too often based on this kind of categorial thinking, with, for example, spreading belief in the evils of immigration, the inherent right of some to more of society's goods, from education to health care to tax relief, etc., our generation's version of "scientific racism" can land on receptive ears.  We cannot assume that the gross evils of the passed are gone, and the lessons learned.

There is a long line of examples of dangerously over-simplified but cute dumbed-down categorical assertions about groups, often in the genetic era from non-anthropologically sophisticated but prominent geneticists.  One from years ago was the sequence of 'mitochondrial Eve', in which a set of mtDNA sequences was used to infer a common ancestral sequence, and that was then attributed to our founding first woman.  There was, of course, one woman in which the imputed mtDNA sequence (or some sequence like it) occurred.  But the rest of that woman's genome, her dual sets of 23 chromosomes, had genetic variation that was also found in countless contemporary women (and men); each variant in each gene found in a different set of those contemporaries, and each 'coalescing' as the term is, in some single ancestral individual at some time and in some place.  This 'Eve' was only our common ancestor in her mtDNA, not her other genes, and so she, as a person, was not our 'Eve'--our shared female progenitor a la Genesis.  Indeed, among all of our genes there was no single, common ancestral time or place--probably not in hundreds of miles, or thousands of years.  Each DNA segment found today has its own ancestry.

Using the 'Eve' phrase was a cute liberty that got the story widely circulated, and as a Barnum & Bailey tactic, it worked very well.  But its reference to the Biblical Eve, a woman from whom all of us are purportedly descended, was culpably misleading even if catchily attention-seeking.  And, of course, the purported common ancestral mtDNA sequence is only inferred in a statistical sense, from today's mtDNA variation. This Eve-imagery came out of the Allan Wilson lab at UC Berkeley, a source of free-wheeling, glibly cute public claims.  That sort of thing gets picked up by a media hungry for cute stories and gives it legs.  So the behavior is rewarded.

More serious abuses of stereotypes
The 'mitochondrial Eve' characterization was cute and catchy, but perhaps harmless.  But categorical oversimplifying by scientists isn't always just cute and harmless.  In my day as a graduate student, a prominent physical anthropologist, at Penn no less, Carleton Coon, said in one of his widely read books on racial variation, that  "No one can express anguish more convincingly by his facial expression than an Italian.  A Negro's facial expression, on the other hand, consists largely of exposing his eyeballs and his teeth.  There is good reason for this difference: the Italian's mobile and moving communication would be lost, under most lighting conditions, on a black face."  

Yet when I was in graduate school, at about the same time as this was published, I took human anatomy at the University of Michigan medical school.  When we got to the superficial facial muscles, here is the illustration of those muscles from my professor's own, prominent, anatomy text:
  

From Woodburne: Essentials of Human Anatomy (4th ed.),  1969

This drawing, uses a black person as an exemplar of human facial muscles.  They are clear and clearly identified as functional; they are not degenerate or minimalized, incapable of full expression.  They are not the muscles of but one category of people: they are the human muscles.

Rumors, at least, were that the eminent Professor Coon had argued, behind the scenes, against integrating schools in the US, on the grounds that 'Negroes' were of intellectually inferior ability.  Categorical thinking, with its typically concomitant value judgments, is nothing new, and it's never over, but sloppy scientific thinking shouldn't contribute to the problem.

Even without making qualitative value judgments, categorical thinking about humans, a form of racism, is historically dangerous, and everyone in science should know that.  Yet, recently, there has been a simple, dramatic story of past human 'breeding' habits that indicates that categorical scientific racism still has legs in our society and, indeed, our most prominent journals. If not intentionally, it's by a kind of convenient default.

Here are the cover, and one of the figures, from a recent issue of Nature.  The embracing hands of people of different 'colors' shown as types who mated, indeed thus producing 'hybrids' between a Neanderthal and a Denisovan parent.  This is a splashy story because these are considered to be different species.  And the journal, naturally, used this as its lurid cover.  The cover figure is about the 6 September story in that issue, from which we reproduce one figure that shows groups represented as regionally distributed people of different color.  Is it unfair to call this stereotyping, of the old-fashioned type, even if only subliminally?  Whatever the intent, the typological thinking is not subtle.

Thinking of this sort should have been long gone from Anthropology because DNA sequencing has clearly shown the internal variation and inter-group (or, better put, inter-geographic) overlap in variation.  But when the publicity engines and the sensationalistic adrenalin are at work in science, whatever sells seems OK.

Even with a very long history of racism, including of course intentional slavery and genocide, we cannot seem to give up on types and categories, even inadvertent habits with no value judgment intended.  But whether intentional and vicious, or merely inadvertent and de facto, this is essentially racism, and should be called out as such.  And racism is dangerous, especially when voiced by scientists who should know better, or even, as I presume in this case, who are not racists in the usual discriminatory sense (that may not apply to their readers!).  As a prominent colleague once said privately to me, he was not a 'personal racist' (he had African friends, after all)--he was just a typologist, a genetic determinist; i.e., a scientific racist.

Even if the authors of the human hybrid piece, happy enough for a cover story in a major journal, are not themselves "personal racists:, they perpetuate classificatory thinking.  Countless people have lost their lives because of careless sloganeering.  No matter its more polite guise, and carefully nonbiological group coloring in the figures, is this any different?

Is science heading back to those good ol' days again?

My sexed-up Jordan Peterson fantasy

Picture me dressed in "a new three-piece suit, shiny and brown with wide lapels with a decorative silver flourish" and my cranium and jaws draped luxuriously, top to bottom, in Jordan Peterson hair.

I even pronounce "so-ree" like he does because I got my first period while living in Ontario, so I earned the right. Also, I don't care if it offends him or you.

I am pulling this off beautifully. Trust me:

This is me being Axl Rose.

Jordan Peterson and I, his chaotic mirror, are sitting across from one another in comfy leather armchairs, with nothing in between to break the gaze of my crotchal region pointed at his crotchal region. I'm as cool as he is. I don't have to act like I've been here before because I have.

I'm leaning in, in the most specific way, towards Jordan Peterson, a model of human success.

I ask my first question.

"Could you please lay out the scientific logic linking lobsters to the patriarchy?"

He says many things, including that people obviously aren't lobsters and how we aren't even chimpanzees, which is reasonable because he is skilled at reason.

Then I say, "You're a man of science. So, what do you have to say about any evidence that contradicts your ideas about the natural ways of hierarchies and how they're particularly relevant to human society? Also, have you thought of any ways your ideas could be tested?"

He says many things, but they have little to do with taking contradicting evidence seriously or having thought through the difficulty of testing much of what's fundamental here. And this is largely because, despite the veneer of science, these ideas have breeched the bounds of reasonable, feasible testing.

"What about this, eh?" I offer, "We take the top lobster from the west side of Prince Edward Island and move him to the east side of the island. Is he going to be the top lobster there too? And would this same experiment work for chimpanzees? Or for humans?"

He says many things but will make it seem like there is no point to what I asked. The idea that humans are not lobsters or chimpanzees will resurface--tethering him, once again, to reason and nuance yet not actually producing anything of the sort for us.

So I continue, "Because if this link to lobster hierarchies is supposed to go not just from lobsters to humans, but to individual humans and their natural strengths and weaknesses compared to other individuals, then context shouldn't matter and if we transplant a lobster or a human then they should each assume their natural position in the local social hierarchy, wherever we plop them."

He says many things that sound reasonable.

Then I add "It's not just the top lobster's lived experience that contributes to his place atop the hierarchy, it's everyone else's below him in that hierarchy too--right?"

He must agree with this and does. He says many things that sound reasonable.

"And so where do you change from lobster to human and acknowledge that bad luck and circumstances of birthplace and family and everything else stick people lower in the hierarchy than they could be in different circumstances?"

He says many things about how this is absolutely true for so many young white men in North America all of whom can improve their station if they just read 12 Rules For Life and fill out the worksheets.

"Could a lobster improve its station in any way comparable to what you suggest for your readers?"

He isn't having my silliness.

"Okay, let's back up. What is evolution?"

He's stunned but plays it off perfectly.

"How would you define evolution to your readers/viewers?"

He says many things straight out of Descent of Man and nods to some of the least huggable atheist superstars.

"It's not a single reader or viewer's fault that they don't know any better and just believe your evolutionary insinuations and assumptions, but don't you think you should know better? ... If I were to become globally influential and I wanted to share ideas about clinical psychology that would influence masses of people, being the Ph.D. and professor that I am, I would go to the cutting edge of the field and learn there first before going public. I would try to understand what is known and what is unknown in that field, your field, and appreciate how those things are known and why there still are unknowns. And, if my masses of followers were misunderstanding my take on clinical psychology or my takes on my own areas of expertise, being the Ph.D. and professor I am, I would go out of my way to clarify my ideas in hopes they'd understand me better. Do you do that with the ways that folks interpret your views, like how some take you literally about sex distribution and enforced monogamy?"

He says he thinks his readers/viewers understand him quite well on those topics. This is vague and elusive and I move on because I feel an odd mixture of disappointment, pity, and disgust and I'd like to leave it behind as soon as possible.

"I believe with confidence that there are fundamental cognitive differences between humans and other animals. Do you agree?"

He says he does.

"Do you agree that these cognitive differences have contributed significantly to our domination of the planet?"

He says sure, of course.

"So why be so limited in your vision for achieving equal freedom, equal opportunity? All I've heard from you is that men should act more masculine (and less feminine) and that so should women if men and women want to succeed. Do you have any other ideas?  Or is that the extent of your imagination? Because it feels like quite an underappreciation of humankind to me. Like, the opposite of a moonshot, eh?"

He says many things that sound epic, I guess, if you are already a fan of him.

"Lobsters don't go to the moon. I think humankind can do better than just man-up."

He just plays it cool in his chair, there. And we can hear his fans all over the world laughing at me. No amount of masculine dress, hair, or swagger can disguise my big powerful lady PhD. And that's not just hilarious, but it also proves that men hold disproportionate power because of simple lobster logic. I've been dominated, which makes Jordan Peterson even more right about everything.

From Darwin's own thoughts. Part IV.

Here is the fourth, and final installment of annotated quotes from Charles Darwin's autobiography (my comments in blue):

"As soon as I had become, in the year 1837 or 1838, convinced that species were mutable productions, I could not avoid the belief that man must come under the same law. Accordingly I collected notes on the subject for my own satisfaction, and not for a long time with any intention of publishing."

Darwin realizes that humans must have evolved, too.  There was no reason, from what he could observe, to except us.  But he knew the dangers of saying so!  We are still under some societal pressure to disavow evolutionary theory, not unlike his days.  Denial is all around us....

"My strength will then probably be exhausted, and I shall be ready to exclaim "Nunc dimittis.""

That means something like 'Enough--time to go!'

"My mind seems to have become a kind of machine for grinding general laws out of large collections of facts, but why this should have caused the atrophy of that part of the brain alone, on which the higher tastes depend, I cannot conceive. A man with a mind more highly organised or better constituted than mine, would not, I suppose, have thus suffered; and if I had to live my life again, I would have made a rule to read some poetry and listen to some music at least once every week; for perhaps the parts of my brain now atrophied would thus have been kept active through use.  The loss of these tastes is a loss of happiness, and may possibly be injurious to the intellect, and more probably to the moral character, by enfeebling the emotional part of our nature."

Darwin bemoans his intellectual narrowness.  He elsewhere (as we've seen) refers to books or poetry he no longer reads or once liked.  How many of us are pressured to be technophilic workaholics, letting some of the deepest pleasures of life pass us by?  Take heed!

"....the 'Origin of Species  is one long argument from the beginning to the end, and it has convinced not a few able men."

"On the favourable side of the balance, I think that I am superior to the common run of men in noticing things which easily escape attention, and in observing them carefully."

A lesson might be not to fall into just accepting fads or what is selling these days, but to pay attention, for yourself, to the nature of what you are studying.

"This has naturally led me to distrust greatly deductive reasoning in the mixed sciences. On the other hand, I am not very sceptical,— a frame of mind which I believe to be injurious to the progress of science."

He means observe the world as it is, don't just accept theory or speculative ideas uncritically.  In not being skeptical he may mean that he believes there are truths out there, generalities or theories, that can be accepted if there is supporting evidence.

"So that here a belief— if indeed a statement with no definite idea attached to it can be called a belief— had spread over almost the whole of England without any vestige of evidence."

One can identify fads (like 'Big Data' or 'precision genomic medicine' or other 'omics?) that feed the System.  But maybe closer, clearer, more patient thinking and observing could serve our impatient results-counting generation well instead.

"Lastly, I have had ample leisure from not having to earn my own bread."

Ah, to be wealthy!

.  .  .  .  .  .  .  .  .  .

My afterthoughts:
So, why did I extract and post these bits by Darwin?  I think he gives us a lot to think about.  This is not just about particular facts, or even the idea of evolution which was, in fact, 'in the air' despite Darwin's denial.

We might not have had the same exact theory today, as Darwin proposed it.  We have vastly more data, an understanding of inheritance, and even much better ideas about species distributions (for example, we know about continental drift).  We have more subtle understanding of the roles of natural selection and chance (genetic drift).  We have much more information on the complex nature of genetic control on our traits.  A century and a half of research, framed by the notion of evolution has framed our investigations themselves.  But the central idea of evolution stands without doubt among scientists.  Nothing diminishes Darwin's patience, observations, experiments, persistence, dedication to using detail to build a general picture, and, by no means least of all, his honor.

Careerist pressures are today often, if not largely, antithetical to the personal traits that worked so well for Darwin.  So, aside from seeing the thoughts of one of the most insightful of all scientists, there are lessons for our own time in Darwin's reprise of his life.

From Darwin's own thoughts. Part III.

This is the third installment of my annotated selection of pithy quotes from Darwin's autobiography (my comments in blue):

Darwin and Wallace both felt inspiration, or a vital explanatory link, in Thomas Malthus' book:
"In October 1838, that is, fifteen months after I had begun my systematic enquiry, I happened to read for amusement 'Malthus on Population,' and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species."

Darwin's reflections on his theory of evolution and his most important work:
"The solution, as I believe, is that the modified offspring of all dominant and increasing forms tend to become adapted to many and highly diversified places in the economy of nature."

"This shows how necessary it is that any new view should be explained at considerable length in order to arouse public attention."

"Though considerably added to and corrected in the later editions, it has remained substantially the same book....It is no doubt the chief work of my life."

"It has sometimes been said that the success of the 'Origin' proved "that the subject was in the air," or "that men's minds were prepared for it." I do not think that this is strictly true, for I occasionally sounded not a few naturalists, and never happened to come across a single one who seemed to doubt about the permanence of species."

Darwin was most elaborating and saw deeply, but actually, there were ideas floating around, as Wallace (but also others, too) proves.  This undoubtedly affects ideas we think about today, too, but we can find our like-thinking contemporaries--or predecessors--by web-searching (if we want to).

"Another element in the success of the book was its moderate size; and this I owe to the appearance of Mr. Wallace's essay; had I published on the scale in which I began to write in 1856, the book would have been four or five times as large as the 'Origin,' and very few would have had the patience to read it.

I cared very little whether men attributed most originality to me or Wallace; and his essay no doubt aided in the reception of the theory."

Darwin, ever the generous man.  But his societal advantages guaranteed his preeminence, and he was more thorough.  Wallace's ideas were more group- than individual-oriented, and may have some merit although Darwinites take pleasure in scorning them.  And nobody can refer to most of Darwin's books as other than quite long!

"Hardly any point gave me so much satisfaction when I was at work on the 'Origin,' as the explanation of the wide difference in many classes between the embryo and the adult animal, and of the close resemblance of the embryos within the same class. No notice of this point was taken, as far as I remember, in the early reviews of the 'Origin,' and I recollect expressing my surprise on this head in a letter to Asa Gray.

Darwin relied on embryological data and ideas from his predecessors, particularly von Baer  in Germany.

"Towards the end of the work I give my well-abused hypothesis of Pangenesis. An unverified hypothesis is of little or no value; but if anyone should hereafter be led to make observations by which some such hypothesis could be established, I shall have done good service, as an astonishing number of isolated facts can be thus connected together and rendered intelligible."

Darwin is right about his idea of Pangenesis (the idea that each part of the body emits particles that he called 'gemmules' that congregate in the gonads and contribute to the gametes) being of 'little or no value', and indeed it was very much like the Lamarckian view he sneered at.  But what is the role for free speculation in science?  Darwin's speculating was pretty clear, since there was no data supporting 'gemmules' or 'pangenesis'.  Yet, as long as they are clearly  marked as guessing, can intelligent guessing stimulate creative thought?  Is it better, or worse, than just saying "we have no idea how this works...."?

From Darwin's own thoughts. Part II.

This is part two, a continuation of my annotated selection of quotes from Charles Darwin's autobiography (my comments in blue):

"In July I opened my first note-book for facts in relation to the Origin of Species, about which I had long reflected, and never ceased working for the next twenty years."

Again, evidence of such patience!  And the result shows why one need not, perhaps should not, rush to publish.

(By Charles Lyell, the distinguished senior geologist and close Darwin friend): ""What a good thing it would be if every scientific man was to die when sixty years old, as afterwards he would be sure to oppose all new doctrines." But he hoped that now he might be allowed to live."

Keeping new and fresh while getting old?  Rarely!  Make your mark while you can....

"Our fixing ourselves here has answered admirably in one way, which we did not anticipate, namely, by being very convenient for frequent visits from our children."

Keeping priorities about what means most in life.

"I have therefore nothing to record during the rest of my life, except the publication of my several books."

On his very extensive many-years' work on barnacles:  
"Nevertheless,  I doubt whether the work was worth the consumption of so much time."

The question and how he mused about it:
"It was evident that such facts as these, as well as many others, could only be explained on the supposition that species gradually become modified; and the subject haunted me. But it was equally evident that neither the action of the surrounding conditions, nor the will of the organisms (especially in the case of plants) could account for the innumerable cases in which organisms of every kind are beautifully adapted to their habits of life— for instance, a woodpecker or a tree-frog to climb trees, or a seed for dispersal by hooks or plumes. I had always been much struck by such adaptations, and until these could be explained it seemed to me almost useless to endeavour to prove by indirect evidence that species have been modified.

I worked on true Baconian principles, and without any theory collected facts on a wholesale scale, more especially with respect to domesticated productions."

Darwin the observer, not the rusher to conclusions!

"I soon perceived that selection was the keystone of man's success in making useful races of animals and plants. But how selection could be applied to organisms living in a state of nature remained for some time a mystery to me."

Yes, agriculture has done it--changed species' traits--but how does it happen in Nature?