Sunday, July 22, 2012

A Digression ~ Microfossils and Life Among Facts

On the evening of August 26, 1868, biologist Thomas Henry Huxley (1825 - 1895) raised high the microfossil in a lecture titled On A Piece of Chalk which he delivered to a group of men from the “operative classes” (i.e., workingmen) of Norwich, England.  This masterful piece of exposition took its listeners from the quotidian (a piece of chalk) to the profound (an understanding of geological and biological processes on an old earth).  It remains one of best examples of popular science writing, flowing easily and succinctly, drawing in the listener (and reader) on a mutual exploration with the speaker.  We are, indeed, on this journey with Huxley; this is no pronouncement from the citadels of science.  (Full disclosure:  Huxley's status in my pantheon of heroes continues to rise and rise.  What an impressive and impassioned intellect.)

National Public Radio science correspondent Robert Krulwich introduced me to this lecture in a post on his blog Krulwich Wonders . . . .  The post, titled Thinking Too Much About Chalk, is an interesting and eminently readable discussion of chalk, focused primarily on the conceit of Huxley’s lecture – that, from a study of a piece of chalk, one can logically derive fundamental scientific understanding.

How could I not find Huxley's lecture appealing with microfossils front and center, playing the critical role?  He described for his Norwich audience the chemical nature of chalk by illustrating how it behaves under circumstances his listeners would probably appreciate – when it is burned or when it is powdered and dropped into vinegar.  But, he went deeper, into the heart of the matter, explaining what one would see if this rock were examined under a microscope.
The general mass of it is made up of very minute granules; but, imbedded in this matrix, are innumerable bodies, some smaller and some larger, but, on a rough average, not more than a hundredth of an inch in diameter, having a well-defined shape and structure.
(I bristled a bit at how easy Huxley seems to make the process of disaggregating the “bodies” from the “matrix.”  As any reader of this blog knows, that’s certainy not been my experience washing sedimentary material to free microfossils from matrix – see this earlier post for example.)

Then he told his listeners what those “innumerable bodies” looked like under the microscope:
[E]ach of the rounded bodies may be proved to be a beautifully-constructed calcareous fabric, made up of a number of chambers, communicating freely with one another.  The chambered bodies are of various forms.  One of the commonest is something like a badly-grown raspberry, being formed of a number of nearly globular chambers of different sizes congregated together.
Huxley identifies the organism creating these bodies as Globigerina, a genus of foraminifera.  (The photo above is of a shell from Globigerina juvenilis Bolli and was downloaded from the Smithsonian website.  It has catalog number USNM PR 5617.  This isn’t a species from the Cretaceous when the chalk formations in England such as the White Cliffs of Dover were laid down, but you get the idea of what the misshapened “raspberries” look like.)

Well, to be even more exact about the genus Huxley identified for his audience, it is Globigerina d’Orbigny, 1826.  (Amazing how insular all of this is.  D’Orbigny is the subject of a previous post.)

It’s these forams in the chalk that enabled Huxley to use a piece of the rock to reconstruct the geological upheavals of the distant past, taking his listeners back to a time when a great sea covered England and Europe, among other places, and the tiny shells of these creatures (and the products of other organisms) very slowly accumulated into great masses on the sea floor, creating raw chalk.

Huxley asserted that the granules in the rock, those which bound it all together, were inorganic, despite having “definite form and size.”  These he named coccoliths.  These coccoliths, he noted, had been found assembled in spheres – coccospheres, “the nature of which is extremely puzzling and problematical.”

In cutting a corner and, I think, to his discredit, Krulwich suggest that in 1868 Huxley understood that the center of his story about chalk were the coccoliths and that he knew them to be products of once living organisms – wrong on both counts.  It particularly grieves me that, in doing so, Krulwich drops forams from the picture entirely.  For Huxley, the primary materials in the chalk created by ancient organisms were the shells of forams and the value of the forams was the tale they told of marine life in an ancient sea.  Were there no forams in chalk, Huxley would probably not have written this piece about chalk, at least not in 1868.

(In a footnote appearing in the printed version of the lecture, as published in the 1908 edition of Discourses:  Biological & Geological that I read (Volume VIII of Collected Essays), Huxley states categorically, I "no longer doubt that they [coccoliths] are produced by independent organisms, which, like the Globigerinae, live and die at the bottom of the sea."  I've traced this footnote back at least to 1886.)

Though coccoliths are, in fact, also produced by living creatures and, indeed, make up the bulk of organically produced remains in chalk, the tale they tell is the same as the one Huxley told.

Krulwich also plays it a bit loose when he states that coccoliths are “single-celled phytoplankton algae.”  Well, that’s not quite right.  Coccoliths are the plates produced by coccolithopores, the actual planktonic organism in question.  (See, Bringing Fossils to Life, by Donald Prothero, 1998, p. 207 et seq., and Microfossils by Howard A. Armstrong and Martin D. Brasier, 2005, second edition, p. 129 et seq.)

(This wonderful picture of a Gephrocapsa oceanica was taken by NEON ja and colored by Richard Bartz.  It is reproduced under the Creative Commons Attribution-Share Alike 2.5 Generic license and is available on Wikipedia.  This is an extant species of coccolithopore.)

I suppose I’m sniping at Krulwich because I envy the flow of his post.  It’s a good read, despite my quibbles.  That said, I have still another nit to pick and a more expansive (digressive) observation.

I don’t understand the title he gave his piece.  Might it be taken to be mocking Huxley, the man of science, for imbuing a piece of chalk with such value?  Though that's certainly not a perspective reflected in Krulwich’s essay itself.  Puzzling.

Finally, other than noting it, Krulwich does little with, what for me is a key context for Huxley’s lecture – that he was addressing the workers of Norwich.  This kind of lecture was near and dear to Huxley; it had value for many reasons.  Not the least of which was the income derived from it (I assume Huxley was paid for this specific lecture).  Not coming from a well-to-do family, he usually had to cobble together a living from writing articles, lecturing, and teaching.

But the value was not only monetary.  In the preface to the 1894 edition of Man’s Place in Nature (as quoted in Life and Letters of  Thomas Henry Huxley, Volume 1 by Leonard Huxley, 1913), he explained one of the roles lectures such as these played for him.
Some experience of popular lecturing had convinced me that the necessity of making things clear to uninstructed people was one of the very best means of clearing up the obscure corners in one’s own mind.  (p. 259)
That squares with my belief that, unless you can explain something to the uninitiated, you don’t really know it.

Further, Huxley inveighed against the label “popular” for the many lectures he delivered over the years to workingmen, preferring to call them “people’s” lectures (admittedly,  he was not consistent in this regard).  These were the people.  He delivered these science talks to workers because they brought to these topics, not an academic, but a real world perspective and real world experience.  As he wrote in 1855, “I am sick of the dilettante middle class, and mean to try what I can do with these hard-handed fellows who live among facts.”  (Letter to Dr. Frederick Dyster, February 27, 1855, Life and Letters, p. 199.)  Indeed, that “life among facts” was at the heart of Huxley’s very approach to science – apply common sense while you go where the facts lead.

Huxley was a recognized educational reformer having been elected to the first School Board of London.  I have only begun to read what he had to say and do about education but, of the educational system he saw around him in mid-19th century England, it’s clear he had little patience.  About the education received by the middle and upper classes, of which the English were so proud, his tone is deeply sarcastic.  Reformers, he said in a lecture on January 4, 1868, to the South London Working Men's College,
ask whether the richest of our public [private] schools might not well be made to supply knowledge, as well as gentlemanly habits, a strong class feeling, and eminent proficiency in cricket.  They seem to think that the noble foundations of our old universities are hardly fulfilling their functions in their present posture of half-clerical seminaries, half racecourses, where men are trained to win a senior wranglership, or a double-first, as horses are trained to win a cup, with as little reference to the needs of after-life in the case of the man as in that of the racer.  (A Liberal Education; And Where To Find It, Lay Sermons, Addresses, And Reviews, 1893, p. 29.)
As for his view of the then current state of the education of the working classes, one detects a note of anger.  He describes the various reasons that so many people at the time, including the clergy and men of business, were questioning the educational system in England, and observes that a “few voices” promote a “doctrine that the masses should be educated because they are men and women with unlimited capacities of being, doing, and suffering, and that is as true now, as ever it was, that the people perish for lack of knowledge.”  This minority of voices is one, Huxley notes, “with whom I confess I have a good deal of sympathy.”  (p. 28.)

At the heart of the reform that Huxley promoted for all of British society was an understanding of “the laws of Nature” conceived broadly.  As he observed in A Liberal Education,
education is the instruction of the intellect in the laws of Nature, under which name I include not merely things and their forces, but men and their ways; and the fashioning of the affection and of the will into an earnest and loving desire to move in harmony with those laws.  (p. 32.)
Embedded in that last observation is a social reform perspective that I don’t quite understand.  It is more bluntly stated elsewhere.  For example, in the 1855 letter to Dyster, Huxley wrote
I want the working classes to understand that Science and her ways are great facts for them – that physical virtue is the base of all other, and that they are to be clean and temperate and all the rest – not because fellows in black with white ties tell them so, but because these are plain and patent laws of nature which they must obey “under penalties.”  (as quoted in Life and Letters, p. 199)
This gross characterization of the working class (that its members are intemperate and unclean, and presumably not virtuous) leaves me a bit uneasy.  And exactly how might an understanding of the forces of Nature, as learned through a lecture on chalk, change such circumstances?  What “penalties?”  That they will lead nasty, brutish, and short lives?  Curious.  Still, for Huxley, the microfossils in chalk were a gateway to such knowledge and so, in his view, potentially, to better lives.

Of course, discussing why Huxley was addressing this particular audience would have been a digression for Krulwich, but I guess my standards are different, reflected by the fact that many of my posts are mostly digressions.

1 comment:

  1. Great blog!! loved going through:):)


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