Tuesday, December 29, 2020

Finding Meaning in a Bunch of Fossil Teeth

Sharks are cartilaginous fish and, typically, very little of them fossilizes, except for their teeth.  An individual shark loses and replaces teeth throughout its life, in the process shedding thousands or tens of thousands of teeth.  No wonder the typical collector may end up with seemingly innumerable fossil teeth stored (sometimes randomly) in baggies, jars, drawers, and display mounts.  Studies of extant sharks show that rates of loss and replacement may slow with age and are affected by a host of other variables, including species and feeding behavior (Visaggi and Godfrey 2010; Purdy 1998; full citations of all sources provided at the end of this post).   Making some meaning out of those myriad teeth is a challenge for any fossil hunter.  A challenge I failed to meet when I once had a great opportunity.

A decade ago, I wrote a post describing an attempt to replicate the findings of a published analysis of two large collections of Miocene fossil shark teeth from the Calvert Cliffs (Visaggi and Godfrey 2010).  Paleontologists Christy Visaggi and Stephen J. Godfrey analyzed the distribution by genus of two groups of teeth that had been donated to the Calvert Marine Museum by collectors:  nearly 1,900 teeth collected in situ as they were exposed in the cliffs, and somewhat more than 24,000 teeth collected from the wash on the beach, so-called float teeth.  The authors identified a number of biases that influenced either of these two sources of teeth including:  payoff bias in which collectors went to where teeth were most likely to be found, and size and prize bias in which collectors skipped over small teeth and gathered up primarily large, rare, or unusual specimens.  (For the latter bias, the really fine specimens were unlikely to be donated and so were mostly missing from the group of teeth found in the shoreline wash.)  The sheer number of specimens and the two different sources of the teeth were believed to reduce the influence of these collection biases.

I attempted to reproduce the results by spending one day collecting every shark tooth I could find in the wash (thereby attempting to address the size and prize bias) along a specific, productive stretch of beach under the Calvert Cliffs (of course, ensuring that my teeth reflected the payoff bias).  I ended up with 157 teeth.  Pictured below are a few of the specimens I collected on a very cold March day in 2010.

The distribution by genera of my sample mirrored rather closely that of the float teeth analyzed by Visaggi and Godfrey for their localities labeled CC9 and CC10 (see Visaggi and Godfrey 2010).  The most common genera represented in their float collection for these localities were:

Carcharhinus (Gray Sharks – 51% of their float teeth versus 45% of the teeth I collected)

Carcharias (Sand Tiger Sharks – 9% versus 8%)

Galeocerdo (Tiger Sharks – 18% versus 17%)

Hemipristis (Snaggletooth Sharks – 9% versus 7%)

Isurus (Mako Sharks – 3% versus 3%).

The most prominent genera in my collection also included these two others:

Negaprion (Lemon Sharks – <1% versus 4%)

Sphyrna (Hammerhead Sharks – <1% versus 3%)

(The teeth from these last two genera are small and so, not unexpectedly, are largely missing from Visaggi and Godfrey’s float portion.)

That’s as far as I went with my analysis.  It seemed sufficient to generally confirm with my one-day effort and 157 teeth what Visaggi and Godfrey found by rigorously analyzing thousands of teeth.  I failed to draw any deeper meaning from my results or those published by Visaggi and Godfrey.  Though they drew attention to what I think is a fascinating aspect of the results of these efforts, I missed it entirely. 

Visaggi and Godfrey stressed that their results applied only to the relative distribution of teeth from different shark taxa, and did not speak to the relative abundance of individual sharks from those taxa.

We do not wish to imply that the percentage of shark teeth in either the float or in situ collections are an accurate reflection of the actual numbers of individual sharks that lived in Salisbury Embayment during the Miocene (Visaggi and Godfrey 2010, p. 31; the Salisbury Embayment was the geological precursor to today’s Chesapeake Bay).

Teeth not individuals.

But . . . not withstanding that statement, I think they do leave the reader of their paper with the implication that the number of teeth are probably not divorced from the numerical diversity of the populations of sharks in those Miocene waters, particularly if the focus is on higher taxonomic groupings:  i.e., orders of sharks.  (Orders are the fourth taxonomic grouping counting down from kingdom, genera are the sixth.)  I should clarify:  an attentive reader would have recognized the implication.

Let me explore that further.  When the seven genera listed above were grouped into their orders, what I failed to see ten years ago became painfully obvious.  Only two orders of sharks are represented.  Two of these genera – Carcharias and Isurus – belong to the Lamniformes order (mackerel sharks) while the remaining five belong to the Carcharhiniformes (ground sharks).  Significantly, as is clear from the percentages given above, the vast majority of teeth collected along the cliffs comes from Carcharhiniformes sharks (over three-quarters of the teeth).  

A shark from each of these two orders is shown below in drawings from Kent (2018).

Sand Tigers are an example of the Lamniformes.

Grays are an example of Carcharhiniformes.

Ichthyologist Leonard Compagno and colleagues have described extant representatives of the former (the Lamniformes) as “mainly large active pelagic sharks” (Compagno 2005, p. 175), and the latter (the Carcharhiniformes) as sharks that are mostly “small and harmless to people, but this order also includes some of the largest predatory sharks” (p. 186).

Significantly, the relative shares of teeth accounted for by each of these orders is the opening to an interesting story of what was happening taxonomically to sharks during the Miocene:  Carcharhiniformes were coming into their own, ultimately surpassing the Lamniformes.  It’s a story I am only now exploring.  In 2010, Visaggi and Godfrey wrote:

Lamniforms flourished from the Cretaceous through the Eocene, whereas carcharhiniforms remained less common.  The diversification of carcharhiniform sharks occurred during much of the Paleogene and by the Neogene carcharhiniforms had surpassed lamniform sharks in abundance.  Both data sets [in situ and float collections] demonstrate the dominance (>70%) of carcharhiniforms . . . over lamniform . . . and other sharks (<30%) during the Miocene at least in terms of teeth produced.  This preeminence of carcharhiniform sharks persists in modern marine environments.  (Godfrey 2018, p. 32, emphasis added)

Paleontologist Bretton Kent’s recent guide to the Miocene fossil shark teeth of the Calvert Cliffs is instructive in this regard (Kent 2018).  He described teeth from 8 genera and 16 species of Lamniformes, and teeth from 9 genera and 16 species of Carcharhiniformes.  (As delineated above, this relatively equal balance in genera and species between the two orders is misleading because it masks the distribution of teeth that a collector along the Calvert Cliffs shoreline will come upon.  My March 2010 collection and the Visaggi and Godfrey paper show as much.  And, as noted, there is an important implication possibly to be derived from those numbers of teeth,)

When Kent analyzed changes in the morphology of shark teeth by individual species from the Cretaceous to modern times, he found that teeth featuring tall, narrow crowns and cusplets (small side crowns) diminished in prevalence by species and were replaced by teeth with a more diverse mixture of morphologies, including the increased presence of serrations.  For example, as is shown by the following pictures of two teeth from the ones I collected in 2010, Carcharias teeth exhibit the former morphology (first picture below), while Carcharhinus teeth show the latter.

Kent posited that teeth with narrow crowns straddled by small cusplets enabled their possessors to grab and restrain prey, while those with serrations supported cutting and clutching prey.  Significantly, he then wrote:

By the late Oligocene and early Miocene shark faunas have a more complex mixture of tooth morphologies comparable to that of the Holocene.  This change is partially correlated with a fundamental shift from faunas dominated by lamniforms to one dominated by carcharhiniforms (Kent 2018, p. 47).

There, that’s the story for which my collection of teeth a decade ago was an early chapter:  one order of sharks in the process of displacing another as the dominant one.

That change is even more robustly reflected in today’s oceans.  Carcharhiniformes are clearly the lead order.  Compagno and his colleagues have identified only 15 extant species of sharks belonging to Lamniformes, while Carcharhiniformes include 225 living species.  The latter order, they wrote, “is the largest, most diverse and widespread group of sharks” (Compagno 2005).

What of the Chesapeake Bay today compared to the Miocene Salisbury Embayment?  Is this changeover reflected there?  Comprehensive, rigorous data describing the shark taxa presently found in the Bay are somewhat elusive.  I certainly have no estimates of the actual number of sharks by species in these waters.  The best data I have found come from the Chesapeake Bay Program (CBF), a partnership of federal and state agencies, nonprofits, and academic institutions working for the restoration of the Bay.  These data suggest that the dominance of Carcharhiniformes worldwide is somewhat reflected in the Bay.  The CBF identifies 12 species that are rare to common in the Bay and adds an additional 4 species for which there is a single record of a sighting in modern times (Eney 2010).  Of these 16 species, Carcharhiniformes account for 11 while Lamniformes are represented by only 2.  But, for both orders, these counts of species are only somewhat marginally related to the relative abundance of these sharks.  Given the decimation of shark ranks in the modern era from human activities, apparently only two of the Carcharhiniformes species are considered common in the Chesapeake Bay as is only one of the Lamniformes species.   

A decade ago, I was swept up in the effort to replicate the Visaggi and Godfrey analysis, and failed to understand the story revealed by what I was finding.  This reminds me of a line from T.S. Eliot’s Four Quartets:

We had the experience but missed the meaning.


Leonard Compagno et al.  2005.  Sharks of the World.

Lindsay Eney.  2010.  Are There Sharks in the Chesapeake Bay?  Chesapeake Bay Program.  August 4.

Stephen J. Godfrey, editor.  2018.  The Geology and Vertebrate Paleontology of  Calvert Cliffs, Maryland, USA.  Smithsonian Contributions to Paleobiology Number 100.

Bretton W. Kent.  2018.  The Cartilaginous Fishes (Chimaeras, Sharks, and Rays) of Calvert Cliffs, Maryland, USA.  Chapter 2 in Godfrey, The Geology and Vertebrate Paleontology of Calvert Cliffs, Maryland, USA.

Robert Purdy.  1998.  Fossil Shark Teeth.  The Paleontological Society.

Christy C. Visaggi and Stephen J. Godfrey.  2010.  Variation in Composition and Abundance of Miocene Shark Teeth From Calvert Cliffs, Maryland.  Journal of Vertebrate Paleontology.  January.

Sunday, November 29, 2020

Empathy Across Time

 My recent post titled Vastly Different Timescales has been nagging me.  In that post, I quoted science writer John McPhee who posited, in Basin and Range (1980), that we human beings find it difficult to relate to periods of time that are beyond those small spans of years that encompass the two generations before us and the two generations after us.  This confounds efforts to really understand greater stretches of time, specifically the enormous expanses of time that we encounter in astronomy, geology, and paleontology.  I summed it up by writing:

As we expand our view beyond that spread of a five-generation period (covering, say, roughly 100 to 150 years), perhaps we’re back to “one, two, many” if only to maintain some sense of self and step back from the full implications of deep time.

I do think a basic aspect of that is correct.  Vast expanses of time – deep time – are extremely challenging to understand.  What understand in this context means is not clear, I guess I’ll know it when it happens.  What has bothered me in particular is that McPhee’s construct, though specific to deep time, raises the prospect that we human beings are actually unable to be comfortable with, relate to, and incorporate into our lives, periods that extend beyond the 100 to 150 years that encompasses five generations but which fall short of deep time.  Upon reflection I find I don’t believe that.  The challenge arises with periods of millions or billions of years, but perhaps not with periods of thousands of years.  That is the focus of the current post.

I think our capacity to understand spans of thousands of years hinges on whether or not those blocks of time involve human beings.  Though it’s true that we may be able to put names and faces to those generations immediately before and after us, and that we may be most concerned about them, the scope of our attention and concern is not limited to that.

My previous post focused in part on the dissonance that comes when vastly different timescales came into contact – for instance, our lifespans and fossils that are millions of years old.  I began that post with a picture of some fossil sand tiger shark teeth found in an area on the Maryland side of the Potomac River near Liverpool Point.  These teeth, Paleocene in age, are a little less than 60 million years old.  I doubted that I could really appreciate what that age meant or the world in which those sharks lived.  Well, I want to consider the implications of a different set of objects that also come from around Liverpool Point.  Here is a handful of projectile points that were found (not by me) in that area.

The  identifications I’ll gingerly put forward for these points are based on some reading, just enough to get me into trouble.  The middle two could be Lamoka points.  They are similar to those identified as Lamoka on the Maryland Archaeological Conservation Laboratory’s Diagnostic Artifacts in Maryland website. Lamoka points are common through the Northeast, particularly the Potomac Valley and date back to some 3500 to 2500 BCE, during the Late Archaic period, though they may have been used much later than that into the Middle Woodland.  The points on either end of this array may be Bare Island points, based on what I find on the Laboratory's website.  These points fall into an age range from 5000 BCE to 1000 CE.  The Laboratory notes that Bare Island points, prevalent in the Northeast, are common in Maryland and “are among the most abundant points found in the Coastal Plain portions of the Patuxent and Potomac.”

I’m not sure that these identifications with their attendant ages make sense given the area in which the point purportedly were found.  This area of Maryland may have been occupied by Native Peoples since at least 900 CE (Piscataway Indian People).  (Scott M. Strickland, et al., Indigenous Cultural Landscapes Study for the Nanjemoy and Mattawoman Creek Watersheds, St. Mary’s College of Maryland, November 2015.)  I cannot even offer complete assurances that these points, in fact, were collected here.

As important as those issues are for those who study these artifacts, they’re really a distraction from the very simple point I want to make with them:  they are probably at least a thousand years old, a time span beyond the five-generation one of which McPhee writes.

The impact that these objects have on me is decidedly different from that which comes from finding fossils such as the sand tiger teeth featured in the prior post.  With these projectile points, there is a communion with the past that I experience when I handle them, one unlike the emotions that fossils inspire.  For the latter, the message that comes through is one of awe in the face of the vast expanses of time and for the dramatically different worlds the fossils signal.  For the former, those products of human endeavor, there is a strong recognition that these points connect me to people, though of a different time and culture, with whom I share a basic and fundamental commonality.  As I’ve considered this, the word that has come to mind is empathy.  This empathy extends far beyond the two generations behind me, it connects me to millennia.

Do I truly understand the people who crafted and used these points?  No, but our shared humanity means that we are connected and that is a start.  At this point, I am prompted to quote Walt Whitman from Song of Myself.  The whole of it is appropriate but this line will do:  “For every atom belonging to me as good belongs to you.”

That empathy serves to bridge gaps of many years came clear to me when I read archaeologist Lisa Rankin’s chapter titled Native Peoples From the Ice Age to the Extinction of the Beothuk (c. 9,000 Years Ago to AD 1829).  (A Short History of Newfoundland and Labrador, Newfoundland Historical Society, 2008.)  In this chapter, Rankin summarized the “Seasonal Round” of life for the hunter-gatherers who lived in the Newfoundland and Labrador area during “prehistory.”  Her exposition on this topic is plain and simple, there’s really nothing poetic and literary here.  Yet, her text moved me, speaking directly to the issue I grappled with when I contemplated the points from Liverpool Point.  With it, Rankin helped me cross temporal barriers and perhaps some cultural ones as well.  I will quote the passage in question at some length:

Because [hunter-gathers] did not domesticate food sources to help them survive, they had to schedule their annual activities to take advantage of the wild food sources available in different locations at different times of the year.  Generally speaking, these prehistoric culture groups took advantage of ocean resources in the spring through autumn when sea mammals, fish, sea birds, and shellfish were readily available.  At this time berries and other plant foods were also harvested.  During the summer months their sites were located along shorelines in both inner and outer bay regions as well as on islands.  In the warm months food was plentiful and people could band together at larger settlements and visit relatives and friends.  It was probably a very sociable time when social, political and economic bonds were forged.  In the colder winter months they split up into much smaller groups, perhaps nuclear families, and travelled to interior regions to hunt caribou and other smaller land mammals.  Winter settlements were usually smaller than summer settlements because winter resources were less abundant and unlikely to feed as many people.  (p. 6)

The ebb and flow of that life, as Rankin described it, is real to me.  As I read those words, I could envision the dance to the music of time that marked the lives of those Newfoundland and Labrador peoples.  Although the Native Peoples of the Liverpool Point area differed culturally and had changed from a hunter-gatherer life style to one incorporating some slash-and-burn agriculture by the time Europeans first arrived, their lives even then still involved movement to the rhythms of the seasons and the migration of animals.  Holding those projectile points evokes that circle of life.

In the end, deep time remains beyond reach in many ways for me, but those shorter time horizons that involve modern humans evoke an empathy that brings some understanding.

Friday, October 30, 2020

Tales From The Ant World ~ A Respite From the Pandemic

When I was an elementary school aged child, I spent some time (a few weeks? months?) putting down bits of food for an ant colony whose scouts explored one corner of the floor of our bathroom.  It never took long for the morsels to be found and swarmed.  These were, I believe, the ant commonly and aptly (though unimaginatively) called “Little Black Ant.”  It bears the somewhat dismissive scientific name of Monomorium minimum.  The genus name reflects the monomorphic nature of these specific ants – workers come in only one type or caste.  The species name speaks for itself.

I recently finished E.O. Wilson’s latest book Tales From The Ant World (2020) and went in search of ants.  Surprisingly, they were scarce, perhaps because the weather, though relatively warm, was overcast and threatening or, much more likely, because I wasn’t patient enough in my questing.  I did spot a Chestnut Carpenter Ant (Camponotus castaneus) on the bark of a tulip poplar in a nearby park.

Still eager to watch ants at work, I reprised my childhood tactic (though outdoors this time) and put out small pieces of a raisin along the back edge of a front step where I’d seen trails of ants in the summer.  Less than a couple of hours later, an area that had been nearly devoid of ants now had them streaming along the step directly to the piece of raisin nearest to their colony.  The raisin was enshrouded in little black ants.  They were old friends, M. minimum.

I turned to my fossil collection where insects as a whole, much less ants, barely make an appearance, and, then, only in two small lozenge-shaped pieces of Myanmar (Burmese) amber, estimated to be 99 million years old (Late Cretaceous).  This paucity isn’t just a function of what I’ve been interested in, but also reflects the challenge of fossilizing these terrestrial creatures.  (I’ve acknowledged on this blog that this kind of amber comes to the paleontological world with real human and cultural costs for the people of Myanmar.  I do remain disturbed about having purchased these items, and I recognize that one might justifiably label me a hypocrite and complain that my concerns weren’t felt deeply enough to prevent this purchase.)

Here is the best image I can make of an ant specimen ensnared some 99 million years ago in one of my amber globules.  The quality of the photograph is due to the damage suffered by the specimen and to the limits of my photographic equipment.

I won’t hazard a guess as to the genus of this specimen.  Though I looked up images of all Mesozoic ant genera that myrmecologist Phillip Barden lists as having been found in Burmese amber, none seemed substantially similar.  (Fossil Ants (Hymenoptera:  Formicidae):  Ancient Diversity and the Rise of Modern Lineages, Myrmecological News, March 2017, table 1.)  For comparison images of these Cretaceous genera, I relied on AntWeb hosted by the California Academy of Sciences.

In Tales From The Ant World, a slender volume (my e-version of the book comes in at 230 pages), Wilson tells stories about the strange and marvelous life of ants.  His book offers a welcome respite from the dread that plagues the human world at the moment.  In prose both informal and graceful, Wilson regales the reader with first hand accounts of the ant world.  [Later edit:  Thinking that Wilson needed no introduction, I failed to provide one.  I trust it suffices to say that he is one of the world's foremost myrmecologists (scientists who study ants), and has had an important and amazingly productive career.]

An early chapter offers an autobiographical account of being enraptured by ants in his youth (this portion is reminiscent of parts of an earlier autobiographical work titled Naturalist (1994)).  The bulk of the chapters treat different aspects of the world of ants through vivid accounts of Wilson’s work with these insects and the insights he’s gained from a lifetime of studying them.  In each of these brief chapters, Wilson tells engaging and often exciting war stories in an informal voice, yet each of these carefully crafted tales comes with a deliberate context and a scientific point or more to be made.  Superb natural history writing, indeed.

According to Wilson, ants inhabit an alien world, dominated by three foundational guidelines:  there is “absolute female rule,” many “eat their dead – and their injured,” and they “are the most warlike of all animals.”  All three of these precepts come together in a critical aspect of the life of a worker ant.  Workers are all female and, as they age, their tasks in support of the colony change and become decidedly more perilous.  Wilson writes, 

In a nutshell and put more plainly, where humans send their young adults into battle, ants send their old ladies.

He makes clear the underlying evolutionary impulse behind this phenomenon.

For ants, service to the colony is everything.  As individual workers approach natural death, it benefits the colony more for the old to spend their last days in dangerous occupations.  The Darwinian logic is clear:  for the colony, the aged have little to offer and are dispensable.

Natural selection works not only at the level of the gene in the individual ant, but also at the level of the colony as colonies of the same and different species compete with one another to survive.

Ant death offers Wilson the opportunity to recount the tale of how he figured out how ants recognize that a nestmate has expired.  First, one must understand that ants communicate through smell and taste; theirs is a world of chemical discourse.  The little black ants on my front step were following the scent laid down by a scout who first discovered the pieces of raisin.  She headed as directly as possible back to the nest, chemically marking her path.  The odors that make up and drive the ant world extend to scents that are unique to each ant colony, providing the means of identifying who belongs and who does not (the latter at risk of quick death).  Wilson describes how ants that die a natural death or of disease inside the nest are picked up by another ant and carried outside of the nest or to a pile of refuse in a separate nest chamber.  When first studying this process, he assumed this social behavior – the removal of the dead – was prompted by some chemical scent and so went in search of the triggering substance.  And a funny (though not without its morbid side) tale ensues.  Out of the bodies of dead ants, Wilson made an essence of dead ant which he painted on little wooden dummy workers.  Sure enough, other workers dutifully removed the fake dead.  He assayed the dead ant scent and determined what in it triggered the living workers’ response.  Using just that, he elicited the same behavior with the dummy ants.  Clearly a moment of joy as he notes, “There is no procedure more pleasing to a biologist than an experiment that works.”

But, he took things a step further, wondering what would happen if a living – that is, a moving, active – worker were painted with this substance.

The result was gratifying.  Worker ants that met their daubed nestmates picked them up, carried them alive and kicking to the cemetery, dropped them there, and left.  The behavior of the undertaker was relatively calm, even casual.  The dead belong with the dead.

Until these living, though dead-smelling, ants managed to rid themselves of the death scent, they were repeatedly returned to the charnel house by their nestmates.

Wilson, like all good raconteurs, often frames his stories around the extremes, for instance, the accounts of the gentlest and the most vicious ants in the world.  In making his case for such labels, he capitalizes on our hunger for the unusual and propensity for treating everything as a “horse race,” while drawing us deeper into the ant world.  Gentlest and most vicious?  For the former, he describes the Dolichoderus imitator as the “most timid” ant “with none of the warrior spirit we usually associate with ants.”  The D. imitator is small and lives in sparsely populated colonies, nesting in decaying leaf detritus in the Amazon.  Disturb the nest and the workers will quickly grab a larva or pupa and speed away, seemingly in random directions.  As Wilson observes, “Ant colonies possess superb resiliency.  Timidity pays off in the rain forest, if you can run fast.”

As for the most aggressive species, Wilson first poses the question of why there might be a range in behavior from “pacifist to warmonger” and explores the answer to the question by considering some candidate species.  In so doing, he illustrates an evolutionary principle:

The more defensible the nest site and the more valuable the resources it contains, the more powerful the defense and the greater the fierceness with which it is applied.   In short, ants are as mean as they have to be in order to protect their home.  No more, no less.  (Italics in original.)

The label “most vicious” is won, in Wilson’s experience, by the Amazonian species Camponotus femoratus which build nests that incorporate plants that grow on tree trunks and in the tree canopy.  In these nests, the ants create gardens for scale insects and mealybugs which dine on sap they draw from the plants and which also provide their ant hosts with nutritionally rich excrement.  As a result of the defensible nature of this nest and the importance of its contents, the C. femoratus are generally held to have “a frightening degree of ferocity.”  I would note that the Chestnut Carpenter Ant pictured at the outset of this post is a much removed cousin of the C. femoratus.

Wilson addresses the relationship of the ants of the Cretaceous, such as the one pictured earlier, with modern ants.  There seems to have been no “straight line” evolution from the Cretaceous ants, the so-called stem-group ants, to the modern ants (crown-group) that surround us now.  As myrmecologists Phillip Barden and David A. Grimaldi note, the fossil record for ants has a very conspicuous roughly 15-to-20-million-year gap that straddles the boundary between the Cretaceous and the Paleogene.  (Adaptive Radiation in Socially Advanced Stem-Group Ants From the Cretaceous, Current Biology, February 22, 2016.)  They conclude that the stem-group ant taxa we have so far found in Cretaceous material failed to make it through that gap.

Woven through these stories is Wilson’s important cautionary note that, though ant societies may have some aspects that we think resemble those of human society, the

real differences between ants and men are profound.  Ants create civilizations by instinct – because they are capable of doing nothing other than what they evolved to create.  For their part, human beings are torn by the competing needs of self, family, and tribe.  We use culture to banish instinct or at least tame it, even while using it to create our values.

This is true, yet distinguishing what ants do from what humans do, regardless of the genesis of the action, can be challenging.  The distinctions can be complex.  Consider the treatment of the elderly.  As I quoted Wilson earlier, as worker ants age their jobs change, becoming riskier.  They are, he notes, following the evolutionary dictum that “the aged have little to offer and are dispensable.”  No retirement, no resting on one’s laurels, rather, going forward into danger for the good of the colony.

Human society is quite different in its attitude toward its senior citizens.  Or is it?  In the midst of the pandemic, some malevolent (revealing my attitude) voices have posited that the elderly, having lived a long life, should be prepared to be sacrificed on the altar of the “return to normal,” to the reopening of the economy and society.  I mean, so the logic goes, seniors have nothing to offer, particularly in comparison to the young, and they should do the right thing and serve the greater good.

I reject that position (and not just because I’m a senior myself).  Wilson offers one wonderful example of why.  I love the tale he tells of the swift “sprinter” species of ant that can be found in Mozambique.  He writes of traveling around that country partly by helicopter studying and collecting different kinds of ants to be taken back to Harvard for its collections.  While searching an inland forest, he found a nest of Ocymyrmex ants which are able to accelerate quickly.  Wilson, working in the blistering heat of a noonday sun (a phrase involving “mad dogs and Englishmen” comes to mind), tried repeatedly to capture some of these speedy workers.  The effort was prolonged and taxing, but ultimately somewhat successful.  The year of this tale was 2015; at the time, Wilson was 86 years old.

[Later addendum:  Upon reflection, I've decided to make it abundantly clear:  this book itself is powerful evidence to wield against those who would cavalierly countenance sacrificing the aged.]

Tuesday, September 29, 2020

Vastly Different Timescales

This is a wandering exposition on the challenge of understanding geological and paleontological timescales and whether we . . . well, whether I am up to the task.

The Aquia Formation is exposed at Purse State Park, located just south of Liverpool Point on the Maryland side of the Potomac River.  It rewards fossil hunters with an abundance of riches dating back to the Late Paleocene epoch, that is, some 59 to 56 million years ago.  Among the most prevalent fossil shark teeth found here are those from Striatolamia striata, a sand tiger shark.  Though distinguishing sand tigers as to species poses a challenge, I believe the teeth shown below are from S. striata (for more on these teeth, see Bretton W. Kent’s Fossil Sharks of the Chesapeake Bay Region (1994)):

Millions upon millions of years ago.  Numbers like 56 million years ago, much less some 350 million years ago deep in the Mississippian Period (I'll return to that at the end of the post), or, better yet, 4.5 billion years ago with the formation of Earth, or 13.8 billion years ago marking the origin of the universe – these all, I think, challenge our understanding.  Geology and paleontology, as well as astronomy, bring us face to face with periods of time on timescales that render insignificant (to the point of nothingness) the timescale with which we are most intimately familiar:  our lifespans.  That is the timescale that makes most sense to us and, as a result, that familiarity may confound comprehension of the periods of time and timescales that paleontologist, geologists, and astronomers work with.

What might it mean to “understand” timescales in millions or billions of years?  I’m really not sure.  Science educators regularly face the challenge of teaching students about these timescales and these huge blocks of time.  It appears that among the key measures of understanding in that context is whether students can work with these vast expanses of time to describe properly a succession of geologic and evolutionary events that occur across these periods, and to describe the duration of some geologic and evolutionary processes.  The former seems easier for most to grasp than the latter, given some prevalent misperceptions about the relationships among rate, size, and duration.  (See, Kim A. Cheek, Exploring the Relationship Between Students’ Understanding of Conventional Time and Deep (Geologic) Time, International Journal of Science Education, 2011.)]

This is, I think, too narrow a definition of understanding in this context.  I assume individuals could demonstrate a comprehension of succession and duration using these timescales without grasping the scientific or the personal implications of them.

Actually, the initial task in trying to truly understand what timescales of this magnitude mean may be making sense of large numbers in the first place.  In a recent article about whether and how we can grasp the extent of fatalities from COVID-19, science writer Sarah Elizabeth Richards wrote:

Ultimately, our biology is working against us.  Researchers say our brains aren’t wired to make sense of big numbers.  (Why Our Minds Can’t Make Sense of COVID-19’s Enormous Death Toll, National Geographic, September, 2020.)  

Is that right?  I do think there may be a hard truth here which affects how we are able, or, rather, unable to understand the timescales in geology, paleontology, and astronomy.  Mathematician Tobias Dantzig observed that historically many societies began with only a limited concept of number, counting a few objects and then immediately segueing to the whole, e.g., “one, two, many.”  (Number:  The Language of Science, 3rd edition, 1945.)  This phenomenon is embedded in most European languages.  For instance, the old-fashioned adverb thrice in English means not only “three times” but also “extremely, very.”  (Compact Oxford English Dictionary, 2003.)  “She was thrice blessed” could mean she was blessed three times or she was extremely blessed.

So, we begin by distinguishing a few – the ones we count – from the many, almost regardless of the magnitude of that “many.”  Perhaps we are still inclined to do that.

Physicist Ross McCluney asserted that we attempt to grasp large numbers using a particular strategy:

We humans are well-developed to see subtle differences in things, while absolute magnitudes can escape us.  Thus we best perceive the sizes of things by relating them to something else, to some standard of size with which we can compare them.  (Conveying Large Numbers to General Audiences, Bridges:  Mathematical Connections in Art, Music, and Science, 1998, p. 170.)

That may be an important step – find the reference set of comparative measurements that make some sense of these large numbers.

The preeminent science writer John McPhee puzzled over this very issue as he explored geology in his wonderful Basin and Range (1981).  Geology, McPhee remarked, brings us face to face with deep time (he coined this term), numbers of years in the millions and billions.

Geologists, dealing always with deep time, find that it seeps into their beings and affects them in various ways. . . .  In geologists’ own lives, the least effect of time is that they think in two languages, function on two different scales.  (p. 128)

Geologists are, as McCluney suggested, inclined to come up with some more easily comprehended scales to help them, as well as the rest of us, relate to the magnitude of the geologic timescales.  McPhee described one such comparative scale that I particularly enjoyed.

With your arms spread wide . . . to represent all time on earth, look at one hand with its line of life.  The Cambrian begins in the wrist, and the Permian Extinction is at the outer end of the palm.  All of the Cenozoic is in a fingerprint, and in a single stroke with a medium-grained nail file you could eradicate human history.  (p. 126)

Does that help?  There is both amazement and terror attendant on how strikingly insignificant the lifespan of complex life on Earth has been relative to the age of the planet.  Perhaps more discomforting for our egos is the realization of how nearly invisible in this timescale is the presence of humans.  (Remarkable and horrifying to think what humans have done in that blink.)  Going still deeper into the source of our growing unease, we find it renders invisible the time each of us has individually.

To bring this back to the deep time example that started this post, does a more familiar scale involving outstretched hands representing the span of Earth's existence make the age of the S. striata teeth I found at Purse more easily comprehensible?  A single line of one whorl in the fingerprint may, I guess, represent the duration of the Late Paleocene when S. striata flourished.  In the scheme of things that is a vanishingly small period of time.

Curious, although it covers several million years of time, the Late Paleocene is both a very long time period and nearly no time at all.  It all depends upon our frame of reference. 

If all time on Earth is too long a frame of reference, we might try a different scale, using the extended arms to represent the period from the Cambrian to the present.  In that case, the Paleozoic runs from the tip of my extended right hand to a bit short of my opposite shoulder; the Mesozoic extends from that point to the base of my left hand; and the Cenozoic barely reaches across the palm to the tip of my index finger.  The Late Paleocene featuring my fossil sand tiger teeth is a narrow strip of skin a third of an inch high a bit into my palm.  Does that help?  Probably not, I’m still left with conflicting perceptions of this length of time.

In the end, I may find truly understanding 56 million years as challenging as comprehending the scope and consequences of  billions of years.  Yes, I recognize that both are very long periods of time, and that 56 million is very much less than billions upon billions.  Yes, I can demonstrate a mastery of succession and duration when addressing aspects of these timescales for geological and paleontological phenomena.  But perhaps not much more.

My difficulty may be inherent in the human beast as science writer Sarah Elizabeth Richards stated.  Much earlier than Richards, McPhee observed the same, positing that I and my fellow human beings may be mostly incapable of reckoning with ages on such orders of magnitude.

The human consciousness may have begun to leap and boil some sunny day in the Pleistocene, but the race by and large has retained the essence of its animal sense of time.  People think in five generations – two ahead, two behind – with heavy concentration on the one in the middle.  Possibly that is tragic, and possibly there is no choice.  The human mind may not have evolved enough to be able to comprehend deep time.  It may only be able to measure it.  (p. 127)

(I’m not sure what the tragedy is in that.)

The key to the phenomenon McPhee identified is, I think, that five generations are periods of time which we may have directly experienced ourselves.  We ourselves may move through each of those generations:  we have been grandchildren and children, we have had parents and grandparents.  These are blocks of time we are likely to know intimately (we put a face to a parent or a grandparent), giving us a scale that we can intellectually and emotionally comprehend.  When we compare that scale to far greater numbers of years, a certain degree of terror may set in – each of us is, in fact, less than a blip in the overall scheme of things in the cosmos or on this planet.

As we expand our view beyond that spread of a five-generation period (covering, say, roughly 100 to 150 years), perhaps we’re back to “one, two, many” if only to maintain some sense of self and step back from the full implications of deep time.

It is true that, at times, when different timescales abut, the phenomenon need not be disquieting.  That’s made clear by a walk in the park.  Consider the insects, the plants and trees, the birds, the dogs, all living lives at timescales that markedly vary.  At times, we may have a fleeting appreciation of what that means about the complexity and fragility of life.  Significantly, during this walk in the park, most of the timescales we might encounter aren’t incomprehensible to us, primarily because they cover periods of time we ourselves have experienced – a few days, a few months, a small clutch of years.

A recent blog post by Kentuckiana Mike for Louisville Fossils is what started me thinking about the difficulty understanding paleontological or geological timescales.  When our quotidian blocks of lived time are put beside timescales that bear no resemblance to those with which we are familiar, the issue is joined.  He illuminated this by implicitly contrasting a timescale measured in millions of years with one measured in a human lifespan.  In this post, he wrote about visiting his family’s cemetery marker where his grandparents are buried.  He presented pictures of the fossils embedded in the rock of which that marker was made.  He wrote, “The marker is made of Bedford(?) limestone.  Time and the elements has eroded part of the surface revealing small crinoid stems and a cross section of a horn coral.  Fossils date from Mississippian Period.”  So, here we go back two human generations and, also, back 359 to 323 million years.  I comprehend the former, perhaps not the latter.

Monday, August 31, 2020

The Nature of Hokusai

This post features no fossils.  There is some consideration of how the natural world is treated in works by the late 18th and early 19th century Japanese artist Katsushika Hokusai.  Mostly, though, this post is an excuse to show some of the remarkable prints Hokusai created and to suggest that time devoted to their consideration is time well spent.

In this time of upheaval and uncertainty, I have found that the art of Katsushika Hokusai (1760-1849), one of the great masters of the Japanese ukiyo-e (“pictures of the floating world”), offers a welcome respite.  His woodblock prints of a bygone era in Japan foster a salutary perspective on our current period.  Hokusai was a careful and sensitive observer of the natural world and the place of human beings in it, a place he seems to suggest is never quite secure.  Yet, so often people are depicted as persevering against natural forces.

Hokusai is best known for his Under the Wave Off Kanagawa (referred to with various other names, including The Great Wave.).   A copy of the print is shown below.  This and all subsequent images of Hokusai’s prints in this post are in the public domain.  They were all downloaded from the Metropolitan Museum of Art’s website.  Highlighted titles provide links to online versions of the prints.

Under the Wave is part of the series of prints titled Thirty-Six Views of Mount Fuji published in the early 1830s and subsequently expanded with an additional ten views of the mountain.  The Metropolitan Museum of Art’s website provides high resolution images of these and other prints by Hokusai.  A wonderful print volume titled Hokusai:  Thirty-Six Views of Mount Fuji with helpful text by Amélie Balcou is published by Prestel Publishing (2019).

This series is, to me, quite compelling, not only for the world that each print reveals with study, but also because of when in the author’s life they were published.  The late 1820s were a seemingly never ending onslaught of difficulties for Hokusai:  he suffered serious financial loses, particularly from trying to address his grandson’s monetary woes; he had what was possibly a stroke; and his wife died.  His daughter, Eijo, an artist in her own right, moved back home to life with him.  (See, Julyan H. E. Cartwright and Hisami Nakamura, What Kind of Wave Is Hokusai’s Great Wave Off Kanagawa?, Notes and Records of The Royal Society, Volume 63, February 2009; and Francesco Carelli, Hokusai:  Beyond the Great Wave, London Journal of Primary Care, Volume 10, Number 4, 2018.)

Yes, Hokusai had compiled many sketch books over the years which he could draw upon, but the significance remains that it was likely during a time of existential challenge that he drew the Thirty-Six Views together.

Jason Farago’s interactive article titled A Picture of Change for a World in Constant Motion that appeared in The New York Times on August 7, 2020, is a particularly enjoyable and informative introduction to one of these views and to the impact the entire series had internationally.  Farago focuses on the print titled Ejiri in Suruga Province (shown below).

He is a perceptive guide, noting that, although this is not one of Hokusai’s best known prints, “I love it most for how it captures an instant, with an exactitude that feels almost photographic.  Here.  Now.  A country road, two trees, daytime:  hold onto your hats.”  The subject matter is quotidian and the people in it struggle against the wind.  A simple, washed out Mount Fuji sits in the background.  Farago describes Western influences on this print and others in the series, and then, in turn, shows some of Hokusai’s influence on Western art.  There is a great deal going on here, beyond just the action it depicts.

For me, this particular view well captures aspects of many of the series’ views.  In a majority, the outside world is, to varying degrees, a cultivated world.  What Farago calls an “ordinary, little marsh” is tamed by a winding path on an embankment that rises above the grasses.  In this and other views, the people often struggle against natural forces, working hard to climb a steep path up a mountain, seriously leaning (as here) into a strong wind, hunkering down to keep boats from succumbing to ocean waves (as in Under the Wave above), . . . .  And so, despite evidence of  “domestication” of some of the landscape, nature continues to exert her power.

The role of the natural world seems to vary from print to print; at times people appear to be at its mercy, at others, they seem at one with nature or, indeed, in the process of taming away much of the wildness in the landscape.  The omnipresent Mount Fuji offers, I sense, a subtle warning that any stability in the scene is contingent upon the quiescence of the natural world whose overarching agent is this active stratovolcano.

One of the Thirty-Six Views I particularly like speaks to this juxtaposition of cultivated nature and the potentially destructive natural world.  Titled Cushion Pines at Aoyama, it shows a father and son climbing the path to Ryōan-ji Temple; the father is motioning to Mount Fuji in the distance.  A group of people are picnicking on an outcropping overlooking the famous Zen gardens of the temple.  To my mind, those gardens designed for purposes of meditation are the essence of the taming and shaping of nature.  The trunks of the pines visible in the print (lower left) are uniform, almost artificial.  Indeed, at one point, there is a trunk that appears to rest perpendicular to the others, creating a lattice.  And, lest there be any confusion about this, at the far lower left is someone, mostly hidden by the trees, carefully raking the ground around the trunks.  It’s a stunning view because, from the cultivated and tamed foreground, one encounters a middle ground with nothing but mist, while rising sharply in the background is Mount Fuji, looming over it all.  For me, this print is about perspective on the permanent and ephemeral, on the here and now and what is to come.  Sit and gain clarity by meditating on the gardens, or continue the climb to the temple.

Novelist James A. Michener, a connoisseur and collector of Japanese art, characterized Hokusai’s prints as “really one of the most impressive accomplishments in ukiyo-e.”  (Japanese Prints:  From Early Masters to the Modern, 1959.)  Though he proceeded to describe the prints with adjectives that confound me because I disagree with most of them vehemently (e.g., “static” and “unreal” – to my mind, the prints are anything but that), he, nevertheless, ended up where I do.  Michener wrote that Hokusai’s prints “sing of nature.”  Amen to that.

There are myriad prints by Hokusai besides the Thirty-Six Views.  Indeed, there are many, many additional views of Mount Fuji, sketchbooks brimming with scenes and people, what appear to be guide books for those artists who might emulate him, and on and on.  It’s quite overwhelming.  But from this treasure, I have drawn a few prints that have helped to show me how nature does sing at Hokusai’s hand.

He was capable of capturing some part of the natural world in exquisite detail.  To take just a couple of the multitude that might be selected, I offer these two images from his Random Sketches, a publication that ran to 15 volumes with the first published in 1814.  Clearly, he was a close observer of the natural world around him.  He used a delicate touch here to depict these creatures, yet each of these animals is wonderfully robust and alive.

One of my favorite sketches approaches the relationship of humans to nature with a humorous touch, at least that was my initial reaction.  Here is a man (gentleman?  warrior?) contemplating two butterflies.  This comes from A Realistic Sketchbook (1814).

The man may be gaining something important by pausing to contemplate the two butterflies fluttering just out of reach.  Perhaps he is finding some perspective on his problems and cares, or on his status?  Are they suggesting some sense of missing balance?  Is he receiving some message about ephemera?

So, there can be whimsy in Hokusai’s art, including his take on the natural world.  Perhaps no more than in the following print from Fugaku Hyakkei (One Hundred Views of Mount Fuji) which is dated to 1834-35.  That's Mount Fuji "caught" in the spiderweb.

Hokusai, in the afterword to Fugaku Hyakkei, addressed the relationship of his artistry to nature with a spirit that I long to internalize, one that I believe carried him through the dark times.  He signed the work, “Gayko Rojin Manji” which means “Manji the old man mad about art.”  And so, at age 74, he wrote:

Since the age of six, I had a habit of sketching from life.  From fifty onwards I began producing a fair amount of art work, but nothing I did before the age of seventy was worthy of attention.  At seventy-three, I began to grasp the structures of birds and beasts, insects and fish, and of the way plants grow.  If only I go on trying, I will surely understand them still better by the time I am eighty, so that by ninety I will have penetrated to their essential nature.  At one hundred, I hope I may have a divine understanding of them, while at one hundred and ten I may have reached the stage where every dot and every stroke I paint will be alive.  May men of great age and virtue see that I am not hoping for too much!

(This text is translated by Julyan H.E. Cartwright and Hisami Nakamura, and appears in What Kind of Wave is Hokusai’s Great Wave Off Kanagawa?  Of note, the authors demonstrate quite convincingly in this article that the Great Wave print is not of a tsunami.)

Wednesday, July 29, 2020

Enchanted Island Under Siege

I believe that, among the great war novels set in the military during or leading into World War II, are Norman Mailer’s The Naked and The Dead (1948), James Jones’ From Here to Eternity (1951), and Joseph Heller’s Catch-22 (1961).  To this group of novels, I would now add Nicholas M. Rinaldi’s The Jukebox Queen of Malta (1999).  It’s a superb piece of fiction that offers me the added delight of hinting at the geological and paleontological wonders of the island of Malta.

On May 27, 2020, novelist and poet Rinaldi died at the age of 86 from COVID-19.  (Nicholas Rinaldi, Writer of Character-Rich Novels, Dies at 86, Sam Roberts, The New York Times, June 11, 2020.)  In the days following his death, through his novel, Rinaldi has guided me on a journey around Malta, an island in the Mediterranean, some 60 miles from Sicily.

(This map is in the public domain and can be found at Wikimedia Commons.)

Malta, the largest of a small string of islands in an archipelago (now making up the Republic of Malta), is graced with protected deep water ports and towering limestone cliffs.  Given its central location in the Mediterranean, Malta, then a British colony, endured an unrelenting aerial bombardment by the Italians and Germans from June, 1940, to November, 1942, a prolonged firestorm that sought to dislodge the British forces on the island and secure the marine supply line to German troops fighting in North Africa.  According to Rinaldi, this onslaught involved an amount of explosives far surpassing that dropped on London during the German blitz of 1940.

(This picture shows bombed buildings in Valletta, May 1, 1942.  It is in the public domain and can be found at Wikimedia Commons.)

That Malta would be at the center of warring forces in World War II should come as no surprise:  the islands have been fought over and occupied since time immemorial by, among others, Phoenicians, Romans, Greeks, Turks, Knights of Malta (Hospitallers), the French, and the British.

Malta has deep roots in Western culture.  According to the New Testament (Acts 28), early in the Christian Era, the ship carrying Paul as a prisoner to Rome was wrecked on Malta.  As the story goes, when the natives of the island built a fire to warm the castaways, Paul gathered brushwood which he tossed into the flames.  A viper escaping the heat bit him.  A sure death thought the Maltese, concluding that Paul was clearly a murderer and receiving the justice he deserved.  When the bite had no effect on him, “they changed their minds and began to say that he was a god.”

Even older roots may tie Malta to Homer’s Odyssey, particularly for those scholars who have spent countless years and pages trying to trace Odysseus’ voyage home to Ithaca from Troy on maps of the Mediterranean.  Malta is sometimes equated with the epic poem’s island of Ogygia on which the nymph Calypso held an enchanted Odysseus prisoner for seven years.

All of this backstory sets the stage for Rinaldi’s The Jukebox Queen of Malta, its action occurring on the island during April to November of 1942.  This tour de force is, as critical reviews of the novel note, evocative of Heller’s Catch -22, but it’s hardly a derivative work.  It stands solidly on its own with a story arc that, though at times as absurd and darkly hilarious as Heller’s novel at its best, tells a different story in a different way.  This is not a sprawling tale of war with countless subplots, rather the novel nearly always keeps a relatively tight focus on the romance between our hero, radioman Corporal Rocco Raven, an auto mechanic from Brooklyn, and our heroine, jukebox seller and repairer Melita Azzard.  Unlike Catch-22 with its portrayal of the pervasive, irrational, and pernicious control of the military over most of its characters, in The Jukebox Queen, Rocco, though a member of the U.S. Army, feels its direct influence only sporadically.  Yes, admittedly, it is the Army that sends him to Malta (in error) at the outset and the Army that orders him to leave at the end.

Rocco is on Malta to help a small contingent of American intelligence operatives led by a Major Webb who, it would seem, was killed just before Rocco’s arrival.  As a result, Lieutenant Jack Fingerly, wearer of tropical sport shirts on which he pins the insignias of his rank (a rank that somehow moves continual upward as he travels to and from the island during the blitz), is Rocco’s commanding officer.

The island is magical and possibly so are some its inhabitants or visitors.  Melita (whose name in Latin means honey and was the Romans’ name for the island) at certain moments manifests a dreamlike quality for Rocco – disappearing into searing light, shrinking to nothing, or walking through walls.  Is she the novel’s Calypso, ensnaring the hero and holding him prisoner?  Perhaps in some ways, but, in general, I think not.  These two are, it seems to me, genuinely in love despite all of the complexities that this brings under the circumstances.  Rocco and Melita are not as unlikely a couple as they might first appear.  Beyond their sexual attraction, they share interests, and are caring and insightful about each other (well, perhaps, as best any one person can be of another).  Both are familiar with the arts, he knows some philosophy and literature, particularly Edgar Allan Poe, she knows much of the classical English canon and was once a student of Renaissance art.  Their relationship feels real.

Fingerly is another with mystical qualities, a shape-shifter often disappearing for long periods, once in awhile returning with new orders for Rocco which are not always obeyed.  Rocco remains unsure of who or what Fingerly actually is, what he is about.  At one moment, early on, Rocco seems to see Fingerly dissolve into smoke.  A statement follows (thought by Rocco or perhaps provided by an omniscient author):  “Malta was doing this – everything shifting, turning, uncertain.”

Whether and how the romance at the center of the novel might transcend the wartime chaos that surrounds the lovers fuels the novel’s dramatic tension.  It plays out against the backdrop of the incessant aerial attacks that find targets to level even as everything seems already destroyed.  Yet, even though, at any moment, death will come from the sky, the people on the island continue to live their lives as best they can, sometimes retreating to underground shelters, other times not.  Food and fuel run short, and water and electricity are often unavailable, nevertheless, there are nightclubs and bars serving customers in wrecked buildings; buses running (albeit intermittently and often targeted by the enemy planes); stores open though with little to sell; and the marvelous jukeboxes being built by Melita’s cousin to be sold and serviced.  Life goes on, love goes on, regardless that all of it might end, is likely to end, unexpectedly and explosively.

The novel poses a fundamental question – does the world care about us, about anything we do, the wars we wage, the love we feel, about the deals we make, the families we create?  The ancient Nardu Camilleri, doorman for a brothel, who lingers near death for the latter portion of the novel, has a grand vision for his homeland.  Early in the novel, he tells Rocco:

Mark my words!  As soon as the war is over, we declare our independence and we throw out the English.  Then we annex Italy.  Sicily we don’t want, it’s too full of thugs and mafiosi.  Rome we give to the pope, but the rest of Italy is ours.  We will call it Greater Malta.

Yet Nardu, close to the novel’s end, says to Rocco:

The earth . . . this earth we live on, has been around for millions of years.  Against all of that, the vastness of time, what is a human life?  We are nothing, not even a whisper.

This isn’t the novel’s answer to that question, at least, not the full response.  As always in the world that Rinaldi has created and set in the mayhem of Malta, there’s some other note of magic that may be struck, a different take, another angle . . . even from Nardu.  He, who posited that a human life is not even worth a whisper, immediately reaches out and touches Rocco’s arm and says:

But the lace trade . . . there is a future in it, it’s worth investing. We talked about that before, did we not?  Buy cheap, sell dear.  That’s the whole secret to existence.

There’s so much more to this novel, so much more to explore, including the real people and events with which Rinaldi populated it.  But, to justify writing about this wonderful novel in this blog, I will describe briefly how it opened doors for me to the geological and paleontological marvels of the island.  The island is enchanted in those terms as well.

Rinaldi knows the geology and paleontology (and archaeology) of this place, offering irresistible signals prompting me to learn more.  In the novel, he observes that the buildings on Malta, those still standing and those now rubble during the siege, are made of limestone.  The island itself is made mostly of limestone.  Ah, a sedimentary rock composed of calcium carbonate, the stuff of shells, of fossils.  The graph below, showing all of the bedrock of the island which ranges in age from the Oligocene to the Miocene, is based on one appearing in The Geology of Malta and Gozo by H.M. Pedley et al. (Proceedings of the Geologists’ Association, Volume 87, Issue 3, 1976.  This paper resides behind a paywall.)  Gozo is the second largest of the Maltese islands.

Atop the bedrock in various places are Pleistocene deposits (more on what that they have to offer in a moment).  Most important, all of the bedrock shown in the graph is limestone in nature.  Anywhere the bedrock outcrops on Malta is a potential paradise for fossil hunters.  Pedley’s description of the each of these formations bears that out.  The Lower Coralline Limestone is full of benthic foraminifera fossil shells, fossil corals, and fossil mollusks, as well as echinoids and brachiopods.  Across the wide breadth of the Globigerina Limestone, it offers up not only shells from those eponymous foraminifera, but also echinoids, gastropods, and various bivalves, along with fossils from extinct crocodiles, turtles, and seals.  Perhaps most engaging for the typical fossil collector, this formation contains fossil teeth from myriad sharks, including megalodons, makos, and snaggletooths.  The Blue Clay yields mostly “microfauna or crushed specimens of macrofauna,” although in the upper levels of the formation, one can find corals, mollusks, echinoids, and disarticulated remains of cetaceans..  The Greensand seems less productive though even here are bivalves and echnoids, along with some vertebrate remains.  The Upper Carolline produces bivalves, echinoids, bryozoan colonies, and brachiopods.  The mind reels.

Pedley has something to say about the quaternary deposit on the island which fill in caverns and fissures.  Some of these are “Pleistocene bone deposits.”

Within these beds occur prolific remains of hippopotami, pygmy elephants and swans.  Deer and horse occur in slightly younger deposits.  Many fissure deposits in Malta contain faunas of land-snails, deer and remains of the giant dormouse.  All these remains suggest that climatic condition were more temperate than today, with perennial stream-systems and abundance vegetation.  It is likely that land connections with Sicily occurred at this time.

And here’s Rinaldi on the treasures of the Pleistocene deposits.  Fingerly takes Rocco with him as he journeys to the western end of the island to await the return of Maroon, a member of the intelligence unit who has been on Gozo with a mission from Fingerly.  Maroon is coming alone in a powerboat, crossing the three-mile channel that separates Gozo from Malta.  It’s sunset, a time when, it’s hoped, pilots of enemy fighter planes will have a hard time zeroing in on targets in the channel.  Fingerly and Rocco watch for Maroon using binoculars.  When he comes into view mid-channel, they discern a large box tied to the back of the boat.

The sun was sinking, a big red ball, half of it already gone.  It did crazy things with the sky, igniting the clouds into a blaze of color.  It did things to the water too, casting a rosy sheen that faded to violet and black.

“He should have taken the ferry,” Fingerly said anxiously.  “I told him to take the ferry.”

“What’s in the box?” Rocco asked.


“Whose bones?”

“An elephant, Raven.  A pigmy elephant.”

Rocco thought about it, then said, “There is no such thing as a pigmy elephant.”

“Not now, no.  But there was.  In the Pleistocene, and they were right here, in this neck of the woods.”  He worked at the binoculars, adjusting the focus.  “That’s what’s in the box, a mini-elephant.  Not a baby elephant but a full-grown beast the size of a St. Bernard.  They have one in the Smithsonian – ever see it?”

And then a German Messerschmitt 109 fighter plane appears.

The stamp below from Malta, issued in 2009, features the fossil skeleton of a Maltese pygmy elephant, Elephas falconeri.

Clearly, I was enchanted by Rinaldi’s novel which deserves to be read for a long time to come.

Monday, June 29, 2020

Transitions ~ An Appreciation of Jennifer A. Clack

Transitions.  Nothing surprising about being preoccupied these days by transitions, given the striking and powerful challenges to this country’s social and political norms.  In a situation of such fluidity, one should be hopeful that meaningful change will be coming, but I don’t hold my breath.  But among the transitions that have garnered a significant portion of my attention these past several days is one that happened in March of this year and ones that lie back, way back, in the Upper Devonian period, some 383 to 359 million years ago.  The first was the death from cancer of paleontologist Jennifer A. Clack (1947-2020); the second is a couplet of transitions:  fish to tetrapods, and vertebrates from an aquatic existence to terrestrial living.  (Tetrapods are any four-legged animal or any animal whose ancestors had four legs.)

Last month I posted a review of paleontologist Neil Shubin’s new book, Some Assembly Required.  Not mentioned in that post was that Shubin occupies a preeminent place among those who study the transitions of vertebrates from water to land, and from fish to tetrapods, particularly with the find in the Canadian Artic in 2004 of the spectacular fossil Tiktaalik, a lobe-finned fish sporting various traits shared by tetrapods, including highly advanced pectoral fins.  As Shubin wrote of the animal’s pectoral fins in Your Inner Fish (2009), “Tiktaalik has a shoulder, elbow, and wrist composed of the same bones as an upper arm, forearm, and wrist in a human.  When we study the structure of these joints to assess how one bone moves against another, we see that Tiktaalik was specialized for a rather extraordinary function:  it was capable of doing push-ups.”  (p. 39)  And, in that book, Shubin noted that push-ups could be useful if one had to navigate in shallow streams straddled by mudflats.  Though clearly a fish living in an aquatic environment, Tiktaalik was a way station en route to tetrapods.

While writing last month’s post, I learned that Jennifer Clack had passed away.  See the piece by Per Ahlberg titled Obituary:  Jennifer Clack (1947-2020): Palaeontologist Who Described How Vertebrates Moved From Water to Land (Nature, Volume 580, April 30, 2020, p. 587).  Ahlberg’s obituary features a wonderful picture of Clack.  She’s wearing a broach shaped like an early tetrapod, probably Acanthostega.  Clack merits inclusion in my pantheon of paleontological heroes for, among other accomplishments, (1) her seminal work on one of the earliest tetrapods, Acanthostega, fleshing out the morphology and environment of that animal through fieldwork in Greenland and meticulous research on the fossils her expeditions found, and (2) the filling of “Romer’s Gap” with, once again, fieldwork, only this time in Scotland, and careful research of her finds.

Though I am likely to get into trouble by venturing into areas about which I know even less than usual, I will consider both of those areas of accomplishment very briefly (hoping, thereby, to minimize misstatements; I will also try to let others describe her work).  The Upper Devonian strata are where fossils reflecting the evolution of fish to tetrapods are to be found.  The clade diagram below is based on one that appears in a recent article by paleontologists John A. Long and Richard Cloutier titled The Unexpected Origin of Fingers (Scientific American, June 2020).  That’s the title of the print version of the article; online it’s:  How a 380-Million-Year-Old Fish Gave Us Fingers which is incorrect since the animal in question is 375 million years old.  The focus of this article is a close relative of tetrapods, perhaps the closest yet found, named Elpistostege watsoni.  As shown in this clade diagram, Elpistostege occupies a position nearer to tetrapods than Tiktaalik, a position that may have resulted largely from the completeness of a fossil of the former compared to that of the latter.

For reference, Tiktaalik is dated at 380 million years, Elpistostege at 375 million years, and Acanthostega (one of Clack's domains) at 360 million years.  As one moves from left to right up the clade diagram from predecessors to Tiktaalik on to Acanthostega, the transition from fish to tetrapod is proceeding.  This transition involved various critical morphological changes, among others, the evolution of limbs from fins and the appearance of a neck.

In 1987 and 1998, Clack undertook fieldwork in Greenland, initially searching an area from which fossils of two very early intermediate animals (Ichthyostega and Acanthostega, the latter known at the time only from skull roof fragments) had been found in the late 1920s and early 1930s.  In that first expedition, she found fossils of Acanthostega which included post-cranial features.  And therein lay treasure because the fossils showed that the limbs of this taxon had the universal tetrapod arrangement of limbs.  To quote Shubin, this is a “one bone-two-bones-little bones-digits pattern” which “is a grand anatomical theme, an ancient pattern that underlies the diversity of every creature with a limb skeleton.”  (Some Assembly Required, p. 119-120.)  Significantly, these limbs of the Acanthostega tetrapod sported more than five digits, broadening the ends of the limbs.

Clack described the importance of the Acanthostega fossils for our understanding of the transition of vertebrates from fish to tetrapod, and that from water to land:
Here was a creature that had legs and feet but that was otherwise ill equipped for a terrestrial existence.  Acanthostega’s limbs lacked proper ankles to support the animal’s weight on land, looking more like paddles for swimming.  And although it had lungs, its ribs were too short to prevent the collapse of the chest cavity once out of water. . . .  In other words, this animal, though clearly a tetrapod, was primarily an aquatic creature whose immediate forerunners were essentially fish that had never left the water.  (Clack, Getting a Leg Up on Land, Scientific American, December 2005, p. 102.)
Clack flipped the orthodoxy concerning the timing of these two transitions which had posited that moving onto land occurred before or concurrent with becoming a tetrapod.  In fact, the intermediate taxa were becoming and became tetrapods before they had to navigate on land.  When that began, the morphological changes they’d already undergone were to serve them in good stead.  Yes, this is another instance of what Darwin posited would be true of some evolutionary developments:  they could occur "by a change of function."  (This is the core premise of Shubin’s Some Assembly Required.)  

As for Romer’s Gap, Clack filled it in with early tetrapods.  In her book, Gaining Ground:  The Origin and Evolution of Tetrapods (second edition, 2012), she described how paleontologist A.S. Romer had observed that the fossil record contained a 30-million-year gap immediately following the Devonian.  This gap from about 359 to 331 million years ago fell early in the Carboniferous period and, as Romer noted, presumably covered the time when the actual movement of vertebrates fully from water to land occurred.  Among the explanations for the gap that scientists had proffered was that the absence of fossils in this time period reflected an actual absence of terrestrial animals due to environmental challenges.

Though Clack acknowledged that the mass extinction at the end of the Devonian played a role in what the fossil record showed, she demonstrated that the gap in the record could be addressed in large part by looking hard for fossils in the right places.  To that end, she undertook the TW:eed Project, searching in Scotland, north of Berwick-upon-Tweed.  Ahlberg describes the success of the project as follows:
These sandstones and mudstones promptly started yielding fossils of previously unknown tetrapods.  Six genera have been described so far and more material awaits description.  They look set to revolutionize our understanding of the early diversification of tetrapods by filling in the wide morphological gap between very primitive ones, such as Acanthostega, and the more modern tetrapods of the Carboniferous.  (Obituary, p. 587.)
Above I mentioned Clack’s book Gaining Ground.  This book is a signal accomplishment, providing a comprehensive, authoritative examination of the transition from fish to tetrapods, delineating the morphological changes of these animals in detail, and also describing the environments within which they lived and its influence on their development.  Shubin describes the book as “magisterial” (Some Assembly Required, p. 224) and as “[t]he bible of this transition” which “will bring a novice to expert status quickly” (Your Inner Fish, p. 212.)  The book is not for the faint of heart given how fully Clack entered into the skeletal complexity of the many taxa she considered.  At the same time, during the course of quite serious analyses of tetrapods and tetrapods-in-the-making, she, on occasion, offered light asides.  I approached the book with high expectations having conflated “magisterial” with “magical" or "majestic;” sadly, I certainly remained a novice after reading it.  The book, in fact, lies somewhere between a paleontology textbook and a lengthy volume of popular science.  It’s neither, though it shares more attributes of the former than the latter.  Dare I say, it is a transition volume.

I’ll close with a tiny bit of biography drawn from the obituary by Ahlberg and from Clack’s own website.  She was born in Manchester, England, and studied zoology as an undergraduate at the University of Newcastle upon Tyne.  Though she would have liked to pursue Ph.D. study of paleontology after graduation, financing wasn’t available.  So she earned a certificate in museum studies and went to work at the Birmingham City Museum and Art Gallery.  After several years there, looking for a paleontological side project, she approached paleontologist Alec Panchen, whose paleontology option she’d taken at the University of Newcastle upon Tyne.  This would profoundly change the course of her professional life.  Here’s how she described that experience.
I approached Alec Panchen for ideas. He said "What about trying to get hold of the holotype of Pholiderpeton scutigerum from Bradford Museum? It's the last remaining embolomere [Early Carboniferous tetrapod] specimen undescribed in this century, and I've never been able to borrow it to work on." I approached Bradford Museums, who, in the intervening years, had changed their policy on loans of material. They recommended that the specimen be transferred to Newcastle to be worked on in Alec's lab, and I took three weeks' study leave from Birmingham to work on it. That was the beginning of my good luck in palaeontology, which seems to have been with me ever since. 

I began to prepare the material, and almost at once, discovered it was more complete than had been previously realised. Having uncovered a curious-looking lump on the previously hidden side of the specimen, I showed it to Alec, who paused and then said "Well I'm damned - it's a braincase!" and then later "There is probably a PhD in this. If you'd be interested, I'll try and get a grant." Was I interested? Thoughts of bears and woods...
Thoughts of bears and woods!!

In 1981, her Ph.D. work at the University of Newcastle upon Tyne led to a position as Assistant Curator at the University Museum of Zoology, Cambridge.  She was a tenured member of the Zoology Department at Cambridge and remained there for the rest of her career.  As she noted on her website:
As Curator, I have several different strands to my work: curation, teaching, administration and research. Each of these is supposed to take about one third of my time (!).
How she managed to fulfill all of her professional obligations while being so fully and productively engaged in her paleontological research staggers the imagination.  Ahlberg probably captured the essence of her character that enabled her to do what she did:
A happy convergence of brilliance, tenacity, opportunity, generosity and modesty enabled Clack (née Agnew) to rejuvenate an entire research field.
I will close by quoting from the author description that accompanied her December 2005 Scientific American article (p. 105).  These two revealing sentences are a delight:
A fellow of the Linnean Society, Clack’s outside interests include choral singing (particularly of early sacred music) and gardening.  She is also a motorcyclist and rides a Yamaha Diversion 900.
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