Monday, December 27, 2021

The Shipping Forecast - A Prayer For Now

 Maybe it’s the time of year or maybe it’s the time of my life, but BBC Radio 4’s The Shipping Forecast has come to offer solace as 2021 winds its way to a bleak end.

I was introduced to The Shipping Forecast (TSF) by a character in Richard Osman’s The Thursday Murder Club (2020), who, as she ponders old, unsolved murders, writes in her diary:

All those murderers remained unpunished, all still out there, listening to the BBC Shipping Forecast somewhere.  (p. 23)

TSF, a weather forecast for British marine waters, casts its spell on the righteous and the sinful alike.

Over its many decades of broadcast, TSF has elicited many responses.  It has been mocked and parodied, and its words and cadences incorporated into poetry and fiction.  All this is testament to its staying power and its centrality to some form of identity for the people of the British Isles.  Mark Damazer, a previous controller of BBC Radio 4 (which currently broadcasts TSF), once said,

It scans poetically.  It’s got a rhythm of its own.  It’s eccentric, it’s unique, it’s English.

(As quoted in Poetics of the Shipping Forecast by Sanna Nyqvist, in Spaces of Longing and Belonging  Territoriality, Ideology and Creative Identity in Literature and Film, 2019.)

BBC Radio 4 broadcasts TSF four times a day; currently at:  00:48 Universal Time Coordinated (UTC), 05:33, 12:01, and 17:54, providing the weather forecast for 31 sea areas surrounding the British Isles.  Each area bears a distinct, evocative name.  These areas go far afield, touching the coastlines of Southeast Iceland, Norway, Denmark, Germany, Belgium, France, and Spain.  They are shown in the map below (along with coastal weather stations marked in red, whose weather is not part of the TSF).  Trafalgar is covered only in the midnight (00:48 UTC) broadcast.

(This map is available from Wikimedia Commons.  It was posted by Emoscopes and is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.)

TSF is prepared by the Meteorological Office (Met Office) and each broadcast begins in the same way:

And now the Shipping Forecast issued by the Met Office, on behalf of the Maritime and Coastguard Agency . . . .

The broadcast is brief, typically read in a soothing, even-keeled tone, devoid of drama.  The first two broadcasts of the day are followed immediately by separate reports drawn from the coastal stations (see map above).

Given the ever-changing nature of weather, TSF’s content differs from broadcast to broadcast, but its structure remains fixed.  Each broadcast first provides a brief warning of where gales might be expected, and then a succinct synopsis of the overall weather pattern.  This is followed by a description of the next 24 hours for each of the general forecast areas in terms of wind direction and speed, weather, and visibility.  The forecast covers those areas in a clockwise fashion, beginning in the Northeast with Viking and ending with Southeast Iceland.

Each iteration of TSF has a specific upper word limit of 350 words, with a small bump at midnight (00:48) to 380 words when Trafalgar is included in the forecast.  As result of this limit, the forecast, in holding to a specific order in what it describes for each area, often drops nouns and verbs (for example, the first words and numbers provided for an area apply to the direction of the wind and its speed), and, in a further word-saving step, merges the forecast for contiguous areas when conditions are the same across them (e.g., "Forties, Cromarty, Forth.  Cyclonic 2 to 4 . . . . .").  This makes TSF sound, at first blush, like code (well, it is code) and perhaps a peculiar English dialect.

Here is the recording of a snippet from the December 23, 2021, midnight broadcast.  (This is my first attempt to insert an audio file in a post and it hasn't gone smoothly.  The embedded audio file may take a moment to begin to play after clicking on the arrowhead pointing to the right in the icon below.  If it doesn't play, refreshing the page might help.  Alternatively, the file can be made available by clicking on the arrow in the box that will appear in the upper right corner of the icon below automatically or when the cursor is moved to that area.)

One need not understand much of what TSF conveys to succumb to its magic, in fact, it probably helps not to translate it as it goes.  But even deciphering a bit of the forecast seems not to lessen its charm.  In the snippet I provided above, the opening forecast for Viking reads as follows:

Cyclonic 3 to 5, becoming northerly or northeasterly 4 to 6, increasing 7 later in north, perhaps gale 8 later in northeast.  Rain or showers.  Good, occasionally poor.

Translation:

Cyclonic = during the forecast period, a depression in the area will provide considerable change in wind direction

3 to 5 = measurements on the Beaufort Wind Scale – 3 is 8 to 12 miles per hour, described as a “gentle breeze”; while 5 is 19 to 24 miles per hour, a “fresh breeze”

becoming northerly or northeasterly = wind direction will shift to come out of the north or northeast

4 to 6 = 13 to 18 miles per hour winds (“moderate breeze”), and up to 25 to 31 mph (“strong breeze”)

increasing 7 later in north = wind in the north of Viking will increase to 32 to 38 mph (“near gale”)

perhaps gale 8 later in northeast = 39 to 46 mph winds (“gale”) possible later in the northeast of Viking

Rain or showers = the overall weather for the 24 hour period of the forecast for Viking

Good, occasionally poor = visibility will be more than 5 nautical miles (“good”) but sometimes between 1,000 meters and 2 nautical miles (“poor”)

Even with such a translation, I hear the words but miss the meaning.

I have come to TSF only recently, so I have no deep ties to it, no memories of listening to it under the covers as a child, no direct connection to the places it covers.  Still, it appeals strongly to me.  Just the names of the forecast areas are engaging, melodic, hypnotic as they are read in the forecast..  I know little about the actual locations - their physical makeup or their histories - but names such as Forties, Forth, Fair Isle, Dogger, or Rockall are wonderful to hear and to say.  These names create images for me, grounded in reality or not.

Further, I gain a curious sense of comfort and safety from the forecast.  That it begins by highlighting gales in the areas covered says plainly, there is danger out there,  Though the forecast spreads the out there across my imagination, that actually emphasizes that I am here, at home, sheltered from the storm.  What a powerful duality that is.  Peter Jefferson, a long-time voice of TSF, asserts that the midnight broadcast in particular has attracted a dedicated audience of listeners who consider it “something of a ‘must hear’ before the cloak of sleep envelops” them.  (And Now The Shipping Forecast:  A Tide of History Around Our Shores, 2011, p. 16.)  Snuggled warm in bed, the soothing tones of TSF gently caress the ears (no matter how turbulent the weather).

And, perhaps, a key element of its appeal to me is its predictability, its unchanging structure.  These days, the idea of a constant, never-failing beacon of light is irresistible.

From its inception, the forecast was, above all, a necessary service for the vessels braving the seas around the British Isles.  Its roots go back to 1861 when Captain Robert FitzRoy (later elevated to Vice-Admiral), head of what became the Met Office, started a storm warning system for British marine waters.  In the 1920s regular weather reports began on the BBC and have continued ever since (interrupted only by WWII between 1939 and 1945).  But TSF no longer provides a critical service for vessel plying these waters whose sailors have other options for securing weather forecasts.  As a consequence, Sanna Nyqvist describes shipping forecasts (she is writing about TSF and similar broadcasts in Finland and Sweden) as “relics.”  But relics that serve myriad other social and cultural purposes.

There are many essays, articles, and books about TSF and other shipping forecasts.  Peter Jefferson’s volume cited earlier is a conversational, congenial exploration of the history, structure, content, and cultural role of TSF.  The Met Office has produced a very useful introduction to the forecast – Shipping:  Fact Sheet 8 – The Shipping Forecast (2015).

Among the best articles is Sanna Nyqvist’s, which I cited earlier.  In it, she explores the  fictional, poetic, and non-fictional literature evoked by three nations’ shipping forecasts, paying close attention to the universality of responses to such broadcasts.  Of the countries she covers – Great Britain, Finland, and Sweden, each considers its shipping forecast unique, something not to be found elsewhere.  According to Nyqvist, the forecasts, sent out over the airways in cryptic language, speak to listeners of the past, of the settings in which they heard the forecasts in their childhoods, and offer a meditative and restorative balm.  It may not all be benign since some listeners may hear the shipping forecast speaking to their national and cultural identities against the threat of others.  Yet, she suggests, shipping forecasts may also engender an appreciation of the interconnectedness of places and people (consider the broad sweep of the areas covered by TSF).

Nyqvist captures an essential quality of TSF and other shipping forecasts where she writes

Through its ritualistic presentation on the national radio, the shipping forecast has become a part of the collective experience to the extent that it has become a secular prayer, a familiar chant sheltering its listeners from storms and perils.  (p. 53)

Would Captain Robert FitzRoy recognize any aspect of TSF, the present product of his vision for the Met Office and a system to warn ships at sea of impending weather?  He most likely would not ascribe any prayerful quality to the forecast given his hardened conservative Christian beliefs.  Prior to assuming leadership of the Met Office, his greatest accomplishments were the surveying voyages he commanded between 1828 to 1836 in the HMS Beagle.  Yes, that Beagle on which a young Charles Darwin sailed between 1831 and 1836.  FitzRoy and Darwin, despite an apparently productive relationship while at sea, fell out once back in England.  The difficult and troubled FitzRoy was critical of his treatment in Darwin’s account of the voyage of the Beagle, and opposed Darwin’s theory of evolution.  Four years after instituting that first storm warning system, FitzRoy committed suicide.

The closing couplet of Carol Ann Duffy’s sonnet titled Prayer may be a fitting conclusion to this post.  The sonnet offers a somber vision of unbidden memories of loss and regret penetrating lives, with comfort coming, perhaps, from the constancy of a quotidian litany.

Darkness outside.  Inside, the radio’s prayer – 
Rockall.  Malin.  Dogger.  Finisterre.

Finisterre is the weather area now known as FitzRoy.


Monday, November 29, 2021

Mammals All The Way Down

Well, not quite all the way down.  Still, mammals and their immediate ancestors have been in the vertebrate mix for a very, very long time.  Fossils of true mammals date back to the Triassic Period (252-201 million years ago).  True dinosaurs make their appearance at the same time.  I suspect the roots of the mammalian public relations problem lies in that coincident arrival of mammals and dinosaurs on the scene.  What’s the PR issue that mammals face?  In particular in the Mesozoic Era (comprising the Triassic, Jurassic, and Cretaceous Periods – 252 to 66 million years ago), to paraphrase comedian Rodney Dangerfield:  “Mammals don’t get no respect.”

Paleontologist Elsa Panciroli wants to remedy that and give mammals in that era their due.  Her new book is titled Beasts Before Us:  The Untold Story of Mammal Origins and Evolution (2021) and it’s an engrossing read.  She’s an amiable and funny companion in the journey across deep time tracing the appearance and evolutionary development of mammals from before and through the Mesozoic.  Although she on occasion appears in the narrative doing her work as a paleontologist, she avoids the trap in popular science writing – making herself the hero of the story.  (I’ve complained about this in previous posts on this blog.)

It's best to begin with the typical narrative about mammalian development in the Mesozoic.  In this version of the story, at the beginning of the era in the Triassic, early mammals and early dinosaurs are merely extras in the cast of vertebrate characters.  Through a great deal of luck after a period of environmental distress, dinosaurs come center stage as the storyline takes us into the Jurassic; dinosaurs dominate the scene through to the end of the Cretaceous.  A physiological arms race between plant-eating dinosaurs and predator dinosaurs drives each dinosaur group to become bigger and bigger.  Mammals, given only brief lines in the text, are small and seemingly quiescent extras, trying to go unnoticed by the thundering reptilian stars.  Only when the Cretaceous ends and non-avian dinosaurs are banished from the story, are mammals free to assume a central place.  (This plot arc is reprised often, including quite recently in geologist Andrew H. Knoll’s A Brief History of Earth:  Four Billion Years in Eight Chapters (2021), a superb book, no matter its treatment of Mesozoic mammals.)

The storyline I’ve just recounted is not wrong in its broad sweep.  But, after reading Panciroli’s volume, I recognize that it comes up short in its nearly sole emphasis on dinosaurs, not acknowledging the dynamic evolutionary action and experimentation taking place among those small animals just off center stage.  Panciroli makes it abundantly clear that marvels were being fashioned in those shadows.  That’s a central part of the “untold story” she has been moved to tell.

If you believed mammals – we fur-ball milk-givers – merely scooted underfoot like terrified snacks for most of the time of the dinosaurs, you are dead wrong.  If you have always repeated the tale that mammals come from reptile stock, wash your mouth out.  We mammals are a lineage all our own.  Our branch stretches away from the others, tied through time by our anatomy and physiology to the first backboned animals on land.  Long ago we struck out in a flowerless Eden, and we made good.  (p. 11 of the print version of the book)

Panciroli traces the evolution of mammals and their ancestors from the tetrapods that, in the Late Devonian Period (perhaps around 360 million years ago), first emerged from the water to live on land.  The path runs through myriad groups, from the synapsids to the therapsids to the cynodonts and so on.  She describes how and when some of those characteristics that have ultimately come to distinguish mammals first appeared.  (Although many core traits of mammals are identified in the course of the narrative, these are not (as far I found) pulled together in the book in a single, comprehensive statement of what defines a mammal.)  

The roots of some of those characteristics lie farther back in time than I realized.  Panciroli sees that, during the Permian Period (299 to 252 million years ago), mammal ancestors were major players, experimenting with different modes of earning a living, from herbivory to “hyper-carnivory,” even as some were acquiring the “key traits we associate with mammals, including warmer blood, higher energy lifestyles, and perhaps even fur.”  (p. 97)

Though the mass extinction at the end of the Permian knocked mammalian ancestors for a loop as it did most animals, it was during the Mesozoic Era when early mammals came into their own.  As Panciroli makes clear, for mammals size mattered, but not in the salacious way (wink, wink, nudge, nudge) comics would have it.  Paleontologists, she notes, long equated large body size with evolutionary success.

Mammals, we are told, did nothing during the time of dinosaurs, so we skip over them in our narrative of life.  Most books on mammal evolution only begin when they are finally free of their masters, and get bigger.  Because bigger is always better.  Right?  (p. 162)

Here Panciroli is making her strikingly revisionist argument regarding mammals, arguing that during the Mesozoic they were a significant source of evolutionary experimentation and development.  Central to her argument is the power of that attribute that has long been held against them, their small size.

The first mammals of the Late Triassic and Early Jurassic were pioneers.  They did something no dinosaur could do:  they shrank and exploited an untapped night-time niche.  To this day, of the 5,500 or so small species alive on Earth, 90 per cent are small-bodied, most of them rodents.  The median body mass for mammals today is less than 1kg (2.2lb).” (p. 170)

Rather than a handicap, the shrinking of early mammalian bodies (quite a useful development in a world with monstrously large reptiles) actually spurred the evolution of profoundly significant physiological traits boasted by mammals.  Equipped with those attributes first emerging in the Permian (a faster metabolism and warmer blood), these shrinking animals became nocturnal (their metabolism enabling them to function in the cold night) and evolved eyes that could see particularly well in low light.  The majority of mammals today are nocturnal.

Further, as mammals shrank, their ability to smell and hear was enhanced.  Panciroli writes, “Although most animals can smell and hear, mammals are among the smelliest and noisiest.”  (p. 165)  There is a direct relationship between size and these attributes.  For instance, Panciroli describes how smallness spurred development of the effective and unique mammalian ear structure, particularly with regard to the bones in the middle ear.  In a diminutive jaw, a strong bite could be accomplished more easily and, as result, several bones at the back of the jaw were no longer necessary.  These were repurposed by natural selection to be incorporated in the mammalian ear to enhance hearing.

The smaller mammalian jaw carried on the modifications in dentition that these animals had been experimenting with for a long time.  Mammalian teeth increasingly varied in the same jaw:  canines, incisors, premolars, and molars were structured to deal with food in different ways.  Further, teeth were increasingly likely to be replaced only twice, instead of continuously so that occlusion between upper and lower teeth was enhanced.

The combination of these attributes in these small animals, according to Panciroli, had another, even more profound effect.

Putting their newfound bite to good use, mammals became the scourges of the insect world.  Hunting in the relative safety of night with senses enhanced, the first mammals grew bigger brains, paving the way for increasingly complex social interaction and behaviour.  (p. 171)

The book is a corrective in more ways than I’ve described above.  Yes, Panciroli’s primary objective is to rescue the early history of mammals, but she also seeks to set several other records straight.  To wit, paleontology, long dominated by white men who have imposed their stamp on the field, has been hostile to women, failing to acknowledge their accomplishments or opening its ranks sufficiently to them.  In the course of laying out the real history of the development of mammals, she highlights the many contributions of women, from Jennifer Clack (whose work has been described in a previous post) to Zofia Kielan-Jaworowska who, Panciroli writes, “should be remembered as one of the greatest scientists of all time.”  (p. 268)  Further, the book also offers an accessible tutorial on modern paleontological methods, from the extensive use of statistical analysis of big data sets to the application of advanced technologies, such as CT scans.  Clearly, it’s not all field work.

If there is a geographical hero of this book, it’s Scotland and the Isle of Skye.  Much of Panciroli’s own work has been on the early mammal fossils of Scotland and she describes several fossil hunting trips there.  It’s clearly mostly cold, wet work.  The Scottish mammal fossils are tiny (fossil hunters spend lots of time on their knees) and typically embedded in matrix.  As a result, current study of those fossils owes a great deal to the application of those changing paleontological methods.

I’ll end with a critical note (perhaps more of my reading than of the book) and a warning.  The critical note is that, despite the overall chronological organization of the book (from deep time to the present), I found it quite easy to get lost, unsure of where we were in the story and who the characters were.  Quite frequently, Panciroli observes, parenthetically, that some subject or person she’s just mentioned will appear later in the book.  Perhaps this simply reflects the fits and starts of the actual evolution of mammals (as she frequently stresses, evolution doesn’t have an endgame in mind) and the course of paleontological work.  Nevertheless, I did lose my way at times, but the grace of her writing and the power of the narrative pulled me through.

The warning is this:  Don’t read this book in the Kindle version.  My first reading of it was Kindle-based.  Only when I came to research this post and acquired the print version, did I discover the book’s beautiful and informative photographs, and, most importantly, the endpapers that provide a wonderfully useful cladogram showing graphically the relationships of most of the major taxa that appear in this story.  Sadly, all of that is missing from the Kindle version.


Friday, October 22, 2021

Bumble Bees' Year Comes to a Close

 At this time of year, bumble bees are well advised to get their affairs in order, for only the young queens who have mated will winter over and see a new spring.  The rest, including each nest’s founding queen, will slow and eventually die, repeating a cycle that has persisted for eons.

When paleontologist Manuel Dehon and his colleagues recently described a Miocene compression fossil found in lake deposits in La Cerdanya, Spain, they made a welcome addition to the meager fossil record of the bumble bee.   The fossil dated from the Miocene’s Tortonian age, making it some 12 to 7 million years old.

(Wing Shape of Four New Bee Fossils (Hymenoptera:  Anthophila) Provides Insights to Bee Evolution, PLOS ONE, Volume 9, Issue 10, October 2014.  The image shown here is from the article and can be found at Wikimedia Commons.  It is reproduced under a Creative Commons Attribution-Share Alike 4.0 International license.)

The Paleobiology Database lists only 17 collections with fossils of purported bumble bee species, all dating to the Miocene epoch (approximately 23 to 5 million years ago).  In fact, the world may have borne witness to the activities of bumble bees for a bit longer than the fossil record would have it.  Evolutionary biologist Heather Hines concludes that the bumble bee genus originated probably some 25 to 40 million years ago (at some point from the late Eocene to the middle of the Oligocene).  The climate at the time was growing colder which favored this animal which had attributes that served it well in temperate regions.  Bumble bees now (and presumably then) have the capacity to thermoregulate.  That is, by shivering with their thoracic muscles, they generate internal heat, sufficiently greater than the ambient temperature to enable them to fly.  (Historical Biogeography, Divergence Times, and Diversification Patterns of Bumble Bees (Hymenoptera:  Apidae:  Bombus), Systematic Biology, Vol. 57, No. 1, 2008.)

To my untrained eye, the fossil Dehon et al. described is quite clearly a bumble bee.  They named this new species Bombus cerdanyensis.  Its species name recognizes where the fossil was found.  Appropriately they placed this species in the longstanding bumble bee genus which bears a name that . . . well, a name I consider one of the most wonderful genus names ever.  Savor the word . . . Bombus . . . a delight to say and to hear.  So beautifully onomatopoetic, coming originally from the Greek bombus meaning “a buzzing” (Donald J. Borror, Dictionary of Word Roots and Combining Forms, 1988, p. 18).

With the wedding of their sound to their colorful fuzziness and their bouncing travel among flowers, bumble bees are irresistible.  Walt Whitman certainly found them so.  In Specimen Days, in a passage written one May, he extolled the bumble bee: 

Nature marches in procession, in sections, like the corps of an army.  All have done much for me, and still do.  But for the last two days it has been the great wild bee, the humble-bee, or ‘bumble,' as the children call him. . . .

As I write, I am seated under a big wild-cherry tree - the warm day temper'd by partial clouds and fresh breeze, neither too heavy nor light - and here I sit long and long, envelop'd in the deep musical drone of these bees, flitting, balancing, darting to and fro about me by hundreds - big fellows with light yellow jackets, great glistening swelling bodies, stumpy heads and gauzy wings - humming their perpetual rich mellow boom  (Is there not a hint in it for a musical composition, of which it should be the back-ground?  some bumble-bee symphony?)"  (Dover edition, published in 1995 as a republication of the original edition issued in 1883, p. 85.)

Bumble bees have been a constant for me this summer.  Earlier this year, some Agastache (Blue Fortune) was planted on a slope in my backyard.  Commonly known as giant hyssop, this member of the mint family features tall, lavender plumes of flowers that drew myriad pollinators, foremost among them, Bombus impatiens, the common eastern bumble bee.


It’s this species that sparked my interest in the bumble bee.  As I weed among the Agastache plants, the bees pay me little heed, going about their business of drinking nectar and gathering pollen.  These docile bees are here in startlingly large numbers, so much so that, even when the wind dies down, the hyssop flowers are in constant motion, dancing as the bees land, explore blossoms, and lift off.

In the Guide to the Bumble Bees of the Eastern United States (USDA Forest Service, FS-972, March 2011), biologist Sheila R. Colla and her colleagues have produced one of those rare treats that the web offers up:  an authoritative, beautifully assembled and edited, free resource.  It’s a highly useful introduction to the 21 Bombus species found in the eastern United States, which are just a small portion of the grand total of 250 species worldwide.  In addition to this publication, I have consulted An Identification Guide:  Bumble Bees of North America by Paul H. Williams et al., 2014.

In general, bumble bees are social animals spending their lives inside and out of a nest composed of a queen, female workers, and, later in the summer, males and potential queens.  (Of note, there is a subgenus of these insects which is a parasite.)  In the spring, the fertilized queen wakes from a dormant state and emerges from the hidey-hole in which she spent the winter.  She feeds and searches for a place to begin creating a small nest.  Some species nest above ground in tall grasses, others (B. impatiens among them) nest in such locations as abandoned rodent burrows, crevices amid rocks, and openings in manmade structures.  With a nest chosen, the queen lays some eggs.  When the larvae hatch, they are fed on a mixture of pollen and nectar; the larvae then pupate and subsequently emerge as adults.  The whole process from egg to adult may take five weeks.  The first adults to emerge are female workers, some of whom forage for food while others tend to in-nest duties that include attending to larvae, pupae, or honey pots.

Later in the summer, males and possible queens begin to emerge from a colony’s broods.  As the year moves into the fall, the denizens of the nest begin to die off, until only young queens who have mated remain.  These find a hiding place (in rotting logs, mulch, etc.) and go dormant until the following spring when they wake and continue the process once again.  This annual cycle has gone on some 25 million times or more.

Colla’s Guide provides phenology charts for each species of eastern bumble bee, delineating the timing of the appearance and subsequent death of each category of bee:  queens, workers (females), and males.  This is the one for B. impatiens:

I do quibble with Colla and her colleagues over one passage because they seem to rob the Bombus of a behavior that is intriguing and remarkable.  They write that bumble bee colonies are “comprised of several different ‘castes’ who divide the reproductive, foraging, defense, and other tasks necessary to their survival.”  (p. 8)  It’s that word “caste” that bothers me because it suggests a rigid or hierarchical division of labor which, it turns out, does not describe how tasks are divided among B. impatiens in-nest workers.  The reality of how chores are undertaken in at least this species is quite different.

In several studies of the interaction among the in-nest B. impatiens workers (that is, those not primarily engaged in foraging outside of the nest), zoologist Jennifer Jandt and her colleagues have shown quite clearly that responsibilities are not fixed for in-nest workers, unlike some other social insects where age or body size dictates duties.  Instead, although workers tend to repeat the same activities regarding care of larvae, of pupae, or of honey pots from one day to the next, in the long run, they change their activities to ones unrelated to what they were previously doing.  “That is, they switch tasks randomly.  We suggest that if bumble bee workers do exhibit specialization within in-nest tasks, it is weak specialization.”  (Weak Specialization of Workers Inside a Bumble Bee (Bombus impatiens) Nest, Behavioral Ecology and Sociobiology, Volume 63, Number 12, October 2009, p. 1833.)

How is that accomplished?  It turns out that the in-nest workers are likely to live their entire lives within specific regions of the nest, regardless of their size or age.  Within the small nest, larvae, pupae, and honey pots – the foci of in-nest activities – are "disorganized," meaning that they are scattered and, as a result, are all in close proximity to any individual worker regardless of where she lives.  This supports workers easily shifting among different tasks.  Quite intriguing.  Are these bumble bees switching tasks instinctively in response to some stimulus in their environment or, perhaps, are they “choosing” what to do next?  Jandt’s use of the adverb “randomly” is suggestive.

Finally, one must acknowledge how critical bumble bees are to many ecosystems, doing what they were doing in the apple tree beneath which Whitman relaxed – pollinating.  They are among the most prolific and important pollinators of wild flowers and crops.  Colla captured this latter aspect of their activity in a wonderfully long, though incomplete, list of the crops bumble bees can pollinate:

tomatoes, peppers, raspberries, blueberries, chives, cucumbers, apples, strawberries, alfalfa, blackberries, soybeans, sunflowers, beans, cherries, apricots, plums, almonds, nectarines, peaches, rosehips, eggplants, and cranberries (p. 9).  

Their success as pollinators may be due to at least a couple of attributes.  They are generalists, not specializing in certain plants, but seeking out nectar and gathering pollen from a broad array of flora taxa.  Further, they are dedicated and persistent foragers.  This I discovered when I turned on my sprinklers to water the Agastache on which they were feeding.  The falling water did nothing to dissuade them from stubbornly flying from flower to flower.  Colla notes that, unlike other pollinators, bumble bees not only ignore rain, but persist in their appointed rounds despite clouds or cold.

So, it is with regret that, as the year moves into deep fall, I say goodbye to these busy, furry, summer companions.

Thursday, September 30, 2021

Consciousness and Intelligence in “Simple” Organisms: You Can Come Home, Edward Heron-Allen

Previously on this blog, I considered some of the implications of the complex behavior of single-celled organisms when I discussed agglutinated foraminifera.  These species of marine foraminifera construct their “shells” out of material their pseudopod-like filaments find in the surrounding substrate; this found material is then cemented together in very precise, species-specific configurations.  A fossil from one such species dating from the Miocene is shown below.


It was argued by some, beginning in the last quarter of the 19th century, that this behavior may demonstrate a form of rational behavior, intelligence, if you will.  I highlighted the position staked out early in the 20th century by Edward Heron-Allen (1861-1943), one of the leading foram experts at the time (and a favorite character of mine).  Heron-Allen was a polymath who wrote fiction, acted, and made violins, among other pursuits.  (The image below of Heron-Allen has no apparent copyright restrictions and is from the Division of Rare and Manuscript Collections, Cornell University Library.)

Heron-Allen also excelled at taxonomic research on foraminifera along with his colleague Arthur Earland (1866-1958); both were unpaid amateurs working at the British Museum.  Heron-Allen, inspired by the accomplishments of agglutinated foraminifers, argued in a 1915 paper, that:

there appears to be no organism in the Animal Kingdom, however simple be its structure, which lives a life of its own independently of any other organism, which is not capable of developing functions and behaviour (including the adaptation of extraneous matters to its use and protection), which in the Metazoa might be called, and would be properly be so called, Phenomena of Purpose and Intelligence.  (A Short Statement Upon the Theory, and the Phenomena of Purpose and Intelligence Exhibited by Protozoa, . . . .   Journal of the Royal Microscopical Society, 1915, p. 556.)

This argument, that all independently living organisms, no matter how simple, could exhibit signs of intelligence, was mocked and beaten back by the scientific community in the ensuing years.  But (ah, the all-important “but”), to date, no consensus explanation of how these forams accomplish this task has been put forward.

Today, I suspect, his contention would find favor in a segment (small, I assume) of the scientific community.  Why that might be is the subject of the present post.  I stumbled onto this topic after unknowingly coming close to it in my previous post on fungi.  In that post, I wrote the following, regarding the network of hyphae or filaments (this network is called the mycelium) that many fungi spread underground:

I find it fascinating that, rather than relying on something like chemical detection in the quest for food, the mycelia use brute strength, “spread[ing] outwards in all directions until they strike digestible objects.  When this happens the colony reacts by redirecting growth towards these locations” [quoting Nicholas P. Money, Fungi:  A Very Short Introduction, 2016].

I missed what biologist and mycologist Money was suggesting in that quotation of his.  That the colony reacts and “redirects growth” more fully toward food sources now has a meaning for me that it didn’t before.  Shortly after writing the fungi post, I found a link in my inbox to a recent article by Money that spelled out what I had missed:  The Fungal Mind:  On the Evidence for Mushroom Intelligence, Psyche, September 1, 2021.

As I began exploring topics discussed in Money’s article, I found myself drowning in a sea of undefined or poorly defined terms.  I did something that Money didn’t do (and others often don’t either, particularly in popular science articles):  assemble definitions of a few of the key terms.  Given below are the common definitions of these terms as provided by the Oxford Compact English Dictionary (2003):

consciousness = state of being “aware of and responding to one’s surroundings”

sentience = the ability “to perceive or feel things”

cognition = “the mental acquisition of knowledge through thought, experience, and the senses”

intelligence = “the ability to acquire and apply knowledge and skills”

I will admit that this exercise in definitions intended to clarify matters didn’t help much.  I remain confused and largely unable to distinguish one from the other (in this I am not alone).

In his piece, Money writes:

[I]n recent years, a body of remarkable experiments have shown that fungi operate as individuals, engage in decision-making, are capable of learning, and possess short-term memory.  These findings highlight the spectacular sensitivity of such ‘simple’ organisms, and situate the human version of the mind within a spectrum of consciousness that might well span the entire natural world.

He describes a number of these experiments particularly some involving the behavior of fungal mycelia.  They are highly suggestive.  He posits that mycelia “actions draw upon an array of protein sensors and signalling pathways that link the external physical or chemical inputs to cellular response.”  Though he acknowledges that the fungi “are not thinking in the sense that a brained animal thinks,” he asserts that “the fundamental mechanisms that allow a hypha to process information are the same as those at work in our bodies.”

I was particularly taken by the results of one laboratory experiment which involved the behavior of hyphae.  When those emanating from a fungus encountered a piece of beechwood, they broke it down and then spread out in search of more food.  When the mycelium encountered a second piece of beechwood and exhausted its nutrients, it began foraging from this second piece in the same direction that had borne fruit when it went foraging from the first.  Memory at work?  Money certainly thinks so:

It remembered that growing from a particular face of the woodblock had resulted in a food reward before, and so sought to repeat its prior success.  The fungus in these experiments showed spatial recognition, memory and intelligence.  It’s a conscious organism.

Tellingly, Money does not restrict his discussion to fungi (despite the title of the article), turning to research on slime mold, that poster child for researchers claiming consciousness and intelligence in single-celled organisms or collectives of single-celled organisms.  It’s not surprising that he does so; the experiments involving slime molds are breath-taking (perhaps even more impressive than those involving fungi), certainly challenging one’s expectations of the capabilities of such organisms.

Although slime molds continue to be placed in the Kingdom Fungi by some authorities, the preferred placement appears to be the Kingdom Protoctista (Protista).  Aspects of their life histories might be seen as fungus-related - they have a spore stage by which they spread, while other aspects are protoctista-like – when the spore germinates, a single-celled, amoeba-like organism emerges and goes in search of food.

There are three taxonomic groups of slime molds.  (See University California Museum of Paleontology, Introduction to the “Slime Molds”.)  One group, the plasmodial slime molds, appears to be the primary type used to demonstrate intelligence in these single-celled organisms.  This plasmodial slime mold may start as a tiny amoeba-like single-celled entity with a single nucleus, but, over time, through the fusion of individual slime mold cells, grow quite large, becoming one cell harboring countless nuclei.  The organism accomplishes its search for food by spreading a thin film, called the plasmodium; when the plasmodium encounters food, some of the plasmodium may concentrate into tubular channels, creating a network to transport nutrients.

Writer and English professor Lacy M. Johnson has written about Fuligo septica, commonly called “dog vomit slime mold” (What Slime Knows, Orion Magazine, no date).

Here in this little patch of mulch in my yard is a creature that begins life as a microscopic amoeba and ends it as a vibrant splotch that produces spores, and for all the time in between, it is a single cell that can grow as large as a bath mat, has no brain, no sense of slight or smell, but can solve mazes, learn patterns, keep time, and pass down the wisdom of generations.

(Dog vomit slime mold is shown below in a photograph by Henk Monster which is reproduced here under the Creative Commons Attribution 3.0 Unported license.  It can found on Wikimedia Commons.)

One of the experiments involving slime molds that Johnson, among many others, describes was performed by a team of Japanese and British researchers (Atsushi Tero, et al., Rules for Biologically Inspired Adaptive Network Design, Science, January 22, 2010).  It’s a classic.  In this experiment, an array of food sources (oatmeal flakes) were disbursed across an area that Physarum polycephalum was able to explore.  As the slime mold, which started in the center of the area, spread its plasmodium throughout the area encountering other food sources, it created, in relatively short order, a network of emphasized connections linking the food sources.  The image below shows the network being created by the slime mold, linking the various caches of oatmeal flakes over a 26 hour period.  At the end, the less effective pathways have faded away and only the most effective remain in play.  (The image is provided by TimTim and reproduced under Creative Commons Attribution-ShareAlike 4.0 International license.  It can be found at Wikimedia Commons.)

In this experiment, the distribution of food sources was not random, rather, it was designed to represent Tokyo (at the center) and surrounding rail stations.  Turns out the network created by the Physarum is remarkably similar to the actual configuration of railway tracks that link these stations.  In a brief video, botanist Mark D. Fricker at the University of Oxford, a member of the research team, shows how the slime mold behaved in this experiment.  (BBC Earth Lab, Can Slime Mould Solve Mazes?)  Well worth watching.  Intelligence at work or a neat parlor trick?

In his article, Money notes that the consideration of consciousness in so-called simpler organisms raises the core question of what we mean by consciousness and which living entities have it.  (No definition is forthcoming from him.)  Understanding consciousness and the organisms in which it is found is important, because I read Money as saying “if no consciousness, then no intelligence” (which stands to reason).  He asserts, consciousness “implies” awareness which, in turn, manifests itself in an organism’s sensitivity to its environment.  Though all living creatures exhibit sensitivity, consciousness has traditionally been reserved for just a fraction of those creatures, the so-called big-brained animals.  In challenging that hierarchical approach to consciousness, Money cites cognitive psychologist Arthur Reber who posited it was impossible to identify the minimal level of awareness necessary for consciousness.

That sent me in search of material by Reber.  He and FrantiÅ¡ek BaluÅ¡ka recently penned a fascinating article that asserts that all living cells are “self-aware, self-organizing.”  Indeed, they argue that, because “sentience was a property of the first forms of life that emerged some 3.5 billion years ago, all species, extant and extinct were and are sentient.”  (Cognition in Some Surprising Places, Biochemical and Biophysical Research Communications, 2021.)  This had to be, they argue, because the first cells could only survive if they were, to some degree, able to respond to the “constantly shifting complex flux that marked the primordial environment.”

Further, they assert (as Money describes above), if the earliest cells were not sentient, then at what point did “a species or clade [shift] from being utterly without internal experience, consciousness, to one with it?”  Reber and BaluÅ¡ka juxtapose their assertion about sentience in the earliest living cells with a quotation from evolutionary biologist Lynn Margulis:  “cognition is a biological function.”  That’s an important connection.  The authors, who equate sentience with consciousness, are here, most importantly, also equating sentience with cognition.  To them, it's apparently “if yes consciousness, then yes cognition.”  How much of a step is it to go from cognition to intelligence?  Does cognition raise the possibility of intelligence or the certainty of it?

Reber and Baluška are proponents of the Cellular Basis of Consciousness (CBC) hypothesis which posits:

that sentience and life are coterminous; that all organisms, based on inherent cellular activities via processes that take place in excitable membranes of their cells, are sentient, have subjective experiences and feelings.  (Abstract of the article.)

This is a heady position to take, one that serves as a lightning rod for criticism.  See, for example:  Peter Jedlicka, Review of “The First Minds” by Arthur S. Reber, 2018, OUP Global Press:  New Consciousness Theory:  Cellular Basis of Cognition or Consciousness?, BioEssays, Volume 42, 2020; or Simona Ginsburg and Eva Jablonka, Review:  Are Your Cells Conscious?, The American Journal of Psychology, Vol. 133, No. 1, Spring, 2020.

But what a provocative hypothesis to argue over, if only we could nail down our terms.  Nevertheless, it's lovely that this all harkens back to Edward Heron-Allen who over a hundred years ago asserted:

every living organism living an independent existence of its own is endowed with the measure of intelligence requisite to its individual needs.

I must admit, in closing, that perhaps the one certainty emerging from all of this is that I have confused consciousness with sentience and cognition with intelligence.  Are these different?  How so?  Are they actually manifested in these "simple" organisms?  For me, sadly, these terms have all merged into a blob of slime mold.


Saturday, August 28, 2021

A Summer Fungi Blast

“Fungi are everywhere and will outlive us by an eternity.”

~ Mycologist Nicholas P. Money


This short post has no connection to fossils, offers no twist or hook, and basically serves as a salute to the fungi that have enhanced my summer.

In a very short video, mycologist Nicholas P. Money, author of the Oxford University Press volume Fungi:  A Very Short Introduction (2016), summarized the “Top Ten Things You Should Know” about fungi.  These ranged from the amazing diversity of fungi to the unimaginable quantity of spores released by mushrooms and other fungi (accounting annually for up to 50 million tons of particulates in the atmosphere) to the Jekyll and Hyde relationship of fungi to other living organisms (crucial for trees in the woods, necessary for other life, including ours, but oft times quite fatal).  He closes his book and this video with the line quoted in the epigraph for this post.  (All quotations in this post attributed to Money are from the Kindle edition of Fungi:  A Very Short Introduction.)

Given that there are over a estimated million species of fungi on this planet and that some 90 percent of the biomass in forest soils (excluding tree roots) consists of fungi, it’s striking how few fungi have been described scientifically, though not surprising given that most are microscopic.  (George Barron, Mushrooms of Northeast North America, 1999.)  Money notes that “[t]he inconspicuous nature of most fungi is one of the reasons that we know so little about them compared with animals and plants.”  He observes that only some 70,000 fungi species have been scientifically described.  Further, it’s probably also not unexpected that he reports that over 90 percent of those belong to two phyla in the Fungi Kingdom:  Phylum Basidiomycota (mushrooms and relatives) and Phylum Ascomycota (sac fungi).  Many of these are the quite conspicuous members of the Fungi Kingdom, producing the frequently wonderfully colored structures that break through the soil in a quest to release spores, those fruiting bodies that we are likely to encounter in our walks in the woods after a rainfall.

Money identifies three characteristics uniting fungi:

they are eukaryotes [organisms with cells housing genetic material in nuclei], which feed by absorption, and reproduce by forming spores.

For me, a key attribute of many fungi is the creation of hyphae or filaments that, as they elongate in the search for food, create a hyphal web or mycelium.  Money describes this as “the fungal colony.”  Yes, we sometimes see that web structure above ground (he suggests looking under a flower pot), but more often than not it’s all spreading below ground, beneath our feet, waiting for the right set of circumstances to launch fruitbodies above ground.  The vastness of some of the mycelia is truly astounding.  Money reports that the subsurface mycelia of one honey fungus in Oregon covers 10 square kilometers, may weigh in at 35,000 tons, and have been alive for 2,400 years.   I find it fascinating that, rather than relying on something like chemical detection in the quest for food, the mycelia use brute strength, "spread[ing] outwards in all directions until they strike digestible objects.  When this happens the colony reacts by redirecting growth towards these locations."  (Money, Fungi.)

Sarah Gibson, reporter with New Hampshire Public Radio, has proven to be quite interested in mushrooms this year.  In a piece titled Summer Rains Bring Mushroom Frenzy to New England (WBUR News, August 9, 2021), she describes a walk with mushroom expert Christine Gagnon in woods along the Piscataqua River (which separates New Hampshire from Maine).  A very wet summer in New England has created ideal conditions for the appearance of myriad mushrooms springing forth from the underground mycelia.  “Everywhere you go, you can’t not see mushrooms,” says Gagnon.  The downside of this is the propensity of the uninformed or misinformed mushroom collector to ingest specimens from toxic species.

Casting the net broader than Gibson, I have found this to be a banner summer for fungi in the Northeastern portion of the U.S.  I was surrounded by mushrooms for much of late July through mid-August in the Jamesport area of Long Island and these riches have been present near my home in Silver Spring, Maryland, bordering Washington, D.C.  Wet conditions have, for the most part, prevailed in these two areas.

So what fungi have I encountered?  Here is a montage featuring a few of the mushroom specimens spotted during my sojourns at Jamesport and Silver Spring this summer.



I’ve numbered the images and present below my early attempts to identify what I photographed, usually only to the genus level and, even then, with lots of doubt.  I chose not to disturb these fungi and so forsook some of the best, though also destructive, ways of identifying fungi.  I’ve used what has come up at iNaturalist and what I learned from Barron’s guide.  In all cases, I most certainly stand to be corrected.

  1. Strobilomyces strobilaceus, Old-Man-of-the-Woods
  2. Sebacina schweinitzii, jellied false coral fungus
  3. Amanita sp.
  4. Boletaceae family
  5. Trametes versicolor ?, Turkey Tail
  6. Chlorophyllum molybdites, green-spored parasol – if my identification is right, this is a monstrously large example of this poisonous mushroom having a diameter of over 11.5 inches
  7. Amanita sp.
  8. Amanita sp.
  9. Russula sp., brittlegill
  10. Lepiota sp.

I close by stressing the sobering import of Money’s epigraph that opened this post.  Despite the many fundamentally constructive and restorative ways in which fungi interact with humans, other life, and the planet in general, and the good uses to which they may be put in the future, they will not save us from ourselves.


Monday, July 19, 2021

Peer Review and Iron Age Fossil Shark Teeth Collecting

Earlier this year, public health experts Nason Maani and Sandro Galea cautioned that a public policy for the pandemic promising to “follow the science” misconstrued science and the role it can and should play in the public arena.  (What Science Can and Cannot Do in a Time of Pandemic, Scientific American, February 3, 2021.)  The details of their cogent arguments aren’t relevant to this present post, but their comment about peer review is:

Peer review, designed to catch our mistakes at the best of times, can suffer from in-group bias and in any case has been put aside to an unprecedented degree in the explosion of preprint research during the pandemic.

And, so, when policymakers (at least, some) are claiming to be subordinating their actions to guidance from science, one of the safeguards that is intended to minimize egregious errors in scientific research is being relaxed.  Of course, it is.

I hadn’t thought much recently about scientific peer review until I came across some archaeological research on an Iron Age (8-9th century BCE) site in Jerusalem.  (Thomas Tütken, et al., Strontium and Oxygen Isotope Analyses Reveal Late Cretaceous Shark Teeth in Iron Age Strata in the Southern Levant, Frontiers in Ecology and Evolution, Volume 8, December, 2020.)  It’s quite a remarkable story about the potential good that peer review can do, and about the role serendipity can play in the scientific endeavor.

Tütken and his colleagues had prepared a research article on a multitude of fish teeth (over 10,000) they had found in the fill dumped into a pool to create the foundation for a private house built in Jerusalem some 2,900 years ago.  Their focus was on what these teeth could reveal about the trade in fish at the time.  As they write, “Identification of fish trade in antiquity is traditionally based on the presence of ‘exotic’ fish remains in archaeological sites, which are distantly located from the original habitat of the fish.”

Among the thousands of fish teeth the authors analyzed were 29 shark teeth.  Not surprisingly, in drafting their article, the authors operated on the logical assumption that any remains, such as the shark teeth, discovered in archaeological layers had a provenance contemporaneous with other remains and objects found at the site.

Then came the peer review process.  One reviewer spotted something curious about the shark teeth depicted in the original piece.  As Tütken said,

We had at first assumed that the shark teeth were remains of the food dumped nearly 3000 years ago, but when we submitted a paper for publication, one of the reviewers pointed out that one of the teeth could only have come from a Late Cretaceous shark that had been extinct for at least 66 million years.  (As quoted in The City of David and Sharks’ Teeth Mystery, Goldschmidt Conference, Phys.Org, July 4, 2021.)

How fortunate that one of the reviewers of the original paper had some exposure to fossil shark teeth and was brought up short by the distinctive shape of a shark tooth among those depicted in the original article draft.  I assume the tooth that sparked this realization was from the genus Squalicorax (I don’t think that’s made clear in anything I’ve read, but, as I note below, it’s a safe assumption).  Ah, the value of a breadth of knowledge among peer reviewers, knowledge that ranges beyond the narrow focus of the paper under review, thus avoiding what Maani and Galea describe as “in-group bias.”

A bit of paleontological understanding is useful to appreciate the impact that this Iron Age research story has had on me and why I think the Squalicorax teeth saved the day.  This genus of sharks, which existed in the Late Cretaceous (from roughly 100 to 66 million years ago), sported teeth so distinctive that they are very easily recognized by even the least experienced collector of fossil shark teeth.  These shark are commonly known as Crow sharks.  Pictured below is a specimen of S. kaupi I found many years ago in Big Brook, New Jersey.  It is 15 mm on its longest axis.

Tütken and his colleagues, using data on the strontium isotope ratios and oxygen isotope ratios found in the teeth of extant fish from different bodies of water in the eastern part of the Mediterranean, determined that all of the shark teeth in their study were not contemporaneous with the Iron Age structure.  Indeed, the isotope ratios in those teeth matched those determined by others for Late Cretaceous fossil shark teeth found in Israel and Jordan.  (Fish teeth retain the isotope ratios present in the waters when the fish were alive.  Thus, a time signature is carried by the teeth and, if read, can separate contemporary from ancient teeth.)

The researchers largely ruled out the possibility that these Cretaceous teeth weathered out of local formations.  Instead, it appears likely they were discovered and removed from a site some 80 kilometers away.  Which raises the key question:  Why were these fossil shark teeth here at this Jerusalem site?  A question to which the authors do not have an answer.  There is no evidence these were being used as ornaments or as tools.  As a result, Tütken has said,

Our “working hypothesis is that the teeth were brought together by collectors, but we don’t have anything to confirm that. . . .  We know that there is a market for shark’s teeth even today, so it may be that there was an Iron Age trend for collecting such items. . . .  However, it’s too easy to put 2 and 2 together to make 5.  We’ll probably never really be sure.  (As quoted in Phys.Org.)

Fossil shark tooth collectors at work three millennia ago?  Amen to that, I’d like to think so.

I am puzzled by one aspect of the discussion in the paper as published.  Tütken et al. write that, at archaeological sites in the area, shark vertebrae are the primary shark remains that are found, not teeth.  That just doesn’t square with my experience working geologic formations that contain shark fossils because teeth vastly outnumber vertebrae.  Even if the research being cited applies to sites to which contemporary sharks were brought, teeth in the specimens would still grossly outnumber vertebrae.  Were sharks decapitated and only their bodies transported to other sites?  Quite curious.

Anyway, score a big one for peer review.  Tütken and his colleagues are quite gracious in their comments in the published paper about the impact of the reviewer’s observation about a Cretaceous fossil tooth which they label a “game changer.”

It led us to perform additional analysis and, ultimately, to rework the narrative of the manuscript, changing the story from shark exportation from the Nile delta to fossil shark finds in cultural layers.  This was a textbook example how a good review should work and we are very appreciative.

Saturday, June 19, 2021

Chronospecies ~ Interesting But Perhaps Not Much Help

 In which the blogger grapples with a concept “new” to him, avoids several issues requiring deeper thinking than he’s capable of, and revisits a tooth to see if it can be identified this time around.

Very recently I encountered the term chronospecies and thought it new to me.  I took this to be  a reflection of how poorly read I am in the paleontological literature.  Subsequently, I found that the term had appeared in a quotation I used in a post nine years ago.  This is even more damning, revealing how inattentive I can be with what reading I do.  (See, Questing After Species:  Tales of Squirrels and Sharks, March 26, 2012).  This current post remedies that oversight (perhaps).

The term chronospecies is, I think, one that can come with an agenda.  That is, it reflects a perspective on how evolution has functioned for the species lineage to which it is applied.  This usage alone says nothing about whether the user believes that this evolutionary mode is pervasive or relatively infrequent, but it should trigger that question.  Chronospecies is defined nicely and quite succinctly by science historian John S. Wilkins as:

Arbitrary anagenetic stages in morphological forms, mainly in the paleontological record.  (Summary of 26 Species Concepts, 2002.)

Actually, this is Wilkins’ definition of successional species, of which he identifies chronospecies as a synonym.  Unpacking this a bit -- a chronospecies is a member of a lineage in which the transition from one physical stage (species) to another occurs through anagenesis, that is, by a slow process over time with one ancestor flowing into a descendant without speciation through splitting or branching.  Given how this evolutionary change apparently occurs, separating the lineage into individual species is an arbitrary act.  It’s unclear where one chronospecies ends and the next begins.

First challenging topic being avoided in this post.  The relative frequency or commonality of anagenesis evolution is at the heart of the discussions about what the fossil record reveals regarding the mechanisms through which speciation occurs.  Much simplified, the contrast is between slow, incremental change (anagenesis), and relatively sudden bursts with branching that follow long periods of little change (punctuated equilibrium).  Paleontologist Donald R. Prothero provides a nice overview of The Species Problem in Paleontology (Bringing Fossils to Life:  An Introduction to Paleobiology, 1998, p. 39-41.)  This is one of those difficult topics I’m avoiding in this post.

My most recent encounter with chronospecies came when paleontologist Victor Perez used it in response to a question during a Zoom presentation on his new and powerful methodology for estimating the body length of Otodus megalodon (the focus of all megatooth shark obsessives).  Critical to testing his approach is utilizing associated O. megalodon dentitions and knowing whether the teeth belonged to mature or immature individuals, and whether the dentitions belonged, in fact, to O. megalodon in the first place.  With chronospecies, this can be challenging if it can be done at all.  (For a detailed look at Perez’s methodology, see Body Length Estimation of Neogene Macrophagous Lamniform Sharks (Carcharodon and Otodus) Derived From Associated Fossil Dentitions, Palaeontologia Electronica, Volume 24, Number 1, 2021, 4-5.)

Additional challenging topics being avoided.  This post is not about ways of estimating how big the biggest shark was (for that, read Perez’s paper cited above).  I’m also not wading into the taxonomic morass that lurks beneath the application of the single generic name Otodus to the lineage of megatooth sharks that reaches back to the Paleocene and earlier and ends with the extinction of O. megalodon in the Pliocene.  In this post, I use Otodus for a simple and very unscientific reason:  I stumble over the pronunciation and spelling of the generic name applied by many paleontologists to most of the species in this lineage, Carcharocles.

Further, I am not in a position to weigh the relative merits of the different hypotheses advanced for the competing generic names.  Again, Perez’s 2021 paper provides a quick overview of this taxonomic debate.

What this post is about.  This post is about my effort to understand the concept of a chronospecies and how it bears on the tooth that was a subject of the 2012 post referenced earlier.  While walking the beach near Randle Cliff Beach along the Calvert Cliffs in 2012, I found the tooth shown below in a small block of material that had fallen from the cliffside.

The tooth’s cusplets are circled because that is one of the critical morphological elements used by paleontologists to distinguish two chronospecies in the Otodus lineage:  O. chubutensis and O. megalodon (below I refer to these two species by only their species name).  In the post from nearly a decade ago, I tried and failed to identify the species associated with it.  Will things be better a decade later?

It’s important to have a sense of the lineage of which these purported chronospecies are a part.  Here is a very helpful graphic showing this lineage which appeared in a paper by paleontologists Catalina Pimiento and Meghan A. Balk (Body-Size Trends of the Extinct Giant Shark Carcharocles Megalodon:  a Deep-Time Perspective on Marine Apex Predators (Paleobiology, Volume 41, Number 3, 2015, Figure 1, p. 480):

Pimiento and Balk summarize this lineage, as depicted in this figure, as follows:

It has been proposed that the megatooth sharks comprise a series of chronospecies (i.e., a group of species that evolve via anagensis and that gradually replace each other in a evolutionary scale) that are distinguished from each other in the fossil record by the morphological changes of their teeth.  These changes include the loss of lateral cusplets; broadening of tooth crowns; and, of most relevance to this study, size increase through geologic time.  (p. 480, citations omitted.)

In another article, Perez and a different set of colleagues tackled the question at the heart of this post.  Their piece is titled:  The Transition Between Carcharocles chubutensis and Carcharocles megalodon (Otodontidae, Chondrichthyes):  Lateral Cusplet Loss Through Time (Journal of Vertebrate Paleontology, Volume 38, Number 6, 2018).  These authors note that, although all chubutensis teeth apparently had cusplets, that’s not a sufficient criterion upon which to distinguish these two species because some members of megalodon also had cusplets, including some juveniles as well as some adults who retained cusplets as vestigial attributes.  Their study was focused on verifying statistically the cusplet changes in these fossil teeth as the sources of specimens along the Calvert Cliffs become geologically younger.  They demonstrate that the Miocene-aged formations exposed along these Chesapeake beaches cover the time period during which the transition from the one cuspleted species to the next uncuspleted species occurred.  That said, Perez et al. assert categorically that “definitive separation” of these two species “is impossible because a complex mosaic evolutionary continuum appears to characterize the transformation from cuspleted to uncuspleted teeth.”

But Perez et al. don’t come away empty handed in this taxonomic challenge.  They conclude that the change from cuspleted chubutensis to uncuspleted megalodon took place in a 2.4 million stretch of time, roughly 16.4 million to 14 million years ago.  Thus, go back further than 16.4 million years ago (in the Calvert Formation) and the likelihood that what’s at hand is chubutensis is very significantly increased; come forward to younger than 14 million year ago (into the Choptank and St. Marys Formations) and a cuspleted specimen is highly likely to be a megalodon (juvenile or with vestigial cusplets)  But, find yourself in that gray zone where the chubutensis to megalodon transition appears to have occurred and all bets are off.

I feel that this is, in some ways, a flipping of the script in the relationship between formation and fossil.  Relevant here is the concept of an index fossil, that is, a fossil of a species with a relatively broad geographical distribution but a relatively brief geological and temporal appearance.  Such a fossil can be used to identify geologic formations.  In essence, if you find the index fossil you know which formation you’re dealing with.  The flow is from fossil to formation, the first can identify the second.  With a chronospecies, the flow is the opposite, moving from formation to fossil.

In the end, because my tooth has cusplets, the odds favor it being a chubutensis.  But, and it’s a critical but, I do not know the bed in the formation that cradled this tooth for the millions of years after it was lost from a shark’s mouth.  Above the beach along which this tooth was found, a fairly broad range of formations is exposed, including the beds that encompass that 2.4 million year long period where the cusplet transition was principally occurring.  Absent that information and, after all of this sound and fury (well, curriebuction, at least) in this post, I’m left standing here with fossil in hand and still I do not know if this is a chubutensis or a megalodon tooth.

Ah, chronospecies, disappointing. 


Monday, May 17, 2021

Natural Phenomena of This Spring ~ Anyone for Six Degrees of . . . Pehr Kalm?

This springtime for me has been marked by two events of nature.  The first is occurring just outside my backdoor where a cluster of Erigeron philadelphicus, commonly known as Philadelphia Fleabane or Common Fleabane, is thriving.  I first noticed the flowers in late April, and the flowers with their many subtle shades from white to light pink or pale magenta have multiplied over the past month.


This is a composite flower, with each flowerhead comprised of more than a hundred rays.  Among the distinguishing features of this flower is the way in which the leaves clasp the flower stalk.  Circled in the picture below is a leaf clasping the stem on one of the Common Fleabane plants in my yard.

These flowers are all volunteers, appearing unbidden.  (They do not have any particular power over fleas, despite their common name.)

The second event heralding this spring is one long expected, having been in the works for 17 years.  My area of the mid-Atlantic states is presently at or near one of the epicenters of the emergence of Brood X of the 17-year periodical cicadas:  Magicicada septendecim, M. cassini, and M. septendecula.  This particular appearance has been awaited with gleeful anticipation by many and with mounting dread by others.  Pictured below is, I believe, a specimen of M. septendecim I spotted recently.  (I should have turned it over to see the underside which is the key to distinguishing among these species.)

In keeping with the past practice on this blog of finding some linkage connecting apparently distinct phenomena, I played the game of "connect the natural phenomena" (à la “Six Degrees of Kevin Bacon” (see Wikipedia article)).  Somewhat to my surprise, I found a good candidate quickly and easily to tie the budding forth of E. philadelphicus to the impending onslaught of Magicicada.  The key is that the full scientific name of the Common or Philadelphia Fleabane is Erigeron philadelphicus L.  That “L.” is the hook.

The Swedish naturalist Carl Linnaeus (1707-1778), to whom we owe the use of binomial nomenclature  to identify organisms, is the authority for the scientific name of this flower (hence, the “L” after the genus and species).  Linnaeus identified and named this flower species in volume II of his 1753 Species Plantarum.  In his first stab at it he made the species name neuter, calling it philadelphicum.  To fit with the masculine genus name, the species name was later changed to the male:  philadelphicus.  

Erigeron, the genus name, is a bit whimsical, coming from two Greek roots:  eri meaning “early,” and geron meaning “old man.”  The Missouri Botanical Garden entry for the Common Fleabane states that these two Greek terms refer to the plant’s “early bloom time and downy plant appearance suggestive of the white beard of an old man.”  An early old man?  Well, for the E. philadelphicus, I would demur; there is much that is young and vigorous about these flowers as they wave happily in a spring wind.

As to the species name, it certainly refers to the city of Philadelphia.  But why?  It’s found there, but not there in particular, and wasn’t back when Linnaeus named it.  A clue lies in Linnaeus’ description of E. philadelphicus in which he noted:  “Habitat in Canada.  Kalm.”  So, the apparent location of this flower was in “Canada” and the person who collected the specimen was named Kalm.

The “Canada” to which Linnaeus referred is not synonymous with today’s Canada.  Botanist Gerry Moore, in a detailed article about scientific names that honor Philadelphia, quotes botanist William Thomas Stearn on this point:  Linnaeus considered Canada to be “a region of northeastern America, partly in [present day] Canada, mostly in the United States where Kalm did much collecting, i.e., roughly from Philadelphia and New York northward . . . .”  (An Overview of Scientific Names Honoring the City of Philadelphia, Pennsylvania, with an Emphasis on Flowering Plants,” Bartonia, Number 69, 2016, p. 93.)

Pehr Kalm (1716-1779), the collector cited by Linnaeus, was one of his early pupils who spent several years in North America collecting plants and observing natural history.  Kalm was born in Sweden to Finnish parents who had fled Finland during the Great Northern War.  He studied with Linnaeus and, under the aegis of the Royal Swedish Academy of Science, traveled to North America in 1749 with the mission of gathering plants that might be successfully planted in Scandinavia.  Kalm stayed in North America until 1751, spending much of the time in the Philadelphia area with a couple of excursions north into Canada.  Among the products resulting from his time on this side of the Atlantic was a multi-volume account of his travels.  Presumably among the plants he collected and carried back to Linnaeus was E. philadelphicus.  In his multi-part history of the ecological sciences, historian Frank N. Egerton described the work of naturalists who visited North America early in its European settlement.  Kalm, he wrote, was “[p]robably the best educated explorer naturalist who came to America in the 1700s.”  (A History of the Ecological Science.  Part 22:  Early European Naturalists in Eastern North America, Bulletin of the Ecological Society of America, Volume 87, Number 4, October 2006.)

How do cicadas connect to Kalm?  Fortunately, the year he arrived in North America, 1749, was one of those magical years when millions of Brood X members emerge and launch into an ear-splitting, cacophonous symphony.  [Later edit:  should have written "billions" of course.]  He was seeing and hearing insects whose descendants, 16 generations later, are now bursting onto the scene in 2021.  After his return to Europe, Kalm penned one of the earliest accounts of the 17-year periodical cicadas, an article with the misleading title Description of a Type of Grasshopper in North America.  It was published in a Swedish journal in 1756.  (Pehr Kalm’s Description of the Periodical Cicada, Magicicada Septendecim L., The Ohio Journal of Science, Volume 53, Number 3, May 1953.)

Despite the title of the article, it’s evident that Kalm knew that the insect he observed in 1749 was a cicada, not a grasshopper.  When he came to write this article several years later, he was quite clearly still aghast at what he had observed and heard.  To these insects as a whole, he applied the adjective “extraordinary.”  To the number of them appearing that spring in 1749, he went for vivid and emotional descriptors:  “astounding,” “dreadful,” “fantastic,” and “shocking.”

Kalm did some historical research through church records and determined that these insects followed a 17-year cycle.  As to the range of these periodical cicadas, Kalm observed

A peculiarity of these insects is that they do not emerge simultaneously in such shocking quantities in all places.  For example, the year the whole of Pennsylvania was swarming with them, not a single one was head of in New England.  This was also true of other localities.  When I left Pennsylvania in May, 1749, I was afraid my ears would be ruined by the noise and the disturbance they made in the trees.  The same hum and din reverberated in the woods in part of New Jersey, but as I travelled toward New York the noise diminished.  Beyond Albany, I head only an occasional one, and I frequently travelled a whole day with hearing any.  The inhabitation of Albany had not heard any more than usual.  It was nine years since their last heavy infestation.

I have been using the smartphone app Cicada Safari,created by entomologist Gene Kritsky and the IT department at Mount St. Joseph University, to do my bit in a citizen-science project chronicling the emergence of Brood X.  Among the pieces of background information presented in the app is the map below showing the disparate areas in which clusters of Brood X are appearing.

Yes, Kalm had it right.  There is a distinct regionality to the appearance of this particular brood of Magicicada.

So there it is:  a completed game of “connect the natural phenomena”: 

Erigeron philadelphicus to Pehr Kalm to Magicicada septendecim.

I avoided the easiest path and didn’t simply use Linnaeus himself to make the link.  There’s no challenge to that since his name is associated with every organism that has been given a scientific name, even if he wasn’t the one who first named it.  That said, Pehr Kalm appeared as a gift from heaven.  Had he travelled to North America a year earlier or a year later, the game might have not ended so quickly and neatly.

 
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