Friday, October 28, 2016

Lyell, Darwin and Wallace (2)

Charles Darwin grew up in a Victorian upper-middle class family.  Dad was a doctor.  Mother was often sick, and died when he was eight.  His older sisters looked after him.  Young Charles loved to collect beetles, shells, birds' eggs and the like.   Going to university for a medical education (Dad wanting him to follow in footsteps) was derailed by Charles' dislike of blood, and positive horror at seeing surgery in the days before anesthesia.  Instead, he joined the dedicated amateur scientist Robert Edmond Grant in his study of sea sponges.  Grant was an atheist and "transmutationist" (both of these very troubling and heretical beliefs) and thought the sponge might be a kind of bridge between the animal and plant worlds.  Darwin also learned geology from the lectures of Professors Robert Jameson and Thomas Charles Hope, who sparred over whether igneous rocks like granite and basalt were precipitated out of water (Jameson) or cooled from a melt (Hope).  Museum and field trips taught him to interpret sedimentary rock layers.

After a year and a half at Edinburgh, Darwin's rather frustrated father moved him to Cambridge University and changed his program of studies to prepare for the ministry--another appropriate career track for one of his station.  He continued to be a mediocre student at best--preferring riding, shooting, and competitive beetle-collecting.  But Charles also found he had some doubts about the beliefs he would have had to subscribe to to become a an Anglican cleric, and put off a decision for the Church.  At the same time, though, he studied and came to love the work of William Paley, who had made an eloquent case for the existence of a Creator by pointing out the unmistakable signs of creation all around, and particularly in the incredible complexity and clear "design" of living creatures -- each one intricately adapted to its place in the economy of nature.  Paley it was who extolled the sophistication of the eye in all its permutations, discussing those of mammals and birds in detail.  (Explaining the evolution of the eye would later become one of Darwin's touchstones when he developed his theory.)  Paley it was who made a generation of minister/naturalists: what better pairing of vocations for appreciating the Creator and His creation?  Meanwhile, true to form, Charles learned botany from Professor John Stevens Henslow and became acquainted with geologist Rev'd Adam Sedgewick and mineralogist Rev'd William Whewell.  At about that time Charles realized that, given his father's wealth, he needn't pursue a lucrative career.

Watercolor of Charles in the 30's, after his return to England aboard Beagle.  He will first make his name by writing a readable and insightful account of the voyage, published as an appendix to the captain's report until its popularity justifies its separate publication.

After graduating with his BA, Charles was persuaded to look into signing on for a voyage aboard the little ten-gun brig, Beagle (Robert Fitz Roy, RN), which would be charting parts of South American waters.  A naval captain in the rigid British society of that time led a lonely life, and Fitz Roy wanted someone of the same social class he could talk to.  With a little persuasion from Charles' uncle, Dad agreed to fund Charles' voyage.

Darwin had come to think of himself as a geologist.  And stepping aboard the Beagle, Charles' captain--an amateur geologist in his own right--presented him with the first volume of Charles Lyell's Principles of Geology.  This, along with the two remaining volumes that Darwin had sent to him during his adventures--was to be Darwin's geology theory textbook for the next five years.

Darwin turned out to suffer debilitating seasickness, and apparently never got over it.  His journal, full of tales of new cultures, dangers, adventures, and exploration as he rides or tramps in South America for weeks and months at a time, falls altogether silent when the Beagle weighs anchor, and takes up the story again only in the new port--silence on weeks, sometimes months, at sea.

Filled by Lyell with the vision of lands constantly eroding into the sea and shoreline and ocean floor just as constantly being raised up into plateaus and mountain ranges, Darwin ever interprets the landscapes he sees in these terms.  He finds flood plains raised far above the sea, abandoned by their former rivers; he collects shells from deposits only a few yards above sea level, and also high in the mountains, judging each deposit by the degree to which the species reflect those still present in the ocean nearby.  (He cannot "date" these deposits as we can today, but concludes that, if the species in a deposit are largely extinct, that deposit is very old.)  He experiences the severe earthquake in Concepcion, Chile on Feb 20, 1835; soon after he notices with satisfaction that large stretches of the coast were concurrently uplifted by many feet.

Though primarily a geologist in his own mind, Darwin does not neglect flora and fauna.  He collects specimens constantly: some he shoots, others--tame from limited exposure to man--he simply knocks on the head with a stick.  He is keenly aware of the distribution of plants in the various islands visited.  He notes the changes in that distribution--even extinctions--caused by alien plants and animals introduced by Europeans, and by the land-use decisions the colonists have made.

Returning at last to England, Darwin fills notebooks with ideas that lean more and more toward the theory of evolution by natural selection he will eventually arrive at.  He marries his first cousin, Emma Wedgewood, and settles into domestic life at Down House in Kent.  He is fond of his children and welcomes them into his study.  He writes, he researches, he does many experiments, he raises fancy pigeons to study variation first-hand, but for decades it seems he will never finish the multi-volume work on "my theory."  Probably he worries about the reception it will receive.  Probably he knows he will need overwhelmingly convincing evidence.  And the whole idea that the appearance of new species can be explained by physical causes always in action pains his devoted and devout wife; she fears he may not accompany her to heaven.  In 1846, a two-hundred-plus page essay on his theory is sealed up with specific instructions for publication in the event of his death, and there Darwin would leave it as he considered the fallout from the publication of an anonymously-written book: Vestiges of the Natural History of Creation.  This author had proposed an evolutionary hypothesis that had all the people talking, but scientists treated it with contempt, as the work of one with an inadequate science background, and little evidence, and Darwin finds it riddled with errors.

Instead of continuing work on the theory, Darwin turns his attention to a strange barnacle he had collected years before in South America.  In the end, he spends eight years developing expertise in the classification of barnacles--a large and difficult group of arthropods--and becomes renowned for this work.  "No one," his good friend the botanist Thomas Hooker observes, "has the right to talk about species who has not minutely observed and classified many."  His final, exhaustive, multi-volume barnacle monograph wins Darwin the Royal Society Medal, and establishes him as a bona fide scientist with a world-wide web of correspondents with whom he has consulted or who have provided the thousands of specimens that had arrived at Down House. 

In 1857 Darwin was 48 and had finished his barnacle work as having become the foremost expert on them; the following year he would open the fateful letter from the younger Alfred Russel Wallace.

Finished at last with barnacles, Darwin resumes work on his theory beginning with biogeography: conducting experiments to see how different species could survive passage to distant islands so as to colonize them.

Just two years later in 1858, Darwin receives an essay from the young naturalist Alfred Russel Wallace, who wants Darwin's help in recommending it to his friend Lyell.  They were already acquainted: Wallace had consulted the elder and established scientist before.  The essay was a bombshell: Wallace has arrived at the same conclusions as Darwin on the origin of species by descent with modification, and the same mechanism: the survival of those endowed with favorable variations in the struggle for existence.  Lyell and others pressed Darwin to present a chapter of his own together with Wallace's essay at a scientific meeting.  Then Darwin gets to work at last on a "brief summary" of his argument, and publishes it the next year: The Origin of Species.

He will do more science, showing that, in temperate regions at least, earthworms are the engineers of the soil.  He will extend his curiosity about human origins (cautiously only hinted at in the Origin) into another whole book along with his novel theory about sexual selection.  (Which posits that an important element of adaptation involves being able to attract a mate--leading to all sorts of "decorative" features in the "chosen" sex that lead in turn to reproductive success.)  Some elements of Darwin's theories are still being tested: only quite recently did researchers show that peacocks shorn of the irredescent "eyes" on the tail feathers do not father as many chicks.

And he will, in his own antisocial and retiring way, continue to battle against those who deny his theories.  (Wallace himself eventually decides that the evolution of humans cannot be explained by natural selection, and supports a supernatural "exception to the rule.")  Indeed, although "common descent" catches on pretty quickly due partly to ground prepared by others and partly due to the evidence he marshals, Darwin's most important contribution--evolution by natural selection--will battle all the way into the 20th century (long after Charles' death) before the dust has finally settled and Natural Selection stands alone in triumph: the only theory ever to successfully explain the amazing adaptations that give living things that "designed" look.

Although Darwin was wrong about many details (he had no real notion of genetics or population biology, for examples) it is remarkable that he got so much right; researchers continue to mine some of his more neglected ideas for new insights.

Darwin will die in April 1882 at home, after telling Emma, 
"I am not the least afraid of death – Remember what a good wife you have been to me
 – Tell all my children to remember how good they have been to me." 

The Origin of Species ends with some of Darwin's most famous lines.  "There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved."  

I've learned much from these books: Darwin: Discovering the Tree of Life by Niles Eldridge, and Darwin and the Barnacle byRebecca Stott; The Voyage of the Beagle, The Origin of Species, and The Autobiography of Charles Darwin, all by Himself.
Wikipedia has great articles for pursuing aspects of Darwin's life, among them Charles Darwin's Education.

Tuesday, October 25, 2016

Ponkapoag 2016

This was our forth annual week at the AMC Ponkapoag camp, and our first time at a cabin within sight of the pond.  While I was busy studying much of the time, I did walk a bit and got out on the pond a couple of times.

Watching the sun set from my desk on the first full day.
If I have to be studying, at least I've got the best office!

A nice breeze off the pond for days meant no pages stayed on my desk
without rocks holding them down.

 The pond, and an animal I didn't expect to see in it (northern water snake, I think).

Mid-week sunset over the pond.

Puppy belonging to the camp manager went after a stick floating in the water, and returned through white water lily pads (Nymphaea odorata) and tape grass (Valisneria americana).

One of the rare times my son was on the dock instead of in the water.
Nearly all the other kids were much younger, but he was a good sport.

 Gypsy moths are another of the imported dangers to the forest.
Each of the brown egg masses on this trunk were laid by a female moth
that feasted as a caterpillar in the same tree.  The eggs will hatch next spring.

 I wrote about this situation three years ago:
"In an open woodland of oak and pine, a dead tree leans on a live tree.  The two form with the ground an isosceles right triangle, the live tree and the ground forming the right angle, the dead tree, fallen from twenty feet away and landed neatly in a crotch of the living tree twenty feet up, the hypotenuse.  -or not really neatly, since the dead tree shed rotten branches as it struck, which now form a sort of giant squirrel's nest where the two trees come together. 

"What happened here?  The living tree is a black oak, tall and straight with the high and narrow crown of a forest-grown tree, its only flaws the vulnerable crotch, a small dead sprout at its base, and a small dead limb in its crown.  From its state of decay and that of its branches, the other was long dead before its fall, so of unknown species, and a little bigger than the one-foot diameter of the black oak.  Perhaps the dead tree got its start a few years or a decade before the living, or perhaps the two were age mates, even siblings, the dead tree's slightly greater and earlier girth the result of a sunnier location, or a little more moisture.  What killed the one?  Not age, but some ill fortune--an infestation of caterpillars or a fungus borne by insects burrowing into its wood, a drought.  Perhaps it died when struck by an earlier dead-fallen tree now long vanished into soil. 

"How will events fall now?  Certainly the dead tree has damaged the slender forked oak, and that in a singular stroke of bad luck: the forking stems so narrow that a matter of a few degrees either way in the fall would meant a complete miss.   Perhaps the falling tree was so decayed that it did little damage.  Or perhaps even so the rotting wood provides habitat to a fungal or insect invader.  Moreover, yet another dead tree, somewhat smaller, stands at a similar distance, and inclines a little toward the burdened oak.  Might lightning strike twice?  Indeed standing dead trees are not uncommon in the wood.  Of course, the tall tree might equally benefit from the deaths of neighbors--if they stand southerly, the openings they create allowing more sunlight to feed the tree.  Every forest is indeed a slow race, with the prize of vital sunlight to the tree that can keep its crown above its shading neighbors.  But the future is never secure, and with the vagaries of chance even the most virtuous may succumb before their time."

The wood is scattered with glacial erratics--boulders bulldozed into place by ice sheets
and left behind at the end of the last ice age.  These boulders have had ten thousand years
 or more to develop "character."

The less water-phobic of our two little dogs went paddling with me about midweek.  (Actually, I did all the paddling.)  A tiny island beckoned.  Its size made possible a nearly-complete census of flowering plants in the space of a few minutes. 

Goose poop is the foundation of the soil here.

Golda, my assistant, eventually decided she'd seen everything.

"Island biogeography" this ain't: the fifty feet of shallow water
separating the island from the mainland is no barrier to plant or animal migration.

 No one was more pleased to be back ashore than Golda.
 She went directly to the door of the cabin.  She was not entirely pleased with me.

Saturday, October 22, 2016

Ecological Footprint

I first encountered the "ecological footprint" fifteen years or twenty ago in a Boston Globe article, and was immediately hooked.  The article referred me to Redefining Progress (which now requires  a modest subscription).  There are so many environmental problems, from habitat destruction to water pollution, to over-fishing, to global climate change--and it's hard to keep them all straight in your mind at once: they all seem so different.  The ecological footprint solves this problem--and quantifies them--by putting them all on the same footing: LAND AREA.  

Land area is needed for farms to feed the world's growing population (and much more is needed to satisfy the developed world's love of meat).  Land area produces our lumber, our paper, our reservoirs for freshwater.  Land area (in forests) is needed to neutralize our air pollution and to soak up the vast amounts of carbon dioxide that comes from our power plants and cars.  And the wildlife habitat we destroy in pursuit of picturesque places to plant our over-sized homes is also land area.  All of the land area needed in all these ways to support your way of life is your Ecological Footprint.  Voila! our environmental problems are tied together: we can compare them, and add them up, and--best of all--know how far we have to go.

(There are, of course, issues not so easily converted into this currency of land area; still, a great many are.  Also, the differences land in land quality in different geographic locations must also be factored in.) 

Right now I'm a long-term substitute teacher in Environmental Science, and rekindling my interest as I teach it, and watch the kids find out their own "footprint."

It is enlightening and sobering to take a "footprint quiz" that will evaluate your lifestyle and determine you personal footprint.  More sobering still to realize that our collective human "footprint" is totally unsustainable--bigger, in fact, than the land area of Earth itself!  As a species, we are living unsustainably: we are using up the earth--consuming the "capital" instead of only the "interest."  Looking at the data nation by nation, we find that Americans have the biggest per capita footprint of any nation on Earth--such that it would take FIVE EARTHS to sustain humanity if everyone lived as we do!  We are head-and-shoulders higher livers than western Europeans, despite similar quality of life.  To make matters worse, the other ten million-odd species on earth must try to subsist on our one species' leavings--often unsuccessfully. 

Footprint quizzes usually have a feature that allows you to recalculate your footprint if you were to make positive lifestyle changes (such as downsizing to a more fuel-efficient car, insulating your home, etc), but of course the real impact comes in collective action and political involvement.  A sobering lesson is that even the most committed "green" American cannot live a sustainable life: there is simply too much greed, consumption and waste built into the very fabric of our society, and we must address it together. 

To that end, it is well worth your time to look more deeply into the "ecological footprint" concept, the relative impact of different aspects of our society (no, I'm afraid recycling barely registers!), and the systemic changes we need to make to have any chance of turning the human juggernaut around.  It is also interesting (for me, at least) to know a little of the ins and outs of how the numbers are calculated, the data sets used, and the assumptions that underlie the models.

Free versions of footprint quizzes include that of the Global Footprint Network, which includes a lot of comparative information.

Tuesday, October 11, 2016

Richard Primack on Fall

Richard Primack is professor of biology and plant ecology at Boston University, and famous among us for his study of effects of climate change, making use of  Henry David Thoreau's meticulous seasonal notes to study long-term seasonal change in Concord's woods.   In a recent interview he walks with WBUR's Meghna Chakrabarti in Webster Woods.  (The audio recording lasts eight minutes.)

The two discuss:
1. drought-induced early leaf color and fall (and even fall of green leaves)
2. governing of timing of fall color by temperature, day length, moisture, & frost events
3. fallen green oak twigs cut by squirrels, a sign of a shortage of food (here mainly insects, and perhaps hickory nuts, since acorns are about as abundant as last year).  Primack says squirrels are eating the inner bark on branchlets and dropping the twigs. 
4. Missing insects and early bird migration
5. I the Massachusetts drought linked to climate change?  No--climate change predicts wetter conditions here, on average.

Some surprises for me here: the big one is that gray squirrels are short of food: many of the trees losing twigs were heavy with acorns.  And some scepticism: the fallen twigs are the result of their eating bark, but there is no bark missing on the fallen parts and the twigs are cut off sharp. 

I have my doubts about the food shortage hypothesis:
this twig was cut with high-quality acorns still in place. 

Monday, October 10, 2016

A Night Out

 It is about three-and-a-half miles from ramp to camp.

I rather pride myself, in a small way, with being an outdoors type.  Yet I haven't spent a night outdoors in over a year.  Columbus Day weekend seemed the last opportunity before cold weather set in.  I figured to reprise a little kayak camping trip from last August.  Kayak camping seems the perfect water adventure: as much fun as a sailing trip, but with much less preparation and fewer logistical hassles.  This time I'd take the bigger boat: Musketequid could not take the full-sized sleeping bag needed for cooler weather.

Since real rain seemed unlikely, I skipped the tent, only adding a small tarp to my gear when the forecast changed to "showers after midnight."  (They forgot to mention the evening drizzle that would precede the showers, and the sixteen hours of steady, soaking rain that would follow.)

The result was one of those unexpected adventures that is short on the prettier aspects of nature, and long on character-building.  

Great blue herons always seem like prehistoric birds as they croak, and flap heavily into the air.

 Conspiracy Island at the mouth of the Assonet is smaller than it's name,and connected to the mainland at low tide.

 The tide is so low that a bar blocks my way at the entrance to the creek.
The low water will mean a slow slog through deep mud at landing.

 Looking downstream.  Salt marsh is zoned, with tall marsh grass nearer the water,
short "marsh hay" forming almost a lawn a little higher up.

 Serendipity hauled up and unloaded; damp camp the next morning.
(Light is so dim camera keeps insisting on flash.)

 First quarter moon means neap tide which shouldn't rise this high, 
but anchoring boat makes better safe than sorry.

I left the Assonet boat ramp Saturday mid-afternoon to take advantage of tidal currents going my way, but didn't think to allow for enough water in the creek I camped beside.  The result was a late-afternoon landing in deep marsh mud well below the level of the marsh.  I got my tarp established in failing light just before the drizzle began.  I spent a very long night trying to keep the edges of my sleeping bag under the too-small tarp while a small but steady rain drummed.  (My stew can had 3/8 inch or rain in it next morning.)

I crawled out into the twilit rain next morning after concluding that it wasn't going to get any brighter.  Both butane lighters refused to light, so no coffee or hot breakfast.  Once I got them lit hours later, the gasoline stove wouldn't light until I'd used up a lot of butane drying it out.  Hot coffee and oatmeal--sitting dry(ish) under a re-set tarp--at long last!  

 Tupelo (Nyssa sylvatica) is very pretty in fall.

A chestnut of pretty good girth has somehow escaped the chestnut blight so far.  

 I love this view.  And tide rising means I might get off without so much mud.

 Re-set tarp makes comfortable place to wait, and drink hot drinks;
view across the creek from my seat.

 I think this is a goldenrod, but don't hold me to it.

High marsh grass, tupelo, and an aster.

 Loaded for departure.

 Hard to make out: a row of cormorants ignoring the plastic owl
(right, on piling) meant to keep them away.

Finally put the paddle up and sailed.

There was some wildlife to make it all worthwhile: the Assonet River was lousy with great blue heron and egrets and a few swans.  As I boiled water for coffee, an osprey circled above the creek with a big fish in its talons.  (The osprey turned out to be one of a pair that wheeled above the creek in the late morning as I prepared to leave.  Do they stay paired year-round?)  Tupelo trees' brilliant leaves and marsh goldenrod lent color to fall foliage that is on the drab side, overall this year.

After changing into dry clothes and breaking camp, I paddled hard against a significant headwind going home, and only got to raise my little sail for a mile or so of sledding near the end.  It rained steadily, and I rued the decision to put an (absorbent) fleece under my jacket, rather than the more effective wool sweater that lay in the bottom of my drybag.  Gotta work on my stay-dry techniques and gear before the next adventure!  (Winter camping, anyone?)