Looking for the Logos of Life II

Pross, Addy. 2012. What is Life? How chemistry becomes biology. Oxford University Press. 200 pp.

I found this an interesting and generally readable book, but I think it promises more than it delivers. My reflections on it are rather lengthy, so I’ll begin with:

Prologue and Chapter 1

Pross’s question is, “What is Life?” His book is offered as an advance over Schrodinger’s 1944 essay, What is Life? He will use “Systems Chemistry” to state a new law on the “emergence, existence and nature,” of living things. He claims to have found an overlooked form of stability in nature. According to Pross, “Darwinism is just the biological manifestation of a broader physical-chemical description of natural forces.” This will allow him to put forward a “generalized theory of evolution.”

Like Schrodinger, he starts with the laws of thermodynamics – heat transfer, entropy, etc. He sees his task as like Schrodinger’s: to account for the stability of a living cell, despite its being far from thermodynamic equilibrium. He also wants to explain how the first one could arise. He says the goal of that understanding is to be able to synthesize a living organism from scratch. I wonder whether in his “generalized theory of evolution” there is a deliberate echo of general relativity? Does this point to scientific hubris or is it an attempt to pump us a thesis is that is really not all that revolutionary?

The discussion begins by identifying certain “strange” characteristics of life that he thinks are problematic: life’s organized complexity, its purposeful and dynamic character, diversity, far-from thermodynamic equilibrium state and chirality (the “handedness” of amino acids)

Like almost every discussion of the origin of living cells, his begins by emphasizing the cell’s complex structure. I think he confounds small size with intricacy of design, which is ok, if you want to compare a cell to a refrigerator, but it seems odd to claim that an eye is a less intricate design than the ribosomes in the cells the eye is composed of. He tries to define complexity in terms of organization. Does that make sense? He uses the shape of a boulder to define complexity one way – what would it take to describe it precisely, I guess he means. He introduces the idea of information at this point. He claims that as far as the definition of a boulder, the exact shape is arbitrary, implying that the information describing a living cell is less so, but is this only because he ignores the internal composition of the boulder, how it acquired its particular shape and the relation between composition and shape, etc? He points out that even tiny changes in DNA can alter a cell, but this is potentially true of boulders as well, if we alter the makeup or distribution of components. Also, both cells and boulders can vary in exact makeup over quite wide ranges.

He says organized complexity and the second law of thermodynamics are inherently opposed. Cells need energy to maintain their ordered state. Does this really mean complexity is opposed to the second law? I find that physical scientists and some biologists make a very big deal out of what seems to me to be an artifact of looking at their experimental subjects in isolation. The opposition only arises if you ignore part of the system – the biosphere as a whole. Pross admits that this is the reason for the apparent contradiction.

Now he sets up another straw man: Darwinian theory only deals with biological systems, so it can’t account for the origin of the first, self-replicator, the protobiont. Darwin’s theory is biological and does not try to account for the origin of life, but does that mean a Darwinian theory can’t? Darwin himself says that natural selection is the result of natural laws, including presumably, those of chemistry and physics. In fact, apart from these, what are biological laws? Geometric growth is in a sense purely mathematical, but arguably so is a lot of physics and chemistry. Genetic variation and struggle for existence, even natural selection, are expressible in mathematical language. His question, “how did a system capable of evolving come about in the first place?” seems wrongly expressed, possibly because evolving is not the fundamental thing. Darwin’s is a theory of the origin of species. Is evolution a capacity or a faculty of living things? It seems more like the overall pattern that emerges. The word evolution has that troubling sense of preordination or unfolding.

He brings up chance and talks about how unlikely a cell is to form spontaneously. I guess you have to rule that out at some point. He refers to the “first microscopic complexity” coming into being, which seems to ignore that things are “complex” at the microscopic level in many ways other than being living things. He does not begin his argument by saying self-replication is the fundamental defining character of life, which I think unnecessarily draws out his discussion.

Talking about the apparent purposiveness of living organisms, he uses the word “teleonomy,” a coinage designed to avoid the supposed meanings of “teleology.” Pross says our interactions with the non-living vs the living world have a different quality, because of living things’ teleonomic character. He says we don’t use teleonomic explanations in the non-living realm, but then why is he always saying systems seek a lower energy state? Is the conservation of energy teleonomic? We can think of machines as having needs and of animals as machines. Teleonomy is a function of our way of seeing the world, not a measurable property of things: you can certainly think of a rock as wanting to fall or electricity wanting to discharge itself, and contra Pross, you can get some guidance from the laws of physics about the likely behavior of animals as well as trying to read their intentions in postures and expressions or consulting your own likely responses (putting yourself in their shoes). He sets it up as a stark duality, but is it? He then lumps under teleonomy things as diverse as chemotaxis and human voluntary behavior. He also identifies function with teleonomy.

In his long discussion, Pross never mentions the telos of teleonomy: self replication. Pross’s rhetorical withholding continues. It gets murkier when he does bring it up, because he says, while we can have a lot of goals as a human, we need to look at simple organisms to get at the real one. So is our purposiveness different from that of living things generally? He refers to it as a powerful replicating drive. What does “drive” mean? He claims teleonomy is as “real” as gravity. But gravity is in some way fundamental, as the physicists say, or at least an aspect of something more fundamental still, while teleonomy seems a by-product of self-replication. Teleonomy cannot, can it, be unified with the other forces of physics. He says gravity is quantifiable and teleonomy is not but that it doesn’t make teleonomy less real. He claims we stake our lives on the teleonomic principle when we drive our cars. What does he mean? Is it the design of the car or my ability to drive it to where I want to go and avoid hitting obstacles or going over cliffs?

Part of the problem is he starts talking about a teleonomic principle, not just teleonomy. Where did the principle come from? Teleonomy seems like an analogy to our own purposiveness, but what laws govern it? Is there any real similarity? Is the analogy in any way useful to reasoning accurately about living things?

Pross says, “Metaphysically…gravity and teleonomy are mental constructs that assist us in organizing the world around us [does he mean sense data?] So is he an anti-realist in the school of Hume and logical positivism or a Realist of the idealist school like Kant? Then again, the Scholastic ideas of gravity and teleology are organizing principles. Is teleonomy like the Scholastic gravity, going to be swept away by a better concept? At one point, he says “all inferred patterns are conceptual and are found nowhere else than in our minds.” How closely can he stick to this principle, and in that case, what is his book going to explain, patterns in our minds?

I think simply admitting that self-replication is a property of living systems, and not the goal, would obviate the need for teleonomy. If there is a need to talk about “purpose” to avoid prolixity when describing biological structures and behaviors that are aspects of self-replication, we should just use the term and not invent new words because we fear someone will accuse us of teleological thinking. I wonder if these constant verbal contortions are because we are still fighting battles with those who identify the ultimate cause with a Creator whose plans are often crudely anthropomorphic, like his appearance.

In the section of life’s great variety, Pross says, “non-living diversity is arbitrary.” That hardly seems true of geology or the atmosphere. Perhaps he means it is easier to see the relatedness of living organisms: classification of plants and animals by non-literate people is often very close to the scientific classification. He repeats the false characterization of species as, “each perfectly adapted to function and survive in its particular ecological niche.” So, he’s not an ecologist or evolutionary biologist, but even popular books like those by Steven Jay Gould warn against that sort of talk.

He claims further that there is an inescapable contradiction between the principle of natural selection and the principle of divergence [of character]. Again, this is not a bad point to bring up, but if it really were a contradiction, then something would be seriously wrong with our theories on the origin of species, and this is not the case. There is nothing preventing diverse things from being selected. If the conditions of life were always and everywhere identical, then selection would prevent divergence. The problem goes away once you include the idea that organisms exist in varying environments. He seems to confuse debates over mechanisms of speciation with debates over these two principles.

In the section on life’s far-from-equilibrium state, he seems to be setting up a straw man to knock over later. Yes, non-equilibrium thermodynamics is exceptional, but it is not confined to living things. The lithosphere, hydrosphere and atmosphere are not in equilibrium, so why should it be surprising that processes occurred at some point that led to small parts of these moving further from equilibrium? As long as there is sunshine and radioactive decay, there’s the possibility of a system being supplied with enough energy to move it far from equilibrium. By far the trickiest part is to get the autocatalytic process going in an environment where it can be safe from degradation long enough to become robust enough to deal with the challenges of a changing environment and to diversify so as to occupy more places. But with no competition from already-existing organisms and billions of years…

I suspect the mystery of chirality (as he calls it) will prove to be another straw man. A phenomenon to be explained, yes, but not really that much of a mystery, at least not in the sense of requiring new principles to account for it.

His claim that we fully understand and can explain the characteristics of water or other inorganic substances, while we can’t understand living things also seems problematic. Do we really know all there is to be known about water? Again, he seems to be trying to hype up the level of mystery, instead of just saying that it’s a really complex problem. This would make his supposedly new principle seem more marvelous, I suppose. His promise is that he will reveal the hitherto hidden essence of life. TO BE CONTINUED.

Colonial lives

Hoyt, Eric.1996. The Earth Dwellers: Adventures in the Land of the Ants. New York. Simon and Schuster. 319pp.

Excellent book about ants at La Selva, the Organization for Tropical Studies’ field station in Costa Rica, both because it describes several species of very different ants from an ant’s eye view and for the endearing descriptions of two great myrmecologists, Bill Brown and E.O. Wilson, at work together in the field. Wilson is known to almost everyone, but Brown was also one of the greatest entomologists of the last century. Their contrasting personalities make them like characters from a movie about the adventures of two mismatched buddies. I was amused and edified by Hoyt’s description of their field techniques and sometimes reckless determination in the search for the miracle ant, Thaumatomyrmex. Brown’s views on taxonomic and systematic work, described here, are worth considering, and it is also worthwhile to look up his and Wilson’s published papers. Hoyt includes interesting biographical accounts of both men and quite a lot of readable information on the biology and evolution of ants and ants’ social behavior.

Wilson, E.O. and Jose M. Gomez Duran. 2010. Kingdom of Ants. Jose Celestino Mutis and the Dawn of Natural History in the New World. Baltimore. Johns Hopkins University Press. 96 pp.

Jose Celestino Mutis spent over forty years as a physician, botanist, linguist and priest in what is now Colombia (when he arrived from Spain in 1761, it was the New Kingdom of Granada). He began studying ants at the suggestion of Linnaeus, whose system he used in his work on plants. His detailed reports on ants are apparently lost, but this little book contains long quotes from his journals, which give accounts of his studies several species, including leaf cutter and army ants. Every aspiring naturalist should study these notes to appreciate Mutis’s clarity, perseverance and, above all, skepticism and honesty. This is best shown in the passages where he explains how he realized that the big-headed “soldier” ants were not the males, but instead, when he finally was able to observe copulation, males turned out to be the small winged individuals, who he originally took for young females, not fully grown. He expresses his gratitude to God for enabling him to correct his error and make such a wonderful discovery. In another entry, he reproaches himself for letting the press of his experiments on smelting metals in the mines cause him to forget to follow up on a potentially valuable observation. Another day, he forgets to record part of what he saw, and so with reservation, he allows himself to write it down the next day. He constantly refers to the need to check his conjectures with more observations and to try to reconfirm what others report to him. He often asks the local farmers for their views, but he never accepts them without the evidence of his own eyes. When he tries to estimate the number of army ants in a colony, he uses several independent methods of arriving at the number. As Wilson and Duran point out, about all you could wish of him is a naturalist is that he had included sketches of his ants to help modern myrmecologists identify them. They wonder why he did not do for ants what he did for plants: fit them into Linneaus’ system and have illustrations prepared. Despite owning a huge library, he was evidently not aware of Maria Sibylla Merian’s work on insects in Surinam or any published works on ants. He was quite on his own, with no prior experience and no expert to guide him when he began his work at age twenty-eight. Linnaeus had named only a handful of ants, all in one genus and with very sketchy descriptions. Although Mutis’s descriptions show him to be clear sighted, he does not attempt any sort of systematic classification of the species he encounters, based for example, on the number of petiole segments or the presence of a sting in the workers. This job was left to later workers. His greatest contributions were to the study of ants’ social behavior. He was without doubt one of the finest scientists of the 18th century. Perhaps only von Humboldt equals him as an observer. On the 200th anniversary of his death, the Colombian myrmecologist, Fernando Fernández and E.O. Wilson, named a new ant species, Pheidole mutisi (Fernández, F.; Wilson, E. O. 2008. José Celestino Mutis, the ants, and Pheidole mutisi sp. nov. Revista Colombiana de Entomología 34:203-208). 

Thanks to Wilson and Duran for making this gem available to naturalists.

Rau, Phil and Nellie Rau. 1918. Wasp Studies Afield. Princeton, NJ. Princeton University Press. 372 pp. [Dover Books reprint]

This is a fascinating early twentieth century work on solitary and social wasps. The Raus carried out their studies in the midwestern U.S. Their research covered hunting wasps with a wide range of prey. The wasps included both soil and wood nesting species in diverse habitats; one even dug in the clay infield of a baseball diamond. The Raus made detailed behavioural observations on many species and did experiments on paper wasp homing ability. They mention the drop off in aggression by paper wasps as winter approaches, all the brood matures and the workers die off and are replaced by overwintering queens. That’s just one example of many behaviors that I have noticed but not really thought about until they described it. Another good read for anyone who aspires to study insects in the field.

Looking for the Logos of Life I

Schrodinger, Erwin. 1967. What Is Life? The Physical Aspect of the Living Cell and Mind and Matter. Cambridge. Cambridge University Press. 178pp.

I wanted to put up this brief post before I launch into some much longer ones on books that purport to extend Schrodinger’s ideas and the tremendous biological discoveries that followed in the ensuing decades. I got started on this when I read another book, Eva Brann’s The Logos of Heraclitus [2011. Paul Dry Books. 160 pp], about which more later.

This is the first of a genre: physicists and chemists look at life. Schrodinger, in these lectures, delivered in Ireland in 1943, introduces the idea that life exists far from the thermodynamic equilibrium that physics sees most systems as tending towards. He is also the source of an idea I first heard when I was a graduate student, that organisms feed on “negative entropy.” The essay is worth reading for the quality of his reasoning and clear exposition, even though his predictions about the nature of the material carrier of heredity turned out not to be quite right.

Just one interesting thought: he points out that whatever molecule the hereditary material consists of carries out its functions in a way different from most of the enzymes in a cell. While most reactions in the cell rely on basically random interactions between molecules, in that you can only predict the general rate of reaction and not whether a specific molecule will react, there’s just one copy of a given gene in each cell. It has to be essentially certain that it will participate when needed in its particular role. Nevertheless, the basic processes of translation and transcription do involve many enzymes, along with the building blocks of nucleic acids and proteins, in what must be the usual sort of collectively predictable, individually unpredictable, dance. DNA is after all, a template, a fixed model against which to construct a product. Keeping that template stable and making sure it is copied correctly is the job of a whole complex set of enzymes in the cell. As Schrodinger points out, a big molecule like DNA can have the stability of a crystal, being held together by essentially the same forces.

V.G. Dethier, entomologist

Dethier, Vincent G.  1992. Crickets and Katydids, Concerts and Solos. Cambridge MA. Harvard Univ. Press. 140 pp.

A wonderful little book, recounting his summer as a field assistant to G.W. Pierce, who studied the acoustics of insect songs. Also gives keys to both the orthopterans discussed and their sounds as well as a bibliography. Lovely pen and ink illustrations by Abigail Rorer .

The chapter entitled The Shield Bearers (p. 100) begins as follows: “The stereotypical entomologist is an odd character, long of nose, short of vision, adorned with Ben Franklin spectacles, and given to dashing madly o’er the lea, with net and beard streaming in tandem in the breeze of his pursuit.” The chapter epigraph is a quote from John Phillips’s “Cyder.”  which advises catching wasps that swarm on ripe apples by hanging up vials of “Moyle,” a kind of cider made from Moyle apples, “Mum,” a type of beer, or “Treacle’s viscous juice,” that is , blackstrap molasses. Just about the formula we still use today for moth bait.

Vince Dethier (1915-1993) is a writer every aspiring entomologist ought to read, especially his To Know A Fly [1962. Holden-Day. 119 pp] or for the serious student, The Hungry Fly [1976. Cambridge MA. Harvard Univ. Press. 512 pp. His writing is humorous, lucid and just fun.

Image: male macropterous form of Russel’s bush cricket – Flickr

For the Love of Leps

bflyLeach, William. Butterfly People. An American Encounter With the Beauty of the World. Pantheon. New York. 388 pp. 2013.

This book, beautifully illustrated, is a history of the discovery and documentation of the butterfly fauna of the United States and of the entomologists, amateur and professional, who fed the public fascination with butterflies in the 19th century – Samuel Scudder, William Henry Edwards, Herman Strecker, Augustus Grote, W. J. Holland, and many others. The author has many reflections on the importance of both Darwin and Romanticism (especially German) on the interpretation of the biology and meaning of butterflies. There is also a lot on the collectors, scientific and commercial, who travelled throughout North America and the rest of the world to satisfy the demand for specimens, often at considerable risk and always with much hardship. Butterflies and moths were much more than a scientific concern: there was a great deal of commerce in specimens, as many, if not most, young men of middle class aspirations had a Lepidoptera collection, even if few collected themselves. It is strange to think in our day of fancy cars, world travel and electronic devices, how much one’s status might have been tied up in various collections, whether, insects, stamps, shells or books.

Leach mentions George Santayana’s The Sense of Beauty several times as a perspective on the 19th-century’s fascination with natural form and color. As well as commercial specimens, large format books with color plates were an important part of the butterfly business. He talks about the illustrators and the changing technology of color reproduction.

The Academy of Natural Sciences of Philadelphia was one of the repositories of collections, including the very early and important Titian Peale collection, which was to have formed the basis of a never-completed series of books by that second-generation Philadelphia artist. The American Entomological Society, founded 1859, played a role as well. The society’s book collection, still housed at the Ewell Sale Stewart Library of the Academy, includes many of the most attractive 19th-century publications.

This is a fine account of what natural history meant to Americans in the first century and a half of the nation and of the friendships and rivalries among these early naturalists.

Contact, Conflict and Cooperation

Soderland, Jean R. 2015. Lenape Country. Delaware Valley Society Before William Penn. Phila. U. Penn. Press. Early American Studies Series. 249 pp.

An interesting, if somewhat repetitive, account of the period from 1630s to mid-1700’s, when Lenape and Susquehanna Indians, Swedes and Finns, Dutch and English contended for the trade in beaver skins, etc. coming down from Canada. Soderland’s point is that most of this struggle was peaceful or at least not open warfare and the Lenape managed to remain masters of the territory surrounding the Delaware (Lenapewihittuck or South) River, until William Penn’s sons and other land swindlers got the last large tract on the west side from them in the 1700s. For much of that time, Swedes, Finns and Lenapes formed an alliance against the Dutch and English, resisting their attempts to acquire and govern large areas of territory. The Europeans were largely confined to small outposts along both sides of the river up to the time that the Quakers began to acquire large tracts for settlers.

Part of her contention is that Penn’s treaty was not anything really new. The Lenape had been fairly skillful negotiators all along and willing to employ threats and force to keep the other groups from extablishing large settlements and plantations, as Europeans had in Virginia and New England. They also had to deal with threats from Maryland settlers, but here they were aided by the other Europeans. She repeatedly points out that the only sizable massacre in the lower Delaware region was near the site of Lewes, Delaware, in 1631, an early show of willingness by the Lenape to use violence to stop large scale settlement.

The Europeans learned not to assume that their concepts of ownership and transfer of rights were understood by the Lenape, and they preferred to keep negotiating peace for the sake of continued trade rather than revenging past wrongs or trying for outright conquest. This may have simply been due to lack of means. Their “companies,” back in Sweden, the Netherlands and England had limited resources and aims and often could not supply trade goods or support for the settlers. Still, she implies that some of the local directors and governors were simply more inclined to diplomacy than war and that the Lenape were more than willing to go along, despite the mockery of other tribes, especially those to the north, who were often agitating for war. She claims that at one point, around the time of Bacon’s Rebellion and King Phillips’s War in the 1670s, if the Lenape had joined the rest of the native Americans in an all out assault, they might have driven out the Europeans. Seems unlikely, but they certainly could have dealt a massive setback in the whole mid-Atlantic region, with unimaginable future consequences, for example for the French position in North America, etc.

The background to all this, of course, is the gradual decline of the native population due to epidemic disease. Does this stark fact lend credence to Jared Diamond’s guns, germs and steel theory? I’d like to not think so. Part of what’s missing in that view is the central role played by trade in keeping both sides in contact with each other throughout the period. The other point is that both sides suffered a lot from diseases, although Europeans may have been somewhat more resistant. There is no suggestion that the epidemics were an actual weapon. In fact, they instigated revenge killings (she calls it “mourning war”) and so were a source of friction between Europeans and Americans.

The other point is that the Lenape and the Europeans rather quickly began to intermingle in many ways – tools, agriculture, marriage. The Lenape didn’t like the Europeans’ domestic animals, which were often a cause of conflict, and they showed little inclination to become Christians, which led a lot of preachers to accuse them of devil worship. But particularly with the Swedes and Finns, there seems to have been a fair amount of cooperation. There are several cases described in the book of both sides handling criminal complaints about the other side in a way that worked fairly well.

One aspect that surpised me was the very low estimate of the number of European heads of household in West Jersey as late as the count in 1671: seven men and no women. Was some segment of the population simply being missed? Do other records indicate that there were Europeans living in some places where they were missed in the count? One of the recent books she criticizes is Bernard Bailyn’s The Barbarous Years. (Knopf 2012), may be worth a look.

Image: Nautical chart of the Dutch colony Zwaanendael and Godyn’s Bay (Delaware Bay), 1639 – Wikipedia

Fearful scimitars

Sabertooth by Mauricio Anton (2013) Bloomington. Indiana University Press. 243 pp.

This is the natural history of an ecological niche: an ambush predator that captures prey by a throw and pin, with powerful forelimbs and a long, strong back, followed by a bite to the neck, using greatly elongated canine teeth, made possible by jaw adaptations that permit a huge gape and a long, strong neck. The bite results in bleed out and death of the victim. It is argued that this leads to quicker and safer kills than the suffocation method employed by modern big cats on large prey. The author does a remarkable job of tracing the paleontology of successive groups of species that have occupied this role since the Permian, although there seem to have been no dinosaurs that did so.

The illustrations of fossils, reconstructed animals and landscapes are beautifully done, in loving detail. The painstaking anatomical analyses to show how these killing machines worked are clear and persuasive, at least to a non-expert. There are interesting accounts of the constantly changing nomenclature of the fossils.

It would be useful to see similar accounts of modern large cats, hyaenids and other carnivores to get a sense of how the sabertooths fit into the big picture of carnivore evolution and why it is they went extinct instead of the others.

The extinction happened several times, as the successive groups of sabretooths disappeared, and they were not quickly replaced. Sometimes millions of years seem to have elapsed before a new lineage appeared to fill the niche. Indeed, sometimes there were no large felids of any kind for extended periods, if we can trust the fossil record. At other times, a new group may have out-competed the current occupants of the sabertooth niche. One might say that there is room at the top of the food web, but it is a precarious position that isn’t always filled.

Perhaps the most recent occupants of the niche went extinct with the megafauna of the old and new worlds, but could they have been done in by more efficient pantherids? Was their technique only suitable for very specific types of prey that got replaced by more wary and evasive herbivores or did vegetation change doom their hunting methods? Did their very specialized anatomy and techniques simply run out of room for improvement against ever more challenging prey? Anton thinks that their very specialized niche may have left them relatively more vulnerable to shifts in prey abundance. This would be a major factor in the late Pleistocene, along with competition from lions and humans, among others. As the least flexible group, they may have been the first to go.

Does it mean there’s an unoccupied niche now, or are those habitats and resources simply gone?

What other convergences in form and behavior has natural selection produced across time and biogeographic realms? We all know at least a few ecological equivalents, like pangolins and armadillos, or moles, marsupial moles and mole crickets. There’s an interesting one involving modern beetles’ and early rodents’ mandibles, but it isn’t clear what the functional significance is (John Acorn in American Entomologist, Summer 2014, p 128). Thanks to Mauricio Anton for presenting this story so beautifully.

Image: Smilodon fatalis – National Park Service

Ecosystem lost and found?

Looking for Longleaf. The Fall and Rise of an American Forest by Lawrence S. Earley (2004) Chapel Hill. University of North Carolina Press. 322pp.

When I was a teenager, my grandfather recalled for me how the longleaf pine forests in eastern North Carolina looked when he was young, some seventy to eighty years before. It was like being in a cathedral, he said, with the trunks of the trees like columns and the forest floor clear as far as you could see. This book gives an introduction to the character and extent of the longleaf pine ecosystem, once dominant over a vast region of the Atlantic and Gulf Coastal Plain, introducing the plant, Pinus palustris, the diversity of associated plants (sometimes hundreds of species in a square kilometer and as many as 40-60 in a square meter) and several of the more distinctive animals, like gopher tortoise and red-cockaded woodpecker.

Earley explains the critical role of fire and soil in establishing the diversity of types within the overall longleaf ecosystem.

The middle part of the book is a historical account of the European encounter with the forest, its exploitation by the naval stores industry and its eventual destruction by that industry and the railroad based loggers. Some of these descriptions fit closely with what I heard from my grandfather and from a friend in North Carolina (whom Earley interviewed for the section on turpentining). He talks about rafting logs down the coastal rivers (as my grandfather, born in 1869, did as a boy) and shipping naval stores (my grandfather also described how the cooper made the barrels for turpentine). He explains that what preserved so much of the forest were the limitation of cutting timber to areas close to usable streams, that is until the railroads came. My father (born 1913) recalled how the railroad was brought in to log some of the most remore and inaccessible places when he was growing up. Some time around 1970, before the railroad was finally abandoned, I saw carloads of longleaf pine stumps waiting to be hauled off to extract the valuable resins or to make fatwood kindling, sold by L.L. Bean, among others. Earley also mentions the continued interest in salvaging sunken logs and getting lumber from old buildings.

The final chapters are on the development of forest management ideas, from failed attempts at replanting to replacement by loblolly and slash pine and the gradual development of methods to regenerate longleaf, first as even aged stands but now moving towards uneven age management and overall ecosystem restoration. Red-cockaded woodpecker played a key role in several changes in policy, driven by court decisions under the Endangered Species Act. Many of the agencies involved, like the US forest Service have serious problems dealing with the steady increase in scientific and ecological understanding of the forests. Institutional change is difficult, especially when institutional memory is impaired by frequent reassignment of key people and political pressures. The US Forest Service has had an especially hard time admitting it has been wrong about fire suppression and even-aged management.

He talks about the role of national and state forests and of large and small private landholders (currently there is increasing longleaf acgeage on federal and maybe state land and on large private conservation holdings, but continued losses on timber company lands and small private holdings) and what the trends may mean for the future of the ecosystem and many of its species. New incentives under the Conservation Reserve Program may be changing the minds of some private owners. It is possible to derive a pretty steady income from restored longleaf, partly through sale of raked needles in the 10th to 15th years after replanting. Poles are much in demand, using middle aged trees. The author seems most impressed by adaptive management approaches using small group-selection cuts and frequent growing season fire. Several interesting examples are described in the next to last chapter on restoration. Some of these areas sound like they would be worth seeing, and there are some groups that can help with restoration, a topic that is on my mind lately, as I and my brothers and sisters still hold a small remnant of thousands of acres of longleaf land owned by my great-great grandfather in the early 1800s. We will soon be clearing the stand of loblolly pine, planted decades ago, to make way for longleaf again.

Neotropical travellers

Essay on the Geography of Plants, by Alexander von Humboldt, and Aimee Bonpland. 2009 (1807). Edited by Stephen Jackson. Translated by Sylvie Romanowski. University of Chicago Press. Chicago. 274 pp with tableau in pocket
This book is pure descriptive natural history, with almost no speculation or discussion of causes. It is divided into Humboldt’s Essay of some 30 or 40 pages and the longer Tableau Physique prepared by Humboldt and Bonpland. Some of Von Humboldt’s fascinations, like barometric pressure, which he includes along with temperature, humidity and “electrical tension” as factors influencing plant distribution, seem peculiar to me, but I have to remember that he was much more limited in what he could measure than we are today. Another peculiarity is his notion of “social” plants, by which he seems to mean those that form dense monocultures as opposed to mixed stands. He says these live “in organized society, like ants and bees…” His examples include mangroves, Cladonia lichens and pines, but also Vaccinium. He notes that such plants are more common in the temperate regions than in the tropics. Mexico is an exception, harboring many temperate species, like pine, oak and sweet gum, which he attributes in part to the vast geographical expanse of the northern part of America, narrowing southwards. Somehow this causes Mexico to be colder than similar latitudes elsewhere. Then there is his idea of “subterranean vegetation,” which seems to mean fungi in caves and mines. He treats these “cryptograms,” alongside lichens and mosses. How aware was he of the fundamental distinction between autotrophs and heterotrophs? Photosynthesis was barely beginning to be understood in his time.
He also lacked a clear notion of geologic time, referring only to remote ages, but with no sense of the scope and significance of the fossil record. Only the epoch of human spread across the earth is accessible to his reflections on the distribution of plants. When compared to Graham’s Natural History of the New World, he has far less to go on, and barely any sense of the potential of fossils to shed light on modern plant communities and their distributions. Yet Graham clearly is following in the footsteps of von Humboldt and Bonpland.
One advance he makes is to point out the importance of physiognomy alongside taxonomy in describing communities of plants (another of his ideas) what we today commonly call life forms or growth forms.
The main thing, though, is the Tableau Physique, the profile of the Andes, using the volcano Chimborazo thought, at the time, to be the highest peak in the world. The detailed data packed into a single illustration is startling and quite beautiful. The other wonderful part is his concluding reflections in the essay on the value of natural history writing and artwork in elevating and liberating our understanding, even if we cannot experience these amazing places directly.

New world history

A Natural History of the New World. Ecology and Evolution of Plants in the Americas, by Alan Graham. 2011. Chicago. University of Chicago Press. 387 pp.
This is an ecological and evolutionary story acted on the stage of two continents from the close of the Mesozoic to the recent. South America starts out isolated or nearly so, while North America begins joined to Eurasia across the proto-Atlantic. It ends with two continents joined by a narrow isthmus and a sporadic connection to Siberia across the Bering Sea. During this time as the Americas override the Pacific plates, a series of great mountain ranges form along the western edges of both continents, altering the directions of rivers and radically altering the climate of the continental interiors. Late in the period, the shift towards glacial climates turns what were temperate climates under a polar insolation regime into boreal forest and tundra, with deciduous forests to the south and new dry ecosystems in the arid west.
It is a dramatic story, with a shifting cast of characters, most impressively the higher angiosperms and the radiating mammals responding to each other as well as struggling among themselves to dominate under the shifting conditions. The rise of groups like the grasses and the ungulates with their associated carnivores are among the most visible and dramatic developments, if not quantitatively as significant as the insects and fungi, which changed much less over the same time. This is a vexed question; megafauna and keystone species enthusiasts on the side of top-down regulation and ecosystem engineering, those of us who look at energy flux and nutrient cycles as keys to ecological processes and who see microbes as the dominant force, alongside plants, on the bottom-up side. Probably both views are right some of the time. No doubt, though, that climate and geology – lithosphere, atmosphere, hydrosphere – are the ultimate regulators, although the biosphere’s impact on carbon cycling is also significant.
This is a very detailed book, giving an account of dozens of types of communities both in the past and the present vegetation of the Americas. It also describes the phases of development step by step, tracking the geologic changes and the shifting vegetation as revealed by pollen and macro fossils. The author is a noted paleobotanist at the Missouri Botanic Garden. There are good photos, maps and graphs of changing temperatures over the epoch. Truly a history of nature.
Graham also has excellent chapters on the techniques of paleoclimate reconstruction and the collection and interpretation of fossils. The text is also a wonderful travelogue, full of historical and prehistorical anecdotes, and covering the modern biogeography of the new world as well as the story of how it came to be as it is.