Wednesday, January 27, 2016

Book Review: Sébastien Steyer: Earth before the dinosaurs

Sébastien Steyer: Earth before the dinosaurs, Indiana University Press, 2012, 173 pages; profusely illustrated: photos, paintings, sketches; bibliography, index.

The magnificent artwork and sketches are by Alain Bénéteau


abbreviation used in this article:

- mya: million years ago (before the present) 

          I originally decided not to review this exasperating - and wonderful - book: too small a potential audience, too specialized, too technical, some serious pedagogical issues..

           However, perhaps against better judgement, here 'tis. Ultimately I was moved to write because I love the book and hope that a few readers will decide to check it out at their local library and enjoy it as thoroughly as I did. (If your library doesn't have it, recommend it to the holdings department. Most libraries welcome suggestions. I suggest several books per year and have been refused only twice. This way you get to read a good book for free and assure that others will have the chance to read it too.)

 Subject: Early tetrapod (four-legged animal) evolution from the Devonian to the Permian mass extinction, 416 - 250 million years ago (mya). This is our history, human history, in deep time since humans are mammals and mammals are modern representatives of tetrapoda, the four-legged tribe.


                 The image above is hynerpteton, a Late Devonian tetrapod, 360 mya. Hynerpeton was an aquatic carnivore living in coastal mangroves, capable of limited motility on land (like a modern walrus or seal). Its primary mode of propulsion was the large tadpole tail, visible in juvenile frogs and the embryos of terrestrial vertebrates. 

             Before the dinos was originally published in French. Chris Spence, an ex-patriate American living in Paris, deserves due credit for the quality of the translation. I had no impression whatsoever that the text had been composed in a language other than English. Good job, Chris! The only gaffe I found was the translation of the Canadian province, Novia Scotia as "New Scotland"! Quite an odd error for a professional translator..

             It is rare that science books, especially highly technical ones, are considered "beautiful" (as one reviewer was moved to remark). The quality of the artwork, in fact, moved me to undertake this review. At times it is stunning. The illustrator, Alain Bénétau, prefers dramatic "cloud-wracked" skies, threatening storm. On the whole the images  are far more life-like (hence interesting) than one would expect for an academic work. 


Eusthenopteron: 385 million years ago, Devonian. A "transitional" fish with some characters of land animals. Note all those fins! Two of the lower pairs developed into tetrapod legs. The above two images are from Before the dinos.

               Some of the images achieve a quasi-photographic quality to the point one can imagine one is looking at a photo of an exotic rain forest critter in National Geographic. The image of archaeothyris, 310 mya, the "oldest known synapsid" (the ancient genetic lineage of which mammals are the sole survivors) could fool most people,passing off as a photo of a somewhat scary looking modern reptile, 20 inches in length.

               The visuals are the book's strongest point. It is literally jammed full of images of all sorts: paintings, sketches and photos, body silhouettes, several per page. Many are photos / sketches of fossils, including in situ photos before removal and preparation of the fossil for display. Fossil photos are generally accompanied with one or more sketches outlining anatomical features of evolutionary importance. I found these a pleasant way to deepen both my knowledge and appreciation of early vertebrate evolution.
 
Ichthyostega (top) and acanthostega: early tetrapods. Ichthyostega had a robust shoulder girdle and front limbs which allowed it to hump about on land by alternately scrunching up its tail to push forward and then using its powerful front limbs to push back (the hindlimbs were useful for swimming only: too short and badly angled to walk with. Fossilized races of body dragging as described above are found in places where ichthyostega was abundant. Acanthostega (bottom), also an early tetrapod, was not to any degree adapted for locomotion on land).

             The biggest, most glaring flaw of Before the dinos is the absence of a technical glossary: absurd for such a technical and highly specialized text, and particularly for one with pretentions of a larger readership. The quality artwork does, in fact, suggests an attempt to appeal to a larger readership, an impression furthered by the blurb on the front and back covers of the original French edition. In addition, prof Steyer included photos of field working conditions and modern paleontological technology (scanners, radio-isotopes..) both of which would be irrelevant if the intended readership was purely an academic or professional one. He also waxes idylically about the pleasures of a career in paleontology on several occasions: also irrelevant for a professional readership. The lack of an adequate glossary is thus as puzzling as it is irritating. I was eventually reduced to inserting book marks in places where technical terms were defined so I could flip back to refresh my memory when I got bogged down in a particularly dense thicket of technical verbiage: ichthyan sarcopterygian versus  tetrapodomorph sarcopterygian for example (!!!) C'mon prof Steyer, give the reader a break..

 

Ichthyostega seizing prey 360 mya in a Devonian coastal mangrove. Note the submerged tree trunk..

History of the tetrapods, the four legged tribe: This history displays the strong dependence of organisms upon their environment and, by inference, the impact of the physical environment on biological evolution. (see footnote 1). Way back in the Paleozoic (early life) earth, the moon was much closer than it is today. This increases the gravitational forces raising tides. In addition, the earth rotated a bit faster, further increasing tidal forces and raising higher tides. The result was that the intertidal zones, the land impacted by daily incursions of tides, were much larger than today's intertidal zones. Marine mangrove ecosystems - intertidal forests - were much, much more extensive and diversified than today.

 
                                     modern mangrove, where sea and forest meet

                Paleozoic mangroves provided a rich, diversified, "fractally broken" network of partially interacting "microclimates", very favorable to evolutionary experimentation and diversification. (note 2) In this perspective the early tetrapods can be seen as highly mutant fish, intermediate in form and function to both fish and land animals. Thus tetrapods, as a group, possessed both lungs and gills. But why lungs

              In the light of current knowledge, lungs did not evolve in some attempt to "conquer the land". It is likely that they were used for dealing with oxygen impoverished water. The large intertidal zones of the Paleozoic, circa 350 - 400 mya, would have been characterized by very high tidal velocities, compared to today's oceans. This is reflected in the large amount of fossilized plant "litter" found in Paleozoic mangrove sites. The litter would have provided nutrients for abundant bacterial blooms, particularly on warmer, subtropical and tropical seacoasts. The bacterial blooms would have de-oxygenated the water, necessitating the evolution of a backup system of respiration: swim bladders modified to serve as lungs. The development of air-breathing was not, therefore, an adaptation to life on land or a "stage" in the "conquest of the land". Lungs and air-breathing were merely an adaptation to an oxygen deprived aquatic environment. Then, since life is opportunistic, only later did some of the critters re-adapt their capacity to breathe air to spend more time on land. The "fractally broken" mangrove, comprised of alternating stretches of shallow swamp and land, could be better exploited by amphibious tetrapods capable of negotiating short stretches of terra firma separating adjacent swamps. They were still aquatic predators: living on the land "for real" would only come aeons later.

Chiridian limbs, you sayThe greatest innovation of the tetrapods, when they were still aquatic (be it noted), was probably "chiridian limbs". These are the limbs of land animals (including cetaceans - whales and dolphins - who returned to the sea). The primary feature of interest here is the termination of chiridian limbs in bony digits as opposed to the cartilaginous rays typical of fishes. See graphic below. Typically, the early aquatic tetrapods and tetrapodomorphs ("close-to-tetrapods"), had 6, 7, or 8 digits per limb, probably reflecting their usage in swimming (big webbed foot to displace a lot of water at each stroke).


 Ichthyostega and the beginning of chiridian limbs, the word "rayons" in the leftmost limb sketch is French for the cartilaginous rays of fish fins. Panderichthys shows a curious hybrid form found in some early tetrapodomorphs: the bones of the limb are analogous those of land animals (modern tetrapods) while the cartilaginous rays are typical of modern fish!! A "missing link" (sort of).. Click on the image for a larger more readable version.

          In reality, no one knows for sure why chiridian limbs evolved in the first place: no one can identify the "selective pressure" driving their evolution. The very earliest chiridian limbs appear on critters whose anatomy did not permit them to crawl about on land. (When critters began spending some time on land, then chiridian limbs, with their robust terminations did indeed prove useful - but they did not evolve for that purpose.) Prof Steyer proposes that they might have been used for seizing and holding the female during mating but admits this is pure speculation. 




         Another suggestion I have come across: chiridian limbs allowed tetrapod predators to sneak up on their prey, walking along the cluttered bottoms of mangrove swamps, concealed by bacterial bloom clouded water. Their prey, like other fish, would have possessed "lateral lines" with sensory endings designed to detected the vibrations set up by the fins of approaching predators. Sneak-walking along the bottom would have produced less low frequency vibrations than swimming. Another possibility (from myself): some of the early tetrapodomorphs and tetrapods have flattened bodies and eyes on the backs of their heads. This suggests that they concealed themselves on the bottom waiting for prey to come by. If so, they could have used their chiridian limbs as shovels and fans to spread mud and fine sand over themselves for concealment..

Missing links - real or imaginary? Prof Steyer rejects the notion of evolutionary "missing links" because, he believes, evolution has no goal, no final purpose. There is no "plan" directing evolution "from" species A to B to C with B the "missing link" between an earlier, more "primitive" form, A, and the "more evolved" form, C. In reality, Steyer argues, when we speak of missing links we are confounding familial likeness with an ordered (intentional) sequence of steps. Similarity in the fossil record merely reflects genetic descendance, not the unfolding of an "evolutionary project".

        From Steyer's "democratic" interpretation of evolution, each species is its own "goal" in the sense that its members seek to survive an propagate their kind. In this perspective, humans are not really "superior" to other life forms. Rather, each form of life possesses its own specificities, its own "essence" or mode of "being-in-the world". Its specificity allows a species to occupy / create an ecological niche which it will occupy until changing environmental / ecological conditions render it "obsolete" and it will be replaced. Ichthyostega was not a "stage" on the road to becoming-human. It was not even out to "conquer the land". Its chiridian limbs provided some mobility on terra firma, allowing this predator to extend its hunting range. It could cross a stretch of dry land to get to the next wet piece of mangrove swamp. With improved mobility, it prospered until environmental conditions changed or until a competitor better adapted to its environment appeared. The only reason ichthyostega bears features in common with tetrapods, mammals and humans is because it belonged to a successful group of species that left descendants, including ourselves. Ichthyostega was merely doing its thing: predating, fleeing, fighting mating, not "striving" to give birth to humanity, a third of a billion years later..

Comment: In principle, prof Steyer is - most likely - correct in denying an overall purpose or identifiable goal in biological evolution (at least as a first approximation to reality). Nevertheless, this should not blind us to the possibility - the likelihood! - that certain "evolutionary strategies" prove more successful than others. Thus vertebrate evolution has established several lineages (birds and mammals) in which "cephalization" has proven a successful "strategy" over time. The brain becomes larger and more complex despite the enormous drain on metabolic resources (oxygen, energy) required to maintain a large brain. The increased behavioral adaptability a large brain permits can, in some environments, offset the increased metabolic demands of feeding a big brain. Minaturization is possibly another emerging evolutionary trait in vertebrates. As the nervous system evolves, cooperation between increasingly intelligent individuals becomes increasingly advantageous from a survival standpoint: two heads are better than one (especially if both are smart..). In this scenario, cooperating individuals have a lowered mortality, hence greater ability to pass their smart genes on to offspring. Each generation will, infinitesimally, tend to be brighter than the previous. Now, this situation generates "selective pressure" for greater population densities: a denser population permits more cooperative interactions between individuals. Unfortunately, natural ecosystems can only feed so many individual per square hectare. A way around this bottle neck - a new "selective pressure"! - is to reduce the average size of individuals thus allowing a greater population density for the same amount of food consumed. If the competitiveness of the species is improved, selection will lead, over time, to smarter, smaller individuals. Some evolutionists believe there is evidence for such miniaturization of modern, highly cephalized vertebrates.




How modern tetrapods, upper right, are related to fish, left. All the critters between lung fish and modern tetrapods - "the missing links" - have gone extinct.. Again, click on the image for a more readable enlargement.


                                Coelurosauravus and fossil. A glider, not a true flier.



                         Moradisaurus grandis, late Permian herbivorous reptile
                         Note the large defensive talons - "don't mess with me!"

  
notes:

1- Climate change as a - or the - major "driver" of bilogical evolution on earth:

internal blog links: keywords: science, book review, climate change

http://transparencycanada.blogspot.ca/2015/07/book-review-catastrophes-and-lesser.html 

http://transparencycanada.blogspot.ca/2015/02/book-review-everything-you-wanted-to.html 

http://transparencycanada.blogspot.ca/2014/08/book-review-end-of-world-at-end-of-world.html 

http://transparencycanada.blogspot.ca/2013/11/book-review-great-extinctions-what.html 

http://transparencycanada.blogspot.ca/2013/05/book-review-ice-ages-solving-mystery.html 

2-  The following quote is from a recent book review of a text on Disturbance Ecology which deals with the biological diversity fostered by fragmented, frequently disturbed ecosystems:

"Disturbances help generate the mosaic makeup of the habitat. A fire burns out a patch of forest and open it up to sunlight. Now, small plants, which had been suppressed by the shade of the trees, can thrive, and then a meadow can develop. Every organism is uniquely adapted to a particular type of habitat and a diverse array of habitats can support many more species than a uniform habitat. A variety of habitat patches, in turn, supports a diversity of species and communities. This biodiversity is the foundation of the natural ecosystem services upon which all life depends. Contrary to common thinking, disturbances are not bad, but rather they are valuable - indeed, they are essential for healthy ecosystems.. The nature of nature is change."


http://transparencycanada.blogspot.ca/2016/01/book-review-disaster-ecology-bright.html?spref=fb 

Thursday, January 21, 2016

Book Review: Disaster Ecology - the bright side of disaster

Seth Reice: The silver lining, the benefits of natural disasters, Princeton University Press 2001, 213 pages, index, photos, graphics.

"The elaborate environmental management system we have created is grounded in an archaic, misguided belief that disturbances are evil and that nature must be controlled. Our history of attempting to control - indeed, to dominate - nature has led to many of the problems we now face.", page 192

                                          wetland meadow with wild irises

           The thesis of prof Reice's book is simple, if revolutionary. Much of what we call "development" or "improvement" (on nature) ain't! We believe we are "improving" on nature when we drain bogs, swamps and marshes and straighten rivers and divert their flow to irrigate crops. We believe that we are reducing economic losses when we erect dikes to contain rivers prone to annual flooding. We believe that, despite the cost and effort of these projects, we gain more than we lose: we expect a positive "return on our investment". Such beliefs reflect, of course, our cultural ideology of faith in Progress (see note 1).

            But is our naive belief in Progress warranted? The state of our global environment tends to suggest otherwise. 

 Half the wildlife has gone missing in the past 40 years?

Guardian: earth-lost-50%-wildlife-in-40-years-wwf

Half of earth's fish stocks have gone missing in the past 40 years?

http://ocean.panda.org/


       Prof Reice teaches Disaster Ecology at the University of North Carolina. Disaster Ecology studies the impacts, positive and negative, of natural or human disasters on ecosystems, their structure and dynamics. The results of this research are surprising, often counter-intuitive.

"Disturbances help generate the mosaic makeup of the habitat. A fire burns out a patch of forest and open it up to sunlight. Now, small plants, which had been suppressed by the shade of the trees, can thrive, and then a meadow can develop. Every organism is uniquely adapted to a particular type of habitat and a diverse array of habitats can support many more species than a uniform habitat. A variety of habitat patches, in turn, supports a diversity of species and communities. This biodiversity is the foundation of the natural ecosystem services upon which all life depends. Contrary to common thinking, disturbances are not bad, but rather they are valuable - indeed, they are essential for healthy ecosystems.. The nature of nature is change." Page 3 (emphasis added)




            Natural "disasters" therefore possess a hidden - unsuspected - face. They, paradoxically, are necessary for the optimal functioning and resilience of many, if not most, ecosystems. In extreme cases, some ecosystems actually require quasi-periodic "disasters" - fire, flood, storm damage.. - in order to exist and persist over time. The dominant tree species in some conifer based forest ecosystems have died off as a result of human attempts to suppress forest fires. The trees require singeing heat to release seeds from pine cones; the seeds, in turn, may require a forest floor free of competing vegetation and covered in mineral rich ash in order to germinate.

plants requiring fire to germinate: chapparal

                           Lodgepole pine cone needs fire to open and germinate

            
                It is now evident that such ecosystems evolved with, through and by their interaction with fire. Robbing them of essential, quasi-periodic fires leads to their decline and death (replacement by competing forms of vegetation and their associated ecosystem types) Since the original - fire-evolved - ecosystem was optimally adapted, through aeons of evolution, to the regional climate, local micro-climates and hydrology, primary biological productivity will fall off. Species diversity will drop, some locally adapted species may go extinct. The new ecosystem created by well intentioned human attempts to "improve on nature" will likely be less resilient, less robust in its response to major disasters in the future. This should be a cause for concern in a world challenged by anthropogenic climate change. Now, more than ever, we need healthy ecosystems to withstand the coming changes. Instead we weaken the surviving ecosystems we have left..



              Disaster Ecology teaches that what we call "natural disasters" are actually part of the normal functioning of ecosystems. Suppressing disasters - with dikes, dams, irrigation, fire suppression - disrupts ecosystems, weakening, sickening, even destroying them. The "ecosystem services" provided by these ecosystems - clean air, clean water, fertile soil, natural crops (wood, fish, game, mushrooms, berries..) - will suffer as a result of our meddling. The result of "improvements" can be, paradoxically, increased economic losses, increased risks to life and the aesthetic deterioration of natural scenery. Natural fish stocks may plummet, wiping out livelihoods and forcing migration of impoverished populations. Floods or fires may be reduced in frequency but, when they do inevitably occur, will be devastating holocausts in terms of lives and economic losses.

            It is only with the last few decades that ecologists have grasped the essential role of natural disasters in promoting ecosystem health, diversity, productivity and resilience. Much of our thinking has undoubtedly been influenced by the Darwinian Evolutionary School and their battles with the Creationist of their time. 

            Religionists argued that Bible stories of the Creation, the Deluge and the promised Kingdom of God at the End of Days were confirmed by the "episodic" nature of fossil strata. The fossil record seemed to indicate that the world's history was divided into Epochs, each stage initiated and terminated by Divine Intervention. Some argued that the "antediluvian monsters" were punished by God for sin of greed: God allowed them to perish in the Deluge. Others held that dinosaurs were simply too big to fit on Noah's ark..
  

 
                Darwin and his followers were, in retrospect, seriously hemmed in by ideological constraints. To differentiate the emerging "scientific worldview" from "creationist obscurantism", the Darwinists contended that the processes of nature were slow and steady, change was gradual. There was no need to seek Divine Intervention in our attempt to understand - and control - nature. Human reason, science, would eventually prove competent to explain / control human destiny. God was, in their eyes, an "unnecessary hypothesis" (Laplace).

               Today, with advances in the earth and life sciences, we have come to understand the Darwinian / Creationist debate of the 19th century in a new light. We see that the Creationists were right but for the wrong reasons. Nature is violent, the earth's biological history is episodic but God had no hand in all that. The Darwinists were wrong but for the right reasons: nature's "gradualism" is punctuated by periods of accelerated - even catastrophic - change but the hand of God is, indeed, nowhere to be found.
  
               Unfortunately, our treatment of nature remains founded on false "equilibria theories" inspired by wrong-minded Darwinian gradualism. Ecology itself has utterly failed till recently to understand the creative roles "disasters" play in healthy ecosystems. The economic and sociopolitical consequences of our misguided conceptions of nature are now becoming increasingly disastrous in their own right..

              For example, it is now known that only a small fraction of the species capable of living in a space actually live there. Why? Darwin's "survival of the fittest"! Competition between species competing for the same ecological niches actually tends to reduce biodiversity as the species best adapted to local conditions drive their competitors out of business. This, in turn, has unfortunate consequences given nature's catastrophic tendencies. If predator species A, B and C compete for the resources of a locality and A is a bit better adapted, A will tend to drive out the other two. Then comes a spate of bad weather, a random or periodically occurring fluctuation in regional climate. What happens to the ecosystem if it turns out that species A - the winner of the Darwinian survival sweepstakes - is "overspecialized": it eliminated its competitors, recall, exactly because it was better adapted to local conditions. But now these conditions no longer hold! If B and C were still present they, in theory, might possess capabilities of adapting to the new conditions (each species has its own skill set..) Alas! B and C are gone and now, under changed climatic conditions, A bites the dust too. If A was a "keystone species" - the bit that holds the whole ecosystem together (say, because it prevented herbivores from overgrazing..), then the entire ecosystem will collapse, biomass productivity will fall precipitously, many species will die off in a "domino effect" cascade. The disappearance of key plant species - from overgrazing by goats in arid environments - may result in catastrophic degradation of the soil with attendant aridification and terminal desertification. In our example, all this might have been avoided  with a more diverse selection of apex predators - to control those overgrazing goats.. Moral: lack of biodiversity kills! 




              Interestingly, natural disasters maintain essential, resilience building biodiversity. Disasters build diversity in several ways. By eliminating competitors in a small region, disasters allow "migrants" from neighboring regions to enter and set up shop. In the case of aquatic ecosystems with flowing water (river, seas coast), the migrants may arrive from quite a distance but formerly were not equipped to deal with a dominant species, fortunately now greatly reduced in numbers. A quasi-regular regime of disaster (recurrent flood, fire, drought, frost, deep snow..) tends, therefore, to maintain biodiversity as it prevents any one species from establishing a monopoly. This, in turn, enhances resilience, the capacity to rebound after a disturbance. A biologically diverse ecosystem has more cards in hand hence more hands to play - more adaptive options to play..

             Increased biodiversity has other advantages than increased resilience in the face of disturbance. By increasing the number of species "working" the land, more ecological niches are created with a generalized increase in total annual biomass production. Diverse ecosystems are more resilient and productive and because there is more biological activity going on. They are better able to provide vital ecosystem services such as water retention and purification, soil production and retention, nutrient transport, etc.

              Natural disasters tend to increase biodiversity in both space and time. In space, because disasters tend to fragment and break up ecosystems. A flood will produce different degrees of inundation with differential impacts depending on land elevation. A quasi-regular regime of flooding allows different micro-ecosystems to establish themselves and flourish, boosting biodiversity, bioproductivity and resilience.
         




               In addition, regular flooding provides essential nutrient transport into wetland ecologies, again boosting productivity and diversity. If humans with good intentions prevent regular flooding, reduced nutrient transport will reduce productivity, fish stocks may collapse and fisherfolk starve or be forced to move elsewhere. Some species may disappear completely if they require flooding to migrate or procreate..

               I should point out that prof Reice is not a romantic Luddite tree-hugger. Some human interventions in nature screw things up, others don't. Some interventions - if based on adequate ecological science (and a bit of dumb luck) - may actually enrich natural ecosystems by increasing soil fertility or biodiversity. On the whole, Reice's message is a positive one: humans can learn to live with nature and both parties can thrive.

              Prof Reice proposes several measures which could alleviate some of our more pressing concerns. We could, for example, begin ecological zoning of land use. Insurance premiums should be keyed to ecological reality and take into account the risk of recurrent flood, forest fire, storm surge or drought. Such enlightened policy would discourage building in ecosystem which require periodic disasters to flourish and rejuvenate. Already progress is being made on this front.

infrastructure for extreme weather / Swiss RE 

             Swiss RE is a major "reinsurer", an insurance company which insures insurance companies. This "spreads out the risk" and prevents the smaller client companies from going under if they have to make massive pay outs following a major disaster. Such disasters are becoming more common due to climate change, so it is in Swiss RE's interest to encourage its clients (smaller insurance companies) to adopt enlightened insurance policies.

             Returning wetlands to their natural state in some places will actually result in reduced economic costs since wetlands act as natural buffers against flooding and coastal storm surges: they slow the advance of floods and dissipate their impact over a large surface. It should be noted that the question of wetlands and coastal flooding will become more pressing in coming years due to sea level rise (linked to global warming which causes sea water to expand). Rejuvenated wetlands will - if we are wise - provide a buffer to slow the ingress of rising seas, giving more time for human populations to migrate and / or adapt.

               New York city has recently spent $1 billion to purchase land bordering the Hudson river in order to preserve, or return, ecosystems to their natural state: natural water filtration / purification plants. A tree hugger folly you say? Nay! Economists estimate the dollar cost of equivalent water treatment plants at more than $ FIVE billion. Five versus one billion dollars: a 400% saving!! In addition, the water treatment plants would consume fossil fuel energy both in their construction and operation, further wrecking our climate and ecosystems with greenhouse gas emissions. In this case "letting nature be" is a win - win outcome for everyone. This is a good example of what sound ecologically-based development could accomplish - if we but had the political will..

              The Big Problem at present is that damned lack of political will. For me, the real risk is that by the time environmental disasters become severe enough to change public opinion, it will be too late to mitigate the worst of the damage. This, of course, could have immense - and presently incalculable - effects on the future course of society's evolution. At the limit, we face demographic collapse, exterminatory warfare, universal pauperisation and the effective suicide of civilization as we know it. This choice is up to us, especially the young who will live in the changed world, and the old who choose to dedicate their last years to assuring the worst won't happen..

               Silver lining is an interesting, well written, and above all, an eye opening book. It is written for the public, not for a specialist audience. All essential concepts are well explained, in detail with abundant examples. This is a book recommended for young people and elders who give a damn about the future.

              
notes:

1- Surprisingly, "Progress" turns out to be a new-fangled idea. Earlier cultures generally did not possess our faith in progress and innovation. The goal of traditional societies was to (magically, ritually, ethically) preserve the natural equilibrium upon which human and non-human life depended. Some legendary innovators (the discoverer of fire..) were honored but most innovation was seen as perversion and deviation from an Ideal (metaphysical, spiritual) order. Examples are hunter - gatherer - farmer cultures like the Hopi of N. America or the Australian aboriginal culture. Even relatively "modern" - urbanized, centralized, literate - societies such as China or ancient Rome placed the Golden Age in a Heroic Past, not in some Utopian Future created by technology and the revolutionary establishment of a "Classless Society".