Saturday, May 16, 2015

What We're Reading: The World Without Us. Maybe.


The Next Species: The Future of Evolution in the Aftermath of Man, by Michael Tennesen

Contrary to what readers might expect (or perhaps were hoping for), this is not primarily a book about the next hominid species that will follow man on earth. Rather, in this book Tennesen speculates mostly about a number of animal (and a few plant) species that might become ascendant if humans were no longer in the picture. There is, however, an inherent problem with an exercise of this sort. The species that seem to be favored in the future are those likely to find an opportunity because of the ongoing environmental depredations of man, who is now the central force for evolutionary change in the world. Presumably, then, the environment-impacting evolution in his absence would be something different than it is now.

About that world, Tennesen doesn't enlighten us much--and how could he? Could anyone have predicted the course of evolution from a vantage point of, for example, the Triassic of 252 million years ago? Or even from a million years ago?  And the reader can't help but wonder what the value might be, in any event, in predicting the character of the flora and fauna of a future world we wouldn't be around to see.  This exercise has value only as a cautionary tale.  It is a way of bringing home to us in a stark and dramatic way the dangerous changes in the natural world we are presently causing and seem fixed on exacerbating.






The Humboldt squid is doing just fine, thank you, in over- fished
oceans with rising acidity like the Sea of Cortez. Populations


are on the rise.                                                                                
This book does not begin, as one might expect, with “the aftermath of man” but rather devotes most of its narrative to making the case that there will be an aftermath, that the human species is headed for extinction in the not-too-distant future, that it is a species that will have a relatively short life span on earth compared to other species. Man will be the “ultimate live fast die young” species. Misanthropes, however, will be disappointed.  The problem with man that Tennesen describes in The Next Species seems to be less a moral defect than a Malthusian one. We have simply been too successful a species. In our short time on earth, our population has multiplied astronomically. Tenneson notes,“It took Homo sapiens less than 200,000 years to reach a burgeoning population of one billion in 1800, but by 2000 we topped off at six billion, and by 2045 we are projected to reach nine billion. It is an unprecedented surge of growth with unimaginable risks and innumerable side effects—the wellspring of a raging crisis.” The “innumerable side effects” and the approach of the “raging crisis” is the real subject of this book.  But one gets the sense that the chapters in this book that examine those effects were written previously as journal articles, pieces that have now been reworked into book form, for which a unifying theme has been chosen. Some of the material feels like it doesn't fit, like the author has gone off on a tangent. It retains too much the character of a miscellany.


Many researchers have linked growing jellyfish blooms in the 
 oceans of the world to warmer water temperatures and decreas-
 ing water oxygen levels, especially in coastal waters.                 

Nonetheless, this is a book worth reading, not so much for what it will tell readers about any future species but because of the case it makes for how we are destroying the planet and flirting with disaster for our own species. It is a disaster likely to come in the next few hundred years, one that Tennesen thinks we will not survive. He examines the problem of population growth, of soil depletion as we try to grow enough food to feed this population, of the decline in species diversity as our presence accelerates the extinction of different plant and animal species on earth. He discusses the relation of environmental fragmentation and loss of plant and animal diversity to the growth of diseases that will affect humans, and highlights the over-fishing of the oceans and the destruction of ocean habitats as carbon and global warming contribute to the growing acidification of the oceans. He reveals the concept of “eco service systems” (the communities of plants and animals that serve man) and the implications for us of their loss. He has identified the fundamental threats and themes of ecological depredation, shown how they relate to each other, and left us to wonder if we are not indeed headed into the perfect storm.

Estimated change in annual mean sea surface pH between the pre-industrial period (1700s) and
the present day.  Calculated from fields of dissolved organic carbon and alkalinity from the Global

Ocean Data Analysis project in the World Ocean Atlas (2005)

His concluding chapters on the possible development of new species of man from Homo sapiens are brief, but they are probably the things we picked up the book to find out about in the first place. These seem cursory and unconvincing. Readers would find more interesting speculation in a science fiction novel. The discussion about Mars as an escape hatch for our incorrigible species as they abandon an Earth they have destroyed seems even less probable after the overview he gives us of all the hurdles that would have to be overcome to travel to Mars and make life sustainable on that planet. One wonders why--if we would be smart enough to make life sustainable in such an inhospitable environment--we would not be smart enough to figure a way to save our own.

Artist Bryan Versteeg's conception of a human base on Mars, a tough place to 
live, and a place where you would probably need to produce your own fuel if 
you ever planned to make a return trip to Earth.                                                    
                                                               
The rejoinder to this, one would suppose--the reason why we will not do the things we know must be done--is that we are by evolution incapable of doing those things. The fault is in the biology of our character. Evolution proceeds not by species making decisions about how, as a species, to preserve their future viability, but by individuals of a species adapting to change and successfully passing their genes on to their offspring. It would seem apparent, then, that the question of survival for humankind as a species depends on some “evolution” in human character and consciousness. Our survival depends not on the innovative individual human adaptations and future speciation of the genus Homo that Tennesen speculates about here. Those speculations are predicated on the model and pattern of evolutionary change as we have known it. Our survival rests on our ability to add, as something innovative and adaptive, a collective concern for our survival as a species.

Will this happen? We don’t know. All we know is that we are going to be the single major impact on the biosphere whether we succeed or fail, that all the rest of life is involved with us now. I put my hope in man as the animal that tells stories. It seems the essential thing about man, that unique ability to spin scenarios based on what we remember about the past, experience in the present, and can imagine about the future. We tell those stories in endless variations, and they are what make us who we are. They give our lives meaning and purpose. All those individual stories are but one story, our human story. The story is always about us. The survival of our species--and our planet--may come down to just this: not any love for the rest of creation, but the fact that we are a species that tells stories, and that it is so inalienable a part of our nature to do so that we are just not willing to let the story end.


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