Coexistence: The Ecology and Evolution of Tropical Biodiversity

by Jan Sapp

This book is about tropical biology in action- how biologists grapple with the ecology and evolution of the great species diversity in tropical rainforests and coral reefs. Tropical rainforests are home to 50% of all the plant and animal species on earth, though they cover only about 2% of the planet. Coral reefs hold 25% of the world's marine diversity, though they represent only 0.1 % of the world's surface. The increase in species richness from the poles to the tropics has remained enigmatic to naturalists for more than 200 years. How have so many species evolved in the tropics? How can so many species coexist there?

At a time when rainforests and coral reefs are shrinking, when the earth is facing what has been called the sixth mass extinction, understanding the evolutionary ecology of the tropics is everyone's business. Despite the fundamental importance of the tropics to all of life on earth, tropical biology has evolved relatively slowly and with difficulties - economic, political, and environmental. This book is also about tropical science in context, situated in the complex socio-political history, and the rich rainforests and coral reefs of Panama. There are no other books on the history of tropical ecology and evolution or on the Smithsonian Tropical Research Institute. Thus situated in historical context, Jan Sapp's aim is to understand how naturalists have studied and conceptualized the great biological diversity and entangled ecology of tropics. This book has potential to be used in tropical biology classes, ecology courses, evolutionary ecology and it could also be useful in classes on
the history of biology.

290 pages, Hardcover

Published November 15, 2016

Reviews

[Ştefan Tiron · Rating 4 out of 5]

Jan Sapp new book is a must for everybody having even the slightest interest in the rainforests & coral reefs that are currently at the heart of 6th extinction & chthulucenic(or capitalocenic) debacle. This book is going to be of interests both the conservationist as well as to those interested in the why & how tropical research centers originate or how various methods of accessing forest canopy got tested and developed(such as cranes or inflatable aerial rafts). I knew of Edward O Wilson and Daniel Simberloff's tests of the theory of insular biogeography, but I was never aware of how important the Barro Colorado Panama research (Smithsonian Tropical Research Institute) center in establishing a permanent station at the tropics. Sapp's style of punctating various historical breakthroughs in biology, of carefully following the arguments and the theoretical filigree leaves no leaf unturned and allows him to gracefully extract unknown particulars (to me at least) about specific developments growing out of various sub-disciplines. I was somewhat familiar with the history of these sub-disciplines, be it cellular biology, microbiology, molecular biology, lichenology (the branch of botany dealing with lichens) and how whitin each specialist community there was fertile ground for counter-currents. These counter-currents, sometimes out of date or sometimes just areas of fresh insight acted as catalysts for further upswells that keep renewing or revolutionizing our understanding of the origins of life (such as the molecular revolution responsible with reshuffling the Tree of Life). For me at least, he was fundamental in clarifying how important the microbiological turn has been and how classification based on molecular clocks, gene sequencing etc have been key in changing the perspective away from the visible, macro-, multi-cellular view on life towards symbiogenesis, bactereality, epigenetics etc
In his words, the discovery and research into the extremophiles & most basal domains of life (Archaea and Bacteria) have reshaped our understanding of chemical aka metabolic 'true' diversity of life. There are very few visible, oldskool morphological criteria to distinguish the types of bacteria, if one works in a tradition of being formally trained to identify and taxonomically organize bird species or insects. Microbiology has been unveiling the hidden diversity that is nested at low end of life, outside of its mammals or other more spectacular amd popular levels. Echoing Stephen J Gould, after the microbiological revolution, life as we know it via Animal Planetary or National Geographic Channel, rich in highly complex (morphological) multicellular forms appears just like as a sort of after-thought, a restricted if flamboyant & chemically drab sub-group of the bacteria and archaea. I could go on and on.

I have read his books with vivid interest and have always profited immensely from its site specificity, particular institutional focus, tracking historical and theoretical side-stories and counter movements. One is easily swept by the particular life stories & background of the scientists themselves as well as their puzzlement & patience in tracing all the scientific research threads up to their final integration into the main yarn.

Coexistence - his new book attracted me first because of its difficult and hard to summarize & co-exist subject matter: the research of tropical biodiversity in both tropical rainforest and coral reefs. The task seems daunting, trying to compress 100 years of field research in some of the most diverse and difficult terrain. Nevertheless, much of this initial research was localized or started at one particular geographical location, a particular conjunction of personal, financial, political and institutional (including detailed accounts of the lives of the scientists involved) context. Sapp shows how important their aim to understand the inescapable pattern, one of the greatest mysteries of planet earth is - the species diversity gradient, the phenomenal increase in species richness from the poles to the tropic.
The book is a slow but incessant burn. Usually I prefer the slow slide followed by dense cumulative effects, of being allowed to enter outer dimensions (other than human worlds & umwelts) via the minutiae related by a specialist entranced by his favorite life-long biological study object probably far from the interest of others(such as Robin Wall Kimmerer A Natural History of Mosses which I hope I will get to review as well), but with Jan Sapp I take exception. I want to first focus on the most vague overall impressions first - how the book affected me and left me completly puzzled. In the end I am under the impression that I managed to unlearn and escape a lot of clunky ideas and a sort of lazy, conformist understanding of tropical forests. After reading Coexistence - I had the sensation I had the first glimpse, of really looking with unsuspecting keen sense into the mystery of these ancient jungles for the first time. I finally managed to get how bizarre, remote and sort of counter-intuitive they must have been to all these evolutionary biologists and ecologists that suddenly took a systematic method to the jungle. For ex. tagging or counting tree species in selected 50 h plots - as part d am expanding & managing to follow their (ordered?) variability in time.
I am saying this not because of the book or the specialized background that is bewilderingly complex, as it will be clear to anybody from chapter one, it is totally readable and there is very little prior knowledge required to get to the major theories of research at the tropics. What has increased while reading is how open-ended is the solution to the tropical rainforest and coral reef diversity and how it opens up yet other perspectives & venues. There is still little consensus about the mechanisms, the scaled-up evolutionary history. We lack a grand unifying theory to actually explain this most pronounced of patterns. But this is for the good. This is actually one of the points Jan Sapp himself makes (and many historians and philosophers of biology have tried to make, at least since Canguilhem) that biology is not physics, that this domain, while completely physical, tangible and molecular and in spite of the great unifying efforts of neo-darwinist synthesis, refuses the reflex for totalizing over-arching unifying final explanatory frameworks. In following the almost detective-like thread of the book I was hoping for some resolve or some conclusion, but the judge is out, great advances have been made, but still opposing views and a disconcerting antinomy inside the researcher community permits various conflicting theories to coexists without eliminating one or the other.

I will never look at the tropical forest with the same eyes I guess, but first I would like to bring 3 things to attention. I've ignored many others including much of the socio political context of the region or the sometimes strained dynamic with the mother institution, the Smithsonian, or the game theory discussion about the ratio of fishes on the reef etc etc Mine are completely personal points highlighting maybe why I think the book has struck a chord with me:

1. The northern bias - there is a very specific bias that once identified by Sapp, keeps on returing, the realization that even if most of the fundamental research and inspiration for the evolutionary theories (work done by Darwin and Wallace) was made at the tropics, while at the same time both researchers and much of their familiar habitat was elsewhere (in the northern temperate zone that provided such a contrast). The big puzzle was this coexistence in the midst of incredible chaotic conditions, in the midst of sheer suffocating variety, refinement over niches and sub niches seemed necessary to explain why they coexisted. The hypotheses about them kept on pushing and the methodological tuning in becoming more and more refined. I think I never fully realized what a difficult task it has been to solve the mystery and how big the actual ecologic-economic disparity is i.e. the unequal distribution of the worlds top biologists (economic wealth) and their area of research - rich in ecological wealth while geographically located in some of the poorest areas. America's military & economic presence looms at the American divide, the Monroe doctrine, Kissinger, the overlapping sociopolitical and biocultural layers in Panama constitute the actual foreground to the history of tropical biology in this study (the Smithzonian - a Panamanian pun on the Canal Zone & questions of autonomy & sovereignty).
Another puzzle - brought by the book Darwin without Malthus: The Struggle for Existence in Russian Evolutionary Thought by Daniel Todes picks up on the specificity of Darwin's (and Wallace's) ideas in Russia. Most of the Russian naturalists argued strongly against a view of nature was in perpetual struggle (read Malthusian British variant) and for cooperation or mutualism as being the most important force in evolution. They based their argument also on the fact that both Darwin and Wallace have been working in the tropics, a place of intense competition in their view at the time. In contrast the northern climes where external causes of struggle where much harsher (cold winters, lack of food) pushed the balance in favor of cooperation roughly, so goes the thesis of many thinkers of many different political orientation but who shared this view. This I couldn't reconcile with the fact that many scientists actually suspected that the situation was inverse, or with jungles as places where time stopped (the 'museum' theory) or where niche formation is paramount, enabling the avoidance of competitive exclusion. Northern bias in evolutionary theory as well as the gradient of diversity increase could accommodate such contradictory or opposing views. In a strange way this diversity of opinion reflects the biodiversity of the wet tropical ecology and even the fact that various styles that fell out of fashion in the academia such as the generalist naturalist of previous centuries became somewhat of an advantage for those working at the Institute for Research in Tropical America at the Barro Colorado Island in the Canal Zone area. At the same time Sapp follows all the changes during the 70s, 80s and a new style more and more collaborative & interdisciplinary work coming into Barro Colorado via a new group of directors & researchers.

2. Diving into the microflora of jungle soil was a total delight. I think that Jan Sapp is somehow at his strongest when uncovering the way game theory, symbiosis, population genetics and the unseen and unthought diversity under the feet of biologists came into perspective. At the root level of the forest or at the level of the endophytes in leaf structure or at the level of symbiotic algae within coral communities lies another whole densly packed chapter that changes again the direction away from the maximum diversity in the canopy standard explanation. Temporal dimensions see to regulate mycorrhizal communities that started with a mixed community and ends up with a different type dominating a particular phase in the life of a tree. In fact these new jumps at various temporal scales seems to challenge researcher long term perspective - assessing stability (niche specificity) or chaos (neutral theory) changes with scale, sample size and going to asses diversity at the level of paleoecological proof over thousands of years.

3. Because of the Barro Alto Institute is the main focus of the book - the Great American Interchange, the geological event that closed the Panama isthmus between the Pacific and Atlantic ocean isolating the two sides, while permitting free transit from the two continents some 3 million years.
The Great Interchange somehow was a great historical experiment at opening up and closing down previously separated landmasses and biogeographical areas with million-year diverging evolutionary histories, a perfect place of encounter where extinction events, or surprisingly high diversity growth under tremendous changes could be studied. Studying the stratigraphy and the fossil record of the area allows us to assess how species introduction is affecting other areas or how big the disruption was.