Rob Dunn

I've come back to this book, some years after reading it. (Actually I was looking for some material about muscle fibres which is actually in Nick Lane's book, "Life Ascending"....but came across this as I searched...hence the current review). I must say, a really fascinating book. On the surface it is an attempt to say something about the documentation of all the living species on earth. A project begun thousands of years ago, at least, by Aristotle...and probably others before him. But as EO Wilson says in the preface: "While it is true that perhaps 80 percent of the flowering plants and 95 percent of the species of birds are known, only a small fraction of the far greater diversity of insects and other invertebrate animals have been discovered. Fewer than 10 percent of fungi and many fewer than one percent of microorganisms are known. Of the species known, less than a tenth of a percent have been studied in any depth-and even then across only part of the range of their entire biology". So it's clearly a big project.

One attempt to get a bit of a handle on the dimensions of the problem was initiated by Terry Irwin in 1979 in Panama where he fogged some trees with insecticide and caught the insects that fell out of the tree on sheets below. He was mainly interested in Carabid beetles but what Erwin saw and what he wondered about was not just the carabid beetles. The animals that had fallen before him were dense, diverse, and, it became clear, mostly unknown..... For two or three years, Erwin sorted the beetles collected in those first trees. There were so many specimens that many of the things that weren't beetles rotted before they could even be processed. Erwin had fogged nineteen trees in total. He had enough specimens, enough new species, to last many years, perhaps his entire life.

Erwin is often remembered for predicting there might be 30 million species on Earth. His prediction was actually bolder. He had predicted 30 million species of tropical forest arthropods. He refrained from making the additional prediction of how many total species live on Earth...... The immediate response to Terry Erwin's paper was silence...... Responses to Erwin's estimate fell into three categories: wonder (Lowman's response), consternation, or outright aggression.
Most people probably responded with wonder!' But the aggressors wrote papers and were more vocal both in print and at meetings".....It's interesting how the "establishment" of scientists fights off new ideas. I guess this is healthy. It means that any new idea really has to prove itself before becoming the new paradigm.

The following is a series of extracts from the book that particularly caught my attention:
"DNA barcoding is a method by which small sections of mitochondrial DNA from specimens are used to identify, rapidly, what a species is and roughly where it belongs on the evolutionary tree. The method was and remains controversial....... When Hebert barcoded Astraptes fulgerator, the barcoding indicated there were at least ten genetically distinct species. The lineage had evolved and diverged but had done so without noticeable changes in adult morphology. The butterflies all looked the same. Once distinguished though, the species stories became clear. The different species seemed to favor different food plants and, now that they were known, their biology could be studied in greater detail.

Janzen goes on, as ferociously as ever, trying. He has barcoded about eighty thousand specimens from Guanacaste. Paul Hebert has barcoded about half a million specimens, including many that have been sent to him by the Great Smoky Mountains National Park ATBI. Janzen and Hebert are now trying to find $150 million to jump-start the world project.

There are somewhere around two million named species on Earth, and there is no complete list even of those species. Perhaps ninety percent of such named species have been studied only once, when they were collected and named. Nothing else is known about these species other than a basic description of their physical structure, their morphology, and the name we have superimposed upon them. Even the European earwig, which you might find under a paving stone on your way to work (and which was, of course, named by Linnaeus), is virtually unknown. It was revealed last year that this earwig has an extra penis in the case of damage to the first.
Lynn Margulis came to the conclusion that key organs of eukaryote cells (mitochondria, chloroplasts, flagella, cilia, and centrioles) had their origins in ancient bacteria engulfed by another cell. As already mentioned, it had recently been discovered that mitochondria and chloroplasts had DNA (most of "our" DNA is in our cells' nuclei).

Woese ran to tell Wolfe, saying, as Wolfe remembers, "these methanogens are not bacteria." Wolfe told Woese they had to be. "Of course they are bacteria; they look like bacteria... Now, calm down; come out of orbit.".... but the result was getting more and more clear: the methanogens were very different. Once "a second methanogen was characterized and showed itself to be related to the first, there was no doubt" that they had found a new form of life, Woese would later say. This form of life had been different from the others, bacteria and eukaryotes, for a very long time..... The New York Times ran the headline, "Scientists Discover a Form of Life That Predates Higher Or-ganisms," on the front page of the November 2, 1977 edition..... The fats in the cells of archaea and bacteria differ, as do the sugars and proteins. Some of the composition of archaea more closely resembles that of eukaryotes than it does that of bacteria, but most of the differences are simply unique. The houses are built to similar specifications, but of different materials. In most cases, the composition of archaeal cells differs in ways that make them tougher, more resistant to heat, cold, and other extremes.

Woese reconstructed the tree of life and in doing so studied the TRNA in archaea, bacteria, and eukaryotes.......If Margulis were right that our mitochondria had once been free-living microbes, their rRNA should be more similar to that of other microbes than it is to the rRNA in our nucleus. And it was. Here was almost unassailable support for Mar-gulis. The mitochondria and even chloroplasts could be mapped onto Woese's tree of life, as easily as if they were still free-living microbes living in the ground.

The life at the vent was thriving not on derivatives of the sun, but on the chemicals released from the vents. Those chemicals included hydrogen sulfide, but, as time and more research would tell, also a variety of other chemicals. Here then was the first example of an ecological realm based almost entirely on energy from the Earth itself....... Before photosynthesis evolved, all living realms used chemical energy, the Earth's energy.

When one scales down to the size of the fossil microbes in the Martian rock, interpretation becomes art. One is up against the limits of microscopy. Forms that are obvious at bigger scales become open to interpretation, vulnerable to preconceived ideas about what is and is not possible. Even scanning electron microscopy is not high enough in magnification to see such small shapes well.

Most microbiologists still believe that there are lower physiological, or simply physical, limits to the possible size of a living cell. If you take an E. coli bacteria cell and pare it down to the bare minimum of necessary genes and parts, the DNA, RNA, and ribosomes alone are big enough to require a cell at least two hundred nanometers....... One hundred nanometers, the biggest dimension of both Kajander's nanobacteria and McKay's Martian microbes remained, to most, too small...... Nanobacteria have now been associated with many diseases, a sort of who's who of bodily bad news: rheumatoid arthritis, cholecystolithiasis, coinfections with HIV, various cancers, Alzheimer's disease, prostatitis, and even lowly periodontal disease. The work on links between nanobacteria and kidney stones in particular has been the subject of research by scientists at the Mayo Clinic and elsewhere...... Then it happened. In 1998, Kajander and Cificioglu isolated RNA from one of their samples. The RNA indicated the nanobacteria were a kind of proteobacteria and so suggested the possibility of billions of proteobacteria, all smaller than it had been predicted...... another team showed that the RNA Kajander had found most closely resembled that of a bacterium common on laboratory equipment." The results appeared contaminated...... At least to Kajander's knowledge, no grants have been awarded for work on nanobacteria in eight years...... The more common and problematic nanobacteria are, the more money Nanobac stands to make. Therefore, Kajander and Ciftcioglu had a financial incentive to find nanobacteria in more and more places.

We have many questions yet to resolve: When, and how many. times, did life evolve on Earth? Did life first evolve on Earth? Has it evolved elsewhere? What are the hottest, coldest, or most extreme conditions where life can live? Is there life in the magma at the center of the Earth (or even: Is there magma at the center of the Earth)? What are the smallest species? Is there a limit to how big species can be? Can life evolve without DNA? Does such life already exist on Earth? Do bacteria make oil and coal? Which kinds of species (bacteria, archaea, vertebrates, plants?) represent the majority of the weight of life on Earth? Do the species on Earth account for all of life in the universe?
Is Earth just one of a million planets with life? Do species disperse from Earth to other planets?
Not one of these questions is ridiculous, and not one of them is even close to being answered.

In Sweden, all of the multicellular species will be named by 2021. I can think of no more apt statement of how far we still have to go. In the country where Linnaeus, 250 years ago, was bent on naming everything in the world, we are only just now getting to name every multicellular Swedish thing..... Dan Janzen, upon hearing of the project, reminded a reporter that as many species could be found in the Guanacaste Reserve in Costa Rica, where he continues to toil, as in all of Sweden.
.... No one in Sweden has said anything about describing all of the bacteria, archaea, viruses, protists, extinct life, or even, for that matter, distinct evolutionary units. It is not in the cards. It is too much. Maybe Ulf is right that we will fill in the last unknown species of multicellular creatures in Sweden in a few dozen years. Maybe we will then move on to the microbes. Maybe we will even someday name all the species of archaea, bacteria, and eukaryotes in the world.
But I doubt it".

Personally, I was a bit disappointed that Dunn didn't even seem to try the exercise of estimating the total number of species in the world: How many fungi, How many archea, how many bacteria. how many insects, etc. He seems content to say something like there are two million named species but makes no estimates or even guesses about the total number of species. (Though, as is pointed out in the book, even the concept of differentiable species is being questioned and it's being suggested that we should be looking more at the DNA trails and accounting on the basis of DNA differences).

Dunn dabbles into nanobacteria (though I thought some Australians at UniQueensland were absolute pioneers in this field. And into astrobiology and there is some interesting history there about some of the apostles that Linnaeus sent out ...and din't really support of give due credit. However, he seems to totally ignore the viruses. I guess, viruses are very hard to pin down to species because they morph so fast....but it seems like huge field for systematics of some sort (likewise with bacteriophage).

I also find myself wondering how it is possible to find billions of dollars per day to wage a ware in Ukraine and similarly in Gaza where a single plane can cost hundreds of millions of dollars but finding $150 million to catalogue "all" the species on earth seems beyond reach. (Actually, I'm sure that once we start on even the fungi, we will realise that much more than $150 million is needed).
Overall, a fascinating book and I enjoyed it very much...even if I am left with many questions. Five stars from me.… (meer)

he book was written in 2015, and it's fascinating to see what the author refers to in the last chapter, is now coming to fruition.
As a nurse, I took care of a lot of cardiac babies, including those with Tetralogy of Fallot & the Blalock surgery. I didn't know where that had come from.
After the chapters on the developments in heart surgery, the author tackles the topic of coronary artery disease, including the lack of studies of the stent procedure vs. doing nothing.
The study of birds - and other species - and their maximum lifetime heartbeats was intriguing. Maybe we can't find a fountain of youth after all.… (meer)