Despite the genius of Charles Darwin’s Origin of Species, there was a question that was never really answered in his life’s work. True, he gave us the inestimable gift of understanding natural selection, sexual selection, and the competition in differing environments for species to adapt to each organism’s surroundings and conditions, and for that we ought to be eternally grateful. Those notions have formed the basis of our biological comprehension for the past two centuries, but the truth remains: Darwin, despite his opus’ title, never posited adequately where speciation has its genesis. Different theories have arisen, but one which has intrigued me, and one I suggest that you might explore, is that covered in Lynn Margulis’ and Dorion Sagan’s book entitled Acquiring Genomes: A Theory of the Origins of Species, 2002, Basic/Perseus Books. For an amateur microbiologist and microscopist, I found it a generally non-technical book, a great read, and a huge inspiration to our appreciation of life at the microbial and especially bacterial level.

The basic thesis of the work, somewhat controversial, is that single celled organisms without cellular nuclei, in a toxic environment such as that which prevailed in most of Earth’s early history, acquired entire genomes from bacteria, and in effect absorbed the bacteria which then became nuclei, the beginning of the eukaryotes. The process is referred to as symbiogenesis, and in these authors’ view, accounts not for the actual origin of the life force itself, but for initial speciation. Without a variety of species, of course, Darwin’s ideas do not work, for without such speciation, there are no options for the organisms to select from. Yes there are mutations and natural selections which occur, but no one has yet to actually observe initial speciation in action until quite recently.

Margulis particularly has been a champion of this theory for some time, and despite much criticism, has now acquired even after her demise quite a following in the science of microbiology. Symbiosis means that as two or more organisms share genomes, each benefits from the special talents of the others, operate together as one, and so in a very real sense, our forbears are not primates or fish, but rather ancient bacteria, very similar to those we witness under high power through our microscopes.

The text is introduced by Ernst Mayr, who writes “Let us never forget the important lesson taught by these authors: the world of life not only consists of independent species, but every individual of most species is actually a consortium of several species. The relation between larger organisms and microbes are infinite in number and in most cases make an indispensable contribution to both partner’s fitness. Some knowledge of this vast branch of biology should be an essential component of the education of every biologist. There is more to biology than rats, Drosophila, Caenorhabditis, and E.Coli. A study of symbiogenesis can’t help but lead to a deeper understanding of the world of life, and there is no better way to gain this knowledge than to study Acquiring Genomes.”

My beautiful wife is a member of the Cree Nation in Canada. It is interesting for me to note the parallel which exists between aboriginal and even Celtic spirituality, and both the new physics and, “new” microbiology, as in Margulis’ and Sagan’s book. The idea that life is a cooperative effort, and has been since its beginning, is profound. At the same time, it reflects the native understanding of the biosphere as being a living, breathing, and ubiquitous macro-organism. This is often summed up in the First Nations’ prayer, “All my relations”.

The book comes with a very helpful glossary and index which points toward further reading resources. For those of us who wish to go beyond the important task of asking what that squiggly thing in our eyepiece is, but wish to look beyond at how it came to be, I cannot think of a better source for contemplation in our chosen field of microbiology.

Margulis and Sagan are not writing something brand new. Others have considered this theory as well, and it is fitting that one of these, I.E. Wallin wrote in Symbiontism and the Origin of Species (1927, Baltimore: Williams and Wilkins) the following:

“It is a rather startling proposal that bacteria, the organisms that are popularly associated with disease, may represent the fundamental causative factor in the origins of species”. Well said, and well worth the guided contemplation of this volume.

Please note that Micscape has another review of a work by Lynn Margulis and Karlene Schwartz, entitled Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth, Third Edition, 1998.

All comments to the author Dale Jeffrey are welcomed.

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