Daniel E. Koshland, Jr.
1920 - 2007
Life and Death
The basic assumption of this book is that What Comes After Homo Sapiens is going to be a living species in the genus Homo. That required me to make sure I (and my readers) understood what is meant by the words genus and Homo. That was easy enough, although the Homo part took three chapters. What I had not anticipated was how difficult it would be to explain the meaning of species. It turns out that books have been written about the definition of species and the species problem is still unresolved. For purposes of this book, I had to arbitrarily adopt a definition and live with it even though I have concluded that species have no existent reality but are simply constructs in the minds of Homo sapiens.
My biggest astonishment, however, is that there is a problem defining the word living! I assumed everyone knew what that meant—until I tried to find a definition. There are many and for each one, it seems there are ambiguities. For example, all plants and animals are considered to be alive, but there are other living things like bacteria. It turns out that while bacteria are considered to be alive viruses are not! Why? What is the essence of living that would incorporate all plants, animals and bacteria but not viruses? My search led me to an essay by Daniel E. Koshland, Jr.
Dr. Koshland was a world renown molecular biologist at the University of California, Berkeley and the editor of Science magazine from 1985 to 1995. He wrote his famous essay on the definition of life after coming back from a conference devoted to this topic, attended by what he called the “scientific elite.” The conferees could not agree on a definition. In his essay, he describes seven “pillars” that he believes characterize life: program, improvisation, compartmentalization, energy, regeneration, adaptability, seclusion. The reason a virus is not alive is because it does not have compartmentalization. That is, unlike all living things, it does not wall itself off from its surrounding environment to enable a self-contained metabolism. A virus must enter some living organism and co-opt its compartmentalization.
My own view is that if the definition is so complex that it requires seven pillars to define it, that living, like species, is simply a construct in our minds and not a real entity.
Dr. Koshland was important in my research for this book regarding another topic: aging. In the chapter on genetic engineering, the topic of possibly being able to delay and even reverse the aging process led to the concept of the Methuselarity. That is the point at which our ability to reduce the effects of aging outruns the aging process and we achieve virtually unlimited lifespans. When discussing the pros and cons of achieving the Methuselarity, Dr. Koshland's essay was again invoked. He stated that death plays two very important roles for us. Without aging-related death, we wouldn’t need to reproduce very often. That would deprive us of our most important mechanism for survival. Reproduction provides the best mechanism for regeneration of tissues. By creating a new, fresh copy of organisms from germline cells, all organs and tissues are regenerated. The DNA slate with all of its accumulated changes during a single lifetime is wiped clean, with the possible exception of some epigenetic changes. Second, reproduction by meiosis provides the opportunity for genetic recombination, which is our best mechanism for adaptation. Without death and birth, we wouldn’t have natural selection. Therefore being good at delaying or preventing death may be good for an individual, but it is bad for the species.