Sex and the Origins of Death [Paperback]

William R. Clark (Author)

Book Description

Publication Date: June 11, 1998 | ISBN-10: 0195121198 | ISBN-13: 978-0195121193

Death, for bacteria, is not inevitable. Protect a bacterium from predators, and provide it with adequate food and space to grow, and it would continue living--and reproducing asexually--forever. But a paramecium (a slightly more advanced single-cell organism), under the same ideal conditions, would stop dividing after about 200 generations--and die. Death, for paramecia and their offspring, is inevitable. Unless they have sex. If at any point during that 200 or so generations, two of the progeny of our paramecium have sex, their clock will be reset to zero. They and their progeny are granted another 200 generations. Those who fail to have sex eventually die. Immortality for bacteria is automatic; for all other living beings--including humans--immortality depends on having sex. But why is this so? Why must death be inevitable? And what is the connection between death and sexual reproduction?
In Sex and the Origins of Death, William R. Clark looks at life and death at the level of the cell, as he addresses such profound questions as why we age, why death exists, and why death and sex go hand in hand. Clark reveals that there are in fact two kinds of cell death--accidental death, caused by extreme cold or heat, starvation, or physical destruction, and "programmed cell death," initiated by codes embedded in our DNA. (Bacteria have no such codes.) We learn that every cell in our body has a self-destruct program embedded into it and that cell suicide is in fact a fairly commonplace event. We also discover that virtually every aspect of a cell's life is regulated by its DNA, including its own death, that the span of life is genetically determined (identical twins on average die 36 months apart, randomly selected siblings 106 months apart), that human tissue in culture will divide some 50 times and then die (an important exception being tumor cells, which divide indefinitely). But why do our cells have such programs? Why must we die? To shed light on this question, Clark reaches far back in evolutionary history, to the moment when "inevitable death" (death from aging) first appeared. For cells during the first billion years, death, when it occurred, was accidental; there was nothing programmed into them that said they must die. But fierce competition gradually led to multicellular animals--size being an advantage against predators--and with this change came cell specialization and, most important, germ cells in which reproductive DNA was segregated. When sexual reproduction evolved, it became the dominant form of reproduction on the planet, in part because mixing DNA from two individuals corrects errors that have crept into the code. But this improved DNA made DNA in the other (somatic) cells not only superfluous, but dangerous, because somatic DNA might harbor mutations. Nature's solution to this danger, Clark concludes, was programmed death--the somatic cells must die. Unfortunately, we are the somatic cells. Death is necessary to exploit to the fullest the advantages of sexual reproduction.
In Sex and the Origins of Death, William Clark ranges far and wide over fascinating terrain. Whether describing a 62-year-old man having a major heart attack (and how his myocardial cells rupture and die), or discussing curious life-forms that defy any definition of life (including bacterial spores, which can regenerate after decades of inactivity, and viruses, which are nothing more than DNA or RNA wrapped in protein), this brilliant, profound volume illuminates the miraculous workings of life at its most elemental level and finds in these tiny spaces the answers to some of our largest questions.

Editorial Reviews

Amazon.com Review

Despite its provocative title, Sex & the Origins of Death is not as sensationalistic as it sounds. William R. Clark is a professor of immunology at UCLA, and his avowed intention is to enlighten his readers rather than to frighten or titillate. Drawing on his broad knowledge of the cellular systems that make up our bodies and the medical and ethical arguments on the nature of death, he presents a compelling tale of the evolution of sex and death interwoven with a story of a man experiencing a heart attack. This juxtaposition humanizes the discussion and grounds the reader firmly in day-to-day reality, even when considering such bizarre topics as immortal bacteria and Sea Monkey spores.

Clark covers the development of sex in microorganisms and how this novelty may have guaranteed the inevitability of death (though perhaps not that of taxes). From this level of thinking, he changes quickly to 20th-century American law, which has pondered the question of death at great length as our scientific prowess has enabled us to maintain deeply traumatized individuals in persistent vegetative states, presumably free from conscious awareness of any kind. Now that death has become a matter of opinion, Clark insists that we pay careful attention to it, both as scientists and as human beings. Sex & the Origins of Death is a great place to start. --Rob Lightner

From Booklist

Billions of years ago, single cells lived, died, and disintegrated. As cells grew larger and multicellular creatures evolved, sexual reproduction entered the picture, and somatic (body) cells had to protect the DNA in the germ cells until it could duplicate itself and continue to exist, at which point the particular somatic cells were no longer needed. Clark points out that there are two basic types of death, one caused by accident or necrosis, and the other caused by suicide or programmed cell death. The latter, apoptosis, was discovered and named just 24 years ago, and much of the information Clark draws on has been more recently discovered. Nature sees no difference between the deaths of brain, liver, or foot cells, but human beings evaluate their minds and bodies in a less impartial manner. Accordingly, Clark explores some of the social, philosophical, and religious aspects of human beings in his lucid, thought-provoking work that concludes that, in the long view, humans differ not at all from other living creatures. William Beatty --This text refers to an out of print or unavailable edition of this title.

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Product Details

• Paperback: 208 pages
• Publisher: Oxford University Press, USA (June 11, 1998)
• Language: English
• ISBN-10: 0195121198
• ISBN-13: 978-0195121193
• Product Dimensions: 8.4 x 5.3 x 0.6 inches
• Shipping Weight: 9.6 ounces (View shipping rates and policies)
• Average Customer Review: 4.4 out of 5 stars  See all reviews (9 customer reviews)
• Amazon Best Sellers Rank: #646,959 in Books (See Top 100 in Books)

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11 of 11 people found the following review helpful:

5.0 out of 5 stars Why we die and how to beat it, January 26, 2003

By 

Brett Williams (Dallas, TX) - See all my reviews
(REAL NAME)   

This review is from: Sex and the Origins of Death (Paperback)

From the outset what UCLA's Wm Clark reports is staggering; Death is "not an obligatory attribute of life" and did not appear with the advent of it. Cellular aging resulting in death may not have occurred for more than a billion years after life's first entry on earth. Programmed cell death (PCD) which we suffer (displayed through wrinkles and forgetfulness) seems to have arisen about the time cells were experimenting with sex.

Sex is an energy costly activity, engaged in because it rolls the genetic dice, inviting variations with each new offspring. An advantage because with environmental change what was well suited in the old world is often not suited for the new. Gene variations may result - through natural selection - in a few offspring amongst the dying progenitors that survive to save the species. For example, bacteria reproduce though cloning themselves, and can do so at a rate of 16 million per hour from one parent (take your antibiotics). But when the environment becomes harsh the parents spontaneously engage in sex, swapping genes with others as a gamble on survival.

In a description of catastrophic cell death Clark displays a talent to meet or exceed even Sagan's best - clear, rich, compelling. Here heart attack and the wonder of cell machinery resist the inevitable as systems and their back ups struggle to counter power failures and starvation in a chain reaction of failing miracles. Like a community, some components are wholly unaware of disaster while others sacrifice themselves transferring energy to last lines of defense - pumps stationed in cell walls countering a siege of water pressing in about to wash them away.

Such stunning, intentioned actions of this tiny, helpless, complex organism, the cell (of which we possess about 100 trillion - about as many cells as there are stars in the nearest 400 spiral galaxies including the Milky Way!) is starkly contrasted against our cell's decision to commit suicide. This happens when life is late, or as early as the womb when ancient relics of evolution are flushed out of us - like reminders of an ocean origin when interdigital webbing of our onetime fins are removed through PCD, leaving what's left between our fingers. Once the nucleus decides to pull the trigger, one last set of instructions emerge as its DNA begins disassembling. All the while a stack of unread instructions are being executed by unwary elements of the cell. The cell detaches from its neighbors, undulates, breaking into globules while still ignorant workers in these blobs work away, floating into a void where they are devoured by immune systems. Awful.

But there are rays of hope for immortality. "Growth factors" are given to cells like lymphocytes to put a safety on their trigger. And there are executioners in this tragedy, T-Cells. Having spotted an invader they do not murder the foreigner, they command the interloper to kill itself, orders dutifully followed. T-Cells know the security code. Paramecium dodge death by letting their macro-nuclei run the show while a micro-version lays dormant. After enough cell splitting, it has sex with another paramecium. Its macro-nuclei suffers PCD and the micro takes over as a newly minted micro-nucleus goes to sleep. Once eukaryotic cells (what we're made of) became multicellular, reproductive DNA would be not only kept in separate nuclei (as the paramecium) but in separate cells - our germ cells (sperm, egg). The rest of us, our bodies, are their guardians, not only redundant and irrelevant but we turn dangerous with too many divisions. When our germ cells meet others, clocks are reset just as they are for paramecium. Sex can save our germ cells but it cannot save us.

These growth factors, security codes, telemeres or some other mechanism may finally be commandeered to salvage us from oblivion. For now, as Clark writes, we must die and there are many mechanisms built into us to make sure we do. Death does not just happen, it is worked toward, with safeguards to assure cells don't backslide into immortality - as cancer cells do, a recipe for disaster. The winner is our species because germ cells are immortal through sex as we contribute molecular chains of ourselves to the future and whoever is made of us. Clark reveals this and so much more. A pure joy to read.

9 of 9 people found the following review helpful:

5.0 out of 5 stars much misrepresented by reviewers, August 27, 2006

By 

Wyote (Seoul) - See all my reviews
(VINE VOICE)   

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This review is from: Sex and the Origins of Death (Paperback)

I delayed to read this book, put off by a reviewer who warned that it was difficult due to the author's use of scientific jargon. But that reviewer was wrong. There is a lot of jargon in this book: all clearly introduced, defined, and rarely used. In fact, the author presents things a little more simply than he could have!

This is one of the better biology books I've ever read (and I read about a dozen each year) because of the issue it deals with: why, literally why, we die. It explains exactly what death is and why, in evolutionary terms, it happens. Here is another one of those subjects which for so long we could only explore through philosophical and religious speculation, now explained clearly, if so much less dramatically, by science. This, indeed, will be the starting point for religions of the future.

Next time a child asks, "Why do people die?" I will have the answer, and an answer likely to appeal to the child's sense of wonder at the universe, likely to inspire her to learn more about her world.

Topics covered include a basic introduction to cell biology, "accidental" cell death (necrosis), programmed cell death (apoptosis), the difference between prokaryotic and eukaryotic cells, sex (in this book, "sex" is simply genetic exchange, not the "sexy sex" we all obsess over; nothing titillating here), the difference between germ cells and somatic (body) cells, the causes of senescence (aging), progeria (a disease of premature aging), the various functions of different parts of the brain, biological and legal definitions of death, permanent vegetative states, biological definitions of life, and cryptobiosis (spores). In addition, embryology, immunology, cancer, metabolism, viruses, and neurology are lightly covered.

All of that is well-explained; if you are curious, you will certainly be able to understand this book.

By far the highlight of the book, the most interesting part, is the minute descriptions of the processes of cell death, incorporated into a detailed description of processes of the death of a human being.

Let me recommend some other books that go very well with this one. Sherwin Nuland has written several, including How We Die: Reflections of Life's Final Chapter which I very highly recommend. It focuses exclusively on human death, and describes how various illnesses lead to death; it also deals with things from a more personal angle. "Sex and the Origins of Death" features a "gene's eye view" of life, which was popularized in Richard Dawkins' classic The Selfish Gene: 30th Anniversary Edition--with a new Introduction by the Author, which I also strongly recommend, along with his other books about biology. (IMHO, he's not so great when he leaves that subject.) In addition, Matt Ridley's two best books are Genome: The Autobiography of a Species in 23 Chapters (P.S.), as fine an introduction to genetics as a layperson could ask for, and The Red Queen: Sex and the Evolution of Human Nature, which brilliantly explores the significance of sex for evolution.

More distantly related to this book, Carl Zimmer's At the Water's Edge : Fish with Fingers, Whales with Legs, and How Life Came Ashore but Then Went Back to Sea has the best account of embryology and evolution that I've read. (If you like that book, another good one in that line is Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body (Vintage)). Zimmer also wrote Parasite Rex : Inside the Bizarre World of Nature's Most Dangerous Creatures (please overlook that horrible title) which explores perhaps the most neglected topic in biology, parasitism, and its importance for evolution - which is very relevant to the evolution of symbiosis and eukaryotic cells, and perhaps sex - and therefore, as you'll see from "Sex and the Origins of Death," very relevant to the evolution of death.

All in all, among lots of great books out there, "Sex and the Origins of Death" is highly recommended.

However, I want to put in a little caveat, as an environmentalist. On page 177, Carrol says that due to the extinction of their natural hosts, which humans have undoubtedly contributed to, microorganisms have begun to infect us, "out of sheer desperation." He gives AIDS and Ebola as examples. However, both of those examples are completely wrong: neither of the original hosts of those diseases (chimpanzees and probably fruit bats) are near extinction. In fact, as far as I know, this entire characterization of the way diseases spread between species is wrong. It's certainly wrong in all the cases I know about, including the two he mentioned, bird flu, bubonic plague, and so on. I can't even imagine how a microorganism could feel desperate....

An argument like that would seem to support environmentalism: if diseases are spreading to us because their natural hosts are going extinct, then we need to protect their natural hosts a little better. It certainly appeals to our sense that bad things happen to us because we do bad things. However, since it's probably incorrect, it would be better not to use it. We have plenty of sound ecological and moral reasons to try to protect the species of our planet without making ones up; and when it's discovered we made some up, unnecessary doubt will be cast on the legitimate reasons as well. So it's better not to make them up. No doubt Clark made his mistake innocently, as this is evidently not his field.

9 of 9 people found the following review helpful:

5.0 out of 5 stars Catchy title, serious book., June 15, 2001

By 

Earl Dennis (San Francisco, California United States) - See all my reviews

This review is from: Sex and the Origins of Death (Paperback)

I can't say enough about UCLA immunologist Dr. William Clark. Despite the brain stem grabbing title of this book (come on, sex and death?) set on a background of struggling sperms, this is a concise, informative primer on cellular biology; a broad subject. Fortunately Clark focuses on some of the more interesting aspects allowing the reader some specific retention from a virtual sea of information. There are probably about a dozen absolutely astounding facts in the anals of science and physics that bring perspective to the wacky world of reality. Clark zeroes in on the biological milieu and sheds some light on what sex and death signify at the biochemical level. For example, dividing bacteria are potentially immortal. They don't necessarily die (although outright death can occur) but simply divide, thereby making more copies of theirselves. Sex, Clark's thesis implores, was natures alternative to bacteria but carried the price of mortality with it. If this isn't an original sin analogy I don't know what is. All the bacteria today are in a sense immortal descendents of the bacteriodal creatures that existed billions of years ago. We, as humans didn't just pop up out of the aether either, but it is our germ cells that are the the catalysts for allowing us to be here in a potentially immortal lineage from the very same ancestors of bacteria. Not our bodies mind you, they're just disposable vehicles for the immortal sperms and eggs ( the ones that get regenerated and fuse with their counterpart in any event). We die, but our sperms and eggs (a few at least), like bacteria, persist in an immortal-like, time spanning existence. Gametes, however, aren't the only eukaryotic cells that are potentially immortal (yes Martha, immortality isn't just a transcendental idea) so are cancer cells. Cancer cells are those disposable body cells that go haywire and lose the genetic program to commit suicide. They become potentially immortal and in some cases revert back to a bacteria like haploid state. You see, body cells, like germ cells, need not die; they do so because they are programmed to. Our genes contain suicide programs in them and that is why we die; of course, if they didn't we'd be just a big wads of cancer: we'd be more like bacteria than people-ergo, death really isn't such a bad thing after all, it does in fact serve a very important purpose. You'll learn about cellular suicide mechanisms like telomere degradation and the Hayflick limit. This little book truly is fun reading. Clark always throws in a sidebar to illustrate his thesis. In this book he takes an old guy who has an attack of acute cardiac failure due to ventricular fibrillation and eventually ends up plugged into life support. Clark's hypothetical victim becomes essentially brain dead but can still breath and exhibit facial expressions doe to continuing brain stem function. What is life and death? Clark uses this imaginary heart attack victim is an effective backdrop to show a person alive by many technical definitions but dead as a door nail for all practical purposes. All in all this book is short and you'll learn a ton and be stimulated to contemplate the concepts of life, death, and immortality at the level of the hard sciences, no gurus need apply.