What Is Sex

by Lynn Margulis, Dorion Sagan

A look at the sexual impulse that is at the root of our very biological existence includes scientific discussions on the origins of gender, sexual strategies of life forms from mitochondria to humans, and the language of sexuality. 15,000 first printing.

Genres: Science, Biology, Nonfiction, Evolution, Sexuality, History

256 pages, Hardcover

First published January 12, 1998

About the author

Lynn Margulis (1938-2011) was a Professor of Geosciences at the University of Massachusetts, a member of the U.S. National Academy of Sciences and the Russian Academy of Natural Sciences.

Reviews

[Francisca · Rating 5 out of 5]

Sex is a ubiquitous presence in our lives. It seems to rule all we do, as important if we try to have it as if we try to avoid it. And even beyond societal and cultural implications, our mere survival depends on it. So, sex must be as old as the world, no?

In fact, sex is quite the new invention and an enormous number of species don't need it. Life on Earth existed for millions of years before the first organism capable of having sex came to be, so why sex? It seems logical that an organism that only needs to divide to reproduce has much better chances to live on and conquer the world than any organism needing a couple to, well, have sex, to survive as a species. So, what are the advantages of sex (no snickering here, please)? Why did organisms evolve from asexual reproduction to sexual beings? And when did this happen?

Providing answers to those questions is the aim of the book. And Margulis does an excellent job at it, explaining these questions, and many more, in a way that is easy to understand but never patronizing. Best of all, she even has fun doing it.

Not everybody will like this book, but if a relentless curiosity sometimes brings you to dark corners full of unanswered questions and you find yourself wondering, why do we need sex? You may get a kick out of it.

[J.D. Steens · Rating 4 out of 5]

For the authors, 'sex' reflects a deeper world view: how beings are composites of other life forms, how the different forms of sex manifest this composite nature, how death is integral to life, and how life is connected to the cosmos. The first two-thirds of the book are the best, but it is slow-going and challenging; the last third of the book is a more standard treatment of our evolutionary history.

The authors define life as an "autopoietic system" that is determined by its internal processes, unlike a billiard ball that only reacts to an outside force. While it's clear that life seeks energy for food and sex, the authors interestingly do not stress defensive reaction. Yet, either through seeking or defending, their basic point is that life forms are able to 'choose' how they interact with the world based on information received from that world. Organisms, the authors write, are "not even things" by which they mean that life cannot exist without this connection to the outside.

The first two billion years of life on earth were bacteria that survived severe environmental challenges by gene transfers (transgenic sex) between bacteria. In the next life stage (protoctist), cells with nuclei combined in the second form of sex (hypersex, or cell symbiogenesis) that involved an "irreversible" (genetic) physical association of cells, organs and organisms, which again provided a survival advantage. It's in the third life stage (animals, fungi, plants) that what we conventionally think of as 'sex' (gender-based meiotic sex) makes its fullest appearance.

Seen this way, sex is the mechanism by which life forms have become composite beings. Formerly independent beings become incorporated into one new being because of the survival advantages that are conferred. Organisms enhance their survival by joining into alliances. "The dictum that 'evolution only works on the level of individuals,'" the authors write, "must be rethought." They go on to say that "all large organisms are composites." This "Coming together, power in numbers, has been crucial in at least two major evolutionary transitions: hypersex that led from bacteria to nucleated cells, and the fusion sex that led to large bodies..."

On the surface, the reason for sex is to produce offspring, but the authors have something more in mind. Although their presentation is not always clear, this is where their argument gets interesting. During environmental stresses (primarily related to seasonal coolness or dryness), survival required eating of close relatives ("engulfment feeding," or "cannibalism" where each "combatant tries to survive the other") that resulted (somehow?) in the fusion of sex cells. This fusion encapsulated (e.g., as seed, embryo; by analogy, hibernation) a joint genetic structure that now possessed a doubling of the chromosomes (diploid state), allowing the new entity to survive until more favorable environmental conditions permitted aggressive growth and development. "Two organisms have become one; their two nuclei have become one larger, swollen nucleus. Now two nuclei float in one bloated body - one from each combatant." The problem is that this process produces "diploid monsters" that would soon have "to recover their optimal form: sleek, effective, single beings with only one set of chromosomes." This occurs through meiosis (birth and emergence of separately gendered individuals). Meiosis relieves this doubleness and enables organisms to return to their original haploid form. "Fusion sex, fertilization followed by meiosis, allowed beings to survive the cycles of the seasons," the authors write, adding that "The brilliant early plant and animal body strategy was to grow in the interim, fused state. Such growth as multicellular diploid embryos opened up whole new ecological possibilities before the necessary return to the ancestral spore or sperm haploid."

For four of the five kingdoms (i.e., except bacteria which uses fission or cell division, not fusion), the authors argue that the price of perpetual life through sexual propagation is death of the propagating individuals. We are composite beings, beginning with a foundation where bacteria operates by an "unfettered cell-division urge." Unlimited cell-growth is problem for beings with nucleated cells and organs that must operate as a defined, collective whole, unless cell growth is limited (regulated) by "programmed cell death." Cell death is also a part of body development. Cells have a natural life span before they die and, eventually, the body itself is programmed to die.

The authors set their theory of the evolutionary basis for sex within a broader cosmic context. The real purpose of life, and sexual propagation, they say, is to reduce the energy gradient between the hot sun and cold space, in accordance with the second law of thermodynamics. Life is particularly good at using the sun's energy and converting it into disorder (waste products - feces, urine, garbage pollution and CO2). In this way, life helps the sun to spend itself.

The writing style in this book is uneven, ranging from an easy-to-read general overview to many hard-to-follow technical narratives. The book requires reading in between the lines and deducing certain chains of thought from what one can understand. That said, what they propose in this book is an alternative or a complement to Neo-Darwinian theory, particularly regarding the role of micro biotic life and our dependence on the external world. What is not clear in this book is how we should understand life's organizing force, which is our fundamental drive to survive. In thinking about the author's argument, it almost seems that they are saying the individual's drive is to survive per se (i.e., 'park' the genes, go into hibernation) and not as the Neo-Darwinians urge, to move genes into the next generation. In other words, genetic survival through sex seems to be a by-product of the individual's attempt to survive as an individual. The author's tie of life's purpose to the second law of thermodynamics seems less than convincing. They argue that our drive to survive is, in effect, to serve a cosmic purpose to break down the cosmic energy gradient. If there is a life contribution in this regard, this too could be a by-product of life's independently formed (by some fortuitous chemical combination) urge to survive. Finally, while programmed cell-death makes sense in their presentation, it is not clear why that process could not continue indefinitely without resulting in the death of the individual itself. In other words, why we die is still not clear.

These concerns over lack of clarity and questions about their argument do not subtract from an otherwise very challenging perspective about the nature of life (and death) within a broader cosmic context. The best part of this book is the author's overall theme that we have been and remain very much a part of a long biological and cosmic legacy. "Technology, culture, civilization and art," they write, "do not distance us from our animal selves but, instead, accentuate and expand our animal natures."

[Aloysius · Rating 5 out of 5]

Si alguien nos puede inspirar al explicarnos las bases termodinámicas del sexo, sin duda es la Dra. Margulis, y que mejor que acompañada de Dorion Sagan.

Si lo juzgamos exclusivamente por su título, “¿Qué es el sexo?” puede sonar a una revisión de la sexualidad desde el punto de vista erótico, pues tal es el punto de vista imperante del sexo actualmente, siendo incluso la reproducción un efecto colateral, y no el propósito superior del mismo, al menos en términos sociales. Pero como bien se puede leer en este mismo libro “el sexo va más allá de la fricción de genitales entre mamíferos”.
Solemos pensar, buscando ya ser algo mas técnicos, que el sexo es el acto de reproducción, cuyo fin es perpetuar una especie. Y en efecto, posee dicha utilidad, pero paradójicamente, la producción de nuevos individuos no es dependiente del intercambio de genes, y el intercambio de genes puede no implicar la formación de nuevos individuos. Y es que nuestra visión esta sesgada, no de una manera antropocéntrica, sino incluso de una forma zoocéntrica, pensando que las únicas formas de sexo se dan entre animales. Pero es licito apuntar que sólo los tetrápodos copulamos, pero el resto de las especies animales tienen formas de intercambio genético mucho más diversas. Si a ello agregamos el resto de la biota, podemos observar entonces, ante esa miríada de formas de intercambio genético y de reproducción, sin que ambas estén siempre ligadas, que nuestra forma de reproducción no es especialmente original, ni mucho menos la más efectiva.

¿Y que hay de la diversidad genética? Los libros de biología suelen señalar que esta es resultado del intercambio genético y de sus errores de replicación. Y si bien la visión darwinista tiene su parte de verdad, no es del todo universal. Nuevamente, hemos de mirar a las millones de especies que evolucionaron sin intercambio genético de por medio, que al día de hoy se aferran en hacer raboiar a los microbiólogos que tratan de clasificarlas por su genoma, pues la transgénesis permite que las adaptaciones biológicas derivadas de mutaciones de genes fortuitas se “compartan” entre las bacterias del planeta. Si a esto añadimos que el proceso de intercambio genético tiene más el propósito de “reiniciar” el reloj biológico de dichos organismos, podemos replantearnos el papel que tiene el sexo.

Lo que queda de nosotros, finalmente, no es nuestro cuerpo, son nuestros genes. Y si bien cada molécula por si misma no es inmortal, si la información que esta contiene, información codificada desde hace millones de años y repartida entre todos y cada uno de los organismos de este planeta. No somos individuos desvinculados del resto, en férrea competencia por imponer nuestros genes. Somos elementos de un super genoma casi omnipresente, que se ramifica y diversifica, pero se autopreserva, pero ¿con qué fin? (He de pedir disculpas a aquellos a quienes esto ultimo suene a un argumento del Dr. Dawkins, pero si bien se estudia el mismo proceso, la línea de ideas es diferente).

Algunos argumentan que la existencia de la vida quiebra las leyes de la termodinámica, pero recordemos que existen diferentes niveles a los que podemos trabajar para comprender los procesos termodinámicos. Apelando al sol como fuente de energía para nuestro planeta, desde su formación hasta la preservación de las condiciones de vida, es entonces que esta misma vida se muestra como de hecho un punto preservador de las leyes de la termodinámica, al disipar el calor del sol en formar químicas diversas, reduciendo así el gradiente solar. Entonces todo el aparato biológico cobra importancia sólo por la maravilla de la complejidad bioquímica que implica por si misma, sino en la monumental acrobacia energética que implica mover la portentosa energía solar a través de millones de organismos que, al intercambiar genes, lograr perpetuar su propia existencia y, así, perpetuar el proceso de reducción del gradiente solar.

La vida no es un milagro, ni el producto de alguna deidad calculadora. Es el resultado de las impersonales e indiferentes leyes de la termodinámica, manifestación de un complejo sistema químico que, en su constante aumento de complejidad, ha llegado a trascender la interacción biológica a nivel ecosistémico, formando una especie capaz de interrelacionarse a nivel planetario. Pero es fortuito recordar que, hace casi 4 000 millones de años, las bacterias primigenias desarrollaron un sistema de intercambio de genes literalmente global, compartiendo información entre millones de organismos. Nuestro sistema es diferente, pues es más complejo, más rápido y resultado de un proceso racional, pero no por ello diferente en esencia.
Dijo alguna vez el famoso ex esposo de Lynn, en una extraordinariamente bella reflexión, que la astronomía era una ciencia que nos enseñaba a ser más humildes, y nos invitaba a ser más empáticos con otros. La microbiología, debidamente comprendida, tiene ese mismo efecto, pero refuerza que debemos ser más empáticos no sólo con otras personas, sino también con el resto de especies con las que compartimos no sólo un planeta, sino además una única herencia genética.

//////////////

If someone can inspire us by explaining the thermodynamic bases of sex, it is undoubtedly Dr. Margulis, and what better way than accompanied by Dorion Sagan.

If we judge it exclusively by its title, "What is sex?" may sound like a revision of sexuality from the erotic point of view, since such is the prevailing point of view of sex today, even reproduction being an effect collateral, and not the higher purpose of it, at least in social terms. But as you can well read in this book, "sex goes beyond the friction of genitalia between mammals."
We tend to think, seeking to be something more technical, that sex is the act of reproduction, whose purpose is to perpetuate a species. And indeed, it has this utility, but paradoxically, the production of new individuals is not dependent on the exchange of genes, and the exchange of genes may not imply the formation of new individuals. And it is that our vision is biased, not in an anthropocentric way, but even in a zoocentric way, thinking that the only forms of sex are between animals. But it is fair to point out that only tetrapods copulate, but the rest of the animal species have much more diverse forms of genetic exchange. If we add the rest of the biota to this, we can then observe, in the face of this myriad of forms of genetic exchange and reproduction, without both being always linked, that our form of reproduction is not especially original, much less the most effective.

And what about genetic diversity? Biology books often point out that this is the result of genetic exchange and its replication errors. And while the Darwinian view has its share of truth, it is not entirely universal. Once again, we have to look at the millions of species that evolved without genetic exchange involved, which today cling to making microbiologists who try to classify them by their genome rage, since transgenesis allows the biological adaptations derived from Random gene mutations are "shared" among bacteria on the planet. If to this we add that the process of genetic exchange has more the purpose of “restarting” the biological clock of these organisms, we can rethink the role of sex.

What remains of us, ultimately, is not our body, it is our genes. And although each molecule by itself is not immortal, if the information it contains, information encoded for millions of years and distributed among each and every one of the organisms on this planet. We are not individuals detached from the rest, in fierce competition to impose our genes. We are elements of an almost ubiquitous super genome, branching and diversifying, but self-preserving, but to what end? (I have to apologize to those to whom the latter sounds like an argument by Dr. Dawkins, but although the same process is studied, the line of ideas is different).

Some argue that the existence of life breaks the laws of thermodynamics, but remember that there are different levels at which we can work to understand thermodynamic processes. Appealing to the sun as a source of energy for our planet, from its formation to the preservation of living conditions, it is then that this very life is shown as in fact a point of preservation of the laws of thermodynamics, by dissipating the heat of the sun in forming diverse chemistries, thus reducing the solar gradient. Then the entire biological apparatus becomes important only because of the wonder of the biochemical complexity that it implies by itself, but in the monumental energy acrobatics that involves moving the prodigious solar energy through millions of organisms that, by exchanging genes, manage to perpetuate their own existence and thus perpetuate the process of reducing the solar gradient.
Life is not a miracle, nor is it the product of some calculating deity. It is the result of the impersonal and indifferent laws of thermodynamics, a manifestation of a complex chemical system that, in its constant increase in complexity, has come to transcend biological interaction at the ecosystem level, forming a species capable of interrelation at the planetary level. But it is fortuitous to remember that nearly 4 billion years ago, primordial bacteria developed a literally global gene exchange system, sharing information between millions of organisms. Our system is different, because it is more complex, faster and the result of a rational process, but not for that reason different in essence.
The famous ex-husband of Lynn once said, in an extraordinarily beautiful reflection, that astronomy was a science that taught us to be more humble, and invite us to be more empathetic with others. Microbiology, properly understood, has the same effect, but reinforces that we must be more empathetic not only with other people, but also with the rest of the species with whom we share not only a planet, but also a single genetic inheritance.

[Angel Bravo · Rating 5 out of 5]

Una revisión breve pero bastante completa sobre la reproducción sexual de los seres vivos. De manera muy amena aprendemos cómo es que bacterias, protistas, hongos plantas y animales realizan la fusión y división de sus células con el propósito de escapar de la muerte. Comparada con la gran cantidad de ciclos reproductivos que conocemos, la reproducción humana es mas la excepción que la regla. Muy bueno.

[Karoles · Rating 5 out of 5]

This book was really empowering to read.

[xenia]

Who doesn't want to write a book about sex with their mom?

[Sarah G Tafur · Rating 3 out of 5]

Lynn y Dorion escriben de una manera muy accesible, diría nivel intermedio, no haciendo densa la lectura de temas densos, por algo hacen parte de los biólogos más famosos.

Me encanta su perspectiva de la vida en función de la termodinámica (de mis temas favoritos de la biología) tanto que estoy segura de releer el capítulo uno muchas veces más el resto de mi vida, en este también incluye el término "autopeyesis" que me parece interesante, el resto del libro se sintió como historia natural, y datos curiosos además de muchas de los estudios biológicos aún vigentes como (sincronización, mitocondiras etc.). El hecho de ser estudiante de biología hizo más entendible la lectura, realmente si puedo seguir estudiando para leer este tipo de disertaciones y entenderlas mejor vale la pena.

Mi mayor problema es que al ver la vida (solo) de modo naturalista y poniéndose en contra de la idea religiosa del mundo llegan a conclusiones que son contradictorias para mí, cómo (citando):

"La vida NO es algo
ÚNICO, sólo es el ejemplo más IMPRESIONANTE de una clase más amplia de
estructuras productoras de entropía"

(¿?)

En especial el final sobre el cibersexo y la aceptación de la perversidad, como en su descripción del sadomasoquismo me parecen honestamente turbias, sin embargo coherentes con personas que solo ven la vida como azar y tiempo y perpetuación de la especie.

PS: Agradecimiento a Fernando Fernández por recomendar el libro y al profe Zerda por recordarme leerlo.

///

(English Review is short because i'm not that good)

Honestly last chapter was So creepy but first chapter was amazing so for me it is a nice book that has a lot of good stuff but with a view of the world that I didn't share. As someone who likes this kind of philosophical-cience based books it really inspires me.

[Chus DELABASTIDA · Rating 3 out of 5]

Complemento indispensable de ¿Qué es la vida?

[Fernando del Alamo · Rating 1 out of 5]

Me he llevado una pequeña decepción con este libro y autoras. Esperaba algo más de tipo divulgativo, pero es uno de aquellos libros que si no has estudiado biología no te enteras de mucho. Por otro lado, esperaba una parte más filosófica, más de pensamiento y menos descriptiva a nivel biológico.
Si quieres leerlo, te recomiendo antes que lo hagas de algunas páginas en las partes inicial, media y final, porque es difícil definir el estilo del mismo.
Sinceramente, salvo por alguna idea, no lo recomendaría.

[Elizabeth]

hardcover w dustjacket

[Alessandra · Rating 4 out of 5]

Not a sexy book unless,like me, you find symbiogenis sexy. (-;