One Thought

Richard Dawkins’s The Selfish Gene is one of the best books I’ve read.  Its subject matter–evolution of life on earth–is important.  Its writing is flawless and its points well-argued.  Its conclusions are significant, controversial, and seemingly inescapable.

The Selfish Gene is not for the faint of heart.  Consider the following excerpt from an Amazon.com review of the book:

I wish I could rate this book at 5 stars and 0 stars at the same time. It is a fascinating book, very well-written, and it conveys a real sense of how life works on the biological level, how all sorts of diverse factors interact with each other to create an incredibly complex system (the evolution of life, in this case); it also just as vividly conveys a sense of how scientists come to understand these processes. …

But at the same time, I largely blame “The Selfish Gene” for a series of bouts of depression I suffered from for more than a decade, and part of me wants to rate the book at zero stars for its effect on my life. Never sure of my spiritual outlook on life, but trying to find something deeper – trying to believe, but not quite being able to – I found that this book just about blew away any vague ideas I had along these lines, and prevented them from coalescing any further. This created quite a strong personal crisis for me some years ago.

The book renders a God or supreme power of any sort quite superfluous for the purpose of accounting for the way the world is, and the way life is. It accounts for the nature of life, and for human nature, only too well, whereas most religions or spiritual outlooks raise problems that have to be got around. It presents an appallingly pessimistic view of human nature, and makes life seem utterly pointless; yet I cannot present any arguments to refute its point of view. I still try to have some kind of spiritual outlook, but it is definitely battered, and I have not yet overcome the effects of this book on me.

I don’t share the reviewer’s pessimism, but I’ll get to that later.  Some background is necessary first.

Richard Dawkins is an evolutionary biologist at Oxford University.  The Selfish Gene, his first book, was published in 1976.  It has since become a classic of popular science literature.  I’m not a scientist and I can’t critique the scientific accuracy of Dawkins’s book, but I don’t need to: The Selfish Gene has been scrutinized for decades, and it has emerged mostly unscathed.

Though it does contain background material, The Selfish Gene is not an evolution text.  Dawkins’s goal with the book is primarily to argue for a gene-based, rather than an organism- or group-based, view of evolution.  He sets out to refute the theory of “group selection,” which had been popular prior to the 1970s.  According to group selection, traits can spread in a population if they benefit groups, even if they are detrimental (evolutionary-fitness-wise) to individuals.  So, for example, group selection implies that a trait for disinterested altruism can spread if groups of altruists are better off than groups of non-altruists.

Dawkins argues that genes, not organisms or groups, are the fundamental unit of evolution.  He terms genes “selfish,” a word he gives a technical meaning.  A “selfish” unit of evolution is one that is selected for–that is copied through the generations–in a Darwinian selection process.  A “successful” selfish unit produces many copies of itself; an unsuccessful one disappears.  Dawkins does not mean, of course, that genes themselves “are” selfish.  Rather he means that they affect the organisms containing them as if they are.  Their effects suggest a selfish disposition.

Genes are passed on based only on their ability to influence organisms to pass them on.  Their benefit to particular organisms or groups is relevant only insofar as it aids their own selfish interest.  Genes must be selfish, as only those most effective at replicating themselves stick around.  The “unselfish” ones all die out.

Genes are “replicators”–they create identical copies of themselves.  Organisms are not–they pass only their genes to the next generation.  Dawkins provides a possible story of the origin of life: in it, primitive replicators emerged in the primordial soup that was earth’s surface hundreds of millions of years ago.  These replicators were stable configurations of molecules that, through the laws of physics and chemistry, caused like configurations to be created around them.  The copying process occasionally made mistakes, which led to a diversity of replicators.  Because the replicators competed for finite resources (molecules), natural selection favored the ones that were best able to survive and reproduce.  More-stable arrangements–and arrangements capable of decreasing rivals’ stability–were favored.  As time progressed, offensive and defensive strategies became increasingly sophisticated, and the molecular arrangements became increasingly complex.

Eventually the replicators “learned” to build bodies for themselves.  Dawkins suggests that a particular strain may have “discovered” (through a mutation) how to build a wall of protein around itself.  He terms these bodies “survival machines.”  Survival machines helped the replicators to move around, to defend themselves, and to reproduce.  As the replicators grew more complex, so did their survival machines.  The living things we now know–amoebas, worms, trees, raccoons, humans–are all survival machines.  The DNA contained in every cell is the medium for genes, which are the replicators.  We are their survival machines.

So ends chapter two of The Selfish Gene.  Dawkins spends most of the rest of the book elaborating on his argument and demonstrating its explanatory power in specific cases.  He covers his bases well and responds to the obvious objections to his theory.  I couldn’t possibly do justice to the finer points of his argument in this review, and I won’t try.  Instead I will briefly cover a few of the points I found most interesting.

Dawkins’s dismissal of group selection, which I mentioned earlier, rests largely on the concept of evolutionary stability.  A behavior pattern (“strategy”) that is prevalent in a population is evolutionarily stable if it cannot be displaced by an upstart strategy.  Strategies for disinterested altruism–which group selection suggests could develop–are not evolutionarily stable.  I’ll illustrate with an example.  Say that a gene “for” sitting on whatever eggs lie around is prevalent in a bird population.  As long as all the members of the population possess this gene, all is well: all eggs will get sat on.  However, if a mutant bird that sits on no eggs enters the population, its genes will spread rapidly: most of its eggs will get sat on (by the altruists), and it will be free to gather food and lay more.  A strategy for sitting on whatever eggs lie around thus is not evolutionarily stable.  (A strategy for sitting on no eggs isn’t stable either.)  As Dawkins shows, a strategy for sitting on only one’s own eggs is stable.

Genes are in competition with one another.  They “want” to propagate more of their own kind, which means that organisms with similar genes tend to have similar interests and organisms with different genes tend to have different interests.  Close relatives, who share many genes in common, tend to have closely-related interests.  Because parents pass half of their genes to their children, parental care isn’t altruism at the gene level–genes have much to gain from influencing organisms to aid others containing them.  Because parents and children do differ genetically, however, their relationship is not purely cooperative.  You’d expect children to “exploit” their parents to a degree–for example, by pretending to be more hungry than they actually are–and such behavior is in fact present in nature.

Dawkins has much to say on the relationship between the sexes.  He defines “males” as organisms with small and numerous sex cells (i.e., sperm) and “females” as organisms with large and few sex cells (i.e., eggs).  Because sperm can be produced cheaply and in great number, male investment in child bearing is low.  Female investment, however, is significant: a large egg must be produced, and a long gestation period may be involved.  This discrepancy leads to differences in male and female strategies regarding sex.  Because males’ genes stand to gain (and lose) more from competition, males are more likely to behave like high-stakes gamblers.  In polygamous species, they fight, sometimes to the death, for females.  The winners’ genes are spread to many offspring, and the losers’ genes are spread to none.  Because females’ reproductive rate is fixed by their ability to produce eggs, they stand to gain less from competition.  They have more to gain from being picky in their choice of mates, and all sorts of female mate-selection strategies have developed as a result.

Before ending, I want to say a bit about the implications of Dawkins’s book.  The reviewer I quoted earlier states that The Selfish Gene presents an “appallingly pessimistic view of human nature, and makes life seem utterly pointless.”  I disagree.  First, as Dawkins points out, our behavior is only partially determined by our genes.  We are self-aware, rational beings, which means we can question the proclivities our genes give us.  We can even “rebel” against them.  Dawkins uses contraception as a simple example–non-reproductive sex certainly isn’t in our genes’ interest.  More importantly, we can choose to behave as true altruists.  We aren’t compelled to obey our genes’ selfish dictates.

Life is only pointless if we think it is.  We can create meaning as individuals and as a species.  How we got here is irrelevant; we now have the power to direct our own destiny.  I strongly recommend The Selfish Gene to anyone who wants to better understand their place in the universe.