A seminal text in evolutionary biology that articulates the gene-centered view of evolution by natural selection. It explains how self-interested genes can give rise to altruism.
The selfish gene theory has been an influential thread in scientific and popular thinking for the past 25 years. It’s been used to explain many phenomena, from altruism to the formation of societies.
The Principles of The Selfish Gene
The principle that genes are selfish replicators is a foundational concept in “The Selfish Gene,” one of the most popular science books of all time. Since its original publication in 1976, it has sold millions of copies and is translated into over 25 languages.
Dawkins explains that genetics has a lot to teach us about our world. He takes readers through the primeval soup, where genes compete for survival in a complex environment.
He describes how genes copied themselves and created a whole set of machines to survive. These machines got increasingly complicated from single-celled organisms to humans.
These genes were able to do so because they had high “copying fidelity,” meaning that they copied themselves without any mistakes. This fidelity ensured that the DNA would be passed on to future generations, allowing evolution to take place.
In a series of thought-experiments, Dawkins showed that certain genes could cause their carriers to behave preferentially toward other people, even when unrelated. These genes were called greenbeards by Dawkins (see Fig 1).
These kinds of genes manipulate the way that genetic transmission occurs. This can include manipulating the odds that a gene will be transferred to a polar body or egg cell during meiosis, or manipulating the distribution of copies between chromosomes in different cells.
The Conclusions of The Selfish Gene
Traditionally, genetics was seen as a highly coordinated network of genes that worked together to produce individual organisms. This view was challenged by the existence of stretches of DNA that could promote their own transmission at the expense of other genes but had no or negative effect on organismal fitness.
This influx of details about selfish genetic elements over the last few decades has brought with it an important shift in thinking about evolutionary biology. It has also prompted the development of new conceptual frameworks to explain these findings.
One such framework is the “gene’s-eye view” of Richard Dawkins and George Williams (Werren 2011). This framework has played a key role in analyzing empirical data and has been influential in generating hypotheses.
However, it is not without critics, and multiple other frameworks have been proposed to account for the phenomenon of selfish genetic elements. Using different approaches may help us build a unified theory of conflict and cooperation in evolutionary biology (Keller 1999; Michod 1999; Queller and Strassmann 2009; Bourke 2011, Foster 2011; Rice 2013).
Despite its flaws, the “gene’s-eye view” still remains a fundamental tool in addressing new empirical data, particularly when studying selfish genetic elements. It can be useful to understand how these elements interact with and coevolve with other elements at the genome, phenotype, and population levels and how these interactions affect evolutionary dynamics and phylogenetic diversification.
The Meaning of The Selfish Gene
There is no book more iconic in the history of genetics and evolution than Richard Dawkins’ The Selfish Gene. Forty years on, it is still a bestseller, and its influence has been felt throughout generations of scientists.
In his introductory chapter, Dawkins describes how genes have a selfish interest in replicating themselves – they want to survive and reproduce. They do this by coding a phenotype that increases their chances of being passed down through the generations.
These phenotypes are what make a gene “successful” in the population. If a gene is able to produce the phenotype that it is coded for, it can improve its own survival and reproduction chances as well as improve the organism it is inserted in because of the way in which the phenotypes help other members of the population as well.
Another interesting point that Dawkins makes in this section is how a gene’s success is linked to its interactions with other genes. If a gene can increase its own chances of being replicated by making connections with other genes, then it is also likely to benefit the entire genome because it is also helping other members of the population to survive and reproduce as well.
This idea is backed by several scientific observations over the years, such as the discovery of genetic conflict between a gene and other elements in the genome. These conflicts can result in changes to the gene itself that have positive or negative effects on its host, depending on which element it conflicts with.
The Main Ideas of The Selfish Gene
The Selfish Gene was one of the most famous books about evolution ever written. It made a huge impact on our thinking, even when it was published over four decades ago.
In this book, Dawkins argued that genes are primarily selfish in their function and that natural selection favors genes that are able to survive in the breeding population over those that are not. This idea had already been popularized by a few scientists at the time, but Dawkins truly took it to the next level and created an amazing book that remained popular for years.
Another major theme in this book is that competition and cooperation can exist at the same time in a biological species. This idea is very important to understand because it is an essential principle for understanding how evolution works.
Many people see evolution solely through the lens of competition, which has led to some false paradigms about a “dog eat dog” world where ruthless individual competition is considered “natural”. But Bar-Yam argues that this idea is outdated and that there are better ways to understand how evolution works.
Fortunately, a number of different researchers are focusing on the topic of how competition and cooperation can exist at different levels in organisms and have found some interesting new insights. This is especially true in the field of systems biology, which has produced a number of fascinating new discoveries.
The Selfish DNA Hypothesis
The selfish DNA hypothesis is a popular concept in evolutionary biology. It was first articulated by the US biologist George C Williams in his book Adaptation and Natural Selection: A Critique of Some Current Evolutionary Thought (1966).
The idea is that genes act as if they are acting on behalf of an organism’s survival interests. This is because they are the only units that show persistence across generations, a necessary condition for natural selection to work properly.
However, critics of the selfish DNA hypothesis say that this notion is too rooted in the past and paints a simplistic picture. They also point out that the concept is based on an abstract notion with origins in theoretical population genetics and that it is not necessarily relevant to the study of molecular biology.
A key problem with the selfish DNA hypothesis is that it posits that all elements within a genome have self-promoting features, which could be harmful to an individual’s health and well-being. This is even though many of these elements are non-Mendelian, meaning they have no specific function.
Another issue is that some elements may be able to cause genetic conflict, which can lead to reproductive isolation in species. This process is known as Bateson-Dobzhansky-Muller incompatibilities and has been studied intensively over the past decades.
In addition, highly self-fertilizing or asexual genomes tend to experience less conflict between selfish genetic elements and the rest of the host genome than outcrossing sexual genomes. This is because sex and outcrossing put these elements into new genetic lineages, and highly selfers/asexuals are homozygous for their genes, reducing the opportunity for conflict.
The Final Words
In The Selfish Gene, Richard Dawkins popularised the idea that evolution was based upon individual organisms rather than groups and species. This had been popularized by a small group of scientists in the 1960s, including Bob Trivers, Bill Hamilton, John Maynard Smith, and George Williams, but it was Dawkins who introduced a radically new picture of evolution to biology in 1976.
This book was a watershed, for it shifted the focus from an overly academic view of evolution to one that was more accessible and easier to understand for the general public. It became a classic and, to date, one of the best-selling books ever published on science.
The main argument of The Selfish Gene is that the genes in an organism are self-serving, meaning that they want to survive as long as possible and dominate their environment. This perspective is not the only way of thinking about evolution.
As a complex systems researcher, Yaneer Bar-Yam has been working on challenging the selfish gene concept and on showing that it is limiting both biologically and mathematically. He argues that competition and cooperation between individuals do not always have to be “dog eat dog” and that there are many more nuanced ways of understanding these phenomena.
As the Human Genome Project completed its first sequencing in 1995, and as thousands of other bacterial genomes have been sequenced since, it has become clear that the selfish gene theory of evolution is fatally flawed. The evidence is that SGEs are not parasites or “self-serving” replicators but rather important motors for evolutionary change and innovation in a wide variety of organisms.