This article focuses on Richard Dawkins’ concept of the “selfish gene” to explore how genes act to survive and how sexual reproduction affects evolution and environmental change.
The title of Richard Dawkins’ book The Selfish Gene is quite provocative. As humans who have been taught respect and consideration for others as human virtues, the idea that the gene that contains all of our information is selfish seems to endorse the vocal theory that humans are inherently evil and need to be taught to be good. However, because of this provocation, The Selfish Gene became one of the world’s most read science books, and many people agreed with its author, Richard Dawkins.
In fact, when the book was first published, many people recoiled at the title: the word “selfish” is usually used in a negative sense, and people instinctively react negatively to it. But as people read Dawkins’ book, they gradually came to understand that the concept of selfishness is not simply a moral judgment. The term “selfish” is used to describe how biological units, such as genes, behave to ensure their own survival, not as a representation of human ethical dispositions. For this reason, many readers have come to sympathize with Dawkins’ point of view beyond their initial repulsion.
Despite the title, many people were able to agree with Dawkins because he emphasized that evolution and behavior should be viewed from the perspective of the genes themselves, in terms of what each gene gains and loses. The book does not simply deal with the concept of selfish genes, but also provides new insights into the role of genes in the processes of biological evolution and natural selection. By explaining genes as if they have strategies for “preserving” and “expanding” themselves, he gives readers a new way of understanding evolutionary theory.
So, from a gene’s perspective, how did sexual reproduction emerge? Before we can discuss this, it’s important to clarify what a gene is. Gene is a very popular and widely understood scientific term, but there is a lot of controversy and confusion about its definition. Among scientists, there are two main ways of referring to genes: molecular and evolutionary. The molecular concept defines a gene as a strand of DNA that encodes a protein. Generally speaking, the DNA strands that encode proteins are exons and regulatory regions that control gene expression, excluding introns, which are removed during the editing process, but the actual production of proteins involves many other RNAs and other environments, so it becomes ambiguous to designate what is a gene.
A gene is not just a biological structure, but also a factor in evolutionary processes that are influenced by natural selection. For this reason, Dawkins emphasizes that genes should be understood as an evolutionary concept that takes into account their influence and role in evolution, rather than simply defining them at a molecular level. The concept that came to replace it is the evolutionary concept. The evolutionary concept defines a gene as a DNA sequence that leads to a difference in phenotype: if substituting one DNA sequence for another leads to a different phenotype, then that sequence is a gene. Of these two definitions, Dawkins argues that we should use the evolutionary definition of the concept, so that when genes that exhibit similar traits become physically closer together through mutations such as translocations, they can be grouped together and newly labeled as genes.
In addition, the lifespan of a gene refers to the time it can be passed on intact through generations, so the shorter the length of a gene, the longer it is likely to be because it is less likely to be cut by crossovers in meiosis. This can be understood as part of the complexity of genes and their survival strategies. The idea is that shorter genes have more chances to survive, and therefore survive longer in the evolutionary process.
According to the selfish gene theory, genes aim to keep themselves, or their replicants, alive as long as possible. So why do we have sexual reproduction rather than asexual reproduction, which leaves us intact? Dawkins argues that sexual reproduction itself is just a trait controlled by one gene, and it doesn’t matter if it’s beneficial to the rest of the genes in the organism or not. He argues that sexual reproduction has spread in the gene pool because it is beneficial to the gene that enables sexual reproduction. A gene pool is the total amount of genetic information contained in a population of organisms, and can be thought of as a collection of all alleles carried by individuals in the population.
In an evolutionarily stable population, the proportion of genes that make up the gene pool would remain constant, so the fact that a gene survives and spreads in the gene pool means that it is in an evolutionarily stable state and can leave copies of itself for future generations. However, Dawkins avoids discussing how sexual reproduction benefits the genes that are sexually reproduced. So in this article, I’ll use Dawkins’ argument to suggest how sexual reproduction could have survived in the gene pool.
To examine whether Dawkins’ argument is correct, we can consider whether the appearance of a sexually reproducing gene in a gene pool with asexually reproducing genes could lead to a process called “evolution,” in which the sexually reproducing genes are not eliminated, but instead go through a transitional period and form a new gene pool. However, since asexual reproduction does not involve the cumbersome process of finding a mate and does not involve crossover, the lifespan of a gene is almost infinite. From this perspective, sexually reproducing genes would be culled from the gene pool.
But is there a reason why sexual reproduction genes survive despite the benefits of asexual reproduction? The advantage of sexual reproduction, which is often taught in school, is that it creates individuals with new traits through the combination of different genes, which increases the chances of survival of the species as better traits are passed on to the next generation. This is the advantage of sexual reproduction from a species perspective. Moving away from this perspective and looking at it from the perspective of the gene, we can speculate on some interesting reasons why sexual reproduction is favorable for the gene.
First, when you reproduce sexually, your offspring will have relatives who are genetically close to you. These relatives are more likely to act altruistically toward the offspring due to their genetic closeness, thus increasing the offspring’s chances of survival. The survival of the offspring is directly tied to the survival of your genes, as it is the survival of the individuals who carry your genes. In other words, you are creating allies to protect your genes.
There are also times when a species benefit is a gene benefit. When there are both sexually and asexually reproducing genes in the same gene pool, if a drastic change in the environment occurs, the asexually reproducing genes will not be able to ensure the survival of the individuals who carry them and, as a result, will not be passed on to the next generation. On the other hand, individuals with sexually reproducing genes will express a mix of traits, resulting in a surviving population. As a result, the genes that remain in the gene pool are the ones that are sexually reproductive. In fact, individuals that reproduce sexually are known to be better able to cope with relatively rapid changes in their environment.
Of course, these explanations are only hypotheses. But the reason Dawkins’ “selfish gene” has gotten so much attention is that it offers a new way to explain natural selection and evolution through the biological concept of genes. This book will help you move beyond simply learning about genetics to understanding the role genes play in larger biological processes and how they shape an individual’s behavior and traits.
