In this blog post, I will explore how Dawkins’ theory of sexual selection and Jablonowski’s principle of handicap can coexist with the theory of natural selection.
In Richard Dawkins’ book The Selfish Gene, the main character of evolutionary theory is not an individual or a species, but genes, and he argues that living organisms are machines that try to preserve their genes. Among the many stories derived from this argument, I will focus on the “principle of handicap” and develop the story. In his “Sex Selection Theory,” Dawkins mentions the conflict between males and females in nature, and he sees two strategies when females choose superior males: choosing males that make their homes happy and males with strong masculinity. Dawkins explains that these two strategies are aimed at helping females preserve their genes and those with strong genes.
Dawkins says that those who are skeptical of choosing a masculine male have come up with Zahavi’s “handicap principle” theory. He said that the “handicap principle” is the exact opposite of the theory of sexual selection, but he pointed out that the arguments against this principle are erroneous. The error is related to the claim that the “handicap principle” and the theory of natural selection cannot coexist. In addition, Dawkins has a different view of the selfish gene published in 1976 and the current “handicap principle.” This essay is based on the 1976 first edition. The handicap principle can explain Dawkins’ theory of sexual selection well, and the reason he opposed it was because he misunderstood the handicap principle. Therefore, I will examine Zahavi’s handicap principle, analyze Dawkins’ objections, and discuss sexual selection and natural selection. Finally, I will show that the two theories are compatible with each other.
First, let’s look at the basic theories of this thesis, Dawkins’s sexual selection and natural selection. Dawkins developed Darwin’s theory of natural selection in the selfish gene to explain that organisms evolve through the processes of replication, mutation, competition, and selection. As living organisms reproduce, their genes are passed on to their descendants, and individuals with mutations appear. At this point, individuals that have adapted to the environment survive, and this can be seen as nature’s selection. In other words, individuals that have not adapted to the environment disappear. In the end, the theory of natural selection that Dawkins talks about is that only genes with traits that are good for adapting to the environment are passed on to their descendants, and the identity of the group is strengthened.
Next, to understand the sex selection theory, we must understand the conflict between the sexes based on the selfishness of genes. Let’s take a look at the selfishness of genes. The assumption that sexual reproduction and crossing coexist is difficult to explain. Sexual reproduction is a very complex process for genes, and it may seem irrational. Sex is a cumbersome way of passing on one’s genes. On the other hand, asexual reproduction is more efficient than sexual reproduction. However, if we view each individual as a survival machine driven by an alliance of genes, then sexual reproduction can also be understood as a trait that is controlled by genes. These genes make other genes obey for their own selfish purposes.
Now let’s move on to the theory of sexual selection. Sex is asymmetrical. The most basic characteristic that proves this asymmetry is the germ cells of males and females. Male sperm are large in number, highly motile, and small in size, but contain few nutrients. In contrast, female eggs are small in number, less motile, large in size, and contain many nutrients. Dawkins believes that this difference is the beginning of the process of males exploiting females.
If you think about it simply, you might think that there is no need for males because there are so many sperm. However, the reason why the number of females tends to be constant can be explained by selfish genes. If the sex ratio of a population is skewed toward females, there is no big problem because males have at least as much sperm. At this point, parents who have a small number of males as their children will benefit greatly. This is because they can produce many offspring. This process can explain sexual selection, in which females choose males with strong masculinity. Dawkins argues that sexual selection does not violate the theory of natural selection because good genes are retained and bad genes are eliminated.
Now let’s learn about Zahavi’s handicap principle. In sexual selection, females crave strong genes from males. For example, a male with a gene that makes his muscles grow easily will be physically larger or have more prominent muscles. Females choose such males to have strong genes. Zahabi argued that the handicap principle can distinguish males with such false appearances from real strong males.
The handicap principle sees the existence of handicaps to distinguish these males. Through the handicap, females determine that the male is an individual with strong genes that can survive despite the handicap. For example, the colorful plumage of a male peacock makes it easy for predators to locate the peacock, but the male that survives nevertheless proves to be the individual with the stronger genes. In other words, the handicap is used as evidence of strong genes.
This selection increases the likelihood that the genes of females that choose males with a handicap will be passed on to their offspring. As a result, the number of males with a handicap increases, and this is the direction in which the individuals with a handicap evolve. In conclusion, females that choose males with a handicap will choose males with superior traits, and these genes will be passed on to their offspring as an advantage. In other words, females can pass on good genes to their offspring.
Now, let’s take a look at Dawkins’s position on the “handicap principle.” Dawkins revised his theory 30 years after publishing “The Selfish Gene.” Nevertheless, he is still skeptical of the handicap principle. Dawkins’s initial position was as follows. There are two strategies for females when choosing a male. One is a male who seeks family harmony, and the other is a male with strong masculinity. The strategy related to the handicap principle is to choose a male with strong masculinity. Dawkins believes that the ultimate purpose of males is to survive and pass on their genes to their descendants. However, the handicap principle sees males as trying to be chosen by females by revealing their handicap. Dawkins says that the handicap principle is at odds with the theory of sexual selection. He also argues that if you can gain an advantage over other males without revealing your handicap, that is the best strategy.
Dawkins admits that those who criticize Zahavi’s handicap principle may not be right. Strategic choice The handicap principle is that males can determine whether they have developed a handicap themselves. According to this, genes do not determine all traits, but rather determine whether a trait is expressed or not. However, Dawkins claims that there is no need to worry about the risks or potential losses caused by the handicap principle, and that only natural selection can judge this. In other words, Dawkins did not acknowledge that the handicap principle can coexist with the theory of sexual selection.
Next, let’s take a look at why Dawkins denies the handicap principle. Dawkins strongly denies the development of animal handicaps in Zahavi’s handicap principle. He argues that if this logic is accepted, individuals with one eye and one ear would evolve over individuals with two eyes and two ears. He explains this with the walrus in particular.
The walrus does not want to show off to the female, but rather to protect his territory by driving out other males and acquiring the territory. The owner of the territory gains an advantage in the competition simply by the fact that he has been protecting the territory. In conclusion, male walruses with a territory have an advantage over other males in competition without a handicap. In addition, females pass on their genes to their offspring by passing on the genes of these strong males. In the end, if males can gain an advantage in other ways without showing a handicap, they can develop their abilities.
Dawkins argued that the transmission of genes unfavorable to survival is not in accordance with the theory of natural selection. According to the above, the handicap principle can be understood as a partial principle of the theory of sexual selection. The reason why females choose males with a handicap is not because of the handicap itself, but because of the advantages of the males due to the handicap. In other words, the handicap is an indicator of sexual selection, which helps females choose good males. Dawkins argued that sexual selection is included in natural selection, so the handicap principle, which is a part of sexual selection, can coexist with natural selection. If the ultimate goal of an individual is to reduce its handicap and pass on good genes for survival, this also does not violate the theory of natural selection. The degree of environmental adaptability of an individual will be related to the point at which it becomes a good male with a handicap and discards the handicap for survival. If the degree of adaptability is high, the individual will have a high chance of surviving even with a handicap.
Next, in the criticism of Dawkins’s handicap theory, the point where Dawkins and Zahavi’s opinions conflict is that “if a handicap is a real handicap, it can have a bad effect on future generations.” This is because good traits that can overcome a handicap are also likely to be inherited, so much so that the handicap is passed on to future generations. As explained in the example of the walrus, Dawkins says that the walrus shows its superiority by occupying the harem. Occupying the harem can be considered a handicap that gives it an advantage in competition. Ultimately, the handicap theory is also a theory that explains the traits that males have in order to be chosen by females, and this can be seen as one way in which females choose masculine males in the sexual selection theory that Dawkins talks about.
Of course, on a superficial level, it can be said that the handicap theory does not conform to the theory of sexual selection. The handicap theory claims that males use inferior traits to attract females, and that the greater the handicap, the better they can attract females. However, from the perspective of natural selection, it is contradictory that a handicap, which is a trait that is disadvantageous to survival, develops. However, when accepting the handicap theory, we should not focus only on the fact that handicaps are traits that reduce the chances of survival. Of course, it is true that genes with handicaps reduce the chances of survival.
For example, the large antlers of male deer are easily visible from a distance, making them easy targets for predators. However, the handicap trait also has the advantage of emphasizing strong genes in situations where females choose males. If a male survives despite having a large handicap, it proves that the male has developed special survival-beneficial traits that are strong enough to overcome the handicap.
In conclusion, if the females consider it beneficial for their offspring to inherit the traits of the males, even if the handicap slightly reduces their chances of survival, the handicap can be an advantage in sexual selection if the genes of the males are passed on to their offspring. Consequently, the handicap principle is not in conflict with the theory of sexual selection, and since the theory of sexual selection is included in the theory of natural selection, the principle of handicap can also be harmonized with the theory of natural selection.
