Have you ever seen a male peacock on the open screen? The colorful tail feathers, when unfolded, resemble a giant fan, shining brightly in the brilliance, and the dots are like gems set on it, which is so beautiful that people can't help but be amazed.
However, from a practical point of view, the male peacock's tail is not at all efficient, but more like a burden. So why do male peacocks still grow such tails? What exactly are the "benefits" of a ostentatious, weird, exaggerated, and manneristic tail for its owner? To The Darwinists, the male peacock's ornate tail seemed to have a spike.
In his 1871 book The Origin of Mankind, Darwin proposed sexual choice as a solution to this dilemma. He believes that it is the selection pressure of the female peacock that creates the strange tail of the male peacock, and the reason why the male peacock decorates and dresses himself is entirely because the female peacock likes to mate with the coolest and most beautiful male peacock. This means that the male peacock's tail can bring mating benefits to its owners and may eventually lead to a more successful reproduction rate. Thus, after a long period of evolution, the male peacock gradually developed its exaggerated and excessive way of showing off.
Why do females make such a choice? Darwin's answer is: good taste, that is, females choose purely for beauty. Thus the long tail of the male peacock is attributed to the female peacock's preference for beauty. However, in Darwin's theory, how female selection evolved remains to be seen. It was not until 1930 that the question of "how female tastes evolved" was given a satisfactory answer by the British biologist Fisher.
At the heart of Fisher's view is the idea that the peacock tail length gene and the gene that favor tail length are tied together. In this case, it can be proved that any existing preference will be further strengthened. Thus, if, for some reason, most females prefer long-tailed male peacocks in peacock populations, this tendency will gradually strengthen. Therefore, the choice that favors the long tail and the choice that favors the long tail, or the male decoration and the female taste, will hold hands, strengthen each other, and move forward together. With mutual reinforcement, the fashion will gradually escalate, eventually producing an increasingly unusual male trait, as well as a stronger female preference for this trait, until natural selection comes forward and stops. In this way, the occasional preference of the female peacock prompts the entire group to form an unshakable fashion, and eventually causes the male peacock to sail into the field of luxury, turning its tail feathers into a big burden without compromise.
Fisher's theory of adaptability confirms that It is possible to believe that Darwin's view that "beauty is only for beauty", so we can call this theory of female selection obtained by the two together as Darwin-Fisher's interpretation of good taste. In this theory, taste can set standards on its own (further research suggests that female preferences are not accidental, but are determined by female feeling biases, etc.), without additional practical considerations. This means that the special tail of the male peacock is popular because it is popular, and it can be made popular and passed down from generation to generation simply through self-reinforcement.
But beyond natural selection, the theory of sexual selection, which has been widely rejected since Darwin proposed it. The most authoritative opponent was Wallace, the other founder of evolution.
When Darwin had reservations about the effectiveness of natural selection in his later years, Wallace took over Darwin's early position, defending the core doctrine of natural selection, a pure Darwinian theory. As a Darwinist who was darwinner than Darwin, Wallace was convinced of the unparalleled importance of natural selection, and he strongly questioned the need to introduce new female selection to explain the tail of the male peacock.
Faced with the target chosen by Darwin's female, Wallace fired a series of arrows. In Wallace's questioning, the most lethal is the aesthetic sense needed in the female selection. In Wallace's view, aesthetic sense is only possible for humans, how can a female peacock have an aesthetic sense?
Darwin's much-maligned view did not have an explanation until the emergence of a new Darwinian theory centered on genes. In this view, when it is said that female peacocks "like" male peacocks with long-tailed feathers, it is only to say that genetic differences in populations in the evolutionary process can lead to differences in behavior. Moreover, because of these differences, some female peacocks have a relatively high probability of mating according to this preference, resulting in the birth of long-tailed feathered sons, and these sons will benefit from the same mating preference. Therefore, the theory of female selection does not lie in "recognizable animals", but in saying "genes with recognition ability". Female selection simply means that there is a genetic selection that has the effect of "making the female appear as if she is choosing."
The revised Darwin-Fisher view of good taste finally gave a theoretically valid answer to the peacock tail mystery. Another answer to this was proposed by Wallace. Wallace insisted that when females choose a mate, they look at useful qualities like vitality and health, or good genes, and they want not a good-looking spouse, but a spouse with good qualities or good genes. In short, Wallace believed that female choice had nothing to do with good taste, but with good reason. The female peacock is a pragmatist, not an aestheticist.
In Wallace's view, the female's choice based on beauty for the sake of taste is only a symptom. The reason for this is only because beauty and good quality are often produced together, and the most energetic and healthy male peacocks with good qualities or high-quality genes are usually the male peacocks with the brightest colors and decorated with the most beautiful feathers, and the male peacocks have more than just a beautiful tail. Since there is a close positive correlation between ornaments and "reasonable" good qualities, females can regard male ornamentation and show-off as the quality indicators she really pursues. But tracing back to the source, the female peacock does not judge the male by the ornament, but uses the reasonable quality that accompanies the decoration as the criterion for judging. Females may seem like they're looking for ornate decoration, but they're actually looking for good qualities. This means that if the female peacock chooses the most brilliantly decorated male peacock, it is only a side effect of the female peacock when she selects a male peacock with good quality or high genes.
The question is, does the rational choice of female peacocks to pursue good qualities really cause those luxurious features that look completely unreasonable at first glance on male peacocks? The development of the theory of evolution explains this.
Since bright color is often closely related to good quality, female peacocks will regard the beautiful long tail of male peacocks as a sign of good quality. As a result, male peacocks with gorgeous long tails are favored. In this way, the use of markers opens up a path: females can select males with good quality, high-quality genes by directly selecting markers. As a result, female peacocks prefer long-tailed male peacocks, as a kind of selection pressure leads males to compete between males for female favor and compete to develop larger and better tails. An evolutionary "arms race" has begun. The selection pressure and the result are linked together to form a powerful escalation mechanism, whereby the male peacock's cumbersome long tail can evolve.
However, wouldn't males deceive females by faking features associated with this? In 1975, Israel's Zahawi proposed that females value only those traits that are honest signs of male fitness. The so-called honesty mark refers to the kind of mark that needs to be produced and maintained at a "high price". For example, male peacocks have long tails with bright colors that must pay a real price, and their existence often becomes a burden to their owners. Zahavi points out that the message of these burdens is that the owner can afford to pay the price! Burdens can only be associated with males with good qualities or good genes. Female peacocks will also understand that if a male peacock still has a way to avoid predators, find food to feed herself, and strive to survive even if she drags a long and large tail, then it must have really good qualities. Because a male who lacks good quality is absolutely unable to pay for the production costs required for a truly eye-catching showy action. In this way, the gorgeous long tail, as the "burden" of the male peacock, evolved into an honest mark that is difficult to fake, and the burden became a real indicator of good quality. Females, on the other hand, use it as a guide to find a mate with good qualities or good genes.
Zahavi's extremely interesting "cumbersome theory of female selection" may seem very counterintuitive, but it has become more and more valued after revision. It makes a clear explanation of the choice of profit, and it also makes a clear explanation of this expensive ornament that seems to be impossible to rationalize, and this is what Wallace's good theory of reason needs most. As a result of the reversal of this new theory, it has finally proved that the theory of good reason has more potential than it was at first glance.
With the development of the theory of evolution, the mystery of the peacock's tail has gone from unsolvable to two credible explanations: good taste and good reason. So, is the answer good taste or good reason? It is somewhat ironic that after the pain of want to the joy of surplus, we are still trapped in the distress of "happiness": there are too many answers, how to choose?
The only way to distinguish which of the two theoretical explanations is correct is through experimentation. However, this is very difficult. Because the male ornaments and dazzling movements seem to occur together with the superiority of rational quality, practical pressure is mixed with aesthetic sense. Only by experimenting to completely rule out all kinds of good rationality can we establish an explanation that female preferences are purely good taste. Because there are so many good qualities of reason that may be popular with females, it is difficult for us to completely close the door to good reason. It seems that if peacock tail wants to get a happy ending, it needs more careful experimentation.