Everything has recovered, the spring breeze has arrived, and it is the season when animals applaud love once again. Gorgeous new clothes must be worn every year, and both sides must fight to the end in order to breed. After all, sexual selection is very important and even drives the evolution of species.
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Thanks to Darwin, a tsunami triggered by The Origin of Species allowed biology to flourish in an evolutionary direction over a hundred years. Darwin recounts two great discoveries in On the Origin of Species:
First, natural selection dominates evolutionary mechanisms and.
Second, all organisms have historically originated from a common ancestor.
None of this explains the question: If natural selection is the sole dominance of evolution, where do those flashy decorative organs in nature come from?
Apparently, Darwin also found this problem, writing in a letter to Asa Gray, a botanist at Harvard University: "Whenever I see the tail screen of a male peacock, I feel blue and thin!" ”
Image from the web
In 1871, Darwin explained in his book The Origin of Man and Sexual Choice: Animals choose their mates according to their aesthetic appeals, are animals and human feelings similar? This theory seemed absurd at the time, and even many biologists who accepted the theory of evolution criticized it.
The result of sexual selection may be that strong people are worthy of wives, and many animals choose to fight for mating rights:
Giraffe dry rack Picture from the web
The picture is from the Internet
Most birds choose to take beauty to the extreme. Like Darwin, who saw the peacock's tail and had a brainache, the zoologist who saw the bird of paradise also issued the same roar: Is this necessary? Is this necessary?
I beautiful I am proud of the bird of paradise picture from Wikipedia
Bird of Paradise, a demon wind in the beauty pageant Picture from the Internet
Zoologists have tried to explain this phenomenon of anti-evolution with many theories. Bateman's Principle holds that a male's potential reproductive success rate is tied to the number of females it mates with, and that males effortlessly hand out all female fertilized sperm and have a full house of offspring. Females, on the other hand, do not produce more offspring by mating more, and their reproductive success rate is limited by the number of eggs she can produce. Therefore, males need to compete with females, and females become picky when it comes to choosing a mate.
However, is the reproductive success rate of males really high enough to fly? Are females so passive?
In fact, most monogamous birds have female infidelity; in primates, females will court males and mate with different males; studies of scorpions have also shown that females and multiple males can increase fertility rates and increase the number of babies...
Therefore, not all the girls who have soaked themselves will give birth to their own children, and the females will also give their fathers green hats in order to have more and better offspring. These studies are evidence that contradicts Bateman's principle.
Bateman is also helpless, it is all the fault of the fruit fly experiment!
The more receptive is Zahavi's "Handicap Principle." The male peacock has such an obstructive tail and still lives well, proving that it must have its advantages in other aspects, such as healthier, more fertile and foraging ability.
But this theory is also widely questioned: if it is to prove the advantage of defects, the disabled bird with one less leg or one eye that has survived should be more popular, but no bird deliberately makes herself lame, and the female bird is obviously not willing to choose a better cripple. Why should they choose "unfavorable conditions" that are obviously aesthetically valuable?
At this point, you can probably understand the uneasiness of zoologists: there is probably no logic or rationality behind sexual selection, and the sexual autonomy of females is the main reason for the evolution of natural beauty.
Courtship in male wormwood grouse Centrocercus urophasianus, we have to admit aesthetics and what and different pictures come from the web
Many females can raise their offspring alone, and males who do not have the opportunity to play an advantage elsewhere have to do whatever they want to please.
Chiroxiphia caudata's collaborative show-off of the swallowtail petite wren image from the web
The more extravagant they are, the more they indicate that the situation of the male is not optimistic: the female red-crowned blue-backed petite genus Chiroxiphia has a very strong preference for mate selection, so that in the competition related to sex, only the most beautiful ones will shine, and there are many more losers than winners. The Coleus colony is like a giant Ponzi scheme, with more than 90% of males destined to fail.
That scene is probably like thousands of girls crazy for the same love bean today, behind them is the lonely eyes of a large number of single dogs.
The nose-covering windbird that failed to courtship is pictured from the network
"You just provided a sperm" is our misconception about males
Presumably in terms of sexual selection, males behave too fancy, and we rarely discuss male-to-female selection. This is understandable, after all, females usually pay more for raising offspring, while males produce more offspring by mating with as many females as possible. Shouldn't males wear the hat of a "scumbag" and not refuse?
"You just provided a sperm" is our misconception about males. Usually, just providing sperm won't satisfy a female – unless you're the most beautiful man in a bird of paradise. In order to get more mating opportunities, some males will pay something more: to protect their partners, to raise offspring together, or to bring a "bride price" when mating.
The more expensive the "investment" required to reproduce offspring, the more it will increase the sexual choices of males to their sisters. In extreme cases, a complete reversal of gender roles can occur.
For example, the three-toed quail, the female gives birth to a nest of eggs after mating with the male, which is hatched and cared for by the male, the warm man is difficult to find, and the female has "three wives and four concubines", correspondingly, they are responsible for fighting for the territory outside.
Yellow-footed three-toed quail Image from Wikipedia
Or like the generous Mormon Ant, males provide females with 27% of their body weight per mating. Seminal vesicles are like a nutritious cake, and when food is scarce, some females will pretend to enter the mating period and deceive male seminal vesicles as food (originally Mormon ant, and it is too urgent to fry).
Mormon Ant, who is very generous to his spouse, is pictured on Wikipedia
Once the effort increases, the number of mating times the male is limited. When there is a large number of females to choose from, or when the quality gap between females is particularly large, the male also becomes picky: what about her reproductive ability? What is her social status? How much energy is she worth my effort? (Three consecutive questions from the man's soul).
Differences in the quality of females who can be mates are the basic spiritual requirements for the evolution of male mate selection. The greater the difference in female quality, the greater the potential benefits and necessity of choosing a mate for the man. The male mate selection definition includes "variations in the number of resources allocated to females of different qualities."
To the female's dismay, after mating, the male may show a more common choice of mate than before mating. Because once accepted by the female, the male can more accurately assess the quality of the female through physical contact, and then decide how much resources to invest in the female in the future.
In the study of insects, many males preferred females with wider abdomen and larger bodies to produce more offspring.
Little tadpoles! Rush the duck!
Sperm competition is also an aspect of choice, if a female mates for the first time, the object's sperm is more advantageous and of higher quality, then the male who meets later may refuse to mate with her, of course, provided that the male can recognize it.
Like most insects, the last male to mate with the female is generally of high priority, so the male will reject the female who is likely to re-mate with other males in order to ensure that he is the "last" solid position.
In general, male insects prefer young females who are breeding for the first time, thereby increasing fertility and reducing sperm competition.
"Rejection" is not a routine procedure for males, who may also adjust their ejaculation volume to cope with different sperm competition.
When males find themselves not picking each other, they reduce their investment rate, such as reducing sperm contribution. For the favorite females, more bride price, more lasting protection or more attentive care for their offspring.
Male stone finches (Petronia petronia) have higher nest defense behavior after mating with attractive females. A study of the grey-backed deer rat (Peromyscus polionotus) found that when males were paired with preferred females, the number and size of pups increased significantly.
The monogamous grey-backed deer mouse image is from Wikipedia
Male mantises are more specific in their consideration, choosing obese females because they seem to eat well and have a smaller chance of eating themselves when mating so that he has a chance to meet the next female mantis.
The black cat sheriff brings us childhood shadows In pictures from the Internet
Brown widows (Latrodectus geometricus) are more individual, although mating with sub-adult females is less risk of being eaten, male spiders still risk death to choose mature females, even if mature females are no more fertile than young females.
Brown Widow Image from Wikipedia
Forget it, just get by
Since male selection exists, why do females rarely evolve so fancy? Zoologists believe that unlike the females who single out the strongest and most beautiful males, it is possible that the males are biased towards "stable choices": too bad to want, too good to compete too fiercely, and the middle grades have the highest return rates.
Preference for female choices will bring fierce competition to males (such as wanting to fall in love with Banhua). At this time, if not so picky, males with different tastes will be in the ascendancy, so the male preferences will not develop in a fixed direction, and the females will not have to look the same and chase the man backwards.
Male selection, on the other hand, is more varied. Obesity, for example, fluctuates during each female's reproductive cycle, and if the male chooses a female based on these variable phenotypic traits, there is little pressure to choose (male: it doesn't matter, she will be fat again next month).
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Most females experience mate selection, but not all males have the opportunity to do so. Mating male selection also exists in the male gallus gallus, but only the eldest brother has the right to choose, and the weak chickens in the subordinate position still have little chance.
The strongest big brother deserves the best woman
The cost of finding and assessing a spouse also counts. Many animals have occasional encounters between male and female, and wasting time looking for another partner can lead to a decrease in reproduction rates. Being picky means a potential cost of not having time towards the end of the breeding season and having to accept a low-quality partner
。
Not to mention the "Cryptic Female Mate Choice" strategy, in which females benefit from each male but fertilize only with high-quality sperm. For example, the white-striped litigiosa (Neriene litigiosa), the male wastes a lot of predation time and female mating, but the female can easily "dissolve the paternity of the mate". Now it's the male's turn to grieve.
Nature is so rich and varied that no study can reach a universal conclusion, and no article can summarize its diversity and interest. All opinions are waiting to be overturned, and there are more magic waiting to be discovered. Curiosity and curiosity are probably the most wonderful gifts that evolution has given to mankind.
Reference
[1] Richard O. Prum, Evolution of Beauty[M], translated by Ren Ye. CITIC Publishing Group, 2019
[2] Sun Ruyong, Principles of Animal Ecology[M], Beijing: Beijing Normal University Press, 2006
[2] Edward D A ,Chapman T . The evolution and significance of male mate choice[J]. Trends inEcology & Evolution, 2011, 26(12):647-654.
[3] Bonduriansky R. The evolution of male mate choice in insects: A synthesis of ideas andevidence[J]. Biological Reviews, 2001, 76(3):305-339.
[4] Gwynne D T . Sexual competition among females: What causes courtship-role reversal? [J]. Trends in Ecology & Evolution, 1991, 6(4):118-121.
[5] Bonduriansky R. The evolution of male mate choice in insects: A synthesis of ideas andevidence[J]. Biological Reviews, 2001, 76(3):305-339.
[6] Andersson M,Iwasa Y. Sexual selection. [J]. Trends in Ecology & Evolution, 1996,11(2):53-58.
[7] Reinhold K ,Kurtz J , Engqvist L . Cryptic male choice: sperm allocation strategies whenfemale quality varies [J]. Journal of Evolutionary Biology, 2002, 15(2):9.
[8] Hill G E . MaleMate Choice and the Evolution of Female Plumage Coloration in the HouseFinch[J]. Evolution, 1993, 47(5):1515-1525.
[9] Waner S , MotroU , Lubin Y , et al. Male mate choice in a sexually cannibalistic widowspider[J]. Discussion Paper Series, 2018, 137:189-196.
[10] https://en.wikipedia.org/wiki/Mormon_cricket
[11]https://en.wikipedia.org/wiki/Bateman%27s_principle
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Refusing to applaud for love will be punished by wives
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