A good-looking egg is a good egg.
Written by | Su Chengyu
This is the world's best-looking egg Credit: Larry Petterborg
This is a finalist for the 2021 Comedy Wildlife Photography Awards, and a long-tailed black-jawed monkey is looking at its own blue egg as if to say: wo! How in this world there are such beautiful eggs.
In fact, not only the long-tailed black-jawed monkey, but also several kinds of monkeys also have blue eggs:
Erythrocebus patas
Image source: deviantart.com
Mandrillus sphinx: Not only are the eggs blue, but the butts are also colorful
Source: National Geographic
Lomami long-tailed monkey (Cercopithecus lomamiensis)
Image source: futurity
They all have blue eggs, of which the long-tailed black jawed monkey is particularly eye-catching, the bluedest and most obvious.
Why so blue?
Because the bluer, the more melancholy
We all know that the male peacock attracts the attention of the female peacock by opening the screen to show its unparalleled sexual charm. The more gorgeous the screen, the easier it is to defeat potential lovers in order to gain the approval of the female and spread her ancestral DNA.
In the same way, the bluer the monkey's eggs, the more advantageous they are in sexual selection. Scientists have found that the deeper the blue color of the long-tailed black-jawed monkey egg in East Africa, the higher its social status in the group, and the higher the social status, the stronger the attraction to females. In addition, the bluer the egg, the more likely it is to bully underage monkeys. And the more aggressive the monkeys, the more male hormones are secreted.
So-called power is the best aphrodisiac, and the same is true for monkeys.
Monkeys corresponding to the data corresponding to different egg color, such as height, weight, egg volume; the aggression of different egg colors, the higher the score, the stronger the aggression 丨 Image source: Literature 1
You'll find it easy for photographers to capture them with their legs spread apart and their eggs looking down.
Image source: Mary Anning
It has to be doubted that they are also confused about their own blue eggs, why!? Why so blue!
Of course, this indecent posture, spreading your legs to show off your eggs, is more like a show off: look, how beautiful my eggs are, how manly.
Why is it so blue?
Mammalian fur has only two pigments: one pigment that makes the hair black or brown, and the other pigment that makes the hair yellow or orange-yellow. Albinism is due to the absence of pigments. Theoretically, if it is just like the paint plate, no matter how the color is matched, these two pigments cannot produce blue no matter how they are adjusted.
But nature has created something called structural color, which is the color produced by the scattering, interference, or diffraction of light when it is incident on an object with a similar period and wavelength. For example, the colorful soap bubbles you see in the sun are a manifestation of structural color.
The blue color on the skin of the monkey egg is also structural. According to a 2004 study, monkeys with blue eggs had unusually neat and orderly collagen fibers on their skin. Once the structure of these collagen fibers changes, even a change in the size or distance of a millionth of an inch will produce different colors. Blue is one of these structures.
So, that's how the monkey's blue egg came about.
Have eggs always been so blue?
Just as human hair turns gray and white with age, the color of eggs changes over time.
For red monkeys, it is sea blue when it is underage and blue-green when it is adult.
For the long-tailed black-jawed monkey, it is a dull blue when it is underage, a bright blue in adolescence, and white when it is old.
But if it's a human egg, it's best not to expect it to turn blue, the so-called Blue ball. "Blue Balls" is a crude phrase from around 1916 that means that when a man is too long to be released, it is technically called: epididymal hypertension. At that time, maybe the egg will have a hint of blue, that is the blue of the vein blood. Of course, it will not be as blue as the monkey, and Lan Cheng is estimated to be...
bibliography
[1] Primate colour predicts social status and aggressive outcome - ScienceDirect
[2] http://www.oaklandzoo.org/Vervet_Green_Monkey.php
[3] Mary Anning's Revenge: 14 Days of Genitals, Day 5: Blue Balls to the extreme (maryanningsrevenge.com)