z Stick insects, I really can't see it, ah, the persistence is so strong!
Olivia Judson, an evolutionary biologist, graduated from Stanford University in the United States, received her Ph.D. from Oxford University in the United Kingdom, and is currently a researcher at Imperial College in London. Animal Sex was quoted as a story by The Economist magazine.
In this section, I try to suggest why there are so many differences between the sexes in their need for civility and their attitudes towards life, and I try to explore the consequences of this difference. The second part is "The Evolution of the Fall." In this section, I explore the extreme forms of gender conflict, which can sometimes lead to terrible consequences, such as rape and cannibalism. In the last chapter of this section, we discuss the rarest and most perverse phenomenon of monogamy. ”
The male Idaho gopher wouldn't let his partner out of his sight, and if she had entered a hole, he would sit at the entrance to the hole to keep the other male gophers from getting close.
The male blue milkweed worm is finished in 10 minutes, but will lie on the female's back to prevent her from flirting with other males.
As for the stick insects, they may have been doing this for more than 2 months.
A.J. Bateman's observations of the yellow fruit fly. Wrong conclusion: male flower heart, female loyalty. Can a frog in heat drown a goldfish? In line with the subjective judgment of the mainstream of society at that time, it was later found that gunnison prairie marmots, sand lizards, slippery barracuda, females and multiple males interbreed would increase the number of offspring.
Prairie marmot
Golden Tree Bear Monkey, a species of bush monkey. The deformed YJ, like a medieval torture device, has flesh thorns, hard short hairs, pimple protrusions, and some are twisted into strange shapes.
Dragonflies, commonly known as bean maidens, male YJs have an airbag with two horns at the top of the airbag, and the airbags are flanked by hard hairs. The black-winged dragonfly uses this device to flush out the JY of other males. The red-tailed dragonfly stimulates the female to ejaculate the JY of the previous lover in a suitable way.
Female termites only mate with one male termite, so there is no difference between male YJs.
Male ghost spider crabs produce a special gelatinous substance that seals the JY of the previous male crab in a corner of the female crab's reproductive tract.
With the exception of swans, ducks and ostriches, the vast majority of male birds do not have YJs and are fertilized by rapidly squeezing the openings of both genitals. The male hedgehog will peck at the female's pussy, prompting her to expel JY. Red-beaked cattle birds, extremely promiscuous, males have false YJs, excrete JY.
The gorilla has a YJ of only 5 cm, while the Argentine brown hard-tailed duck has 20 cm and has protrusions.
Brown hard-tailed duck
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When the male bee reaches orgasm, it explodes its genitals, leaving it inside the queen bee. This is to avoid the queen bee from mating with other males. However, the queen bee mated up to 17 times, and the male wasps involved in the pursuit of the queen could reach up to 25,000. The male bee is hatched from unfortilized eggs, the female is hatched from fertilized eggs, and if a queen bee mates only with one male, and the male is genetically determined by sex as the queen, half of her fertilized eggs will hatch into sons who will not be able to have children, and her daughter will eat the male bees. However, the male wasp's YJ has a furry tissue at the top that can get the former YJ off.
Female fox squirrels will pull out or even eat "plugs" to make it easier for them to find other males. This struggle is constantly evolving.
Fox squirrel
"It's hard to be a male, especially when you have to make sperm that's 20 times larger than your own body, when the latter needs to ejaculate billions of sperm per ejaculation, or when you need to have sex 100 times a day to meet your partner's needs, or when you need to show incredible sexual skills."
The Wren is only the size of a fist, and is known for having good fornication, and will go out with pink flowers to meet her lover. Ejaculate 8 billion sperm at a time.
wren
The number of sperm and eggs in fish is not much different.
Sperm competition. Experimental observations of yellow fecal flies have found that after at least 10 generations, the size of the testicles changes.
Both seahorses and spiky-billed fish (sea dragons) are males responsible for pregnancy, and scientists have not calculated their ejaculation. However, there is one species of seaweed spiky-billed fish whose sperm counts, and the number is almost negligible.
Sperm die in large numbers before they reach their destination, and scientists have discussed it for more than 300 years, with no decent explanation yet. Some animals will retain JY for several years, while others never store sperm.
Acidic environment, mucus in front of the cervix, white blood cells. Within 15 minutes of XJ, a woman can assemble 1 billion white blood cells and kill sperm.
In addition to the large number, it may also be won by quality, such as large size.
The 3 mm long fruit fly produces sperm up to 58 mm long, 1,000 times the length of human sperm.
Sperm of American possums, aquatic beetles, millipedes, housefish, and some sea snakes are sperm pairs.
North American possum
Hook-shaped sperm, the sperm of koalas, rodents and crickets.
The sperm of the protozoa is flattened disc-shaped.
The sperm of the crayfish resembles a Catherine cookie. (Sorry, I didn't find the picture.) ）
The sperm of a snail is spiral-shaped.
Roundworm sperm will change back and forth.
The big octopus would shoot out a 1-meter-long sperm sac containing 10 billion sperm like a bomb.