For animals that do not have a "thinking" consciousness, they do not have love, and even the so-called "monogamy" in the eyes of humans is only a better way for them to survive and reproduce.
Christopher Oppei, an anthropologist at University College London in the United Kingdom, and others reported in the Proceedings of the National Academy of Sciences that there is infanticide in polygamous animals, that is, males will kill babies that are not related to them, thereby improving their chances of reproducing offspring with the mothers of these babies. To reduce the risk of infanticide and protect offspring, primates evolved monogamous about 16 million years ago. A male paired with a female and raising offspring is beneficial to protect the offspring and reduce the risk of infanticide.
Therefore, the monogamy of most animals is called, ecologically, a critical type of one male and one female. Both the male and female are forced by environmental pressures to jointly incubate the eggs and brood in order to breed successfully, thus showing "monogamy". And as long as they have the opportunity to spread their genes without endangering their offspring, they will not hesitate to choose - "cheating".
Using a statistical model of 230 primate species, Oppei et al. found that 9 percent of mammals adhered to monogamy, compared with up to 25 percent of primates.
Knowing that animals do not produce love, same-sex mating between animals has confused many scientists. According to incomplete statistics by scientists, at least 130 species of vertebrates have same-sex mating behavior, which biologists call "same-sex contact" or "same-sex crawling".
In fact, we need to know that any behavior of animals is carrying out the instructions of genes, and the purpose of genes is only one, that is, to ensure their own existence and continuation, and genes are most concerned with the survival and reproduction of individuals.
Same-sex mating behavior between animals is also based on this purpose, and scientists have found that same-sex mating behavior between animals is mainly for this purpose:
1, the solution of the reproductive instructions, in addition to humans, animals have a estrus period, they will generally consider the time required for pregnancy or incubation of eggs, choose the most appropriate time to estrus, in order to improve the survival rate of offspring. In addition, for plant-eating animals, there is a need to avoid predators during the estrus period, because breeding is often a great opportunity for predators to hunt. Therefore, the animal's hormones will be more exuberant at a certain time to allow the animal to enter the estrus period and thus give birth to cubs.
However, not any male animal can get a mate, in some female and male populations or in the very strict hierarchical sequence, excellent male animals are often more able to win the favor of female animals, for example, in the mating season, the males in the deer herd should be more hoofed and whose physique is stronger; pheasants will see whose feathers are more beautiful; are more pleasant than whose cries are more pleasant...
Female animals choose those excellent male individuals to mate with, and the remaining "bachelors" cannot find a mate, are not eligible to participate in the breeding group, and can only perform same-sex crawling behavior to release the energy accumulated in the body. And such objects are not only of the same sex, but sometimes may be prey, muppets, and so on. This is a helpless act, for animals, the instructions for reproduction make them have to find the object of mating, but the reality is often very bone, so they can only crawl across the same sex.
2, learning behavior, animal same-sex behavior is not good for species reproduction, but its existence also has a certain biological and animal sociological significance. Animal same-sex sexual behavior is sometimes just a learning behavior, helping animals to better grasp the way of mating, thereby increasing the probability of reproductive success.
For example, young primates sometimes have some crawling behavior when playing. At this time, they are still only sub-adults, not yet mature, no mature organs, and there is not enough hormone stimulation, and the crawling between them is not a sexual behavior, but a behavior between small animals imitating adult animals, but this behavior is of positive significance for the reproduction of species.
3. Indicate friendly needs. Individuals in social animals often have confrontational conflicts, especially between same-sex animals, such as bonobos, which are easily agitated animals, often fighting for small things, but their fights seem to subside faster than they happen, and one of the ways is through mating. It can be seen that same-sex sexual behavior has the effect of maintaining the stability of animal populations.
4. Declare their status, climbing across is largely related to the change of rank between adult males, which is manifested as a high-order individual climbing across a low-order individual. Same-sex creeping occurs when social relations intensify in communities. For example, seasonally reproducing species compete for mating rights during the mating period, ritualized, lethal fights between strong adult males until new hierarchical sequences are re-established, during which time same-sex climbing is frequent.
In addition, aggressive individuals often crawl across individuals who are defeated by them and those who voluntarily succumb to their deterrence. Some species, such as chimpanzees, have this invasive same-sex crawl in both sexes. Some only occur between single-sex individuals, such as male green baboons and male Sichuan golden snub-nosed monkeys, two same-sex friction between each other's organs, while the opposite sex occurs true mating behavior, they use this behavior to show goodwill, calm the fight, in order to reduce the loss of the family and themselves.
5, the way animals greet each other, many populations will greet each other through such mating behavior, primates, when two individuals meet again after a period of separation. In the process, it is common to see an individual accepting its mating. Seven species of monkeys are known to exhibit this behavior, including black monkeys, pygmy long-tailed monkeys, green baboons, South African baboons, Japanese monkeys, macaques, and long-tailed langurs.
For primates, the odds of same-sex mating are greater because primates generally have a basic hierarchy, with individual primates having a separate hierarchical relationship that is not influenced by other members. It is rare in fauna because each individual lives with his own relatives and other members, is in some sort of subordinate relationship, and has his own subordinate hierarchy. They also have the need to maintain the stability and reproduction of animal populations.
Primates that engage in same-sex mating behavior
Same-sex creeping involves almost all ages in the group, both male and female, and appears in almost all social situations of animals. Scientists also regard their social function and the occurrence and development of participating individuals as an important topic, and become an important indicator to measure whether an individual's growth and development are normal and divide its development stages.
Humans, who evolved from primates, also carry such recessive genes, and after humans have autonomous consciousness, they develop such behaviors into love, which is the difference between humans and animals.