The Asian Blue Dragon (a lizard species) was born from an egg at the Smithsonian National Zoo in Washington, D.C., and its guards were shocked. The reason for their surprise was that his mother had never been with a male blue dragon. Zoo scientists have discovered genetically engineered material through genetic testing (August 24, 2016) through a well-known reproductive process Parthenogenesis Is produced. Parthenogenesis is the Greek word for creation; But it specifically refers to the asexual reproduction of the female.
While many people may think that virginity is in the realm of science fiction or religious texts, this behavior is surprisingly common throughout the tree of life and is found in many creatures, such as plants, insects, fish, reptiles, and even birds. Because mammals, including humans, need certain genes that come from sperm, they cannot reproduce.
Creating a child without sperm
In sexual reproduction, a male and a female are involved, each of which provides genetic material in the form of an egg or sperm to produce a unique child. Reproduction in most animal species occurs sexually; But females of some species produce eggs that contain all the genetic material needed for reproduction. Females of this species include some vesicles, crustaceans, and lizards that reproduce only by fertilization. Compulsory virginity Called.
Specimens of different species that reproduce involuntarily are best shown in animals kept in zoos. Some examples include the Asian Blue Dragon at the Smithsonian National Zoo or the small black fin shark at the Virginia Aquarium.
Animals with non-compulsive reproductive characteristics usually reproduce sexually; But sometimes they may have cycles that produce ready-to-grow eggs. Scientists have learned that involuntary fertilization may be an inherited trait; That is, females are more likely to have offspring with the ability to reproduce in females who experience infertility.
How do females fertilize their eggs?
In order for fertilization to occur, a series of cellular events must be successfully performed: Females must be able to ovulate without stimulation caused by sperm or mating; ۲. Eggs produced by females must begin to grow on their own and form an embryo that has the power to grow; 3. The offspring must be able to be successfully born from an egg.
Any stage of this process, especially the second stage, which requires the duplication of chromosomes within the egg so that the child has a complete set of genes as it grows, can easily fail. Alternatively, the egg can work with the cells left over from the egg production process Polar objects Are called, to be fertilized falsely. Each of these methods, which initiates embryonic development, ultimately determines the degree of genetic similarity between mother and child.
The events that give rise to infertility are not fully understood; But environmental changes seem to play a role in this process. In species such as aphids that have the ability to reproduce sexually and reproduce, stressors such as crowding and hunting may cause females to turn from reproduction to sexual reproduction; But the opposite does not happen. At least in some freshwater plankton, high salinity seems to cause this behavior change.
Spotted lizard monster (Aspidoscelis flagellicauda) is one of the few all-female species of spotted lizards that reproduces by virginity.
Benefits of independent reproduction
Although non-forced fertilization seems to be rare, it does have advantages for a material with this capability. In some cases, females are allowed to produce their own mating partners. The sex of the offspring is determined in the same way that the sex is determined in the species itself. For organisms in which sex is determined by chromosomes, such as chromosomes (female XX and male XY in some insects, fish, and reptiles), the female reproduces her offspring using only her sex chromosomes; Therefore, his children are always Article XX. In contrast, for organisms in which females have ZW sex chromosomes (such as snakes and birds), all living offspring produced will be either ZZ and male or, more rarely, WW and female.
Between 1997 and 1999, a checkered sock kept at the Phoenix Zoo in Arizona gave birth to two male children who eventually survived to adulthood. If a female mates with a male that she has produced through virginity, it is considered endogenous. While endogenousness can lead to many genetic problems, it is evolutionarily better than not having children.
Also, the ability of females to produce male offspring through infertility suggests that asexual reproduction may be more abundant in nature than previously thought by scientists. According to long-term observations by biologists, species that are obligate virgins are often extinct due to disease or parasites or changes in habitat. Endogenous endemicity to virgin species seems to be effective in their short shelf life.
Current research on reproduction seeks to understand why some species can reproduce and reproduce sexually, and whether occasional sexual reproduction is sufficient for species survival.