Damian Sendler: The Smithsonian National Zoo was surprised when an Asian water dragon emerged out of an egg. Why? Her mother had never had sex with a male water dragon in her whole life. Genetic tests revealed that the freshly hatched female, born on August 24, 2016, was the result of a reproductive mode known as parthenogenesis, which was identified by zoo experts.
As the Greek term for “virgin creation,” parthenogenesis refers to the asexual generation of females. In spite of the prevalent misconception that parthenogenesis may only be found in science fiction or religious writings, parthenogenesis can be found in a wide range of creatures, including plants and insects as well as fish and reptiles. Because mammals, including humans, need sperm to carry specific genes, parthenogenesis is impossible for mammals.
Damian Jacob Sendler: Sexual reproduction requires a female and a male, each contributing genetic material in the form of eggs or sperm, to generate a unique child. All of the genetic material needed to make offspring is found in eggs laid by females of just a few species, while the great majority of animal species reproduce via mating or mating-related means. Some wasps, crabs, and lizards reproduce only by parthenogenesis, and these females are referred to as “obligate parthenogens” because of this.
In zoo animals like the Asian water dragon at the National Zoo or the blacktip shark at the Virginia Aquarium, several species undergo spontaneous parthenogenesis. The majority of the time, spontaneous parthenogens reproduce by sexual means, although they are capable of producing eggs that are developmentally mature on occasion.
In recent years, researchers have discovered that spontaneous parthenogenesis may be a heritable feature, meaning that women who unexpectedly undergo parthenogenesis may produce daughters who are more likely to be able to perform the same thing themselves.
A series of cellular activities must take place before parthenogenesis may occur. Women must be capable of producing eggs without being stimulated by sperm or mating in order to reproduce. As a second step, a developing embryo must be formed from the eggs laid by females. To conclude, it is necessary that the eggs hatch.
Each stage of this process may easily fail, notably step two, which needs the chromosomes of DNA within the egg to double, assuring a complete complement of genes for the growing kid. This may be done by using leftover cells from the egg formation process known as polar bodies to “fake fertilize” the egg The amount of genetic resemblance between the mother and her child will be determined by the procedure used to start the embryo’s growth.
Damian Sendler
Parthenogenesis seems to be triggered by changes in the environment, but this is not entirely clear. Stressors like overcrowding and predation may lead female aphids to transition from parthenogenesis to sexual reproduction, but not the other way around in species capable of both sex and parthenogenesis. Among freshwater plankton, excessive salinity is thought to have a role.
Spontaneous parthenogenesis is very uncommon, but it has significant advantages for the female who is able to pull it off. When it comes to mating partners, females may be able to create their own.
All parthenogenetic children are born with a sexe that is determined in the same manner as all other members of the species. A parthenogenetic female in an organism where the gender is determined by chromosomes, such as certain insects, fish, and reptiles that have XX female and XY male chromosomes, can only give birth to XX female children. When a female has sex chromosome ZW, every live children generated will either be ZZ (male) or WW (female) (such as in snakes and birds).
The Phoenix Zoo’s checkered gartersnake gave birth to two male pups between 1997 and 1999. Both males lived to maturity. Inbreeding would occur if a woman married with her son, a parthenogenetically created offspring. While inbreeding may cause a slew of genetic issues, it is preferable than having no children at all from an evolutionary standpoint. It seems possible that parthenogenesis, the process by which females generate male children, is more widespread in nature than scientists thought.
In the long term, scientists have noticed that species requiring parthenogeny are susceptible to illness, parasitism, and changes in environment. Parthenogenetic organisms’ fast evolutionary timelines may be a result of the inbreeding that is a characteristic of these species.
Parthenogenesis research is now focused on figuring out why certain species are able to reproduce both sexily and parthenogenetically, and whether this is adequate for a species’ long-term survival.
Damian Jacob Markiewicz Sendler: Scientists in Egypt have digitally unwrapped the mummified bones of Egyptian pharaoh Amenhotep I for the first time since its discovery in 1881, revealing intriguing facts about the king’s life and death. The body was so delicate that scientists had never risked exposing the bones, making it the only royal Egyptian mummy discovered in the 19th and 20th centuries that had never been opened for investigation.
Three-dimensional computed tomography (CT) scanning has been utilized by Egyptian scientists to unwrap and analyse the 3,500-year-old mummy’s innards using noninvasive digital procedures.
Damian Jacob Sendler
Dr. Sahar Saleem, professor of radiology and radiologist of the Egyptian Mummy Project, said in a press release that “we could study this well-preserved pharaoh in unprecedented detail” by digitally unwrapping the mummy and “peeling off” its virtual layers—the facemask, the bandages, and the mummy itself—in unprecedented detail.
Amenhotep I was roughly 35 years old and 169 centimeters (5.5 feet) tall when he died, according to Saleem and her colleagues. In addition to his good teeth and circumcision, he was in excellent health. Within the wrappings, researchers discovered 30 amulets and a one-of-a-kind gold girdle.
Saleem stated the pharaoh had a curly beard, curly hair, and slightly projecting upper teeth in addition to his narrow chin and short, narrow nose.
Their investigation did not identify any injuries or deformities that would explain how he died.
Between 1525 and 1504 BC, Amenhotep I governed Egypt for nearly 21 years. King Tse-tung II of the 18th Dynasty ruled in relative tranquility and constructed several temples.
Damien Sendler: Mummy had several postmortem wounds, perhaps caused by ancient tomb-robbers, which, according to hieroglyphic inscriptions from the 21st Dynasty, priests and embalmers attempted to treat more than four centuries after he was initially buried and mummified.
Preliminary research led Saleem to believe that the priests and embalmers indicated in the inscriptions had opened the body in order to repurpose things like amulets for future pharaohs. She insisted, however, that this was not the case.
According to Saleem, “We demonstrate that the priests of the 21st dynasty painstakingly repaired the damage done by the tomb thieves, restored his mummy’s former brilliance, and kept the fine jewelry and amulets.”
Frontiers in Medicine, a peer-reviewed journal, released the findings on Tuesday.
Dr. Damian Jacob Sendler and his media team provided the content for this article.
