If Female Condors Can Reproduce Without An Assist From Males, Why Can’t Humans And All Other Animals? 15 Points That Help Explain ‘Parthenogenesis.’

1.    In a paper published on October 28, 2021, in the peer-reviewed Journal of Heredity, scientists from the San Diego Zoo revealed that at least two California condors born over the last 40 years or so are biologically fatherless. A genetic database maintained since the 1980s showed no trace whatsoever of paternal genes in their DNA.

2.    No one knows whether reproducing asexually is a new talent for California condors. Maybe the species has always been capable of it. California condors almost went extinct in the 1980s, and they are still endangered. Because of this, the number of animals in the genetic database is too small for anyone to address the question reasonably.

3.    The scientists who discovered asexual reproduction in California condors are still scratching their heads about why the eggs of two particular females began developing in the absence of sperm. After all, when those females got pregnant, they were housed with fertile males. What’s more, neither female had a clear aversion to mating; both had previously hatched eggs that males had fertilized with no human intervention.

4.    The scientific name for asexual reproduction is parthenogenesis. (In Greek “parthenos” means virgin and “genesis” means birth or creation.)

5.    Parthenogenesis is uncommon among mammals. It’s uncommon among birds, too—except for turkeys and chickens. However, it is the very comme il faut of reproduction for many invertebrate species. Some fish, reptiles, snakes, and scorpions reproduce this way, as well.

6.    For whiptail lizards, even though males aren’t necessary for reproduction, a little sex sometimes sets reproduction going. To be clear: the sex is between females. (There aren’t any male whiptail lizards.) The species, endemic to desert grasslands of New Mexico, Arizona, and northern Mexico, seems to have resulted from the hybridization of two other species, both of which have males. When two female whiptail lizards have sex, they enact the mating ritual of males and females of one of their progenitor species. One whiptail lizard takes the typical male mating position (top) and the other takes the female position (bottom). Ready, set, go ... and, as Elvis might have said, a whole lotta shakin’ starts going on. Afterward, odds are fair that an ovum of the bottom lizard will set out on its parthenogenic way.

7.    For most animals, broods resulting from parthenogenesis are entirely female. There is one parthenogenically-producing scorpion species that sometimes produces all-male broods.

8.    The two California condors with no biological fathers were both males.

9. Theoretically speaking, parthenogenesis is not out of the question for humans. Some scientists have considered attempting to encourage it biochemically. The goal would not necessarily be the creation of living humans but of embryos from which stem cells could be harvested. Potential ethical conflicts have yet to be resolved.

10. Practically speaking, parthenogenesis already happens spontaneously in humans, though it doesn’t result in live births. Instead, it produces dermoid cysts on ovaries. They can contain human materials like fat, cartilage, teeth, and hair. Usually, the cysts are benign and easily removed surgically. In 2018 the magazine Insider reported that a dermoid cyst the size of an orange was removed in 2017 from a young freelance writer named Calle Hack. Insider quoted Ms. Hack as saying that her surgeon had described the cyst as like a “rotten chicken wing.... It was like if you lost hair, and teeth, and bones in the bathroom drain and they were just pulling that out.” A picture is here. The cyst may have been the size of an orange, but it seems to have been shaped more like an embryo.

11. Increasingly, parthenogenesis is being documented in species once believed to be incapable of reproducing that way. Most often, these discoveries are made in captive animals. Even so, in 2012 biologists from North Carolina State University in Raleigh found parthenogenetically-produced offspring in wild specimens of two closely related snake species. In 2015, a group of marine biologists from several American institutions documented parthenogenesis in wild sawfish, a type of ray also known as a carpenter shark.

12. For some non-human animals, what looks like a talent for parthenogenesis isn’t. Certain species’ females are capable of storing sperm for such a long time that, when they turn up pregnant, observers have no idea there was any sperm involved in the process. Reptiles are particularly good at this trick.

13. Parthenogenesis is probably inferior to sexual congress as a reproductive strategy. In a 1931 article, geneticist Hermann Joseph Muller (second cousin to science fiction author Ursula K. Le Guinn) proposed that sexual reproduction effectively accelerates positive evolutionary change. When one animal with a favorable mutation mates with another animal with the same or another favorable mutation, the genomes of the two lucky individuals are combined into one lineage.

14. Muller won the 1946 Nobel Prize in Physiology or Medicine, though not for his ideas about sexual reproduction. It was for showing that the ionizing radiation from x-rays can cause genes to mutate.

15. When thinking about parthenogenesis, many people wonder if the virgin birth of Jesus Christ was an example. No trace of either Mary’s or Jesus’ corpse has ever been found, so it’s impossible to tell. The mythology of ancient Greece also offers an example of virgin birth. According to British classicist Robert Graves, the nymph Metis was a goddess particularly endowed with wisdom and knowledge. She served as counselor to Zeus, who seduced her and swallowed her whole. When he did, she had already impregnated herself with no help from him or any other god or man. Metis continued to give Zeus counsel from within his belly. She also gave birth there. Her child was Athena (also spelled “Athene.” Athene’s Roman mythology analog was Minerva). While still inside Zeus’ belly, Metis hammered out armor for Athena. From this point on, versions of the myth diverge: In one version, Zeus got a terrible headache, possibly caused by the noise Metis made while banging on the armor. In dire need of relief, he asked Prometheus to split his head in two, and when Prometheus did, out stepped Athena, fully formed and outfitted for life as the goddess of war. In another version of the story, Athena just walked out of Zeus’ head through some orifice or other. Either way, even though many think of Athena as the favorite child of Zeus, by both of these versions of the myth, biologically she would have been Metis’ daughter alone.

Source: https://www.forbes.com/sites/rebeccacoffey/2021/11/08/if-female-condors-can-reproduce-without-an-assist-from-males-why-cant-humans-15-points-that-explain-parthenogenesis/?sh=3b17c3b1a9ef