Why some species experience 'virgin births'

Recommendable! Notice the reduced chance of survival!

Why Do Male Organisms Exist?

Recommendable! However, the article does not really contribute anything new to the subject it seems.

One day in the not so distant future natural reproduction for humans will most likely be a thing of the past. What evolution did in hundreds of millions of years, humans can do better and faster!

"In recent years, more and more instances of parthenogenesis have emerged as “virgin births” in crocodiles, condors, and king cobras. While these animals can create babies without males in a pinch, a few other species have fully committed to parthenogenesis, going male-free for more than a million years.1

“There are a lot of advantages to getting rid of males and just reproducing by parthenogenesis,” said Michael Kearney, a physiological ecologist at the University of Melbourne. “The most powerful one is that everybody in the population is producing offspring, so the population growth rate doubles.” Parthenogenesis also protects animals from the dangers of sex, including exposure to predators and sexually transmitted infections.

At least in the short-term, this can be a highly successful strategy: Warramaba virgo, an all-female grasshopper species, hasn’t had sex in a quarter million years and appears to be thriving. Although single nucleotide polymorphism analysis revealed much less genetic variation in W. virgo compared to closely related sexual species, when ... colleagues investigated 14 fitness-related traits, including heat and cold tolerance, reproductive output, and longevity, they found that the parthenogens were on par with their sexually-reproducing relatives. ...
And indeed older parthenogenic species may feel these costs: Some parthenogens have higher parasite loads, fewer positively selected genes, and a faster accumulation of deleterious mutations than their sexually-reproducing relatives. ..."

Why Do Male Organisms Exist? | TS Digest | The Scientist Some species of lizards, grasshoppers, and crustaceans have adopted a ladies-only lifestyle.

Virgin birth genetically engineered into female animals for the first time

This is not the very latest research news, but it is big news!

This induced asexual reproduction is then passed on from generation to generation.

"Scientists alter the genomes of female fruit flies, allowing them to reproduce without any contribution from a male.

For the first time, scientists have used genetic engineering to trigger ‘virgin birth’ in female animals that normally need a male partner to reproduce."

"Earlier this year, caretakers at a zoo in Costa Rica reported an unprecedented case of a crocodile who made herself pregnant – a phenomenon called virgin birth. Now, scientists have induced the same process in female fruit flies for the first time, identifying a set of genes that allowed the insect to reproduce without a father. ...

Parthenogenesis has been observed in over 80 vertebrate species, including some lizards, snakes, sharks, and rays. In the vast majority of cases, this was observed in captive animal populations. However, some researchers think this may be more common in some species than we think, it's just that we haven't observed it yet. ..."

From the highlights and abstract:

"Highlights

• Parthenogenetic D. mercatorum displays genomic and transcriptomic signatures

• A genetic cause underlies facultative parthenogenesis in drosophilids

• Facultative parthenogenesis can be genetically induced in D. melanogaster

• Induced parthenogenesis can result in polyploid D. melanogaster

Summary

Facultative parthenogenesis enables sexually reproducing organisms to switch between sexual and asexual parthenogenetic reproduction. To gain insights into this phenomenon, we sequenced the genomes of sexually reproducing and parthenogenetic strains of Drosophila mercatorum and identified differences in the gene expression in their eggs. We then tested whether manipulating the expression of candidate gene homologs identified in Drosophila mercatorum could lead to facultative parthenogenesis in the non-parthenogenetic species Drosophila melanogaster. This identified a polygenic system whereby increased expression of the mitotic protein kinase polo and decreased expression of a desaturase, Desat2, caused facultative parthenogenesis in the non-parthenogenetic species that was enhanced by increased expression of Myc. The genetically induced parthenogenetic Drosophila melanogaster eggs exhibit de novo centrosome formation, fusion of the meiotic products, and the onset of development to generate predominantly triploid offspring. Thus, we demonstrate a genetic basis for sporadic facultative parthenogenesis in an animal."

‘Virgin birth’ genetically engineered into female animals for the first time (no public access) Scientists alter the genomes of female fruit flies, allowing them to reproduce without any contribution from a male.

Virgin births: Genetically engineered fruit flies can reproduce without males, but it won’t work for humans It could one day help with the control of insect populations.

Team Identifies Genes for Asexual Reproduction in Fruit Flies For the first time, scientists have induced asexual reproduction in an animal that usually reproduces sexually: the fruit fly Drosophila melanogaster. Once induced, the ability is passed on through the generations: the offspring can reproduce either sexually or asexually.

A genetic basis for facultative parthenogenesis in Drosophila (open access)

Figure 1 Comparison of sexually reproducing and parthenogenetic D. mercatorum genomes to each other and D. melanogaster

Figure 4 The inception of parthenogenesis Drosophila embryos

How does this all-female species reproduce? Parthenogenesis

Very recommendable! About asexual reproduction!

A New Study On Immaculate Conception

Trigger

I just read an article titled “Wissenschaftliche Studie\Die Legende der jungfräulichen Geburt\Beruht Weihnachten nicht auf einem Wunder, sondern auch simpler Biologie? Einer Studie zufolge wird jedes 200. Kind in den Vereinigten Staaten von einer Jungfrau geboren – schreibt das British Medical Journal.” (German language).

Pregnancy Without Intercourse Or Reproductive Technology

This article refers to an article (public access, hurrah) published in the British Medical Journal. To quote from the abstract of this study:

“Objective To estimate the incidence of self report of pregnancy without sexual intercourse (virgin pregnancy) and factors related to such reporting, in a population representative group of US adolescents and young adults. ...

Conclusions Around 0.5% of women consistently affirmed their status as virgins and did not use assisted reproductive technology, yet reported virgin births.”

0.5% or every 200th woman reported an immaculate conception. About 21,000 respondents were included in this study. Were all these women just lying or making up or covering up or saying this for other reasons (e.g. religious)? Is this study bogus?

Is Parthenogenesis Possible In Humans?

From what little I understand, natural asexual reproduction such as Parthenogenesis is only possible in some plants and animals (mostly invertebrates), but not in humans until we find the Black Swan.

One thing seems to be certain, a pregnancy without sexual intercourse or use of reproductive technology is difficult to prove for at least as long no one can provide a verifiable prove that such a thing is not possible at all.