Asexual Reproduction : Imagine this. What if you could possibly reproduce without a partner? Wouldn’t that be great? As they say, life always finds a way; and for instance, perhaps parthenogenesis is just one of these life’s tricks.
The logic behind this phenomenon goes: if no suitable male partner is present, why waste more time when you have the ability to make “half-clones ” of yourself?
Parthenogenesis[1] , or more colloquially known as virgin birth, is a form of asexual reproduction wherein offspring are produced in the absence of fertilization or the fusion of gametes.
In this process, the resulting offspring is called the “parthenogen[2] ” wherein animals maleness ” (ZW sex determination) will always produce all male offspring while animals with two similar chromosomes for “femaleness ” (XY sex determination) will always produce female offspring.
One great advantage why organisms resort to this kind of reproduction is to perpetuate their species even without their mate. However, one major disadvantage of it is the gradual loss of genetic diversity because of the limited (to no) shuffling of genes.
Already curious about it? So let’s not wait any longer, here are the top 10 most spectacular animals with asexual reproduction (i.e., virgin births):
Asexual Reproduction In Organisms or Virgin Birth Creatures
1. Zebra Shark Kingdom Order Family Genus Species Animalia Orectolobiformes Stegostomatidae Stegostoma Stegostoma fasciatum
The first organism to be included in this asexual reproduction organisms list is the zebra shark Stegostoma fasciatum. While there have already been previous studies about virgin births in sharks, recently, in January 2017, a report
[3] about a female zebra shark giving birth after three years of separation from her mate, shocked the scientific world.
The zebra shark named Leonie, housed in an aquarium in Australia, was the first ever recorded female zebra shark that had shifted its reproductive strategy to asexual from sexual. Sharks normally practice parthenogenesis in order to survive and perpetuate during long periods of isolation.
2. Water Flea Kingdom Order Family Genus Species Animalia Cladocera Daphniidae Daphnia Daphniasp.
As its name suggests, the water flea
[4] Daphnia sp . Is characterized by the hopping motion of a flea, only underwater. Intriguingly, during most of the wet phase of the vernal pond, the population of water fleas is all composed of females.
The reason is pretty much obvious as these asexual organisms are capable of reproducing via parthenogenesis. And because of that, their female offspring are just exact copies of their mother. During reproduction, the female water flea produces eggs and then puts them inside a dorsal brood (egg) pouch until they are ready to be hatched.
3. Walnut Gulch Scorpion Kingdom Order Family Genus Species Animalia Scorpiones Vaejovidae Serradigitus Serradigitus miscionei
Walnut Gulch Scorpion (Source: Flickr The next asexually reproducing animal in this list is the Walnut Gulch Scorpion that is endemic only to southern Arizona. The members of this species are characterized by having reddish to brown head and abdomen.
A study[5] published in the journal Euscorpius revealed that among the 187 specimens of scorpions in the family Vaejovidae, all are identified to be biologically females. Such report is the first ever record of parthenogenesis from North America. In addition, it is believed by scientists that parthenogenesis in scorpions is often induced by a particular bacteria known as Wolbachia that triggers feminizations of arthropods.
4. Parasitic Flatworms Kingdom Order Family Genus Species Animalia Tricladida Dugesiidae Schmidtea Schmidtea polychroa
The parasitic flatworm Schmidtea polychroa
[6] is one of the few species of flatworms that are capable of parthenogenesis. These flatworms are hermaphroditic but are also capable of producing both polyploid and parthenogenetic eggs and even haploid sperms.
Despite this, there are still scientific evidences[7] that proved the prevalence of occasional sexual activities by these parasitic worms. Apparently, about 12% of the whole population is observed to practice such activity.
5. Turkey Kingdom Order Family Genus Species Animalia Galliformes Phasianidae Meleagris Meleagris sp.
[8] is very rare and more complicated. Regardless of the fact these organisms produced by parthenogenesis have only a mother, they are not clones. Normally, the offspring carries both half the genes of its mother and the other half to be provided by its father. During parthenogenesis, however, the maternal chromosomes doubles in order to produce the supposedly complement. Perhaps the best understood[9] parthenogenetic vertebrate is the turkey Meleagris.
Studies revealed that up to 30% (and about 40% when selectively bred) of unfertilized turkey eggs can just arise. Turkeys, like any other birds, bear the Z and W chromosomes (males have ZZ while females have ZW). In 1975[10] , about 50 mature “fatherless ” turkeys were documented by the US government. Eggs produced through parthenogenesis usually take longer incubation[11] time as compared to their normal counterparts which are result of fertilization. However, their stay inside the uterus is rather short as not much shell is ought to be created.
6. Komodo Dragon Kingdom Order Family Genus Species Animalia Squamata Varanidae Varanus Varanus komodoensis
Like birds, the sex chromosomes of Komodo dragons are labeled as Z and W The parthenogenesis of female Komodo dragons leads to offspring that have either ZZ or WW genotype; but since there is no WW genotype, the embryo will just be aborted and die. This then results to offspring which are all males (ZZ).
A study published[12] in the journal Naturereported seven virgin births of unfertilized Komodo dragons in European zoos.
7. Whiptail Lizards Kingdom Order Family Genus Species Animalia Squamata Teiidae Aspidoscelis Aspidoscelis uniparens
Our next another animal capable of virgin birth (or asexual reproduction) is the whip-tail lizard that is endemic to Mexico and southwest United States. This all-female population of lizards exclusively reproduce via parthenogenesis.
Interestingly, this species of lizards still display mating[13] behaviors despite the absence of males in their population. Such behavior of mounting other females, which is believed by scientists to be hormonally driven, is highly advantageous because it further stimulates their reproductive success.
8. Boa Constrictor Kingdom Order Family Genus Species Animalia Squamata Boidae Boa Boa constrictor
Parthenogenesis has already been reported in several species of snakes. In 2010
[14] , the first ever asexual reproduction exhibited by this species of snake was reported.
This Boa constrictor had two virgin births despite of the fact that it was placed inside a cage with multiple males. More surprising though, is that no vertebrate that had the WW genotype has ever been recorded to produce a viable WW offspring until this one[15] .
9. Cape Honeybees Kingdom Order Family Genus Species Animalia Hymenoptera Apidae Apis Apis capensis
Among insects, virgin birth is very common in honeybees, particularly Cape honeybees. Usually, in a bee colony, it is only the queen bee that can be fertile and be able to mate with the male drones. The resulting offspring of the queen and the male drone are the female working bees.
Interestingly, the female working bees, through parthenogenesis, give rise to these male drones. In addition to this, some strains of parasitic bacteria can induce parthenogenesis to happen in female worker bees.
10. Bdelloids Kingdom Order Family Genus Species Animalia Adinetida Philodinavidae Rotaria Bdelloidea
Coming from the Greek word “
bdella ” which means “
leech “, bdelloids or members of the class Bdelloidea
[16] that is composed of rotifers that resemble the creeping movements of leeches. Check out
immortal animals article where this creature has made into that list as well.
This class of rotifers[17] is perhaps one of the most important organisms in the study of evolutionary biology as they are considered as the “most ancient asexuals “. This class is composed of all female members that produce their own (female) offspring from unfertilized eggs asexually.
For most of the aforementioned organisms, virgin births might only be their last option in order to perpetuate their species. Most scientists believe that it is an evolutionary strategy developed by early vertebrates that found that simply multiplying themselves is far more efficient and advantageous rather that spending time to find a mate.
Even with present-day technology, a lot is still yet to be discovered about the origin of virgin births as well as how many organisms are capable of reproducing in this manner.
After all, scientists still have a lot more to learn about this phenomenon; and probably the next ultimate question that comes into their minds is: “Could a human naturally be produced by virgin birth too “?
Cite This Page References [1] – “Switch from sexual to parthenogenetic reproduction in a zebra shark | Scientific Reports” . Accessed July 23, 2017. Link .[2] – “Are There Really Virgin Births? | Mental Floss” . Accessed July 23, 2017. Link .[3] – “Zebra shark surprises scientists after giving birth without male – CNN.com” . Accessed July 23, 2017. Link .[4] – “Water Flea – Sacramento Splash” . Accessed July 23, 2017. Link .[5] – Study – PDF .[6] – “Heredity – Paternal inheritance in parthenogenetic forms of the planarian Schmidtea polychroa” . Accessed July 23, 2017. Link .[7] – “Population genetic structure of parthenogenetic flatworm populations with occasional sex – SÁNCHEZ NAVARRO – 2012 – Freshwater Biology – Wiley Online Library” . Accessed July 23, 2017. Link .[8] – “Strange but True: Komodo Dragons Show that "Virgin Births" Are Possible – Scientific American” . Accessed July 23, 2017. Link .[9] – “BBC – Earth – Spectacular real virgin births” . Accessed July 23, 2017. Link .[10] – “What Dad didn’t tell you about the birds and bees.” . Accessed July 23, 2017. Link .[11] – “Parthenogenesis: Embryonic development in unfertilized eggs may impact normal fertilization and embryonic mortality – The Poultry Site” . Accessed July 23, 2017. Link .[12] – “Parthenogenesis in Komodo dragons : Abstract : Nature” . Accessed July 23, 2017. Link .[13] – “The Verge Review of Animals: the all-female whiptail lizard – The Verge” . Accessed July 23, 2017. Link .[14] – “Girl Power: No Male? No Problem for Female Boa Constrictor | NC State News | NC State University” . Accessed July 23, 2017. Link .[15] – “BBC – Earth News – Snake gives ‘virgin birth’ to extraordinary babies” . Accessed July 23, 2017. Link .[16] – “Rotifera: Bdelloidea (PDF Download Available)” . Accessed July 23, 2017. Link .[17] – “Introduction to the Rotifera” . Accessed July 23, 2017. Link .
What you have pictured as a “Turkey” in #5 is actually a Guineafowl. Some in Europe refer to guineafowl as “turkey”, but there exists some confusion in your article because you reference the family Phasianidae, that normally contains the Turkey species native to North America. The Guineafowl that is pictured, normally originates in the family Numididae, and has origins in North Africa.
From everything I’ve read, it is the North American Turkey that is capable of asexual reproduction as you have described, not the guineafowl.
Cheers!
Good catch Jack! Fixed it now.