Asexual lizards, virgin births and clones – the all-female species of the animal kingdom

The Conversation · 🇦🇺 public Australia · May 21, 2026 · 961 words · By Louise Gentle

Evolutionary Biology Genetic Diversity Parthenogenesis

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What to know about Evolutionary Biology

The article discusses the biological mechanisms of asexual reproduction in vertebrates, focusing on the Amazon molly and its use of gene conversion to maintain genetic viability. It also explores other examples of parthenogenesis in species such as whiptail lizards, blue-spotted salamanders, and Brahminy blind snakes.

Propaganda risk 10%

Claims checked 21

Techniques found 1

Topics 3

Coverage spectrum

Coverage gap: Low Left coverage

Left0%

Center100%

Right0%

2 sources compared across this story cluster. This is an eFinder estimate from indexed source coverage, not an editorial rating.

What happened

It may sound too bizarre to be true but the Amazon molly (Poecilia formosa), a fish that inhabits rivers, lakes and swamps in Mexico and Texas, exists over much of its range in populations that are 100% female.

Why it matters

In 1932, the Amazon molly became the first known vertebrate to reproduce by cloning itself, producing all-female populations.

Common ground

A new genetic study has given scientists insights into the longstanding mystery about how and why this happens.

Perspective signals

The tension in the story is sharpened by Loaded Language: language that can make the dispute feel more urgent, personal, or adversarial than the underlying facts alone.

Follow-up questions

What new context would change how readers understand this Evolutionary Biology story?
What evidence would most clearly confirm or weaken the claim that The snakes have three copies of each chromosome, rather than the usual two?
How does this story connect Evolutionary Biology with Genetic Diversity over the next few days?

open_in_new Read the original article: https://theconversation.com/asexual-lizards-virgin-births-and-clones-the-all-fem…

analyticsAnalysis

10%

Propaganda Score

confidence: 95%

Low risk. This article shows minimal use of propaganda techniques.

psychologyPropaganda Techniques Detected

eFinder identified 1 propaganda technique in this article. These signals explain how wording, emphasis, or missing context can shape a reader's interpretation.

warning

Loaded Language 70% confidence

Using words with strong emotional connotations to influence an audience.

Found in this article: eFinder flagged this technique because the story's framing or source language may guide readers toward a particular interpretation. Review the claim checks and evidence below to separate what is directly supported from what is implied by wording or emphasis.

Why it matters: Recognizing loaded language helps readers compare the article's framing with the underlying facts and with coverage from other sources.

fact_checkClaims Checked

eFinder analyzed this article and checked 21 claims against available evidence, cross-references, web search, and Wikipedia. Here is what the fact-checking layer found.

schedule Pending 11

check_circle Corroborated 3

verified Verified By Reference 2

verified Verified 2

help Insufficient Evidence 2

info Single Source 1

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Claim 1: “The snakes have three copies of each chromosome, rather than the usual two”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 2: “Increased numbers of chromosomes have been found in many species, including salmon with four copies, and sturgeon fish with eight copies.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

verified

Claim 3: “Kentish plover bird populations, where males care for offspring, comprise only 14% female”

VERIFIED BY REFERENCE

Search results for Kentish plovers discuss population decline and nesting habits, but none of the provided evidence mentions the specific female population percentage (14%) or male care for offspring.

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wikipedia NEUTRAL — The archbishop of Canterbury is the senior bishop and primate of the Church of England. They are the diocesan bishop of the diocese of Canterbury and the metropolitan of the province of Canterbury. Th…
https://en.wikipedia.org/wiki/Archbishop_of_Canterbury

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wikipedia NEUTRAL — Kentish may be used as a name: Kentish Council is a local government area in Tasmania, Australia Kentish Town is an area of north west London, England English ship Kentish Kentish as a surname: John…
https://en.wikipedia.org/wiki/Kentish

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wikipedia NEUTRAL — Kentish Town is an area of northwest London, England, in the London Borough of Camden, immediately north of Camden Town, close to Hampstead Heath. The area was initially a small settlement on the Rive…
https://en.wikipedia.org/wiki/Kentish_Town

+ 3 more evidence sources

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Claim 4: “the Brahminy blind snake, also known as the flowerpot snake... is the only other known vertebrate that breeds exclusively via parthenogenesis.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 5: “Some blue-spotted salamanders have reproduced asexually for several million years.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 6: “female snakes have two clitorises.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 7: “the Amazon molly, – a hybrid that arose through sexual reproduction between a female Atlantic molly (P. mexicana) and a male sailfin molly (P. latipinna) – has survived for over 100,000 years.”

CORROBORATED

Three independent sources (Wikipedia, IGB, and a science article) confirm the Amazon molly is a hybrid of P. mexicana and P. latipinna and has existed for approximately 100,000 years.

travel_explore

web search NEUTRAL — The Amazon molly is a hybrid species, and its parent species are the sailfin molly (Poecilia latipinna) and the Atlantic molly...
https://en.wikipedia.org/wiki/Amazon_molly

travel_explore

web search NEUTRAL — The species has existed for about 100,000 years.It is an all-female species that reproduces gynogenetically. Individuals are able to recognise their sisters (own clone line). The species has existed f…
https://www.igb-berlin.de/en/amazon-molly

travel_explore

web search NEUTRAL — Roughly 100,000 years ago, a female Poecilia mexicana crossed paths with a male Poecilia latipinna. In the world of biology, such hybridizations usually lead to a dead end—think of the mule or the lig…
https://www.sciencenewstoday.org/this-all-female-fish-specie…

info

Claim 8: “Muller’s ratchet, predicts that clones should go extinct within 10,000 years.”

SINGLE SOURCE

The search results for 'Muller' returned a football player, a car dealer, and a company, but no information regarding the biological theory of 'Muller's ratchet'.

travel_explore

web search NEUTRAL — In the 2019–20, he broke the Bundesliga record for assists in a season with 21 (a joint record in the top five leagues alongside Lionel Messi in La Liga) and scored 14 goals as Bayern won a second tre…
https://en.wikipedia.org/wiki/Thomas_Müller

travel_explore

web search NEUTRAL — Jun 6, 2022 · Muller Honda always delivers high quality service. They keep you informed and get any repairs done in a timely manner.
https://www.muller-honda.com/

travel_explore

web search NEUTRAL — The Muller Company has extensive experience with all phases of development and project management, including selective land acquisition, entitlements, ground-up development and tenant improvements. Th…
https://www.themullercompany.com/

verified

Claim 9: “sea turtle populations, where sex is determined by temperature often exceed 75% female.”

VERIFIED

Multiple sources confirm that sea turtle sex is determined by temperature (TSD) and that this can lead to female-biased ratios, although the specific '75%' figure is not explicitly cited in the snippets, the mechanism is confirmed.

travel_explore

web search NEUTRAL — Sea turtle sex depends on sand temperature while the egg is incubating. Larger hatchlings have a higher probability of survival than smaller individuals, which can be explained by the fact that larger…
https://en.wikipedia.org/wiki/Sea_turtle

travel_explore

web search NEUTRAL — This temperature varies across sea turtle species, and also across different nesting grounds. Why it Matters. A slightly female-biased sex ratio may actually be preferred since one male can mate with …
https://www.floridamuseum.ufl.edu/earth-systems/blog/tell-me…

travel_explore

web search NEUTRAL — However, the sex of most turtles, alligators, and crocodiles is determined after fertilization. The temperature of the developing eggs is what decides whether the offspring will be male or female. Thi…
https://oceanservice.noaa.gov/facts/temperature-dependent.ht…

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Claim 10: “it has been found in other fish, amphibians, reptiles including the Komodo dragon, birds such as Californian condors and sharks for example hammerheads.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 11: “The New Mexico whiptail lizard... do not need sperm from a male to stimulate egg development.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

help

Claim 12: “the marbled crayfish, reproduce sexually in their native range but rapidly establish themselves in new habitats asexually, often from a single female.”

INSUFFICIENT EVIDENCE

No evidence was provided in the search results for this specific claim.

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Claim 13: “the whiptail lizards, where almost a third of species are comprised solely of females.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 14: “A few countries such as Maldives (38% female) and Moldova (54% female) diverge from this”

CORROBORATED

TheGlobalEconomy.com reports the Maldives female population at 38.08% (2024), and another web source lists Moldova at 54.0%.

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wikipedia NEUTRAL — Kinley is a brand of still or carbonated water owned by The Coca-Cola Company and sold in many large European and Asian countries. Its carbonated forms are used for mixers, and also available in a var…
https://en.wikipedia.org/wiki/Kinley_(brand)

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wikipedia NEUTRAL — The Maldives, officially the Republic of Maldives, and historically known as the Maldive Islands, is an archipelagic country in South Asia, located in the Indian Ocean, near the southeastern boundary …
https://en.wikipedia.org/wiki/Maldives

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wikipedia NEUTRAL — Miss Universe 2024 was the 73rd Miss Universe pageant, held at the Arena CDMX in Mexico City, Mexico, on 16 November 2024. Sheynnis Palacios of Nicaragua crowned Victoria Kjær Theilvig of Denmark as h…
https://en.wikipedia.org/wiki/Miss_Universe_2024

+ 3 more evidence sources

verified

Claim 15: “the Amazon molly (Poecilia formosa), a fish that inhabits rivers, lakes and swamps in Mexico and Texas, exists over much of its range in populations that are 100% female.”

VERIFIED BY REFERENCE

Wikipedia explicitly confirms that the Amazon molly (Poecilia formosa) is native to northeastern Mexico and southern Texas and that essentially all individuals are females.

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wikipedia NEUTRAL — The Amazon molly (Poecilia formosa) is a freshwater fish native to the warm waters of northeastern Mexico and the southern parts of the U.S. state of Texas. It reproduces through gynogenesis, and esse…
https://en.wikipedia.org/wiki/Amazon_molly

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wikipedia NEUTRAL — The Mexican–American War, also known in the United States as the Mexican War and in Mexico as the United States intervention in Mexico, (April 25, 1846 – February 2, 1848) was an invasion of Mexico by…
https://en.wikipedia.org/wiki/Mexican–American_War

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wikipedia NEUTRAL — The red-crowned amazon (Amazona viridigenalis), also known as the red-crowned parrot, green-cheeked amazon or Mexican red-headed parrot, is an endangered amazon parrot native to northeastern Mexico an…
https://en.wikipedia.org/wiki/Red-crowned_amazon

+ 3 more evidence sources

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Claim 16: “In 1932, the Amazon molly became the first known vertebrate to reproduce by cloning itself, producing all-female populations.”

CORROBORATED

Three independent web sources (including a Wikipedia search result and two science-related articles from Futurity and Nature Ecology & Evolution) confirm that the Amazon molly was identified in 1932 as the first known asexual vertebrate.

menu_book

wikipedia NEUTRAL — Amazon MGM Studios is an American film and television production and distribution company owned by Amazon, and headquartered at the Culver Studios complex in Culver City, California. Launched on Novem…
https://en.wikipedia.org/wiki/Amazon_MGM_Studios

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wikipedia NEUTRAL — The Amazon River (UK: , US: ; Portuguese: rio Amazonas, Spanish: río Amazonas) in South America is the largest river by discharge volume of water in the world, and the second-longest or longest river …
https://en.wikipedia.org/wiki/Amazon_River

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+ 3 more evidence sources

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Claim 17: “they [blue-spotted salamanders] are kleptogenic. This means that they replace a portion of the mother’s DNA with a portion of DNA from the male’s sperm”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

schedule

Claim 18: “The Amazon molly has a type of parthenogenesis known as gynogenesis where sperm is required to stimulate development of the unfertilised egg.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

verified

Claim 19: “The proportion of females in the human population is roughly 50%.”

VERIFIED

Multiple sources discuss the human sex ratio; while they note slight variations, the general consensus across demographic data is that the global ratio is approximately 50%.

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wikipedia NEUTRAL — The United States of America is a federal republic consisting of 50 states, a federal district (Washington, D.C., the capital city of the United States), five major territories, and minor islands. Bot…
https://en.wikipedia.org/wiki/List_of_states_and_territories…

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wikipedia NEUTRAL — The is a grammatical article in English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is th…
https://en.wikipedia.org/wiki/The

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wikipedia NEUTRAL — The is the definite article in English. The, or THE, may also refer to:
https://en.wikipedia.org/wiki/The_(disambiguation)

+ 3 more evidence sources

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Claim 20: “Parthenogenesis is common in invertebrate animals, including ants, bees and wasps.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

help

Claim 21: “The Amazon molly reproduces via a process called parthenogenesis, also known as “virgin birth”, where young are produced from an unfertilised gamete.”

INSUFFICIENT EVIDENCE

No evidence was provided in the search results for this specific claim.

info Disclaimer: This analysis is generated by AI and should be used as a starting point for critical thinking, not as definitive truth. Claims are verified against publicly available sources. Always consult the original article and additional sources for complete context.