'Virgin births' for giant lizards

Bounty · Post by **Bounty** » 2006-12-20 01:30pm

The largest lizards in the world are capable of "virgin births".

Scientists report of two cases where female Komodo dragons have produced offspring without male contact.

Tests revealed their eggs had developed without being fertilised by sperm - a process called parthenogenesis, the team wrote in the journal Nature.

One of the reptiles, Flora, a resident of Chester Zoo in the UK, is awaiting her clutch of eight eggs to hatch, with a due-date estimated around Christmas.

Kevin Buley, a curator at Chester Zoo and a co-author on the paper, said: "Flora laid her eggs at the end of May and, given the incubation period of between seven and nine months, it is possible they could hatch around Christmas - which for a 'virgin birth' would finish the story off nicely.

"We will be on the look-out for shepherds, wise men and an unusually bright star in the sky over Chester Zoo."

Flora, who has never been kept with a male Komodo dragon, produced 11 eggs earlier this year. Three died off, providing the material needed for genetic tests.

These revealed the offspring were not exact genetic copies (clones) of their mother, but their genetic make-up was derived just from her.

The team concluded they were a result of asexual reproduction, and are waiting for the remaining eight eggs to hatch.

Abnormal phenomenon?

Another captive-bred female called Sungai, at London Zoo in the UK, produced four offspring earlier this year - more than two years after her last contact with a male, the scientists reported in the same paper.

Again, genetic tests revealed the Komodo dragon babies, which are healthy and growing normally, were produced through parthenogenesis.

Sungai was also able to reproduce sexually, producing another baby offspring after mating with a male called Raja.

Richard Gibson, an author on the paper and a curator at the Zoological Society of London, said: "Parthenogenesis has been described before in about 70 species of vertebrates, but it has always been regarded to be a very unusual, perhaps abnormal phenomenon."

It has been shown in some snakes, fish, a monitor lizard and even a turkey, he said.

"But we have seen this in two separate, unrelated female Komodo dragons within a year, so this suggests maybe parthenogenesis is much more widespread and common than previously considered."

He added: "Because these animals were in captivity for years without male access, they reproduced parthenogenetically.

"But the ability to reproduce parthenogenetically is obviously an ancestral capability."

He said the lizards could have evolved the ability to reproduce asexually when, for example, a lone female was washed up alone on an island with no males to breed with.

Because of the genetics of this process, he added, her children would always be male. And like Sungai, she would be able to switch back to sexual reproduction, so she could breed to establish a new colony.

There are fewer than 4,000 Komodo dragons in the wild, and they are found in three islands in Indonesia: Komodo, Flores and Rinca.

Adult males can grow up to 3m (10ft) in length and weigh up to 90kg (200lb) - making them the biggest lizards on the planet.

The researchers said that, to ensure genetic diversity of Komodo dragons kept in captivity, zoos should perhaps keep males and females together to avoid asexual reproduction.

Superman · Post by **Superman** » 2006-12-20 01:37pm

I'm pretty sure there are also documented cases of chickens doing this.

Losonti Tokash · Post by **Losonti Tokash** » 2006-12-20 02:32pm

I can't really express how awesome the idea of Jesus returning as a giant man-eating lizard with poisonous saliva is. In 8 different bodies.

Molyneux · Post by **Molyneux** » 2006-12-20 02:49pm

Don't tuataras reproduce exclusively through parthenogenesis now?

Shroom Man 777 · Post by **Shroom Man 777** » 2006-12-20 02:49pm

Holy fucking crap. This is awesome. It's like...woah.

Komodo dragons > Panda

Pick · Post by **Pick** » 2006-12-20 02:52pm

It's sort of like raptor Jesus!

Seggybop · Post by **Seggybop** » 2006-12-20 02:59pm

all praises unto raptor jesus

Lord of the Abyss · Post by **Lord of the Abyss** » 2006-12-20 10:01pm

As I recall, there are entire species of lizards that reproduce parthenogenically. Including some that are interspecies hybrids, and get around the difficulty of not having a mate of the same kind by not needing one.

It's not quite the same thing, but I remember that there's a species of wasp that mostly reproduces parthenogenically, because a bacterium that passes only from female to female makes it that way. When the wasp is cured, it breeds normally with males. I mention this just to repeat the great line, "Virgin birth is curable with penicillin."

Drooling Iguana · Post by **Drooling Iguana** » 2006-12-20 10:28pm

It's just like[size=0] the giant lizard that had absolutely nothing in common with[/size] Godzilla!

Quadlok · Post by **Quadlok** » 2006-12-20 11:30pm

Maybe this is a stupid question, but do they ever bother to check in cases like these whether the mother is a hermaphrodite, with two sets of genitals? They don't go into how its done beyond throwing out the big fancy Latin term, and since all the species they named have cloaca and internal genitalia in both sexes, I would find it easy to accept that these offspring were the results of what is basically an extreme form of masturbation.

mr friendly guy · Post by **mr friendly guy** » 2006-12-21 02:56am

You and a creationist are watching the news. The current article describes how a female komodo dragon gave birth without male contact. This type of process is called parthenogenesis and has been observed in other species as well.

Suddenly the creationists face turns white. He thinks God has abandoned us because a mere animal to experienced a virgin birth. You explain that the process is most probably an ancestral ability from before we evolved sexual reproduction.

The creationist stubbornly repeats that God has abandoned us and that the Komodo dragon offspring is the new child of God.

And on another note

He said the lizards could have evolved the ability to reproduce asexually when, for example, a lone female was washed up alone on an island with no males to breed with.

This sounds a bit strange as evolution occurs between generations and amoung populations rather than individuals. Unless they are using the word evolution very loosely its almost as it he is describing larmarkianism.

Elfdart · Post by **Elfdart** » 2006-12-21 05:50am

Superman wrote:I'm pretty sure there are also documented cases of chickens doing this.

I remember an article many years ago in OMNI about turkeys and parthenogenesis. The result is always female.

Molyneux · Post by **Molyneux** » 2006-12-21 10:00am

mr friendly guy wrote:You and a creationist are watching the news. The current article describes how a female komodo dragon gave birth without male contact. This type of process is called parthenogenesis and has been observed in other species as well.

Suddenly the creationists face turns white. He thinks God has abandoned us because a mere animal to experienced a virgin birth. You explain that the process is most probably an ancestral ability from before we evolved sexual reproduction.

The creationist stubbornly repeats that God has abandoned us and that the Komodo dragon offspring is the new child of God.

And on another note

He said the lizards could have evolved the ability to reproduce asexually when, for example, a lone female was washed up alone on an island with no males to breed with.
This sounds a bit strange as evolution occurs between generations and amoung populations rather than individuals. Unless they are using the word evolution very loosely its almost as it he is describing larmarkianism.

Maybe they're using 'evolution' in the standard English definition (that is, 'change') rather than the biological?

Post by **Kuja** » 2006-12-21 12:27pm

Jumping Jesus lizards, the reptiles are making a comeback!

Ritterin Sophia · Post by **Ritterin Sophia** » 2006-12-21 12:49pm

Kuja wrote:Jumping Jesus lizards, the reptiles are making a comeback!

What'd you say?

Darth Raptor · Post by **Darth Raptor** » 2006-12-21 01:33pm

Kuja wrote:Jumping Jesus lizards, the reptiles are making a comeback!

They were never on hiatus. Protect your mammaries!

Coalition · Post by **Coalition** » 2006-12-22 05:05am

Unto us a lizard is born.
Unto us a dragon is given.

(a bit of a parody, but seemingly appropriate)

Loner · Post by **Loner** » 2006-12-22 10:06am

Seggybop wrote: all praises unto raptor jesus

Raptor Jesus went extinct for our sins.

Gil Hamilton · Post by **Gil Hamilton** » 2006-12-22 11:57am

And I suppose the Holy Reptiles would come, indeed Crocodylus Pontificus, to baptize the new Raptor Jesus.

SirNitram · Post by **SirNitram** » 2006-12-22 11:59am

Pffft. It's a Komodo, not a Raptor. You all speak blasphemy against our new Draconic savior!

Isana Kadeb · Post by **Isana Kadeb** » 2006-12-22 07:41pm

Wait, wouldn't the offspring just be clones of the parent? So I don't understand this bit:

"Because of the genetics of this process, he added, her children would always be male. And like Sungai, she would be able to switch back to sexual reproduction, so she could breed to establish a new colony."

Why are the offspring males? If its asexual reproduction, they should be genetically identical to the parent. Where's the y chromosome coming from? Or is the biology behind sexual differentiation different with reptiles?

TithonusSyndrome · Post by **TithonusSyndrome** » 2006-12-22 07:56pm

The power of Vril has come to pass! Make a throne for Shiva-Vrillon in this world and the next!

Gil Hamilton · Post by **Gil Hamilton** » 2006-12-22 10:33pm

Isana Kadeb wrote:Why are the offspring males? If its asexual reproduction, they should be genetically identical to the parent. Where's the y chromosome coming from? Or is the biology behind sexual differentiation different with reptiles?

In reptiles, assuming Komodo Dragons follow the same pattern that most reptiles and many birds do (and they do, I looked it up), they do a ZW chromosome pattern rather than an XY and exhibit female heterogamety (Males are ZZ and females are ZW). That means if they self fertilize, they can either get a ZZ (male) or a WW (dead) offspring. They cannot get a heterogametous condition there, which requires sexual reproduction.

Reptile sexuality is complicated, to say the least.

Winston Blake · Post by **Winston Blake** » 2006-12-22 10:44pm

Isana Kadeb wrote:Why are the offspring males? If its asexual reproduction, they should be genetically identical to the parent. Where's the y chromosome coming from? Or is the biology behind sexual differentiation different with reptiles?

Wiki wrote:The offspring of parthenogenesis will be all female if two like chromosomes determine the female sex (such as systems where XX is female and XY is male), but male if the female sex is determined by unlike chromosomes (such as systems where WZ is female and ZZ is male), because the process involves the inheritance and subsequent duplication of only a single sex chromosome.

mr friendly guy wrote:This sounds a bit strange as evolution occurs between generations and amoung populations rather than individuals. Unless they are using the word evolution very loosely its almost as it he is describing larmarkianism.

It's weird because just above that he had already said "But the ability to reproduce parthenogenetically is obviously an ancestral capability.", so it would have been there the whole time, and wouldn't have to evolve. They could be mangling this quote from Kevin Buley from a slightly earlier CNN article:

"The genetics of self-fertilization in lizards means that all her hatchlings would have to be male. These would grow up to mate with their own mother and therefore, within one generation, there would potentially be a population able to reproduce normally on the new island," Buley said.

Shannon · Post by **Shannon** » 2006-12-22 11:53pm

Don't tuataras reproduce exclusively through parthenogenesis now?

Not AFAIK. Our local museum has been breeding them successfully for several years.
http://www.southlandmuseum.com/tuatara_-_facts.htm

Though just because I haven't heard of them doing it doesn't mean they can't.