Dec
21
2006

Komodo dragons deliver virgin births

Ms. Komodo dragon says: "I want to be alone.": Photo courtesy stuartmoulder at Flickr.
Ms. Komodo dragon says: "I want to be alone.": Photo courtesy stuartmoulder at Flickr.

Early last year a visiting Komodo dragon at the London Zoo laid a clutch of viable eggs that mystified zookeepers. The female dragon, Sungai, had been brought to England from Paris in hopes that she’d mate with one of the male Komodo dragons there. Unfortunately, she gave birth before she had a chance to meet her potential suitor.

Scientists clamored to explain the apparent immaculate conception. Sungai’s last known sexual encounter had been two years previous, but it was speculated that perhaps she was able to store the sperm for later use.

But now it turns out that it was indeed a virgin birth. Genetic tests done at the University of Liverpool shows that the DNA in all the offspring came from just the mother. The research appeared in the recent issue of the journal Nature

The asexual reproduction process displayed by the lizard is known as parthenogenesis, a Greek word meaning “virgin birth”.

“I am delighted that the mysterious parentage of our Komodo dragon babies has been solved and that we have discovered something new to science at the same time,” said Richard Gibson, curator of herpetology at the Zoological Society of London.

“Knowing that the world’s largest lizard can reproduce like this suggests that many other reptiles may also do this more often than we thought and may lead to changes in the way we manage this and other species in breeding programs.”

Parthenogenesis has been known to take place in some reptiles but never the Komodo dragon species (Varanus komodoensis). The lizards can grow up to nine or ten feet in length, and are known to bite their prey with choppers full of lethal, bacteria-ridden saliva that slowly kills them

Sungai has since died, but another Komodo dragon, named Flora, at the Chester Zoo in England has laid eggs that are expected to hatch next month. And Flora has never met a male Komodo in her life. Tests done on three of her eggs that collapsed confirm the make-up of the DNA all derive from Flora.

Parthenogenesis is distinct from cloning. All of Flora’s offspring will be male because female Komodo dragons carry only dissimilar chromosomes (W and Z), so when one of their eggs divides it’s comprised only of similar chromosomes, either all W or all Z. (In humans it’s the male that carries the dissimilar chromosomes).

“This discovery has very important implications for understanding how reptiles are potentially able to colonize new areas. Theoretically, a female Komodo dragon in the wild could swim to a new island and then establish an entirely new population of dragons,” said Kevin Buley, curator of lower vertebrates and invertebrates at the Chester Zoo. “Essentially what we have here is an immaculate conception.”

Flora’s brood could hatch just in time for Christmas.

LINKS

London Times
National Geographic website

Your Comments, Thoughts, Questions, Ideas

Anonymous's picture
Anonymous says:

I am bothered by the media's use of the word virgin in reporting this story. According to Mosby's Medical, Nursing, & Allied Health Dictionary. Edition 5, 1998 p93E8., a virgin is 1) a person who has never had sexual intercourse, or 2) uncontaminated. Scientifically speaking, the komodo dragon is not a virgin, as the article itself clearly states "Sungai’s last known sexual encounter had been two years previous..." It seems to me that this is a perfect example of the media distorting science to market it. This story would probably not include the word virgin if it were published in June. Is anyone else bothered by this?

posted on Thu, 12/21/2006 - 6:47pm
Liza's picture
Liza says:

Sungai, you're right, is not a virgin. However, Flora, the other "virgin" Komodo dragon awaiting the arrival of little lizards, has never been around a male. So the word virgin IS applicable in her case.

Personally, I think you'd have seen headlines using the words "virgin birth" even if it was July. And the fact that Flora's little bundles of joy are expected in January just makes it irresistable. Hey, you read it, right?

It's kind of weird, though, that the phenomenon was undocumented by science, only to have two cases pop up within months of each other. But I suppose it's a small world, and news of the first case would put keepers on notice everywhere to look twice at eggs, whether they thought they'd be fertilized or not...

posted on Thu, 12/21/2006 - 10:23pm
jason barndon's picture
jason barndon says:

I am less bothered by the media and more bothered by scientists who appear to have held an opinion for hundreds of years that was entirely false. Lets admit that when scientists make claims, they are not gods and most of the prevailing beliefs of science involve just as much faith as religionists. Science can prove things occur but scientists cannot prove that things do not occur absolutely. To prove that things do not occur (anywhere in the universe) they must inhabit and test all of the known universe simultaneously. They can't do this otherwise they would have absolutely disproven any idea of God. Lets look at Christianities claim of Jesus being born of a Virgin. No historical event be empirically tested? But people testified that they saw it. Sad to say history can only be tested using eye witnesses. I bet in 10 years time people will laugh at the scientists that claimed to have witnessed this kamodo dragon virgin birth.

posted on Thu, 01/25/2007 - 4:13am
Gene's picture
Gene says:

We've debated science and faith elsewhere. Science operates on evidence -- reproduceable, objective evidence. While there are numerous other lizards that reproduce asexually, no one had ever observed this in Komodos before. It's not so much a refutation of the scientific method as it is simply a new discovery.

posted on Thu, 01/25/2007 - 1:49pm
loser's picture
loser says:

creepy

posted on Thu, 12/21/2006 - 9:34pm
mdr's picture
mdr says:

The term "virgin birth" is appropriate to use in both cases since the process of a female giving birth without male fertilization is called "parthenogenesis" which, as stated in the article, is Greek for "virgin birth".

posted on Fri, 12/22/2006 - 12:14am
Gene's picture
Gene says:

This post is not about science, and it's not about religion. Rather, it's about the careful and proper use of language -- something the folks at SMM know I will drone on about at length! ;-)

The curator of the Chester Zoo misuses the term "immaculate conception." In Catholic teaching, the term Immaculate Conception does not refer to Jesus being conceived by Mary without sex. Rather, it refers to Mary being conceived by Sts. Joachim and Anne in the usual fashion, but without the stain of original sin. So common is this mistake that Wikipedia refers to it as "the immaculate misconception."

And a merry Christmas to all!

posted on Fri, 12/22/2006 - 9:24am
Liza's picture
Liza says:

Ah, yes...If I learned nothing else in 12 years of CCD, I did learn this. :)

posted on Fri, 12/22/2006 - 10:35am
Anonymous's picture
Anonymous says:

Did you read the article, Flora is a virgin.

posted on Sat, 12/23/2006 - 11:59am
Anonymous's picture
Anonymous says:

its komodo jesus!!!

posted on Fri, 01/12/2007 - 10:48am
Liza's picture
Liza says:

Flora's eggs have hatched! She's now mom (and dad) to five bouncing baby dragons, with two more in the incubator and expected to hatch anytime...

posted on Wed, 01/24/2007 - 11:01am
mdr's picture
mdr says:

It's a miracle!!

posted on Thu, 01/25/2007 - 3:01pm
Gene's picture
Gene says:

Nah, it's just parthenogenesis. ;-)

posted on Thu, 01/25/2007 - 6:57pm
Anonymous's picture
Anonymous says:

mama mia!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

posted on Sun, 03/04/2007 - 3:48pm
Liza's picture
Liza says:

Hey, remember those discredited Korean stem cell researchers who claimed to have created the first cloned human embryo? Turns out that they did make a major breakthrough--it just wasn't the one they published. Instead, they found a way to "trick" a human egg, without sperm, into developing into an embryo. And the resulting embryo was used to generate a stem cell line. Human parthenogenesis!

posted on Thu, 08/02/2007 - 12:16pm
elizabeth's picture
elizabeth says:

thats creepy man!

posted on Fri, 11/09/2007 - 4:38pm

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