Female Boa constrictor reproduces without help from males

There is, perhaps, nothing terribly shocking about a female snake, placed in an enclosure with four male snakes, giving birth to two litters of baby snakes.

But what if those babies carry only their mother's genetic material?

Parthenogenesis—breeding without the, you know, breeding—has been documented in only a small handful of vertebrate species, but it does happen. However, usually, it takes the complete absence of males to get the vertebrate ladies going all virgin birthy. These baby boa constrictors, on the other hand, had plenty of potential fathers. But genetic tests have shown that none of the available male snakes is the dad. In addition, the babies are all female. All carry a rare caramel coloration. And all have a very weird mix of sex chromosomes.

In place of X and Y, snakes and many other reptiles have Z and W chromosomes. In all snakes, ZZ produces males and ZW produces females.

Bizarrely, all the snakes in these litters were WW.

This was further proof that the snakes inherited all their genetic material from their mother, as only females carry the W chromosome. "Essentially they are half clones of their mother," says Dr Booth. That is because the baby snakes have inherited two copies of one half of their mother's chromosomes, including one W chromosome.

You know the drill—I, for one, welcome our new female snake-Jesus overlords.

Biology Letters: Evidence for viable, non-clonal but fatherless Boa constrictors (And you can read the full text of the article for free! Also rare!)

BBC: Snake gives 'virgin birth' to extraordinary babies

Via Peter Kobel

Image: Wikipedia user DestructiveEyes, via CC

Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.

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Anonymous

Had I been able to accomplish this, my life would be much easier right now!!
Jack

Female Boa constrictor reproduces without help from males, because all she needs is Chuck Norrisâ€™ glare to fill her snake uterus to the brim with babies.
Tzunun

It’s already been used by Sheri S. Tepper in her novel Gibbon’s Decline and Fall (1996). The whiptail lizard on the cover is a tip-off – there are a number of species in that family that are parthenogenic, including some in Tepper’s home state of New Mexico.

Interesting that these baby boas were all females, because it’s my understanding that turkeys produced by parthenogenesis have always been males (ZZ). It will be interesting to see if these boa girls grow up to be parthenogenic like their mama.
bardfinn

They are technically /not/ females, since ‘female’ in this species is defined as ‘ZW’ sex chromosomes. They have female physiognomy, and can likely sexually produce female offspring(and “uber”-female offspring), but they’re an entire other gender (“uber”-female – ?).

And hypothetically, if the other chromosome in the mother was the one that half-cloned, she could produce males from the parthenogenesis.

Interestingly, modern science has shown that it’s im-freakin-possible for a human female (XX) to parthenogenetically fertilise (and thus eventually give birth to) a human male (XY), as human females lack Y chromosomes, and 47XXY, 47XYY, and 48XXYY individuals develop as physically male.

There is still the possibility of true hermaphroditism allowing for such an event, however — in which case technically the resultant offspring’s mother is also his/her sister as well.

Insert joke here.
Flying_Monkey

The exciting / scary thing is that apparently lots of reptiles we thought couldn’t do this, we now know can… including Komodo Dragons! http://www.nature.com/nature/journal/v444/n7122/abs/4441021a.html
Trisha D

Thank god this doesn’t happen to humans.
- Anonymous
  
  it does. yy males are uncommon, and imprisoned at an unbelievably higher rate than xy males.
cjp

Komodo dragons have been known to do this, too. From Scientific American: “In parthenogenesis, the mother’s half-set of chromosomes doubles up to generate the full complement. Hence, the offspring derives all its genes from the mother, but they are not a duplicate of her genome.”

http://www.scientificamerican.com/article.cfm?id=strange-but-true-komodo-d
Cochituate

This bodes well as a major plot device for another Jurassic Park movie.
Anonymous

Supposedly it did happen to one human done 2000 years ago lending credence to the “V” theory of religion. Damn tricky those alien reptiles. Damn tricky.
Devlin

Must be all the midichlorians.
Anonymous

midichlorians? So Jesus Snake Jedi overlords?
Pasketti

Boa Constrictors are an invasive species in Florida. The pythons are getting more press, but the boas are there, too. I’m wondering how much this capability contributed to that.
Flying_Monkey

I believe that most species only do this in extremis, i.e. it isn’t a very evolutionarily-sensible thing to do on a regular basis.
- Anonymous
  
  Not true! Few species rely exclusively on parthenogenesis, but it’s still common. A common pattern in animals like insects and crustaceans is to use it to spread quickly in the spring, and then start shuffling genes once resources are more limited.
  - Flying_Monkey
    
    Sorry, Anon (#13), you’re right I should have said ‘most higher animal species’ or something similar.
Anonymous

Pythonogenesis?
Anonymous

Amazing.
Anonymous

Note ALL the Royal Society’s pubs are free until the end of the month only (“to celebrate Open Access Week and the 350th Anniversary of the Royal Society”).

So get in there while you can…
ganesha71

Thanks for getting Shriekback looping in my head….

Priests and cannibals, prehistoric animals
Everybody happy as the dead come home
Big Black Nemesis, parthenogenesis
No one move a muscle as the dead come home
Steve Stair

The H in Jesus H. Christ does stand for Haploid.
Anonymous

They’re not female snake-Jesus overlords, they’re female snake-Mary overlords. Just saying . . .
LeFunk

Also – turkeys.

http://www.straightdope.com/columns/read/1350/can-turkeys-reproduce-without-benefit-of-sex

(the more you know, more overlords, etc)
Flying_Monkey

@cjp – err, yes, read the first comment on the thread.
Mark Crummett

Thanks for the Shriekback reference! Any song that uses the word “parthenogenesis” is OK by me!
g0d5m15t4k3

Wow, that’s amazing. I want to have my own babies. Are there laws about carrying your own clone?
capl

Reminds me of the War Games quote:
Mr. Liggett: Now there seems to be a lot of confusion on this next question: asexual reproduction. Could someone tell me please who first suggested the idea of reproduction without sex?
David Lightman: Umm.. your wife?
Stjohn

Came for the Shriekback reference. Leaving satisfied. +1 internets to ganesha71.
tgvaughan

And of course it’s just a coincidence that both of the snake sex chromosomes look like little snakes..?!