
Virgin births in animals are no longer rare - SwellJoe
http://www.bbc.com/earth/story/20141219-spectacular-real-virgin-births
======
philh
I think what surprises me most about this is that the Boa produced only female
offspring.

Per [http://en.wikipedia.org/wiki/ZW_sex-
determination_system](http://en.wikipedia.org/wiki/ZW_sex-
determination_system) \- humans have XY chromosomes, with XX female and XY
male. Boas have ZW chromosomes, with ZZ male and ZW female. I'd expect
parthogenesis to produce unviable WW offspring, and viable ZZ ones. But WW
turns out to be viable, and ZZ either doesn't happen, or isn't viable.

I'd previously read about this happening in Komodo dragons, which also have
ZW, and there the viable offspring were all male - which makes slightly more
sense to me, genetically speaking, because the children can mate with the
mother to get slightly more genetic diversity in their offspring.

Quick google,
[http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjo...](http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001643)
might shed some light on this: in boas, the W and Z chromosomes look
identical, in other species they look very different. That might (partially?)
explain why WW is viable. But I'm way out of my depth here.

~~~
vorg
> Boas have ZW chromosomes, with ZZ male and ZW female. I'd expect
> parthogenesis to produce unviable WW offspring, and viable ZZ ones.

If the female is ZW, then I'd expect three possible choices -- unviable WW,
female ZW, and male ZZ -- because both Z and W are present in the female.

~~~
carlob
Apparently WW can be a viable female:

[http://news.bbc.co.uk/earth/hi/earth_news/newsid_9139000/913...](http://news.bbc.co.uk/earth/hi/earth_news/newsid_9139000/9139971.stm)

------
cygx
Relevant Wikipedia quote [1] about New Mexico whiptail lizards:

 _An interesting aspect to reproduction in these asexual lizards is that
mating behaviors are still seen, although the populations are all female. One
female plays the role played by the male in closely related species, and
mounts the female that is about to lay eggs. This behaviour is due to the
hormonal cycles of the females, which cause them to behave like males shortly
after laying eggs, when levels of progesterone are high, and to take the
female role in mating before laying eggs, when estrogen dominates._

It blew my mind when I first stumbled upon it:

There's a species of lesbian lizards that reproduce by cloning!

[1]
[http://en.wikipedia.org/wiki/Parthenogenesis#Reptiles](http://en.wikipedia.org/wiki/Parthenogenesis#Reptiles)

~~~
jessaustin
The way to tell if a cow is in heat, is when she stands still while other cows
mount her in the same fashion a bull would. It isn't odd that very important
behavior is at least partially determined by genes found on the other
chromosomes.

------
georgespencer
I recall Josh McDowell citing the virgin birth as one of the defining reasons
for believing Christ was the son of God.

I quite enjoyed Christopher Hitchens' take on Parthenogenesis: "Even if I
grant you that, you still have all your work ahead of you to prove that he was
divine."

Things like this add to that workload. Fascinating and festive and very HN.

~~~
happyscrappy
The Hebrew word for young girl was very close to the word virgin, there was
only a subtle difference in the spelling.

~~~
everydaypanos
The new testament was written in Greek, not in Hebrew. And yes, back then, the
word virgin could actually have allegoric meaning(young/innocent/beautiful/...
girl). Imagine if she was actually the first ever mammal to asexually
reproduce..

~~~
nocman
Yes, but the prophecy that Jesus fulfilled by being born of a virgin was from
the _Old Testament_ (Isaiah 7:14), not the _New Testament_. (the Old Testament
was written in Hebrew)

[https://www.biblegateway.com/passage/?search=isaiah+7%3A14&v...](https://www.biblegateway.com/passage/?search=isaiah+7%3A14&version=NKJV)

~~~
gohrt
Yes, but Isaiah 7:14 wasn't originally written in English, and the Hebrew word
"almah" didn't mean "virgin" in the Old Testament.

[http://en.wikipedia.org/wiki/Almah](http://en.wikipedia.org/wiki/Almah)

~~~
nocman
Well, in fairness (strictly going by that article) it didn't _have_ to mean
"virgin" \-- but it sometimes did:

"Almah (עלמה, plural: alamot עלמות) is a Hebrew word meaning a young woman of
childbearing age who has not yet had a child, and who may be an unmarried
virgin or a married young woman."

I'm not saying that Wikipedia gets the final say here, just pointing out what
the quoted article says.

------
_nedR
As a non-bio person, I wonder what's the evolutionary reason for this not
happening in more species. Sure, sexual reproduction is the way to go if you
have the option, but wouldn't a wouldn't a mother capable of both asexual and
sexual reproduction have higher chances of propagating her genes than a mother
who is only capable of sexual reproduction. (I know I shouldn't be playing
these mind games with zero knowledge of the subject, but I am curious)

~~~
GuiA
_> I wonder what's the evolutionary reason for this not happening in more
species._

There's rarely an "evolutionary reason" for a trait not developing. Wings
would certainly be a net benefit to mice survival-wise; but unless there's a
strong evolutionary pressure for such a trait to develop, it's unlikely to
appear.

It's the same for asexual reproduction: unless there's a strong advantage for
a species to reproduce asexually, it's likely not going to appear.

In other words, evolutionary selection is really about the strict minimum
needed for a species' population to thrive; evolution selects, but it doesn't
optimize.

You also have to account for things that are hard to predict: even though on
paper it seems like asexual reproduction would lead to a higher chance of
propagating genes, perhaps in reality the lack of diversity in the resulting
offspring would be negative to the species' survival (or while it sounds like
mice developing wings would be an advantage, in reality the energy needed to
develop wings would make it a survival disadvantage).

An interesting case were these rules are "suspended" are in closed ecosystems
where certain species have no predators and plenty of sustenance; e.g.
paradise birds in pacific islands, which can develop completely superfluous
feather patterns and attributes at no evolutionary "cost".

~~~
_nedR
>>unless there's a strong advantage for a species to reproduce asexually, it's
likely not going to appear.

I was under the (perhaps wrong) impression that asexual reproduction predated
sexual reproduction in the history of life (prokaryotes predating eukaryote?)
so I always thought that organisms "lost" the trait of asexual reproduction
somewhere down the line. Probably an assumption without basis.

>>perhaps in reality the lack of diversity in the resulting offspring would be
negative to the species' survival.

Yes. I imagine the answer would be something like that, but the question of
what is the exact reason still stands.

Like i said I haven't the foggiest idea of the subject matter but always liked
to think and speculate about it. Origin and Nature of Life, Physical nature of
consciousness and Neuroscience in general are all topics I find fascinating.
If anybody know any popular science books they can recommend on any of these
topics, it would be great.

~~~
GuiA
Dawkins' books, especially the earlier ones (e.g. Blind Watchmaker), are quite
a good and gentle introduction.

Yes, you are right that life originally started as asexual reproduction and
sexual reproduction appeared later; my answer was more about the likelihood of
a species that already reproduces sexually moving towards asexual
reproduction.

Regarding the question of why the asexual->sexual shift happened in the first
place, the wikipedia article on asexual reproduction has this to say:

 _Current hypotheses [2] suggest that asexual reproduction may have short term
benefits when rapid population growth is important or in stable environments,
while sexual reproduction offers a net advantage by allowing more rapid
generation of genetic diversity, allowing adaptation to changing
environments._

~~~
rational-future
>> Yes, you are right that life originally started as asexual reproduction and
sexual reproduction appeared later

No, that's a hot research topic.

E.g. a popular hypothesis is than in an RNA world very early and simple
organisms had inefficient metabolism and error-prone genetic copy. They didn't
have enough energy to sustain a backup of their genetic information, RNA is
not very stable, etc. So the only way to keep functioning was to constantly
mate with other organisms and exchange good replacements for broken genes.

------
carlob
Heh, what an appropriate theme for Christmas :)

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lazylizard
[https://en.wikipedia.org/wiki/Marmorkrebs](https://en.wikipedia.org/wiki/Marmorkrebs)

------
dynofuz
This is nothing new. Lizards reproduce asexually in deserts often when the
conditions become extremely stable--no new genetic info is needed. One day the
whole world, once we've learned how to control it, will become female, or at
least ones that can change into male if they wish.
[http://www.scientificamerican.com/article/asexual-
lizards/](http://www.scientificamerican.com/article/asexual-lizards/)

------
Htsthbjig
I have my own terrarium inside the home with everything enclosed from outside.
It includes LED lighting.

Somewhat Aphids appeared and created havoc inside. They reproduce in so many
different ways, sexually, asexually or mixed that is really hard to eradicate
them(in a natural way).

In the end I decided to use ladybugs to control them. Now I need something
that controls ladybugs too.

~~~
baldeagle
Be careful, that is a long road to go down...

[http://www.amazon.com/If-You-Give-Mouse-
Cookie/dp/0060245867](http://www.amazon.com/If-You-Give-Mouse-
Cookie/dp/0060245867)

------
graycat
Ah, apparently the BBC forgot about the scene in the first movie _Jurassic
Park_!

~~~
frik
Why was it downvoted? It is in some way relevant.

I remember in Jurassic Park 1 the premise was that the dinos reprocuded
themselves because the contained parts of an African frog DNA, a species that
needs only females to reproduce.

~~~
graycat
Right. As in the script of _Jurassic Park_ at

[http://www.imdb.com/title/tt0107290/quotes](http://www.imdb.com/title/tt0107290/quotes)

early in the movie we have a discussion saying that the animals can't breed in
the wild due to them all being female:

"John Hammond: [as they gather around a baby dinosaur hatching from its egg]
I've been present for the birth of every little creature on this island.

Dr. Ian Malcolm: Surely not the ones that are bred in the wild?

Henry Wu: Actually they can't breed in the wild. Population control is one of
our security precautions. There's no unauthorized breeding in Jurassic Park.

Dr. Ian Malcolm: How do you know they can't breed?

Henry Wu: Well, because all the animals in Jurassic Park are female. We've
engineered them that way."

and later with three of the characters wandering in the park we have

"Dr. Alan Grant: [finding egg shells] Oh my God. Do you know what this is?
This is a dinosaur egg. The dinosaurs are breeding.

Tim: But Grandpa said all the dinosaurs were girls.

Dr. Alan Grant: Amphibian DNA.

Lex: What's that?

Dr. Alan Grant: Well, on the tour, the film said they used frog DNA to fill in
the gene sequence gaps. They mutated the dinosaur genetic code and blended it
with that of a frog's. Now, some West African frogs have been known to
spontaneously change sex from male to female in a single sex environment.
Malcolm was right. Look..."

So, yes, the movie anticipated the OP from the BBC.

------
ramgorur
I can imagine the title of the next bbc article -- "Eloquent speech by a 3
months old middle eastern Homo Sapiens is no longer rare".

------
throw_away_001
More proof of our One True Lord:

[https://www.youtube.com/watch?v=unZI3MVIZ4o](https://www.youtube.com/watch?v=unZI3MVIZ4o)

