Interesting. To biologists, anyway.

[zotz]

Trying to check on an item in the Grauniad on the subject, I found this in Nature:

In a bizarre war of the sexes, little fire ants have evolved a novel way to fight for their gender's genes, according to new research.

The sperm of the male ant appears to be able to destroy the female DNA within a fertilized egg, giving birth to a male that is a clone of its father. Meanwhile the female queens make clones of themselves to carry on the royal female line.

The result is that both the males and females have their own, independent gene pools, leading some to speculate whether each gender ought to be technically classified as its own species. "We could think of the males as a separate, parasitic species that uses host eggs for its own reproduction," says Denis Fournier of the Université Libre in Brussels, Belgium, who led the work.

The page is here, but I think you may need a sub to see it. Any way up, that's the weirdest thing I've seen for a while. The implications make my head hurt.

Comments

[dennyd.livejournal.com]

Gosh.

[devilgate.livejournal.com]

But... if the male's sperm kills the female's DNA and the female (somehow, not specified in the extract) kills the male's DNA; isn't that a lot like mutually assured desdtruction?

[zotz]

Only when they both happen at the same time. Presumably both sides can survive the resulting wastage.

[dennyd.livejournal.com]

Presumably not every batch of eggs gets fertilised by a male, or there are more eggs than sperm maybe?

[zotz]

Some eggs have a full (rather than half) complement of chromosomes and develop into clones of their mothers. Most of the rest are fertilised and develop into sterile workers, but some of the fertilised ones have their maternally-derived chromosomes destroyed and become male.

[devilgate.livejournal.com]

Yes, having RTFA (for which you don't need a registration, BTW):

Little fire ant queens produce two types of eggs: one that carries the full complement of maternal genes and develops without fertilization into future clones of the queen, and a second group that carries only one set of chromosomes and is fertilized with sperm from a male. Of this latter group of eggs, most develop into sterile workers. In some of the fertilized eggs, however, the maternal genes are somehow destroyed, leaving the eggs to develop into male ant clones.

[zotz]

you don't need a registration

Excellent. I read it (and paraphrased that paragraph) but I'm never sure if I can see it because people generally can see it or because the Uni has a sub.

Thanks.

[dennyd.livejournal.com]

Quite a system. If there's still some standard fertilisation occuring without the female DNA being destroyed then presumably they can't really be classed as two species yet?

[zotz]

At that level, it's semantics. The offspring are sterile hybrids, so you could argue that the parents are separate biological species. You could also argue, if you wished, that the offspring are a third species, like mules.

[shaunotd.livejournal.com]

Are mules classified as a species?

[zotz]

Not a brilliant example, to be honest, but I'm sure somebody thinks they should be. There are at least two cases of them breeding successfully.

[shaunotd.livejournal.com]

That would be more of an argument for horses & asses being a single species, Shirey?

I know, depends on how you define species.... I'm working on what may be a single highly-structured species, or 3 hybridising species with all 3 interspecific hybrids coexisting, & all of them largely asexual so it's a bugger trying to breed them in the lab to find out... argh.

[zotz]

Yes, but popularly horses, donkeys and mules re seen as three separate kinds of animal.

I'm working on[ . . . ]

That sounds at least as mindbending, actually.

[shaunotd.livejournal.com]

It is...just not as interesting 8-/

[valkyriekaren.livejournal.com]

Well, no - they've just diverged into two species, one male and one female. The females reproduce by parthenogenesis, and the males reproduce by fertilising female eggs, then killing off the female DNA input so that the resultant offspring are male and clones of the male parent.

They're still symbiotic though, as the male couldn't reproduce without the female eggs to fertilise, and presumably there's some benefit to the females of keeping the males around (food-gathering, protection etc).

[zotz]

There might be some advantage in having more genetically varied workers, though. After all, they're sterile and therefore don't result in the Twofold Cost.

[shaunotd.livejournal.com]

Sorry, not sure I follow you there (been dealing with Daphnia too long, where males & females are all clones of their mother).

[zotz]

If, say, the workers were more resistant to disease because of being more varied, this might be an advantage without being enough of an advantage (to the queens) to justify only passing on half their genes to their fertile offspring. This way the worker, at least, would be more resistant, and the queens would pass on their full complement to all their breeding progeny.

Does that make sense?

[shaunotd.livejournal.com]

Pretty much. Not sure where the twofold cost bit comes into it though.

[zotz]

The concept, or how it applies to this case?

[(Anonymous)]

The application.

[shaunotd.livejournal.com]

D'oh! Put brain in gear Shaun...
Yes, indirectly. The queens need males to fertilise eggs to produce workers, without which they couldn't raise more queens. The males need the workers to raise queens for them to mate with & produce more males.
They're not really symbiotic IMHO, more like estranged parents competing for attention from their children...

Very interesting stuff!

[zotz]

They could be headed for the situation you described, though (all they need to do is stop needing fertilisation to produce workers), in which case you were entirely right. Alternatively, there may be some unidentified advantage to the current setup which makes it stable.

Hmmm.

[ex-lark-asc.livejournal.com]

parthenogenesis

*instant earworm*

[sushidog.livejournal.com]

That's very cool.

[ex-lark-asc.livejournal.com]

bugmenot.com means you don't need to subscribe.. (http://www.bugmenot.com/view.php?url=http%3A%2F%2Fwww.nature.com%2F)