This is nuts. If I'm understanding correctly, the M. ibiricus queen mates with a M. structor male, uses his sperm to create sterile, hybrid female worker ants for her colony, then she (astonishingly) can also lay eggs that develop into fertile M. structor males, which means she has removed her genetic material from the egg and effectively cloned the male she previously mated with.
The original paper discusses this in more detail. There is a well understood phenomenon called sperm paratism where male sperm will take over the egg, instead of sexually reproducing with the egg.
In sexual reproduction the offspring has 50% of its genetic material from both parents. In sperm parasitism the offspring is 100% related to the male and the female’s genetic material has been destroyed.
These inbericus females are allowing the messor male line to reproduce by sperm parisitism to maintain a domesticated messor line that they can then later sexually reproduce with to create hybrid worker ants.
This is a really interesting discovery. In ants it's apparently common for one species to stop being able to produce workers on their own, and use the sperm from another species instead.
In this case, that happened. But if you do that, you can only expand as far as the other species expands. So you can expand further if you can find a way to keep the males of that species around with you.
This species does that by having a reproductive pathway that, if a queen is fertilized by that 'domesticated' species, the DNA of the 'host' species is removed from the eggs. So you get an ant that has none of the host's DNA. Except they do inherit the mitochondrial DNA (it always comes from the mother). The 'domesticated' males and the 'wild-type' males do look slightly different - it's not clear if this is because of the mitochondrial DNA or because they're raised differently or what.
I read someone compare the domesticated species to a 'superorganism organelle' - just like an archaea cell sucked up a bacteria to become a eukaryote, the host species sucked up the domesticated species to become some combination of both.
Wild to think what other crazy ways of living and makin babies must be out there that we haven't figured out yet.
This is wild.
But eusocial insect have a lot of bizarre eccentricities in sex determinism.
less than 1% of the colony can actually reproduce, every other being is there for the betterment of the 1%. The workers will mutilate, sacrifice and kill themselves just for the queen to have 0.1% better survivability.
It is helpful to think of the whole colony as a singular organism as opposed to individuals, because our understanding of individual starts breaking down at these levels
Fantastic science, very cool discovery. I'm surprised to learn that ant colonies don't really produce males in lab conditions, that must make this research incredibly difficult.
> For M. ibericus, this adaptation ensures they have plenty of workers, which are responsible for many important tasks in a colony
I don't understand this part, though. It doesn't address why it is beneficial for the workers to be hybrids instead of pure M. ibericus. At some point M. ibericus lost the ability to make non-hybrid workers, but that must have happened after.
Ants, and wasps too, have an incredible variety of amazing resources. Some species will have more than one queen, other will cultivate fungus or sheep aphids, others make nests the size of a nut and others the size of the ecuator, some are parasitic of an specific specie. There are sun reflecting desert ants, amazonian river floating ants, container ants full of sweet for the colony, mechanical ants with cyborg-like mandibules with absurd power ratios, you have bridge building ants that use their own body. Their genetic tricks are amazing and diverse too.
It's better than sci-fi, if you like strange creatures, dive into myrmecology.
So the queen can lay 3 types: hybrid female, Ibiricus male, structor male. Did they do karyotyping? Is it actually that the queen somehow removed its own genetic material from the nuclei or does it somehow get silenced when the M. structor genetic material is present in the nuclei (which is interesting by itself). Perhaps some kind of complex imprinting is happening.
On the one hand, this seems nuts. On the other hand, the mechanism compared to all the other things biology can and has done doesn't seem that crazy.
Create egg, remove nucleus of egg, replace nucleus of egg with one or two nuclei from stored sperm that initiate replication and growth of the other species from there (depending on the exact mechanism which it sounds like they're still figuring out).
This seems on the surface to violate Hamilton's Law (rB > C)
The hybrid worker ants should still share 75% of their DNA with the queen and therefore it makes sense for them to cooperate regardless of the source of DNA for their father.
The M. structor male clones however do not share any DNA with the queen presumably.
I wouldn't be surprised if further studies found that the M. structor genes were behaving selfishly. They must have some sort of aggressive mechanism for hijacking and evicting the queen genes for making clones.
Alternatively there could be a parasitic organism propagating through the reproductive procress.
There's an excellent series of lectures from Stanford's Robert Sapolsky [1] about Human Behavioral Biology. While not about ants or insects, he brings up various examples from different species to explain the crazy "optimization war" of evolution. It's mind-expanding to learn about the many mechanisms at work - much more than just what can be encoded and passed on with genes.
Biology is not "defied", whatever that could possibly mean, and there's no need to rethink the concept of species--there's a sizable literature laying out how this is a fuzzy vague concept that humans use to categorize things but that it doesn't "carve nature at its joints"--nature doesn't have joints.
Reminds me of the Ambystoma salamanders that reproduce via kleptogenesis. They are all female, and they "steal" sperm from males of 3 or 4 related species. Most of the time they discard the male's genetic material, but sometimes they incorporate it, which results in embryos that have multiple sets of chromosomes. It's wild. The offspring can contain genetic material from up to 4 different parental species.
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[ 3.3 ms ] story [ 59.4 ms ] threadIn sexual reproduction the offspring has 50% of its genetic material from both parents. In sperm parasitism the offspring is 100% related to the male and the female’s genetic material has been destroyed.
These inbericus females are allowing the messor male line to reproduce by sperm parisitism to maintain a domesticated messor line that they can then later sexually reproduce with to create hybrid worker ants.
https://www.nature.com/articles/s41586-025-09425-w
In this case, that happened. But if you do that, you can only expand as far as the other species expands. So you can expand further if you can find a way to keep the males of that species around with you.
This species does that by having a reproductive pathway that, if a queen is fertilized by that 'domesticated' species, the DNA of the 'host' species is removed from the eggs. So you get an ant that has none of the host's DNA. Except they do inherit the mitochondrial DNA (it always comes from the mother). The 'domesticated' males and the 'wild-type' males do look slightly different - it's not clear if this is because of the mitochondrial DNA or because they're raised differently or what.
I read someone compare the domesticated species to a 'superorganism organelle' - just like an archaea cell sucked up a bacteria to become a eukaryote, the host species sucked up the domesticated species to become some combination of both.
Wild to think what other crazy ways of living and makin babies must be out there that we haven't figured out yet.
It is helpful to think of the whole colony as a singular organism as opposed to individuals, because our understanding of individual starts breaking down at these levels
> For M. ibericus, this adaptation ensures they have plenty of workers, which are responsible for many important tasks in a colony
I don't understand this part, though. It doesn't address why it is beneficial for the workers to be hybrids instead of pure M. ibericus. At some point M. ibericus lost the ability to make non-hybrid workers, but that must have happened after.
It's better than sci-fi, if you like strange creatures, dive into myrmecology.
More seriously, what those ants are doing is kind of unbelievable.
Create egg, remove nucleus of egg, replace nucleus of egg with one or two nuclei from stored sperm that initiate replication and growth of the other species from there (depending on the exact mechanism which it sounds like they're still figuring out).
Compared with fungus that creates zombie ants (this is a real thing - https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis) and birds that change their eggs to match those of other species (https://en.wikipedia.org/wiki/Brood_parasitism) it almost seems tame.
The hybrid worker ants should still share 75% of their DNA with the queen and therefore it makes sense for them to cooperate regardless of the source of DNA for their father.
The M. structor male clones however do not share any DNA with the queen presumably.
I wouldn't be surprised if further studies found that the M. structor genes were behaving selfishly. They must have some sort of aggressive mechanism for hijacking and evicting the queen genes for making clones.
Alternatively there could be a parasitic organism propagating through the reproductive procress.
[1] https://www.youtube.com/playlist?list=PL848F2368C90DDC3D
The egg came before the chicken.
https://en.wikipedia.org/wiki/William_Morton_Wheeler