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.
alphazard 5 hours ago [-]
If you take the idea of genes as the target of evolution seriously, then every possible "bargain" between different genes that moves towards a pareto optimal for those genes, will eventually be discovered through the brute force search.
ajkjk 4 hours ago [-]
brute force search can still be limited in the states it can reach. If there's some limitation on the types of moves you can make, which presumably there is, then you're limited to states that have paths between them.
philipov 1 hours ago [-]
And in Pareto, there's a rule like that built in because you're only allowed to make moves that increase utility. You're not allowed to move backwards, which can lead to getting trapped in a local maximum.
IAmBroom 4 hours ago [-]
Assuming no extinction, climate change, nor heat death of the universe.
Evolution is not a particularly fast optimizer, on the scale of human perception.
jcims 2 hours ago [-]
I still struggle with the brute force search a bit. Just naively a very small gene has 4^500 possible combinations.
treyd 7 minutes ago [-]
The actual space is a lot smaller than it looks. Many amino acids have multiple codons that encode for them. You can also exclude cases where you have repeating stop codons (which detatch the RNA from the ribosome).
There's lots of processes that favor certain patterns over others, only considering the biochemistry of the cell, not even the fitness of the animal.
HarHarVeryFunny 44 minutes ago [-]
Genetic variation from one generation to the next is incremental - not a matter of tearing it all up and try some something random, not brute force exploring our way through all combinations.
Evolution seems more like building a tree where mostly all you can do is ascend the tree and add finer detail, leaving the trunk and branches (our evolutionary history) in place. It seems unlikely that, say, vertebrates are in the future going to "undo" the major evolutionary developments of the past and lose their skeleton, body symmetry, number of limbs, lungs, alimentary canal, nervous system, brain, etc. We see things like these developing in the evolutionary tree and mostly staying in place once created. Sure some fins turned to limbs, some gills to ears, but once things like that happened they seem to stay in place.
I wonder what evolution would look like if we could see it sped up from the origin of life to billions of years into the future? A building up of complexity to begin with, but those major branches of the evolutionary tree remaining pretty stable it would seem. Continual ongoing change, but of smaller and smaller scope, perhaps - building on what came before.
didibus 27 minutes ago [-]
It's not brute force search, more like stochastic sampling of random variants. It's a directed search where feedback from the environment prunes and weights the search space, and reproduction is a stochastic process biased by fitness. And fitness is defined by the survival and chances of successful mating, aka reproductive success.
Basically, your sex drive is the main search optimization :p
Edit: This is essentially how genetic algorithms in computer science work. They’re often remarkably effective at finding good solutions without needing brute force.
Tagbert 2 hours ago [-]
It is possible that not all combinations are equally likely.
jcims 1 hours ago [-]
Yeah it's working so something's going on .
4 hours ago [-]
szundi 2 hours ago [-]
[dead]
sidewndr46 6 hours ago [-]
Yeah, I came here to say the same thing. I'm really confused how the female can produce a clone of the male of another species. Wouldn't the other males sperm contain only half the genetic material needed to reproduce? But apparently ant DNA doesn't work that way for sex:
somehow a male ant has one set of chromosomes while the female ant has two sets of chromosomes. So a male ant sperm must contain enough information to make a complete male? Then when they mate with the female of the other species, the females egg actually gets blanked out so to speak, containing none of the females own genetic material. Then the male sperm fertilizes the egg with one set of chromosomes producing a male offspring that is a clone?
sampo 4 hours ago [-]
> I'm really confused how the female can produce a clone of the male of another species.
In normal ants, the queen can produce haploid (single set of chromosomes) unfertilized eggs that hatch into males. Normal ant males are haploid. They don't have a father, they can not have sons (but the do have a grandfather, and their daughters will make them grandsons). When the ant queen decides to produce sons, she will make haploid eggs via meiosis as normal, and just won't fertilize them with male sperm.
Ants don't have sex chromosomes. An individual with a single set of chromosomes (haploid) is a male, an individual with double set of chromosomes (diploid) is a female. Ant males are almost like sperm cells that grew into multicellular organisms.
Now, a Messor ibericus queen can produce eggs with her own genetic material removed, and fertilize these with the single set of chromosomes from a Messor structor male. (It will still have the mitochondria and mitochondrial DNA from the queen.) And because the male only has a single set of chromosomes, the sperm and the resulting offspring has an identical single copy of the father's genetic material (except the mitochondria that came from the mother). So the son is a clone of the father (except for mitochondria).
The queen can also mate with males of her own species, contributing half of her own chromosomes to combine with the full single set of the male chromosomes, to produce to-be-queen female offspring. Here we have the normal genetic recombination (though only on the mother's side) to keep the evolutionary benefits of the variation from sexual reproduction.
subroutine 2 hours ago [-]
What are the odds this behavior is not completely hostile from the side of the builder ant? There seems to be some implication of symbiotic relationship, but maybe I'm reading too much into it.
The interesting part is whether M. ibericus queens do actively remove their own genetic from eggs fertilized with builder sperm. Why would they do this?
sampo 1 hours ago [-]
M. ibericus queens produce ibericus males and ibericus females, so that these can mate and produce more ibericus queens. This keeps the normal sexual reproduction of the species going on.
M. ibericus queens produce ibericus×structor hybrids as infertile female worker ants.
M. ibericus queens produce structor males, so future queens can keep producing the hybrid worker ants.
My guess is, maybe there is some benefit having the workers to be hybrids and not pure ibericus ("hybrid vigor" [1]). So it's worth the effort of keeping the structor males along, to be able to produce the hybrid workers. But I think the pure ibericus genes in the line of queens are in control.
Note that many, many animals have non-genetic sex determination. Most fish, amphibians, and reptiles have the same genes for both males and females. Sexual differentiation typically depends on things like the egg temperature or salinity and so on. Some species can even change sex during their adult lifetimes, with external conditions triggering a complex hormonal shift that convert an adult, fertile male into an adult, fertile female.
Having genetic differences between males and females is mostly a bird and mammal thing, at least among vertebrates.
duskwuff 2 hours ago [-]
> Having genetic differences between males and females is mostly a bird and mammal thing, at least among vertebrates.
Also: the configuration and function of sex chromosomes is not consistent even within mammals. There are a number of species - primarily rodents - with unusual sex-determining systems, like species with XX/X0 (i.e. where males have an unpaired X chromosome) or even X0/X0.
Man, the bible missed all of this when they were talking about the two animals of every species on the Ark. What else did they leave out?
rsynnott 4 hours ago [-]
This always struck me as a bit odd, because it was a somewhat common belief around then, and for long after, that many animals reproduced by abiogenesis anyway. Why bother taking two mice on the ark; everyone knows that mice spontaneously emerge from river mud!
(It’s possible that this was just a Greek quirk and never made it to Palestine, I suppose.)
philistine 3 hours ago [-]
Listen, we still don't know how eels reproduce. Our knowledge has never been all inclusive and properly disseminated. The fearful cave-dwelling scribes who wrote the old testament were clearly not up to date on their biology.
dormento 3 hours ago [-]
I didn't know either, but hn came to the rescue. In case you're one of today's lucky 10000:
The idea persisted into the Middle Ages. Can't say for certain that it was continuous, however; the medieval supporters quoted Aristotle et al.
tsimionescu 5 hours ago [-]
To be fair, you almost always still need two individuals to get reproduction going - you just don't need to be as picky about which two individuals as you might think. There are a rare few animals that can sometimes self-reproduce, but it's not a common strategy in the animal kingdom, even among hermaphroditic animals.
duskwuff 4 hours ago [-]
They're less rare than you might think. Parthenogenesis ("virgin birth") occasionally occurs in some domestic birds, including chickens and turkeys. Due to the way sex determination works in birds, the offspring created this way are always male.
Parthenogenesis is not uncommon in animals:
https://en.wikipedia.org/wiki/List_of_taxa_that_use_partheno...
(I am mostly quibbling with "rare few animals" but I can't really say much about the relative prevalence of parthenogenesis compared to sexual reproduction.
sampo 4 hours ago [-]
> What else did they leave out?
Plants. Fungi.
IAmBroom 4 hours ago [-]
The latter they brought with an especially rank pot of Grandma Noah's sauerkraut.
NewJazz 3 hours ago [-]
Leviticus rightfully instructs you not to eat bats, but it seems to mistake them for special birds rather than mammals.
nyeah 48 minutes ago [-]
There can't be much meat on a bat anyway.
sidewndr46 1 hours ago [-]
It was an early deployment of RAID1. Two copies of everything
bethekidyouwant 4 hours ago [-]
They were actually intelligently designed this way any animal you can’t sex easily as a hermaphrodite
IAmBroom 4 hours ago [-]
Here's some punctuation: ....,,,;;;:::!!!???
I don't have the space to help on your other issues.
collingreen 2 hours ago [-]
That's ok, the space key seems to work just fine :troll:
jcul 42 minutes ago [-]
> It was very difficult, because in lab conditions, it’s nearly impossible to have males,” says co-author Jonathan Romiguier, an ecologist at the University of Montpellier in France, to New Scientist’s Tim Vernimmen. “We had something like 50 colonies and monitored them for two years without a single male being born. Then we got lucky.
This confuses me too.
Did the queen once mate with one of these males and save the sperm for two years? Or are the queens somehow born with a copy of the genetic material.
Or does the old queen produce one, which mates with the new queen, and then dies off. And the new queen is able to hold onto that sperm for years (forever?). And they only produce a handful of males for this purpose?
Also why is it so difficult to have males in lab conditions?
ants_everywhere 4 hours ago [-]
Ants seem to be nature's favorite way to experiment
IAmBroom 4 hours ago [-]
The Bacteria Kingdom coughs and smiles knowingly at the Archaean supercluster.
rsynnott 4 hours ago [-]
It may not be as weird as all that (of course, it’s still spectacularly weird) because fertile male ants are haploid!
Razengan 6 hours ago [-]
Imagine this on a alien planetary civilization scale.. and the real Zerg and Tyranids and Xenomorphs that must be out there...
HarHarVeryFunny 4 hours ago [-]
I'm no expert, but why does the female need to remove her own genetic material from her eggs to produce clones? Isn't it possible that during the DNA recombination phase the male DNA somehow dominates?
This ability of the female to give birth to "multiple species" seems to me best understood as the two "species" not having yet actually become distinct, since the only meaningful definition of speciation is when two sub-populations of a species have genetically drifted so far apart that they can no longer successfully interbreed and produce fertile young.
During the process of speciation (one species splitting into two) there are going to be various messy half-way stages such as lions and tigers still able to interbreed and so not fully speciated (even if well along, and not going to typically interbreed), horses and donkeys still able to interbreed but producing infertile young (mules), and these ants in this strange state where interbreeding apparently only results in males. It would be cool to be able to speed up the evolutionary timescale to see the process happen, but what we have here is like a still frame from a movie.
og_kalu 3 hours ago [-]
Ants, bees, and wasps operate on a genetic system called haplodiploidy. It works like this.
Queens don't actually mate to produce male offspring.
Females are Diploid: They are created from a fertilized egg. They have two sets of chromosomes - one set from the mother (the queen) and one from the father's sperm, which the queen releases from the spermatheca when she wants a female.
Males are Haploid: They are created from an unfertilized egg. They have only one set of chromosomes from the queen located in the nucleas of the egg. The queen does not release the male's sperm when she wants a male offspring. They have no father. They hatch from an egg that contains only the mother's genetic material, meaning they are essentially a haploid (single chromosome set) version of the queen.
The M. ibiricus queen produces 2 kinds of offspring with the M. structor:
Sterile Female Hybrid Workers: These are produced in the standard way. The queen lays an egg (containing her genes) and fertilizes it with the sperm from the M. structor male. The resulting worker has DNA from both parents. It's a true hybrid. There is no "dominance"; it's a merger of two different species' DNA.
Fertile Male M.structor Clones: This is where things get really bizzare.
Remember that in the normal case:
- The queen does not use a male's sperm to produce male offspring.
- Joining both DNA always results in a female (males do not have two sets of chromosomes)
There can only be one conclusion. The queen creates this special clone from the male's DNA only, probably by somehow purging her DNA from the nucleus of her egg.
wizzwizz4 4 hours ago [-]
> M. ibericus and M. structor are not closely related, evolutionarily speaking. The two species diverged more than five million years ago, according to the paper.
HarHarVeryFunny 4 hours ago [-]
Time means nothing - species can stay stable for very long periods of time (e.g. coleocanth), and more to the point it makes no sense to call two animals different species if they can still successfully interbreed, since there then still remains the possibility that they could recombine. NOT being able to interbreed successfully (donkey & horse) marks the point of no return where they are now bound to genetically drift further apart over time.
IAmBroom 4 hours ago [-]
Regarding coleocanths... we have no data on how much drift has happened in their DNA. Our only real data is that they are morphologically very similar to their ancestors over a long range.
Your last sentence correctly points out the frailty of our definition of "species". However, this is not the only time our data has confounded our artificial, if often useful, definition of species boundaries.
HarHarVeryFunny 3 hours ago [-]
True - I guess examples like these ants, or lions and tigers, where we have DNA available for both, give a better idea of the speed of genetic drift, or at least some datapoints. We can compare the DNA, and estimate how long those numbers of changes took to accumulate, without yet having got to the point of no return.
I wonder what are the most visually, or structurally, or genetically, different animals that can still interbreed. Things like lions & tigers, polar bears & grizzlies, and zebras & horses, come to mind ... what else ?!
OkayPhysicist 3 hours ago [-]
The American paddlefish and the Russian sturgeon is a pretty wild one. They're in different families (your examples at least share genuses). As far as looking really different (but actually being pretty recently related) beluga whales and narwhals can hybridize.
OkayPhysicist 3 hours ago [-]
The definition of speciation is more complicated than your highschool bio class lead you to believe. There's a dozen definitions, and if you choose one you end up with at least a couple of exceptional cases.
For example, American bison and domesticated cattle can interbreed to produce fertile female beefalos, but the males are sterile. Are domesticated cattle the same species as buffalo?
Then there's ring species: populations of animals where population A can interbreed with populations B and D, but not with C, but C can interbreed with B and D. (often the rings are larger than that). For example, the genus Ensatina salamanders here in California can interbreed with neighboring populations as you go around the mountains, but if you drove one from one side of the central valley to the other it couldn't interbreed. We've mostly decided in that case to call them a bunch of different species, but it's a weird case.
Shit gets even weirder when you leave the animal kingdom. All varieties of pepper will cross pollinate. Bacteria just sort of spread their genetic material to anything that's nearby. Don't even get me started on the absurdity of declaring all the asexually reproducing organisms as being single species individuals.
Basically, a species is a group of animals that has enough of the following characteristics that biologists can agree they're sufficiently different things:
1) They appear distinct from other things
2) They exclusively select mates from their group
3) They exclusively produce fertile offspring with their group
4) They occupy a distinct niche in their ecosystem
5) They are more genetically similar to other members of their group than to other things we consider distinct species
6) Their common ancestor with another group we identify as a species is extinct and considered a different species
7) They really seem like they should be a species
HarHarVeryFunny 2 hours ago [-]
Interesting - thanks.
I hadn't really considered the definition of asexually reproducing species - it seems that things are much more clear cut for ones that sexually reproduce since then we can use the more clear cut "point of no return" definition.
I suppose in cases like beefalos and mules, or these ring species, this "point of no return" comes down to is there any path for to the DNA of these divergent animals to recombine, so a fertile female beefalo (or the occasional fertile female mule) still provides that chance.
It seems that in general it's rare for widely divergent animals like zebras and horses to interbreed in the wild, but apparently western wolf-coyote hybrids are not that uncommon, so it's more than just a theoretical possibility. Who knows, maybe global warming will force polar bears to adapt to warmer climates and increasingly interbreed with grizzlies.
nonameiguess 1 hours ago [-]
Even in the cases of species that roughly meet the naive high school definition, it is at least sometimes the case that they can still interbreed, they just don't. Usually, this is because of geographic isolation. Take African and Indian elephants, for instance. They diverged long enough ago that they're morphologically distinct, not just genetically distinct, but they can still interbreed. They don't because they live on different continents, and they probably wouldn't if they were put together outside of captivity because they're intelligent, social animals with culture and learned histories who rely on not entirely biological cues regarding who to breed with, just as much as humans do.
In reality, we first categorized life into species because they either looked different or we found them exclusively in different places, and only centuries later did we attempt to figure out exactly why and how this was the case and reverse engineer some sensible definition onto the pre-existing categories, but it turns out there is no single definition that works universally and has zero exceptions. It's frustrating if you're a language pedant who likes clarity, but a lot of categories and definitions are like this.
ogig 5 hours ago [-]
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.
soperj 5 hours ago [-]
Wasps evolved from ants didn't they?
edit: i might have that backwards
IAmBroom 4 hours ago [-]
"Wasps" is non-phylogenetic. The LUCA of Hymenoptera was probably a wasp-like animal; there are several extant lines called "wasps" that diverged early; bees (Apoidea) and ants (Formicidae), however, diverged late from "wasps".
suriya-ganesh 5 hours ago [-]
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
HarHarVeryFunny 4 hours ago [-]
Evolution in general works at the level of sub-populations rather than individuals. Genetic variation builds up over time in entire intra-breeding sub-populations of a species (mostly isolated for whatever reason - e.g. forest elephants vs plains elephants), then once in a while there will be a big environmental change (famine, disease, new competition, etc) that may suddenly make these accumulated changes in one sub-population (different from the accumulated changes in the other sub-population) critical to survival rather than benign.
The high-school version of evolution, playing out on an individual level, generation by generation (one baby giraffe, with a longer neck than another, reaches higher leaves and does better) gets the idea across, but evolution is about entire species not individuals, and for the most part any single genetic variation isn't going to have much impact, unless it's fatal.
suriya-ganesh 31 minutes ago [-]
I agree but in these cases the genetic variance that is being accumulated, is only limited to a few individuals who more or less don't interact with the world, except through their workers. But the workers themselves have no way of accumulating or passing on the genetic variation.
In some sense the genetic feedback loop for ant population is designed in such a way that, it makes sense when looking at each ant colony as a singular organism
Unlike the giraffe, or elephants, who are individually capable of accumulating genetic variations.
hearsathought 5 hours ago [-]
> 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
Can't the organisms be viewed as individuals with a shared common goal.
suriya-ganesh 25 minutes ago [-]
Maybe.
The workers are involuntary but willing participants, in a grand scheme where the queens and males get to create new generations.
But this is possible only if we anthropomorphise a lot.
because at the level of ants/bees I'm not even sure what "individual" even means.
But genetically they originate from the same individual, live for the betterment of the whole, and have very minor say in what happens to themselves or their genes. Much similar to cells in a human being does.
afavour 4 hours ago [-]
I think you can argue it either way. Either one is trying to map human concepts onto non-human existence and that's an inherently muddy process. What does "individual" really mean, anyway...
lo_zamoyski 5 hours ago [-]
Indeed. They are individual organisms, not one large organism. Talk of "superorganisms" seems to presuppose that each individual must seek his own survival and reproduction, but that's untrue. From the point of view of the species and its propagation and survival, it is not a question of individuals. That's just one strategy that may characterize the reproductive behavior of some species, but not others.
notorandit 13 minutes ago [-]
There are more things under these skies that a fervid imagination can produce.
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.
bsza 22 minutes ago [-]
All the workers are hybrid. Queen gets to have workers, which she otherwise couldn’t produce. M. structor males get to pass on 100% of their genes. There is no altruism involved.
synapsomorphy 6 hours ago [-]
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.
fainpul 2 hours ago [-]
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.
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.
cs702 4 hours ago [-]
Thankfully the other species is not human beings, as in the Alien movies!
More seriously, what those ants are doing is kind of unbelievable.
titanomachy 5 hours ago [-]
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.
yorwba 4 hours ago [-]
If ibericus/structor hybrid females become sterile workers, but pure ibericus females become queens, that increases the share of ibericus genes in the next generation. So as soon as a mutation arose that had this effect, it outcompeted all other lineages, but also made ibericus dependant on hybridization with structor males to produce workers for the colony. The adaptation that is the focus of the article works around this drawback by letting ibericus colonies produce their own supply of structor males.
So there are roughly three evolutionary phases:
1. Hybridization is common, but largely inconsequential.
2. Hybrid queen elimination.
3. Male cloning.
Jensson 2 hours ago [-]
It does mean the males can't evolve further though, so at some point this will die out when situation changes and those males can no longer survive as well.
gowld 24 minutes ago [-]
Every egg-born species was hatched from a different species, at some point in the past.
The egg came before the chicken.
danielinoa 5 hours ago [-]
So the egg does indeed come first before the proverbial chicken.
Evolution is not a particularly fast optimizer, on the scale of human perception.
There's lots of processes that favor certain patterns over others, only considering the biochemistry of the cell, not even the fitness of the animal.
Evolution seems more like building a tree where mostly all you can do is ascend the tree and add finer detail, leaving the trunk and branches (our evolutionary history) in place. It seems unlikely that, say, vertebrates are in the future going to "undo" the major evolutionary developments of the past and lose their skeleton, body symmetry, number of limbs, lungs, alimentary canal, nervous system, brain, etc. We see things like these developing in the evolutionary tree and mostly staying in place once created. Sure some fins turned to limbs, some gills to ears, but once things like that happened they seem to stay in place.
I wonder what evolution would look like if we could see it sped up from the origin of life to billions of years into the future? A building up of complexity to begin with, but those major branches of the evolutionary tree remaining pretty stable it would seem. Continual ongoing change, but of smaller and smaller scope, perhaps - building on what came before.
Basically, your sex drive is the main search optimization :p
Edit: This is essentially how genetic algorithms in computer science work. They’re often remarkably effective at finding good solutions without needing brute force.
https://press.uni-mainz.de/determining-sex-in-ants/
somehow a male ant has one set of chromosomes while the female ant has two sets of chromosomes. So a male ant sperm must contain enough information to make a complete male? Then when they mate with the female of the other species, the females egg actually gets blanked out so to speak, containing none of the females own genetic material. Then the male sperm fertilizes the egg with one set of chromosomes producing a male offspring that is a clone?
In normal ants, the queen can produce haploid (single set of chromosomes) unfertilized eggs that hatch into males. Normal ant males are haploid. They don't have a father, they can not have sons (but the do have a grandfather, and their daughters will make them grandsons). When the ant queen decides to produce sons, she will make haploid eggs via meiosis as normal, and just won't fertilize them with male sperm.
Ants don't have sex chromosomes. An individual with a single set of chromosomes (haploid) is a male, an individual with double set of chromosomes (diploid) is a female. Ant males are almost like sperm cells that grew into multicellular organisms.
https://en.wikipedia.org/wiki/Haplodiploidy
Now, a Messor ibericus queen can produce eggs with her own genetic material removed, and fertilize these with the single set of chromosomes from a Messor structor male. (It will still have the mitochondria and mitochondrial DNA from the queen.) And because the male only has a single set of chromosomes, the sperm and the resulting offspring has an identical single copy of the father's genetic material (except the mitochondria that came from the mother). So the son is a clone of the father (except for mitochondria).
The queen can also mate with males of her own species, contributing half of her own chromosomes to combine with the full single set of the male chromosomes, to produce to-be-queen female offspring. Here we have the normal genetic recombination (though only on the mother's side) to keep the evolutionary benefits of the variation from sexual reproduction.
The interesting part is whether M. ibericus queens do actively remove their own genetic from eggs fertilized with builder sperm. Why would they do this?
M. ibericus queens produce ibericus×structor hybrids as infertile female worker ants.
M. ibericus queens produce structor males, so future queens can keep producing the hybrid worker ants.
My guess is, maybe there is some benefit having the workers to be hybrids and not pure ibericus ("hybrid vigor" [1]). So it's worth the effort of keeping the structor males along, to be able to produce the hybrid workers. But I think the pure ibericus genes in the line of queens are in control.
[1] https://en.wikipedia.org/wiki/Heterosis
Having genetic differences between males and females is mostly a bird and mammal thing, at least among vertebrates.
Also: the configuration and function of sex chromosomes is not consistent even within mammals. There are a number of species - primarily rodents - with unusual sex-determining systems, like species with XX/X0 (i.e. where males have an unpaired X chromosome) or even X0/X0.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8617835/
(It’s possible that this was just a Greek quirk and never made it to Palestine, I suppose.)
https://www.newyorker.com/magazine/2020/05/25/where-do-eels-...
https://www.sciencedirect.com/science/article/pii/S003257911...
Plants. Fungi.
I don't have the space to help on your other issues.
This confuses me too.
Did the queen once mate with one of these males and save the sperm for two years? Or are the queens somehow born with a copy of the genetic material.
Or does the old queen produce one, which mates with the new queen, and then dies off. And the new queen is able to hold onto that sperm for years (forever?). And they only produce a handful of males for this purpose?
Also why is it so difficult to have males in lab conditions?
This ability of the female to give birth to "multiple species" seems to me best understood as the two "species" not having yet actually become distinct, since the only meaningful definition of speciation is when two sub-populations of a species have genetically drifted so far apart that they can no longer successfully interbreed and produce fertile young.
During the process of speciation (one species splitting into two) there are going to be various messy half-way stages such as lions and tigers still able to interbreed and so not fully speciated (even if well along, and not going to typically interbreed), horses and donkeys still able to interbreed but producing infertile young (mules), and these ants in this strange state where interbreeding apparently only results in males. It would be cool to be able to speed up the evolutionary timescale to see the process happen, but what we have here is like a still frame from a movie.
Queens don't actually mate to produce male offspring.
Females are Diploid: They are created from a fertilized egg. They have two sets of chromosomes - one set from the mother (the queen) and one from the father's sperm, which the queen releases from the spermatheca when she wants a female.
Males are Haploid: They are created from an unfertilized egg. They have only one set of chromosomes from the queen located in the nucleas of the egg. The queen does not release the male's sperm when she wants a male offspring. They have no father. They hatch from an egg that contains only the mother's genetic material, meaning they are essentially a haploid (single chromosome set) version of the queen.
The M. ibiricus queen produces 2 kinds of offspring with the M. structor:
Sterile Female Hybrid Workers: These are produced in the standard way. The queen lays an egg (containing her genes) and fertilizes it with the sperm from the M. structor male. The resulting worker has DNA from both parents. It's a true hybrid. There is no "dominance"; it's a merger of two different species' DNA.
Fertile Male M.structor Clones: This is where things get really bizzare.
Remember that in the normal case:
- The queen does not use a male's sperm to produce male offspring.
- Joining both DNA always results in a female (males do not have two sets of chromosomes)
There can only be one conclusion. The queen creates this special clone from the male's DNA only, probably by somehow purging her DNA from the nucleus of her egg.
Your last sentence correctly points out the frailty of our definition of "species". However, this is not the only time our data has confounded our artificial, if often useful, definition of species boundaries.
I wonder what are the most visually, or structurally, or genetically, different animals that can still interbreed. Things like lions & tigers, polar bears & grizzlies, and zebras & horses, come to mind ... what else ?!
For example, American bison and domesticated cattle can interbreed to produce fertile female beefalos, but the males are sterile. Are domesticated cattle the same species as buffalo?
Then there's ring species: populations of animals where population A can interbreed with populations B and D, but not with C, but C can interbreed with B and D. (often the rings are larger than that). For example, the genus Ensatina salamanders here in California can interbreed with neighboring populations as you go around the mountains, but if you drove one from one side of the central valley to the other it couldn't interbreed. We've mostly decided in that case to call them a bunch of different species, but it's a weird case.
Shit gets even weirder when you leave the animal kingdom. All varieties of pepper will cross pollinate. Bacteria just sort of spread their genetic material to anything that's nearby. Don't even get me started on the absurdity of declaring all the asexually reproducing organisms as being single species individuals.
Basically, a species is a group of animals that has enough of the following characteristics that biologists can agree they're sufficiently different things:
I hadn't really considered the definition of asexually reproducing species - it seems that things are much more clear cut for ones that sexually reproduce since then we can use the more clear cut "point of no return" definition.
I suppose in cases like beefalos and mules, or these ring species, this "point of no return" comes down to is there any path for to the DNA of these divergent animals to recombine, so a fertile female beefalo (or the occasional fertile female mule) still provides that chance.
It seems that in general it's rare for widely divergent animals like zebras and horses to interbreed in the wild, but apparently western wolf-coyote hybrids are not that uncommon, so it's more than just a theoretical possibility. Who knows, maybe global warming will force polar bears to adapt to warmer climates and increasingly interbreed with grizzlies.
In reality, we first categorized life into species because they either looked different or we found them exclusively in different places, and only centuries later did we attempt to figure out exactly why and how this was the case and reverse engineer some sensible definition onto the pre-existing categories, but it turns out there is no single definition that works universally and has zero exceptions. It's frustrating if you're a language pedant who likes clarity, but a lot of categories and definitions are like this.
It's better than sci-fi, if you like strange creatures, dive into myrmecology.
edit: i might have that backwards
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
The high-school version of evolution, playing out on an individual level, generation by generation (one baby giraffe, with a longer neck than another, reaches higher leaves and does better) gets the idea across, but evolution is about entire species not individuals, and for the most part any single genetic variation isn't going to have much impact, unless it's fatal.
In some sense the genetic feedback loop for ant population is designed in such a way that, it makes sense when looking at each ant colony as a singular organism
Unlike the giraffe, or elephants, who are individually capable of accumulating genetic variations.
Can't the organisms be viewed as individuals with a shared common goal.
The workers are involuntary but willing participants, in a grand scheme where the queens and males get to create new generations. But this is possible only if we anthropomorphise a lot.
because at the level of ants/bees I'm not even sure what "individual" even means.
But genetically they originate from the same individual, live for the betterment of the whole, and have very minor say in what happens to themselves or their genes. Much similar to cells in a human being does.
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.
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.
[1] https://www.youtube.com/playlist?list=PL848F2368C90DDC3D
More seriously, what those ants are doing is kind of unbelievable.
> 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.
So there are roughly three evolutionary phases:
1. Hybridization is common, but largely inconsequential.
2. Hybrid queen elimination.
3. Male cloning.
The egg came before the chicken.