@stuartyeates @llewelly @Quantensalat

This paper does the same thing many math papers (and talks) do. They start out obviously trying to write for the more general audience. Explaining all of the basic concepts as they come up. But, when they get into the exciting bit they become giddy and stop breaking everything down with as much care.

It's that meme where a student is in a math class and the board says "1+1=2" then she looks away for one second and looks back and it's full of calculus.

@stuartyeates @llewelly @Quantensalat

Stuart, Llewelly can you you help me understand this bit from the paper?

"This strategy may have been selected either to benefit from potential worker hybrid vigour or to prevent queen-only production due to the fixation of a caste-biasing genotype"

It's in the section about "Maintenance of a clonal lineage of males"

I understand the hybrid vigor bit, but what do they mean by "fixation of a caste-biasing genotype" ?

https://www.nature.com/articles/s41586-025-09425-w

@stuartyeates @llewelly @Quantensalat

But I am like a snow plow, I will figure this out.

@stuartyeates @llewelly @Quantensalat

Stuart, Llewelly can you you help me understand this bit from the paper?

"This strategy may have been selected either to benefit from potential worker hybrid vigour or to prevent queen-only production due to the fixation of a caste-biasing genotype"

It's in the section about "Maintenance of a clonal lineage of males"

I understand the hybrid vigor bit, but what do they mean by "fixation of a caste-biasing genotype" ?

https://www.nature.com/articles/s41586-025-09425-w

@futurebird @stuartyeates @llewelly @Quantensalat

I haven't read the paper, but I'd interpret it to mean that the species may have developed such a strong tendency to suppress reproductive male offspring in favour of reproductive females that it risked becoming fixed in parthenogenetic reproduction with no males. This is true of various insect lineages. Having an external source of sperm would ensure sexual reproduction can continue.

@dhobern @stuartyeates @llewelly @Quantensalat

That makes sense. I'm still confused about what a "caste-biasing genotype" is. I assume caste here means the reproductive caste of queen. So, if they became ants that just used queen producing parthenogenesis and there were no males that would be a "cast-biased genotype" which reduces species adaptability and all of the other benefits of sexual reproduction?

@dhobern @stuartyeates @llewelly @Quantensalat

That makes sense. I'm still confused about what a "caste-biasing genotype" is. I assume caste here means the reproductive caste of queen. So, if they became ants that just used queen producing parthenogenesis and there were no males that would be a "cast-biased genotype" which reduces species adaptability and all of the other benefits of sexual reproduction?

@dhobern @stuartyeates @llewelly @Quantensalat

That makes sense. I'm still confused about what a "caste-biasing genotype" is. I assume caste here means the reproductive caste of queen. So, if they became ants that just used queen producing parthenogenesis and there were no males that would be a "cast-biased genotype" which reduces species adaptability and all of the other benefits of sexual reproduction?

@futurebird @stuartyeates @llewelly

I'll be delighted if you can explain it afterwards

@Quantensalat @futurebird @stuartyeates @llewelly fwiw, I'm an evolutionary biologist by profession (more molecular than population, tho), and can try to clarify anything that gives your snow plow trouble. Though I know essentially nothing about ants.

@Quantensalat @futurebird @stuartyeates @llewelly somehow missed the whole thread and didn't see @dhobern there answering your specific question.

@stuartyeates @llewelly @Quantensalat

They are talking about the evolutionary benefits of Social Hybridogenesis. What's going on with these ants goes beyond Social Hybridogenesis.

ScienceDirect

(www.sciencedirect.com)

@futurebird @stuartyeates @llewelly @Quantensalat after reading this paper, I've a question of my own (ok, so many.. But top of the list). In the left most panel of fig 1 they mention "typical hybridogenesis" which I guess is the Pelophylax water frog (wikipedia). they mention "discarding" the other species genome.

I immediately wonder how that works?!

Does the cell "know" one genome from another? That would require evolution of some reader/writer system that says which is which. There is a paper (https://link.springer.com/article/10.1007/BF01134041) that implies this is the case but no mechanism is proposed.

To me that seems evolutionarily difficult. Im trying to imagine a mechanism that doesn't require new functions for proteins but only something like "start making lots of eggs, many will be crap" since that's easier to dial up. But unsure if the data fit such a model.

I know, less to do with ants, but now I'm gonna need to do a deep dive to see if anybody has at least proposed how this works (or maybe it's more obvious to ppl who study this sort of thing ‍️).

@notoriousiptg @futurebird @stuartyeates @llewelly @Quantensalat In line with the pile eggs theory, it seems like there must be some combination of the genomes that is viable, and some combo that is not. And the hybrids which survive to maturity are the viable combinations.

@notoriousiptg @futurebird @stuartyeates @llewelly @Quantensalat The Ants Canada captions today referenced an ability of black crazy ants to selectively reuse ancient drone DNA to prevent inbreeding since they have so many queens and breed in the nest. And I was like, hold on, so the ants DO have the ability to 'read' DNA, or is it that they selectively store ant semen, or ... what?

@Wyatt_H_Knott @notoriousiptg @futurebird @stuartyeates @Quantensalat
I think the ability to store sperm for long periods of time is moderately common in insects generally, but especially ants. But I don't know what they meant by "ancient drones".

ref: https://en.wikipedia.org/wiki/Spermatheca

@llewelly @notoriousiptg @futurebird @stuartyeates @Quantensalat From your ref: "Some species of animal have multiple spermathecae." <--- this is what I was kinda imagining. The ants have multiple spermathecae, or possibly older queens can share the contents directly with younger queens somehow?