The first obvious guess was mages enabling homosexual couples to reproduce.  It's a very elegant and clear-in-retrospect guess which would have instantly explained how sexual attraction could have come uncoupled from the previous sexual polarities, to the point where Thellim is ashamed she took as long to consider that hypothesis as she did.  But it was a very good hypothesis before Isabella shot it down.

Thellim had even got as far as deducing that, with sexual reproduction uncoupled from the original binary polarity, a new binary polarity would probably start to emerge for the same reason it originally emerged in sexual organisms; hypothesized, but not known, to reflect a divergence of sexual strategies between "fertilize all the other organisms" and "actually raise the children".  That would be the 'dom' and 'sub' part, or so Thellim had been guessing; and once 'doms' and 'subs' had started pairing off, the set of all 'doms' and the set of all 'subs' making equal contributions to the next generation would have stabilized their relative population frequencies at 1:1, for the same reason that males and females were thus stabilized.  Or to be more precise, parental investment would have stabilized at 1:1, so if raising a 'dom' takes twice as many parental resources as raising a 'sub', there should be twice as many 'doms' as 'subs'.

The part Isabella mentioned earlier about 'doms' assuming more control and 'subs' having less control in relationships, on this view, would represent a new iteration of the not-entirely-pleasant strategy-divergence between "insert your genetic material into other organisms" and "accept that genetic material and raise the resulting offspring" that gave rise to men and women.  Even with the specific events of prehistory screened off, dath ilan doesn't hide that general truth of the past.  The consequence of that evolutionary logic, as executing adaptations in men and women, is too obvious to need any historical records; it's immediately visible to anybody who knows evolutionary biology and has read a few romance novels.  The untrained male has an instinct to seize and guard a woman's reproductive capacity, instinctively using violence to stop her from interacting with other men at the same that he instinctively displays other forms of commitment to try to earn her acquiescence.  The untrained female has adaptations that assume an environment in which men will try to pressure her into more sex than is optimal for her own reproductive fitness, so her adaptations push her to instinctively resist that pressure while also instinctively trying to increase the number and quality of men who'll be interested in her.  There is a long-running dichotomy-tradeoff-argument in dath ilan between the position that this is just stupid, and somewhat evil, and was structurally evil back when the very first sexually recombinant organisms started to specialize in injecting their genes into other organisms; and that current humans should opt out entirely from the more conflicty and combative ways that sex evolved to work.  Versus the position that it's (1) not that bad, (2) actually quite fun in saner versions, and (3) now baked into humanity's core utility function as a top-level value that is not up for debate from merely instrumental considerations or how it originated a billion years earlier.  Almost nobody completely believes in either extreme, of course, but people differ in where they place themselves on that spectrum of opinion.

Thellim had gotten as far as reasoning through all that, and wondering whether the new 'dom' versus 'sub' sexual polarity had ended up better or worse from the standpoint of 'how awful would it look to a generic nice alien' or, possibly, Thellim herself.

Except that apparently mage-assisted reproduction is not what's going on.

It was a very pretty hypothesis, but it is, apparently, not what's going on.

So Thellim needs to properly let this beautiful hypothesis die, mourn it, and then start over.

The first obvious guess was mages enabling homosexual couples to reproduce.  It's a very elegant and clear-in-retrospect guess which would have instantly explained how sexual attraction could have come uncoupled from the previous sexual polarities, to the point where Thellim is ashamed she took as long to consider that hypothesis as she did.  But it was a very good hypothesis before Isabella shot it down.

Thellim had even got as far as deducing that, with sexual reproduction uncoupled from the original binary polarity, a new binary polarity would probably start to emerge for the same reason it originally emerged in sexual organisms; hypothesized, but not known, to reflect a divergence of sexual strategies between "fertilize all the other organisms" and "actually raise the children".  That would be the 'dom' and 'sub' part, or so Thellim had been guessing; and once 'doms' and 'subs' had started pairing off, the set of all 'doms' and the set of all 'subs' making equal contributions to the next generation would have stabilized their relative population frequencies at 1:1, for the same reason that males and females were thus stabilized.  Or to be more precise, parental investment would have stabilized at 1:1, so if raising a 'dom' takes twice as many parental resources as raising a 'sub', there should be twice as many 'doms' as 'subs'.

The part Isabella mentioned earlier about 'doms' assuming more control and 'subs' having less control in relationships, on this view, would represent a new iteration of the not-entirely-pleasant strategy-divergence between "insert your genetic material into other organisms" and "accept that genetic material and raise the resulting offspring" that gave rise to men and women.  Even with the specific events of prehistory screened off, dath ilan doesn't hide that general truth of the past.  The consequence of that evolutionary logic, as executing adaptations in men and women, is too obvious to need any historical records; it's immediately visible to anybody who knows evolutionary biology and has read a few romance novels.  The untrained male has an instinct to seize and guard a woman's reproductive capacity, instinctively using violence to stop her from interacting with other men at the same that he instinctively displays other forms of commitment to try to earn her acquiescence.  The untrained female has adaptations that assume an environment in which men will try to pressure her into more sex than is optimal for her own reproductive fitness, so her adaptations push her to instinctively resist that pressure while also instinctively trying to increase the number and quality of men who'll be interested in her.  There is a long-running dichotomy-tradeoff-argument in dath ilan between the position that this is just stupid, and somewhat evil, and was structurally evil back when the very first sexually recombinant organisms started to specialize in injecting their genes into other organisms; and that current humans should opt out entirely from the more conflicty and combative ways that sex evolved to work.  Versus the position that it's (1) not that bad, (2) actually quite fun in saner versions, and (3) now baked into humanity's core utility function as a top-level value that is not up for debate from merely instrumental considerations or how it originated a billion years earlier.  Almost nobody completely believes in either extreme, of course, but people differ in where they place themselves on that spectrum of opinion.

Thellim had gotten as far as reasoning through all that, and wondering whether the new 'dom' versus 'sub' sexual polarity had ended up better or worse from the standpoint of 'how awful would it look to a generic nice alien' or, possibly, Thellim herself.

Except that apparently mage-assisted reproduction is not what's going on.

It was a very pretty hypothesis, but it is, apparently, not what's going on.

So Thellim needs to properly let this beautiful hypothesis die, mourn it, and then start over.

The first obvious guess was mages enabling homosexual couples to reproduce.  It's a very elegant and clear-in-retrospect guess which would have instantly explained how sexual attraction could have come uncoupled from the previous sexual polarities, to the point where Thellim is ashamed she took as long to consider that hypothesis as she did.  But it was a very good hypothesis before Isabella shot it down.

Thellim had even got as far as deducing that, with sexual reproduction uncoupled from the original binary polarity, a new binary polarity would probably start to emerge for the same reason it originally emerged in sexual organisms; hypothesized, but not known, to reflect a divergence of sexual strategies between "fertilize all the other organisms" and "actually raise the children".  That would be the 'dom' and 'sub' part, or so Thellim had been guessing; and once 'doms' and 'subs' had started pairing off, the set of all 'doms' and the set of all 'subs' making equal contributions to the next generation would have stabilized their relative population frequencies at 1:1, for the same reason that males and females were thus stabilized.  Or to be more precise, parental investment would have stabilized at 1:1, so if raising a 'dom' takes twice as many parental resources as raising a 'sub', there should be half as many 'doms' as 'subs'.

The part Isabella mentioned earlier about 'doms' assuming more control and 'subs' having less control in relationships, on this view, would represent a new iteration of the not-entirely-pleasant strategy-divergence between "insert your genetic material into other organisms" and "accept that genetic material and raise the resulting offspring" that gave rise to men and women.  Even with the specific events of prehistory screened off, dath ilan doesn't hide that general truth of the past.  The consequence of that evolutionary logic, as executing adaptations in men and women, is too obvious to need any historical records; it's immediately visible to anybody who knows evolutionary biology and has read a few romance novels.  The untrained male has an instinct to seize and guard a woman's reproductive capacity, instinctively using violence to stop her from interacting with other men at the same that he instinctively displays other forms of commitment to try to earn her acquiescence.  The untrained female has adaptations that assume an environment in which men will try to pressure her into more sex than is optimal for her own reproductive fitness, so her adaptations push her to instinctively resist that pressure while also instinctively trying to increase the number and quality of men who'll be interested in her.  There is a long-running dichotomy-tradeoff-argument in dath ilan between the position that this is just stupid, and somewhat evil, and was structurally evil back when the very first sexually recombinant organisms started to specialize in injecting their genes into other organisms; and that current humans should opt out entirely from the more conflicty and combative ways that sex evolved to work.  Versus the position that it's (1) not that bad, (2) actually quite fun in saner versions, and (3) now baked into humanity's core utility function as a top-level value that is not up for debate from merely instrumental considerations or how it originated a billion years earlier.  Almost nobody completely believes in either extreme, of course, but people differ in where they place themselves on that spectrum of opinion.

Thellim had gotten as far as reasoning through all that, and wondering whether the new 'dom' versus 'sub' sexual polarity had ended up better or worse from the standpoint of 'how awful would it look to a generic nice alien' or, possibly, Thellim herself.

Except that apparently mage-assisted reproduction is not what's going on.

It was a very pretty hypothesis, but it is, apparently, not what's going on.

So Thellim needs to properly let this beautiful hypothesis die, mourn it, and then start over.

The first obvious guess was mages enabling homosexual couples to reproduce.  It's a very elegant and clear-in-retrospect guess which would have instantly explained how sexual attraction could have come uncoupled from the previous sexual polarities, to the point where Thellim is ashamed she took as long to consider that hypothesis as she did.  But it was a very good hypothesis before Isabella shot it down.

Thellim had even got as far as deducing that, with sexual reproduction uncoupled from the original binary polarity, a new binary polarity would probably start to emerge for the same reason it originally emerged in sexual organisms; hypothesized, but not known, to reflect a divergence of sexual strategies between "fertilize all the other organisms" and "actually raise the children".  That would be the 'dom' and 'sub' part, or so Thellim had been guessing; and once 'doms' and 'subs' had started pairing off, the set of all 'doms' and the set of all 'subs' making equal contributions to the next generation would have stabilized their relative population frequencies at 1:1, for the same reason that males and females were thus stabilized.  Or to be more precise, parental investment would have stabilized at 1:1, so if raising a 'dom' takes twice as many parental resources as raising a 'sub', there should be half as many 'doms' as 'subs'.

The part Isabella mentioned earlier about 'doms' assuming more control and 'subs' having less control in relationships, on this view, would represent a new iteration of the not-entirely-pleasant strategy-divergence between "insert your genetic material into other organisms" and "accept that genetic material and raise the resulting offspring" that gave rise to men and women.  Even with the specific events of prehistory screened off, dath ilan doesn't hide that general truth of the past.  The consequence of that evolutionary logic, as executing adaptations in men and women, is too obvious to need any historical records; it's immediately visible to anybody who knows evolutionary biology and has read a few romance novels.  The untrained male has an instinct to seize and guard a woman's reproductive capacity, instinctively using violence to stop her from interacting with other men at the same that he instinctively displays other forms of commitment to try to earn her acquiescence.  The untrained female has adaptations that assume an environment in which men will try to pressure her into more sex than is optimal for her own reproductive fitness, so her adaptations push her to instinctively resist that pressure while also instinctively trying to increase the number and quality of men who'll be interested in her.  There is a long-running dichotomy-tradeoff-argument in dath ilan between the position that this is just stupid, and somewhat evil, and was structurally evil back when the very first sexually recombinant organisms started to specialize in injecting their genes into other organisms; and that current humans should opt out entirely from the more conflicty and combative ways that sex evolved to work, starting with using mental discipline to counteract those tendencies and eventually trying to select them out of humanity's descendants.  Versus the position that it's (1) not that bad, (2) actually quite fun in saner versions, and (3) now baked into humanity's core utility function as a top-level value that is not up for debate from merely instrumental considerations or how it originated a billion years earlier.  Almost nobody completely believes in either extreme, of course, but people differ in where they place themselves on that spectrum of opinion.

Thellim had gotten as far as reasoning through all that, and wondering whether the new 'dom' versus 'sub' sexual polarity had ended up better or worse from the standpoint of 'how awful would it look to a generic nice alien' or, possibly, Thellim herself.

Except that apparently mage-assisted reproduction is not what's going on.

It was a very pretty hypothesis, but it is, apparently, not what's going on.

So Thellim needs to properly let this beautiful hypothesis die, mourn it, and then start over.

The first obvious guess was mages enabling homosexual couples to reproduce.  It's a very elegant and clear-in-retrospect guess which would have instantly explained how sexual attraction could have come uncoupled from the previous sexual polarities, to the point where Thellim is ashamed she took as long to consider that hypothesis as she did.  But it was a very good hypothesis before Isabella shot it down.

Thellim had even got as far as deducing that, with sexual reproduction uncoupled from the original binary polarity, a new binary polarity would probably start to emerge for the same reason it originally emerged in sexual organisms; hypothesized, but not known, to reflect a divergence of sexual strategies between "fertilize all the other organisms" and "actually raise the children".  That would be the 'dom' and 'sub' part, or so Thellim had been guessing; and once 'doms' and 'subs' had started pairing off, the set of all 'doms' and the set of all 'subs' making equal contributions to the next generation would have stabilized their relative population frequencies at 1:1, for the same reason that males and females were thus stabilized.  Or to be more precise, parental investment would have stabilized at 1:1, so if raising a 'dom' takes twice as many parental resources as raising a 'sub', there should be half as many 'doms' as 'subs'.

The part Isabella mentioned earlier about 'doms' assuming more control and 'subs' having less control in relationships, on this view, would represent a new iteration of the not-entirely-pleasant strategy-divergence between "insert your genetic material into other organisms" and "accept that genetic material and raise the resulting offspring" that gave rise to men and women.  Even with the specific events of prehistory screened off, dath ilan doesn't hide that general truth of the past.  The consequence of that evolutionary logic, as executing adaptations in men and women, is too obvious to need any historical records; it's immediately visible to anybody who knows evolutionary biology and has read a few romance novels.  The untrained male has an instinct to seize and guard a woman's reproductive capacity, instinctively using violence to stop her from interacting with other men at the same that he instinctively displays other forms of commitment to try to earn her acquiescence.  The untrained female has adaptations that assume an environment in which men will try to pressure her into more sex than is optimal for her own reproductive fitness, so her adaptations push her to instinctively resist that pressure while also instinctively trying to increase the number and quality of men who'll be interested in her.  There is a long-running dichotomy-tradeoff-argument in dath ilan between the position that this is just stupid, and somewhat evil, and was structurally evil back when the very first sexually recombinant organisms started to specialize in injecting their genes into other organisms; and that current humans should opt out entirely from the more conflicty and combative ways that sex evolved to work, starting with using mental discipline to counteract those tendencies and eventually trying to select them out of humanity's descendants.  Versus the position that it's (1) not that bad, (2) actually quite fun in saner versions, and (3) now baked into humanity's core utility function as a top-level value that is not up for debate from merely instrumental considerations or how it originated a billion years earlier.  Almost nobody completely believes in either extreme, of course, but people differ in where they place themselves on that spectrum of opinion.

Thellim had gotten as far as reasoning through all that, and wondering whether the new 'dom' versus 'sub' sexual polarity had ended up better or worse from the standpoint of "how awful would it look to a generic nice alien" or, possibly, to Thellim herself.

Except that apparently mage-assisted reproduction is not what's going on.

It was a very pretty hypothesis, but it is, apparently, not what's going on.

So Thellim needs to properly let this beautiful hypothesis die, mourn it, and then start over.

The first obvious guess was mages enabling homosexual couples to reproduce.  It's a very elegant and clear-in-retrospect guess which would have instantly explained how sexual attraction could have come uncoupled from the previous sexual polarities, to the point where Thellim is ashamed she took as long to consider that hypothesis as she did.  But it was a very good hypothesis before Isabella shot it down.

Thellim had even got as far as deducing that, with sexual reproduction uncoupled from the original binary polarity, a new binary polarity would probably start to emerge for the same reason it originally emerged in sexual organisms; hypothesized, but not known, to reflect a divergence of sexual strategies between "fertilize all the other organisms" and "actually raise the children".  That would be the 'dom' and 'sub' part, or so Thellim had been guessing; and once 'doms' and 'subs' had started pairing off, the set of all 'doms' and the set of all 'subs' making equal contributions to the next generation would have stabilized their relative population frequencies at 1:1, for the same reason that males and females were thus stabilized.  Or to be more precise, parental investment would have stabilized at 1:1, so if raising a 'dom' takes twice as many parental resources as raising a 'sub', there should be half as many 'doms' as 'subs'.

The part Isabella mentioned earlier about 'doms' assuming more control and 'subs' having less control in relationships, on this view, would represent a new iteration of the not-entirely-pleasant strategy-divergence between "insert your genetic material into other organisms" and "accept that genetic material and raise the resulting offspring" that gave rise to men and women.  Even with the specific events of prehistory screened off, dath ilan doesn't hide that general truth of the past.  The consequence of that evolutionary logic, as executing adaptations in men and women, is too obvious to need any historical records; it's immediately visible to anybody who knows evolutionary biology and has read a few romance novels.  The untrained male has an instinct to seize and guard a woman's reproductive capacity, instinctively using violence to stop her from interacting with other men at the same that he instinctively displays other forms of commitment to try to earn her acquiescence.  The untrained female has adaptations that assume an environment in which men will try to pressure her into more sex than is optimal for her own reproductive fitness, so her adaptations push her to instinctively resist that pressure while also instinctively trying to increase the number and quality of men who'll be interested in her.  There is a long-running dichotomy-tradeoff-argument in dath ilan between the position that this is just stupid, and somewhat evil, and was structurally evil back when the very first sexually recombinant organisms started to specialize in injecting their genes into other organisms; and that current humans should opt out entirely from the more conflicty and combative ways that sex evolved to work, starting with using mental discipline to counteract those tendencies and eventually trying to select them out of humanity's descendants.  Versus the position that it's (1) not that bad, (2) actually quite fun in saner versions, and (3) now baked into humanity's core utility function as a top-level value that is not up for debate from merely instrumental considerations or how it originated a billion years earlier.  Almost nobody completely believes in either extreme, of course, but people differ in where they place themselves on that spectrum of opinion.

Thellim had gotten as far as reasoning through all that, and wondering whether the new 'dom' versus 'sub' sexual polarity had ended up better or worse from the standpoint of "how awful would it look to a generic nice alien that reproduced asexually" or, possibly, to Thellim herself.

Except that apparently mage-assisted reproduction is not what's going on.

It was a very pretty hypothesis, but it is, apparently, not what's going on.

So Thellim needs to properly let this beautiful hypothesis die, mourn it, and then start over.

The first obvious guess was mages enabling homosexual couples to reproduce.  It's a very elegant and clear-in-retrospect guess which would have instantly explained how sexual attraction could have come uncoupled from the previous sexual polarities, to the point where Thellim is ashamed she took as long to consider that hypothesis as she did.  But it was a very good hypothesis before Isabella shot it down.

Thellim had even got as far as deducing that, with sexual reproduction uncoupled from the original binary polarity, a new binary polarity would probably start to emerge for the same reason it originally emerged in sexual organisms; hypothesized, but not known, to reflect a divergence of sexual strategies between "fertilize all the other organisms" and "actually raise the children".  That would be the 'dom' and 'sub' part, or so Thellim had been guessing; and once 'doms' and 'subs' had started pairing off, the set of all 'doms' and the set of all 'subs' making equal contributions to the next generation would have stabilized their relative population frequencies at 1:1, for the same reason that males and females were thus stabilized.  Or to be more precise, parental investment would have stabilized at 1:1, so if raising a 'dom' takes twice as many parental resources as raising a 'sub', there should be half as many 'doms' as 'subs'.

The part Isabella mentioned earlier about 'doms' assuming more control and 'subs' having less control in relationships, on this view, would represent a new iteration of the not-entirely-pleasant strategy-divergence between "insert your genetic material into other organisms" and "accept that genetic material and raise the resulting offspring" that gave rise to men and women.  Even with the specific events of prehistory screened off, dath ilan doesn't hide that general truth of the past.  The consequence of that evolutionary logic, as executing adaptations in men and women, is too obvious to need any historical records; it's immediately visible to anybody who knows evolutionary biology and has read a few romance novels.  The untrained male has an instinct to seize and guard a woman's reproductive capacity, instinctively using violence to stop her from interacting with other men at the same that he instinctively displays other forms of commitment to try to earn her acquiescence.  The untrained female has adaptations that assume an environment in which men will try to pressure her into more sex than is optimal for her own reproductive fitness, so her adaptations push her to instinctively resist that pressure while also instinctively trying to increase the number and quality of men who'll be interested in her.  There is a long-running dichotomy-tradeoff-argument in dath ilan between the position that this is just stupid, and somewhat evil, and was structurally evil back when some of the first sexually recombinant organisms started to specialize in injecting their genes into other organisms; and that current humans should opt out entirely from the more conflicty and combative ways that sex evolved to work, starting with using mental discipline to counteract those tendencies and eventually trying to select them out of humanity's descendants.  Versus the position that it's (1) not that bad, (2) actually quite fun in saner versions, and (3) now baked into humanity's core utility function as a top-level value that is not up for debate from merely instrumental considerations or how it originated a billion years earlier.  Almost nobody completely believes in either extreme, of course, but people differ in where they place themselves on that spectrum of opinion.

Thellim had gotten as far as reasoning through all that, and wondering whether the new 'dom' versus 'sub' sexual polarity had ended up better or worse from the standpoint of "how awful would it look to a generic nice alien that reproduced asexually" or, possibly, to Thellim herself.

Except that apparently mage-assisted reproduction is not what's going on.

It was a very pretty hypothesis, but it is, apparently, not what's going on.

So Thellim needs to properly let this beautiful hypothesis die, mourn it, and then start over.

The first obvious guess was mages enabling homosexual couples to reproduce.  It's a very elegant and clear-in-retrospect guess which would have instantly explained how sexual attraction could have come uncoupled from the previous sexual polarities, to the point where Thellim is ashamed she took as long to consider that hypothesis as she did.  But it was a very good hypothesis before Isabella shot it down.

Thellim had even got as far as deducing that, with sexual reproduction uncoupled from the original binary polarity, a new binary polarity would probably start to emerge for the same reason it originally emerged in sexual organisms; hypothesized, but not known, to reflect a divergence of sexual strategies between "fertilize all the other organisms" and "actually raise the children".  That would be the 'dom' and 'sub' part, or so Thellim had been guessing; and once 'doms' and 'subs' had started pairing off, the set of all 'doms' and the set of all 'subs' making equal contributions to the next generation would have stabilized their relative population frequencies at 1:1, for the same reason that males and females were thus stabilized.  Or to be more precise, parental investment would have stabilized at 1:1, so if raising a 'dom' takes twice as many parental resources as raising a 'sub', there should be half as many 'doms' as 'subs'.

The part Isabella mentioned earlier about 'doms' assuming more control and 'subs' having less control in relationships, on this view, would represent a new iteration of the not-entirely-pleasant strategy-divergence between "insert your genetic material into other organisms" and "accept that genetic material and raise the resulting offspring" that gave rise to men and women.  Even with the specific events of prehistory screened off, dath ilan doesn't hide that general truth of the past.  The consequence of that evolutionary logic, as executing adaptations in men and women, is too obvious to need any historical records; it's immediately visible to anybody who knows evolutionary biology and has read a few romance novels.  The untrained male has an instinct to seize and guard a woman's reproductive capacity, instinctively using violence to stop her from interacting with other men at the same that he instinctively displays other forms of commitment to try to earn her acquiescence.  The untrained female has adaptations that assume an environment in which men will try to pressure her into more sex than is optimal for her own reproductive fitness, so her adaptations push her to instinctively resist that pressure while also instinctively trying to increase the number and quality of men who'll be interested in her.  There is a long-running dichotomy-tradeoff-argument in dath ilan between the position that this is just stupid, and somewhat evil, and was structurally evil back when some of the first sexually recombinant organisms started to specialize in injecting their genes into other organisms; and that current humans should opt out entirely from the more conflicty and combative ways that sex evolved to work, starting with using mental discipline to counteract those tendencies and eventually trying to select them out of humanity's descendants.  Versus the position that it's (1) not that bad, (2) actually quite fun in saner versions, and (3) now baked into humanity's core utility function as a top-level value that is not up for debate from merely instrumental considerations or how it originated a billion years earlier.  Almost nobody completely believes in either implausibly-oversimplified-policy-stance extreme, of course, but people differ in where they place themselves on that spectrum of opinion.

Thellim had gotten as far as reasoning through all that, and wondering whether the new 'dom' versus 'sub' sexual polarity had ended up better or worse from the standpoint of "how awful would it look to a generic nice alien that reproduced asexually" or, possibly, to Thellim herself.

Except that apparently mage-assisted reproduction is not what's going on.

It was a very pretty hypothesis, but it is, apparently, not what's going on.

So Thellim needs to properly let this beautiful hypothesis die, mourn it, and then start over.

The first obvious guess was mages enabling homosexual couples to reproduce.  It's a very elegant and clear-in-retrospect guess which would have instantly explained how sexual attraction could have come uncoupled from the previous sexual polarities, to the point where Thellim is ashamed she took as long to consider that hypothesis as she did.  But it was a very good hypothesis before Isabella shot it down.

Thellim had even got as far as deducing that, with sexual reproduction uncoupled from the original binary polarity, a new binary polarity would probably start to emerge for the same reason it originally emerged in sexual organisms; hypothesized, but not known, to reflect a divergence of sexual strategies between "fertilize all the other organisms" and "actually raise the children".  That would be the 'dom' and 'sub' part, or so Thellim had been guessing; and once 'doms' and 'subs' had started pairing off, the set of all 'doms' and the set of all 'subs' making equal contributions to the next generation would have stabilized their relative population frequencies at 1:1, for the same reason that males and females were thus stabilized.  Or to be more precise, parental investment would have stabilized at 1:1, so if raising a 'dom' takes twice as many parental resources as raising a 'sub', there should be half as many 'doms' as 'subs'.

The part Isabella mentioned earlier about 'doms' assuming more control and 'subs' having less control in relationships, on this view, would represent a new iteration of the not-entirely-pleasant strategy-divergence between "insert your genetic material into other organisms" and "accept that genetic material and raise the resulting offspring" that gave rise to men and women.  Even with the specific events of prehistory screened off, dath ilan doesn't hide that general truth of the past.  The consequence of that evolutionary logic, as executing adaptations in men and women, is too obvious to need any historical records; it's immediately visible to anybody who knows evolutionary biology and has read a few romance novels.  The untrained male has an instinct to seize and guard a woman's reproductive capacity, instinctively using violence to stop her from interacting with other men at the same time that he instinctively displays other forms of commitment to try to earn her acquiescence.  The untrained female has adaptations that assume an environment in which men will try to pressure her into more sex than is optimal for her own reproductive fitness, so her adaptations push her to instinctively resist that pressure while also instinctively trying to increase the number and quality of men who'll be interested in her.  There is a long-running dichotomy-tradeoff-argument in dath ilan between the position that this is just stupid, and somewhat evil, and was structurally evil back when some of the first sexually recombinant organisms started to specialize in injecting their genes into other organisms; and that current humans should opt out entirely from the more conflicty and combative ways that sex evolved to work, starting with using mental discipline to counteract those tendencies and eventually trying to select them out of humanity's descendants.  Versus the position that it's (1) not that bad, (2) actually quite fun in saner versions, and (3) now baked into humanity's core utility function as a top-level value that is not up for debate from merely instrumental considerations or how it originated a billion years earlier.  Almost nobody completely believes in either implausibly-oversimplified-policy-stance extreme, of course, but people differ in where they place themselves on that spectrum of opinion.

Thellim had gotten as far as reasoning through all that, and wondering whether the new 'dom' versus 'sub' sexual polarity had ended up better or worse from the standpoint of "how awful would it look to a generic nice alien that reproduced asexually" or, possibly, to Thellim herself.

Except that apparently mage-assisted reproduction is not what's going on.

It was a very pretty hypothesis, but it is, apparently, not what's going on.

So Thellim needs to properly let this beautiful hypothesis die, mourn it, and then start over.