[HN Gopher] Algae with three sexes that mate in pairs identified...
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Algae with three sexes that mate in pairs identified in Japanese
river (2021)
Author : animal_spirits
Score : 144 points
Date : 2022-03-09 06:07 UTC (1 days ago)
(HTM) web link (www.sciencedaily.com)
(TXT) w3m dump (www.sciencedaily.com)
| loudtieblahblah wrote:
| empthought wrote:
| This article does not describe a species with three sexes. It
| describes a species with two sexes that can co-exist (or not) in
| the same individual organism.
|
| It's somewhat unique because of the "(or not)" -- most
| anisogamous species have either two phenotypes that produce one
| and only one of the gametes, or a single phenotype that produces
| both (like many flowering plants).
|
| Still only two sexes, though--just more than two phenotypes.
| rsynnott wrote:
| For a very different, but interesting, example, see these
| sparrows, which kind of have four sexes:
| https://www.nature.com/articles/539482a
| aaaaarghZombies wrote:
| There's also fungi with a fuck ton of genders, excuse the pun.
| rbanffy wrote:
| _Schizophyllum commune_ , putting the "fun" in "fungi".
| awglkjl34kj wrote:
| mPReDiToR wrote:
| Piers Anthony, Cluster series, Spicans.
|
| Some people say fact is stranger than fiction, but art and life
| have such parallels.
| ctoth wrote:
| I was just thinking about this series the other day and am
| pleasantly surprised to run across someone else who has read
| it.
| hombre_fatal wrote:
| Heh, I was just thinking about the Xanth and Cluster series
| and how I don't hear about them much these days. I devoured
| Piers Anthony's books in my teens.
| klodolph wrote:
| _Schizophyllum commune,_ known as the splitgill mushroom, has
| over 23,000 sexes. Two individuals are sexually compatible based
| on genes at two sites in their genome. If a pair has matching
| genes at either location, the pair is not sexually compatible.
| empthought wrote:
| These are not sexes but mating types. Schizophyllum is
| isogamous and has no sexes. An organism's sex is defined by
| anisogamy.
| [deleted]
| rmbyrro wrote:
| Imagine the number of pronouns...
| giovannibonetti wrote:
| Maybe a HyperLogLog (HLL) data structure would be useful to
| store all of those options.
| dymk wrote:
| It's only 23,000 options, a plaintext file would work fine.
| Computers are fast.
| [deleted]
| im3w1l wrote:
| So just adding more about it, it seems that the sex consists of
| 4 parts, A-alpha, A-beta, B-alpha, B-beta. To be compatible it
| has to have differences in (A-alpha OR A-beta) AND (B-Alpha OR
| B-beta).
|
| I can't help but think that this complex system has to have
| evolved to very precisely control inbreeding rates.
| londons_explore wrote:
| In plants, your genetic siblings are in many cases growing
| very physically close to you - especially if the seed
| dispersal mechanism isn't great.
|
| That makes mechanisms to reduce inbreeding even more
| important.
| lliamander wrote:
| That brings up the question of what one means by "sex". As I
| understand it, sex is primarily about the kinds of gametes one
| produces - either large gametes (female) or small gametes
| (male). The genetic implementation of that is in some sense a
| secondary detail, since it varies between organisms. Reptiles,
| for instance, only have XX chromosomes and sex is determined by
| environment (or something like that).
|
| I would expect that in this case the mushroom still only has
| two types of gametes, and hence only two sexes. There's just an
| added bit of complexity determining whether a particular pair
| of gametes can produce a new organism.
| empthought wrote:
| No, they're isogamous and have no sexes. They do have mating
| types.
| mywacaday wrote:
| Is there any possibility that humans could be similar given
| that not every couple can have children naturally?
| sharpneli wrote:
| There is a massive difference. With that kind of mushroom one
| can expect that any random pair is very likely to match up.
| With humans you have tad less of 50% chance of being able to
| make kids with any random otherwise fertile human.
| openfuture wrote:
| Err, that is an uncharitable reading of GP imo. If you pair
| males and females (rather than just "humans") then the
| anology holds quite well no?
| sequoia wrote:
| I think the topic is getting a bit muddled here. Are we
| talking about couples who can't have children because one
| or the other is infertile/sterile, or couples who could
| have children with _someone else_ but not one another?
|
| I'm not familiar with this latter scenario. A man being
| sterile is nothing like this algae's situation, as it has
| nothing to do with "pairing," he's simply unable to
| produce children with anyone.
| InitialLastName wrote:
| How often is the inability to have children naturally
| dependent on direct compatibility, rather than the ability of
| one or both partners to have children at all, regardless of
| partner?
| chrisdave wrote:
| This is an interesting idea because it seems like it could
| be true and we've just never noticed. I'm not sure how
| you'd go about designing a study but I guess it would be
| easy to find volunteers.
| InitialLastName wrote:
| > but I guess it would be easy to find volunteers.
|
| I don't know, in my experience people are sure picky
| about procreating with random strangers (and the ethical
| concerns regarding the output of the study are...
| significant).
|
| From people I've known undergoing fertility treatments
| (and from my own limited research), the issue is
| frequently traceable to a specific cause in one or both
| partners (although it appears to be unexplained in about
| 20% of couples who seek treatment, which would be a small
| subset of the general population).
| luckystarr wrote:
| And it's still one species? Wild.
| b3lvedere wrote:
| "each sex can enter fertile pairings with 22,960 others"
|
| Imagine its Tinder profile :)
| dang wrote:
| We detached this subthread from
| https://news.ycombinator.com/item?id=30625506.
| Jenk wrote:
| I can't get past the mental visualisation of the gender drop-
| down list on the registration. Or the "seeking" list.
| xattt wrote:
| A list would only work if selection is limited. A better UI
| decision would either be a "sex cloud" akin to a word cloud,
| or the bubble UI that Apple Music uses to identify your
| preferred genres.
| rbanffy wrote:
| In the late 90's I designed a dating website and we had
| about 5 axis to have categories for morphology,
| preferences, compatibility, etc. Sadly, I didn't stay long
| enough to see it deployed to production, and never actually
| used the application (Amigos Virtuais, at Universo Online,
| in Brazil). The PO and I had a _lot_ of fun with all other
| personality dimensions that we had.
| Jenk wrote:
| To be a success you'd need to create some kind of yubikey
| specifically for DNA sequences.
|
| Hell I'd imagine you'd need something like that just to
| meet people at a bar.
| rmbyrro wrote:
| Now imagine the list of pronouns they'd need to choose to
| create a Tinder profile...
| geodel wrote:
| Or Twitter pronouns.
| vmception wrote:
| When defining by which pairs can reproduce, or at least
| "connect corresponding mating organs", humans are also still
| limited to 2 sexes, pronoun discussion (in American English)
| acknowledges 2 sexes and decouples gender from that. A one to
| many relationship, instead of a one to one relationship.
|
| (I've found in other English variants, consensus is evolving
| differently with non-binary genders equalling additional
| sexes, this can make things confusing online - like on
| Twitter - if you aren't noticing that maybe Commonwealth
| countries are forming this conversation differently)
| mschuster91 wrote:
| > When defining by which pairs can reproduce, or at least
| "connect corresponding mating organs", humans are also
| still limited to 2 sexes
|
| For ~98.3%, yes. About 1.7% [1] are... more difficult to
| answer that question for. For example, take a person with
| XX chromosomes but a penis and a person with XY chromosomes
| and a vagina. The "connect mating organs" step will work,
| but the pair will be infertile in almost all cases.
|
| Even when one disregards social gender identity and purely
| focuses on "biological" attributes, nature has given
| humanity a _lot_ of options - most people will fit into the
| "standard" model of hormones, chromosomes and the presence
| of naturally-grown genitalia, but a lot of people will not.
|
| [1]: https://www.unfe.org/intersex-awareness/
| zajio1am wrote:
| > About 1.7% are ...
|
| According to https://pubmed.ncbi.nlm.nih.gov/12476264/ it
| is more like 0.018 % than 1.7 %.
| nobodyandproud wrote:
| "As a user, I only want to search for users whom I can pair
| with. All incompatible users should be excluded by default".
|
| Now go and build it.
| dfxm12 wrote:
| Tinder is not necessarily about "fertile pairings" though, but
| I guess humans (and some monkeys) are pretty unique in nature
| in that regard :)
| dragonwriter wrote:
| In using Tinder at all? Yeah, that's pretty much just humans.
| willcipriano wrote:
| It's almost entirely about secondary sex characteristics and
| those exist exclusively to find fertile mates. Gay people
| still look at their potential partners secondary sex
| characteristics when deciding to mate with them. It's sort of
| a distinction without a difference situation.
| nephrite wrote:
| So those aren't a third sex, it's individuals with both male and
| female reproductive cells.
| smrk007 wrote:
| But they're calling it a third sex because it's due to "normal
| expression of the species' genes", not because of
| hermaphroditism.
| empthought wrote:
| It is a third (or fourth) phenotype, not a third sex. The
| abstract of the source article is careful to spell this out;
| the clickbait site introduced the error.
|
| "Three sex phenotypes in a haploid algal species give
| insights into the evolutionary transition to a self-
| compatible mating system." -- i.e. how might self-pollinating
| plants have developed?
| YaBomm wrote:
| TAKEMYMONEY wrote:
| Are we defining sex by the type of gametes produced by an
| organism?
|
| > they can produce normal male or female colonies when they
| reproduce sexually with other P. starrii colonies
| openfuture wrote:
| Like in "the player of games" the third sex was both female and
| male.
| fastball wrote:
| Is that how it was? If my memory serves the third sex was
| effectively "female", in that you had:
|
| - producer of small gamete (human male)
|
| - producer of large gamete (half of human female)
|
| - incubator of embryo (half of human female)
| kerneloftruth wrote:
| [deleted]
| stimpson_j_cat wrote:
| Sound the alarms!
|
| Odd, my friend completed their sexual reassignment surgery
| _because_ they identified so strongly as male-gendered.
|
| I'm going to need to remind them they're actually trying to
| get rid of gender! Silly them! Let's hope they're never
| "normalized!"
| dymk wrote:
| Sounds like a third sex
| chiefalchemist wrote:
| I think it depends on how you define sex, or perhaps even
| gender would be more accurate?
|
| In any case, I think what's being proposed is there are still
| on 2 unique sexes.
|
| - some of the species have one - some of the species have the
| other - some have the ability of both.
|
| Technically, yes, that's still only two.
| nkrisc wrote:
| How _do_ you define sex? Because what you just described
| sure sounds like a third sex to me.
|
| Your description is premised on the assumption that there
| are only two sexes to begin with, and define the third sex
| in terms of the two sexes you assume to be the only ones
| that exist. Instead you could describe them as sexes A, B,
| and C where any of following pairings are valid for
| reproducing: A and B, A and C, B and C, or C and C.
| chiefalchemist wrote:
| Actually. No.
|
| You need two differnt "widgets" to tango, not three.
|
| Unless you say Sex A and Sex B together is a third sex
| Sex A+B. But that would only make sense if A+Bs were
| unique in the sense that they can only mate with other
| A+Bs. Then A+B would be a third sex. That's not the case,
| is it?
|
| Put another way, sex is a property, not a class.
| [deleted]
| [deleted]
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