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| ▲ | _aavaa_ 7 days ago | parent [-] | | From the actual paper [0]:
"Our long-term genotypic analysis builds on previous work [6, 7] and, through extensive genotyping of thousands of individuals over more than two decades, confirms that white morphs are almost always heterozygous for alternative chromosome 2 alleles (2m/2). We find that 99.7% of white morphs are heterozygous (n = 1,014; Table S1) ... As a consequence of obligate disassortative mating the species effectively has four sexes, wherein any individual can mate with only 1/4 of the individuals in the population." The actual sex chromosomes of the birds, and hence they're gametes, have significant differences between the two colours. You can quibble over if this technically fits the current definition, but the original characterization is pretty far from "complete nonsense". [0] https://www.sciencedirect.com/science/article/pii/S096098221... | | |
| ▲ | anonfordays 7 days ago | parent | next [-] | | >The actual sex chromosomes of the birds, and hence they're gametes, have significant differences between the two colours. This is an incorrect understanding of gametes and supergenes [0]. There are still only two gametes (only two sexes), but the two morphs (white and tan supergenes[0]) can only effectively reproduce with the same morph of the opposite sex (again, only two sexes, only two gametes between the four morphs). This means each morph only effectively breeds with 1/4 of the population, which gives the aberration of "four sexes", even though there is a small amount (around 1%) of cross-morph breeding. The claim that this species truly has four sexes (four gametes) is unscientific nonsense. [0] https://en.m.wikipedia.org/wiki/Supergene | | |
| ▲ | foldr 6 days ago | parent [-] | | It seems that you should take issue with the paper rather than with the journalist who reported what it says. | | |
| ▲ | anonfordays 6 days ago | parent [-] | | There is no issue with the paper. The paper does not support the claim. | | |
| ▲ | foldr 6 days ago | parent [-] | | The paper literally says that "...the species effectively has four sexes..." I don't know if that's true or not, but Helmuth was just reporting a claim made in a peer-reviewed journal article. | | |
| ▲ | anonfordays 6 days ago | parent [-] | | Yes, it literally states "effectively has", and later states: "Indeed, because of disassortative mating based on both chromosomes 2 and 2m and the W and Z sex chromosomes, the species operates as though there are four sexes." Only two sex chromosomes, and acts "as though" there are four sexes, which means there aren't four sexes. The paper does not make the claim that there are four independent sexes. Helmuth incorrectly reported a claim that the paper does not make. "Squirrels fly through the air as though they are birds" Squirrels are not birds and the previous statement does not support that claim. | | |
| ▲ | foldr 6 days ago | parent [-] | | I looked up Helmuth’s original tweet and it seems like a reasonable one sentence summary of the paper to me. I think the problems here are (i) twitter being twitter (not a great venue for detail and nuance) and (ii) a paper reporting its results in an overly sensational way. If there absolutely definitely aren’t more than two sexes in a given species, don’t say that there “effectively” are. | | |
| ▲ | codocod 6 days ago | parent [-] | | It's how she reacted to scientists who responded to her tweet politely challenging her assertion that this species has four sexes that is more the issue: doubling down, blocking anyone who disagreed. An editor of a science magazine should be willing and open to discuss science with scientists. Particularly if they're trying to help correct a misconception. | | |
| ▲ | foldr 6 days ago | parent [-] | | That doesn't sound good, but I haven't managed to find the record of those interactions, as I think the original tweet has been deleted. I don't tend to trust second-hand summaries in this sort of case. |
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| ▲ | kgwgk 7 days ago | parent | prev [-] | | That’s also why it makes complete sense to say that in places/times with anti-miscegenation laws in place there were effectively lots of sexes. | | |
| ▲ | anonfordays 7 days ago | parent [-] | | Almost made this exact comment! It's likely to be poorly received, but this is 100% inline with the aforementioned study. |
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