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Were you just saying that for the pun? Regardless, I wanted to point out that the title, while interesting, is hardly "click bait and switch." These birds DO h
by erroneousfunk 10y ago
Were you just saying that for the pun?
Regardless, I wanted to point out that the title, while interesting, is hardly "click bait and switch." These birds DO have four sexes, from the point of view of their chromosomes, which results in behavioral differences between the four sexes, and produces birds that can only mate with a quarter of the entire population.
The biologist that said the "these birds act like..." quote was not the author of the paper being discussed. Also, later on he says "...in a four-sex system, each bird must work that much harder to find a mate — a white female is not just looking for a male, she needs a tan one — so selection will favour a more advantageous two-sex system instead."
So which is it? "A four-sex system" or something that "looks like a four sex system"? I think the article makes it pretty clear that it's the former.
Also, from the article: "Some animals, such as reptiles, have two sexes and no sex chromosomes, whereas the freshwater protozoan Tetrahymena thermophila has seven sexes, each of which can mate with any type except its own. Two sexes with one set of sex chromosomes is the most common arrangement, and has evolved independently many times. But there's no reason a species can't have more sex chromosomes, Wilson Sayres says. “If you've got two genes linked together that can't cross over during meiosis, and one of them plays a role in sex determination, suddenly you can have a new sex chromosome.”"
How is the title incorrect?
- unclenoriega 10y agoYes, I was. Sorry. Still, I do think there's an unfortunate amount of truth in my comment, even in the likely case that the parent is incorrect that it applies to this article.
- woliveirajr 10y agoWell, I would think that having a 4-sex-system would lead to all possible combinations of those. Let's say there are A, B, C and D individuals. You would have a breed from A x B, A x C, A x D, B x C, B x D and C x D. But what I got is that there males and females. But some of them have a different chromosome, to that it's transmitted for their little cute birdies. Let's call it n and m versions, and keep the males (Y) and females (X) So you have Ym, Yn, Xm and Xn. You just have Ym x Xm or Ym x Xn. OR Yn x Xm or Yn x Xn. You don't have Ym x Yn. Nor Xm x Xn. You just have 4 possible combinations, not the whole 6 combinations if there really were 4 different sex. Perhaps I'm missing something from the article, from the paper, or from biology, but since those special mutation from the chromosome 2 doesn't generate infertile offspring, I simply understand it as "birds with a white hair prefer those with red hair, instead of opposite-sex with the same hair color, generating a offspring that will have white or red hair with the same probability."
- erroneousfunk 10y agoThat's not what the paper described at all. Even the article explicitly said that the birds could only mate with 25% of the population -- the "opposite sex" along two dimensions, instead of just one. Those "special mutations" on chromosome 2 result in a chromosome that cannot recombine like a normal chromosome -- a new separate sex chromosome.