hot XXXXXXXXXX action

[eub]

http://www.newscientist.com/news/news.jsp?id=ns99996568

In most mammals, including humans, sex is decided by the X and Y chromosomes: two Xs create a female, while XY creates a male. In birds, the system is similar: ZW makes for a female, while ZZ makes for a male.

But in platypuses, XXXXXXXXXX creates a female, while XYXYXYXYXY creates a male. In other words, rather than a single chromosome pair, platypuses have ten-chromosome chains that determine their sex.

Comments

[ralphmelton.livejournal.com]

That seems as if it would offer a lot of opportunities for error with things going slightly awry. What happens if you get an XYZZYXYZZY?

[jinian.livejournal.com]

the ten chromosomes form chains during the sort of cell division that creates sperm or eggs.

Wow! That's the really cool part.