One in 500 men carry extra sex chromosome

From ScienceDaily.com. The article is finding a correlation between an increase in certain cardio and pulmonary illness such as throwing a clot, or COPD, and an extra sex chromosome. Curious because there is no clue towards cause, and it does not matter if it's an extra X or y. Therefore this will be the trail-head of an ongoing research path.  

But this gives me an opportunity to mention something in "Sweet," Sevens.

In "Sweet," Sevens are a type of Venusian male that can fly. They are XXy and the book goes on at length why, crossing through genetics 101 but stopping short of genetics 315. 

I set them up like that reasoning that a genetic-engineering society would work themselves towards one gender. The idea being genetic-engineers would want to make themselves easier to engineer, and want to have maximum freedom. But "Sweet" is held at a time when that kind of stuff must be further down the line. I pushed the believably with Venusians enough as was, actually having to resort to "creative-freedom" once or twice. 

Sevens though, I'm very proud of. They address a lot of complaints I've had over the years. The existence of XXy as effectively a 3rd gender seems a fact politicians are unaware. I loved the lymphatic system when I studied A&P and wanted to use it, and I can't stand how Angels and Succubi are never anatomically feasible. Sevens let me put all these torments to rest.