>The original definition is indicative of chauvinism being a uniquely male trait

That's a bit of a distortion, I think. Seeing as how it was applied in a very narrow sense to overly patriotic "veterans of the Napoleonic Wars", that pretty much excludes women (without saying anything directly about them)! I'm not going to claim that sexism wasn't (or was) rampant at the time, but neither does this word, in the original sense, say anything about it. (IMHO)

>. I was unaware of the many other definitions you have given above, tsuwm (Carl Sagan - a chauvinist? Shurely not.) but perhaps the current meaning has evolved from the resurgence of the word through contemporary '60s/'70s literature.

Take another look at the OED citations if you get a chance. With these you can trace the evolution of the usage. I don't think you can make the case for any "resurgence".
Clearly, the move from the narrow, jingoistic sense to the broader usages follow. I think that the Carl Sagan usage was to the effect that people who expect aliens to have a humanoid appearance are being carbon-chauvinists! (see, there you go assuming I meant Carl was a sexist!! ;)