If you're talking about which planet was colonized first, I believe that in both it is the planet in the Centauri system. In EV it's called Landfall, and in EVO it's called First Centauri.
However, I don't think that the two games are supposed to be connected. In EV it says that one of the alien battlecruisers escaped, and then it reappears. It's a reasonable assumption that most of the alien battlecruisers were similar in capabilities, if not the same. So if EV is actually set in the same universe as EVO, then the battles referred to in EV cannot be against any of the races from EVO because no one is even near that technology. Plus the vast majority of systems are different. So unless humans changed the names of the systems for some reason, there is no connection.
I have always assumed there was no connection between the universes, in the same way that I would not assume there was a connection between the E3 universe of Frozen Heart and the universe of EVO.
Paradigm
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