In the game, Mordin actually mentions that Salarians don't see much past 40 (Earth) years. However, if you look on the Mass Effect 2 website, they will have you believe that Mordin himself is 50 years-old... hmmmm
I think it's similar to the average age at which people die. These days the average age that people die at varies around 70-80 in modern countries with 60, 50 or less in less modern countries. It of course doesn't mean that people simply have to die at 70, as there are some that reach 90 and even 100 and go on.
For instance I believe that asari in the game live up to 1000 years, but it doesn't automatically mean that they live exactly that much. Some can die before 1000 other surpass it... at least in my opinion.
In our case - in our solar system - that's about 225-250 million years! I don't think I could stand to live that long!
I think the developers used Earth years because, for one, humans are playing it. Another is that whenever age comes out of a conversation, like with Mordin or other asari, they compare it to humans or to Shepard.
Plus, unrelated in the topic but related to Mass Effect, why do they speak in English? I always though that aliens speak off-worldly languages.
I've wondered about them all speaking Human English too. I mean in Mass Effect 1 we're told that the Human species is new to the "Mass relay" era - especially when they say the "First Contact War" with the Turians was only 25 years ago. So how can all the Galactic species speak Human English within 25 years (27, if you bring it to ME2 date)?
Not only that, but same species people talk Human English to each other too!! I mean, come on.. why would two Asari, two Krogan, two Turian, two Quarian speak Human English to each other?!
Please.. correct me if I'm wrong!
They use universal Translators, Although they only explain it in the book's.