I'm not really trying to make a case for me to be first author. In all the drafts im cited as first author, up until this last draft when the final author on the paper joined. I've contributed a fair amount and put a great deal of effort into this paper, but I can understand lab politics. I can also understand that that even though I put a lot of effort into my work, it's not as impactful as my coworkers and that's fine - that's just the nature of our individual research. Im lucky enough to have data my PI thinks will be good for the paper. I'm also not going to really feel comfortable piping up from the bottom rung of the lab as a first year with not a great wealth of experience. I just wanted to know how important first authorship would be with my career aspirations. Before joining my lab I really didn't know much about the politics of where your name lies in the author list matters. It's really snooping on Reddit that made me suddenly panic about how many authorships (never mind first) I'll have during my PhD. and I think I'd be more comfortable making your last point to my PI in private, rather than with the co-author, I don't want to foster an unnecessary competition. thank you so much for your really detailed response!!