Orac, someone I read for his tirades against quack medicine (And for his interesting comments on cancer research) poses an interesting conundrum, though not a fresh one: Let's say you got sucked back in time, 500 years if you're in Europe, 300 if you're in a colonized area. You have nothing but the shirt on your back, your shoes on your feet. How well could you do? How well could you do at your modern job?
That's an interesting thought experiment, for sure. I'm interpreting it as me having the survival basics for Alaska: My jacket, boots, hat, and a pair of car-hart bibs. It doesn't matter much if I get sucked back 500 or 300, since this part of Alaska is pretty much the same either way.
On the basics, I could probably do slightly better than average. The biggest problem would be language, since this is Athabascan turf ca. 300 years ago. I don't speak a lick of it, so I'd head down river as soon as I could. I'd be better if I could come in winter, when I could trap. I'm spoilt by rifles, but I can make improvised traps with the middle-est of them! I could also catch a moose, which would give me a leg up on dozens of things. You just funnel them into a spot, and snare their leg or head. It's deadly effective (and not illegal 300 years ago). I even know how to make the hang-man's variant.
Summer I'd have a rougher go. I know enough wild edibles, but I couldn't get fresh game. Fish, maybe, but I don't know how to make my own fishing gear from scratch. I'd manage to make it to winter, before I really came into my own and could be reasonably fed. Either way, after that first winter, I'm golden. I can make a boat (I know how to build a Kayak from naught, even without power tools), and down river I go. It's worth noting that Yup'ik I speak, and Yup'ik spoken 300-500 years ago would be very different. It's like going back to Edwardian times, in English - words change, grammar drifts, and inflection tweaks over time. However, I'd do better with it than I would do with my lack of Athabascan! Down river, I could at least trade for tools I need, or knowledge of how to make said tools. Sure, everyone can hunt and trap in those days, but extra food or skins are always worth something. All and all, I could scrape along, until I learn to hunt and fish without modern tools.
With the latter point - how well could I recreate my job? Well, to begin with, beyond knowledge everyone of that day already has (where/when animals are), most of my field would be bum useless. Carrying Capacity? The relatedness of beavers? Evolution? Although all that knowledge has modern, practical applications, in the Qasgiq 500 years ago, it's useless beyond pure knowledge. If I was in Europe, I could recreate electricity, introduce pasteurization. Germ theory would be handy. Here, there's no native metal beyond some gold, and gold is pretty useless until you get into advanced metallurgy. I could make glass (it'd take a while), and maybe help some people with a crude monocle, but a microscope and showing germs would be... well, useless. Except. Except for one thing, which is anti-biotics. See, Penicillin sp. looks pretty characteristic. It's like a hand waving to you. I could isolate at least one antibiotic. This would make me very, very popular. Even if I couldn't produce oral forms (which takes a lot of preparation, IIRC).
If I wound up in Europe, I could write extensively. My ability to read and write would make me very valuable - heck, even 1700s it's a rare skill. I could ply that for a job. Not so much in the lower Yukon. I could leave notes on papyrus, but no one could ever read them (unless I taught folks how to read, which is a useless skill until late 1800s when English material shows up). But I could leave notes on natural selection, descent with modification, how genetics work in broad strokes. The composition of cells, and the use of DNA. The existence of cells, period. Basic sanitation. Making a prism would require finer glass working than I could do on the lower Yukon, but if in Europe, I could prove light is made of multiple colours.
The bulk of my chemistry would be bum useless, since I wouldn't have chemical extracts. My knowledge of spectography would be useless. I do know how to isolate phosphorus, though. With some fooling around, I could probably get it on a stick, and make matches. Fish wheels aren't complicated. I'd need to take material with me from the Fairbanks region (They're wood intensive, and I want big logs), but the ability to make one would make me popular, too. CPR. Heimlich maneuver. Both vaguely useful.
So, I think I would do all right, but the bulk of my biology knowledge requires advanced tools to exploit. Most of what is useful is my medical, physical and chemical knowledge (in that order). I'm just in a rotten place for time travelling and setting up shop as a biologist. If I really wanted to do that, London is the place for me to be. Amusingly, I'd be a better general doctor than biologist. London, or 300 years ago, Boston. Survival, I could do in Alaska, though I'd never be a Nukalpiaq by 300 or 500 years ago's standards. Snow machines and guns have made us all today lazy.
So, I suppose I'll pass this on: How well could you re-create your job 300 or 500 years in the same place? How well could you survive?