Yes, they are very welcome. I'm personally a big fan of getting as much different frameworks as possible represented on Code Review and we have no rules against exotic variants.
To address your concerns:
Some challenges are not fully language-agnostic, but require specific framework, such as biopython.
Many real-world problems are not language-agnostic in that sense. One of the first things a programmer should realize is one should always use the right tool for the job. Regardless of whether that tool turns out to be C++, JavaScript, COBOL, Grails or Python. If your tool needs a specific environment, so be it.
It can't hurt to explicitly state what frameworks/environments are required to run the code. In some cases it's even required. Don't forget a description of what problem your code solves is also very important.
Some challenges can't be tackled without a partial shift in focus: you have to think about the biological aspect of of the problem too.
While this is true for writing the code, don't be alarmed if the answers will not touch this specific problem. Answers on Code Review are allowed to be about any and all aspects of the code, regardless of their priority. Of course, answers giving you exactly what you need are preferred and are usually (or at least should be) higher scoring.
Code Review is not about what you want. It's about what you get.
If you still have doubts, take a look at the following tags. We don't discriminate based on language.
assembly vhdl tis-100 brainfuck lolcode unity3d cmake