This is a really interesting, and not easy question to answer. Not easy because it’s hard to predict, in my opinion. It depends somewhat on what and where you see yourself at the end of your grad school run. And it also depends on what’s “hot” out there in terms of science. I’m gonna go out on a limb here and just mention some cases I’ve seen happen through the years.
In a way science might be a bit like fashion, it has its seasons where certain things are super hot. Ten, probably 15 years ago PCR and yeast genetics were “da bomb.” Don’t get me wrong, because these techniques and organisms are important and are still key in today’s science. But 10-15 years ago it seemed as if everything people wanted to do was work on yeast and/or do PCR, that was their thesis and their life. Before that was DNA, before that hemoglobin … you see a pattern here. I’m not saying there’s anything wrong studying problems and solving them using yeast or PCR, but today it seems as if pharmacology, bioinformatics, neuroscience and some cell bio are the “it kids” in terms of topics and techniques tto do or know, thus today if you had your PhD in those topics you’d probably stand a better chance of finding a job and a project you like within your geographical area. I think (from what I’ve seen at job postings which I’ve been monitoring closely for the last year) that universities are actively recruiting in those areas. Now, will those areas will still be hot in 4-7 years, by the time you’ll be done if you were to start your PhD today? There’s no way to predict what will happen, but from experience, even though my topic and technique are highly valued and super interesting (and a rare gem in my opinion), they’re not in demand in the geographical areas where I’m interested in pursuing a long term career. So, this just serves to say that you need to consider your options carefully. Go to a lab where you not only enjoy the topic, and research, but also where you’ll be equipped with transferable skills in case you’re stuck in a situation like mine, or explore your geographical options and see what’s needed more and how you can train in those areas so that you (hopefully) stand a better chance of getting your desired job. I partly blame my choice of lab and topic for why I didn’t keep up with some of the “hot” techniques used in say … 75% of labs, and why I’m doing a postdoc where I’m doing it and in what I’m doing it. I want to get in contact with my cell bio and biochem side, so that my lack of knowledge will not impede my future success.
As always, leave a comment or send an email if you have any questions or want to talk about your experience and want some insight.