kcsphil asked, [edited for typos by yours truly]
If the PI's don't keep current on lab techniques and then teach them to the grad students or post-docs, how do the PIs expect to get their science done? And what's the point in having them mentor the grad students or Post-docs if they have nothing to teach?
This question is really loaded with possibilities. I'm going to try to break it down in parts but I'm SURE the comments will pick up on anything I might miss.
1. If the PI's don't keep current on lab techniques
In general: they can't. They don't. "Current on lab techniques" to a PI is what they learn
a) at meetings, where they see data presented in a talk (that includes their own lab meetings)
b) from reading
c) in the ideal case, if they go on sabbatical.
"Current on lab techniques" to those of us in the trenches is
a) tried it
b) multiple ways
c) have seen all the things that can go wrong
d) know how to fix them.
2. how do the PIs expect to get their science done?
This makes me laugh.
The system right now is predicated on a hierarchy. All labs are different, but typically there are two types of lab members.
a) Senior members.
This includes the PI, lab managers who have been there more than a couple of years, grad students nearing the end of their PhD, and postdocs getting ready to leave.
The benefit of these people is that they serve as the 'institutional memory', if you will, of the lab.
The drawback is that they are usually very busy, often beyond the point of really learning the newest hottest techniques, and/or one foot out the door.
b) junior members.
That's you, new grad students and new postdocs. You don't know the history of the lab, and if you switched fields after your PhD, you might not know much about the history of the field (beyond what you've learned from your extensive reading!).
The old Apprenticeship model, upon which science is supposedly based, went something like this:
Master trains first Apprentice.
Apprentice becomes Journeyman.
Journeyman trains subsequent Apprentices.
Disputes and promotion decisions are resolved by the Master.
Only when the Master dies, or if a new position opens up in a faraway village, is the Journeyman promoted.
The main problem with this system, you understand, is that it is at least in part a game of telephone. In each round, some of the original information gets lost or distorted.
The main advantage of this system is the division of labor. The Master supervises. Because the 'team', as it were, has grown, production can increase.
3. And what's the point in having them mentor the grad students or Post-docs if they have nothing to teach?
As many of us have written before, it's not that PIs have nothing to teach. It's just that they're not really taught how to be good mentors and/or don't want to, and there is nothing in the system now that really forces them to.
Mentoring and teaching are different things.
Once upon a time, in a different era, PIs spent more time with their grad students. Labs were not so big; publishing was very slow before the internet; there were no such thing as postdocs.
The main incentive to mentor AND teach was to create Journeymen.
The quickest way to get an Apprentice to the Journeyman level is to teach them how to design, execute, troubleshoot and interpret experiments.
PIs had to do this themselves if they wanted their lab to be productive.
As the postdoc position became more prevalent, PIs were able to stay farther and farther away from the Apprentices.
Good PIs take their senior Journey-people under their wing and help them learn how to write papers and grants, polish their talks, mediate collaborations and reagent requests, and help them figure out their next career step(s).
That's the kind of mentoring we're typically talking about. Career mentoring, which is really one step up from the actual day-to-day of getting experiments to work.
But essentially this means that Journeymen (postdocs) are the ones who are teaching the Apprentices (grad students) how to design, execute, troubleshoot, and interpret their experiments. It's not that the Master is not involved. In some labs, they are. But in most labs I've seen, the Master makes a 'suggestion' and the Apprentice makes a beeline for the Journeyman who has actually used that technique, to ask whether to do it and how. Some Masters know this, some do not.
Masters are often too busy to notice. There is plenty for PIs to do because the operations are much bigger now than they used to be. Grants are harder to get, and papers are harder to publish. Projects are bigger, longer, and way more expensive than they used to be. And it's all a lot more competitive than it once was.
Unfortunately, Journey-people are not rewarded for mentoring Apprentices. Many of us do it, generosity of spirit, mostly (or if we're lucky, for middle-authorship and brownie points with the Master). In the long run, we gain experience. So when we have our own labs (if), we will be able to mentor our first Apprentices until we can get some Journey-people of our own.
PIs are typically good mentors if
a) they like helping people or doing experiments (in which case they might suck at getting funding because they're not spending enough time writing grants or papers)
b) they don't want to be embarrassed at their students' committee meetings
c) they don't have postdocs to pick up the slack
But as you'll note,
(a) is dangerous and rare simply by natural selection;
(b) is not much of an incentive because grad students are cheap and plentiful, easily replaced, so the strategy is more of a screening than a cultivation;
(c) is rare in the current climate because postdocs are cheap, plentiful, productive, and terrified of demanding even the most basic maintenance level of mentoring.
There is the extremely rare case where the PIs is wildly successful AND a good mentor because they just like helping people.
But my strong impression is that in MOST of those cases, behind the scenes the postdocs are actually writing large parts of the grants and otherwise doing significantly more work to keep the lab afloat than they're getting credit for, out of sheer survival instinct.
You might think you're joining a lab to work with the (famous) Master. But it's not about the destination. It's about the Journey.