You can study whatever you want, I am questioning if you can be considered "expert" if you profoundly fail at the topic of your field.
In the end, those are 2 different domains. Knowing a certain theory and overcoming all the limitations of applying those are very different.
Let me give you another example: Formula 1 or MotoGP. The engineers are not driving the thing, and the drivers are not engineering it. Claiming that one needs to be able to be a master in the other is weird.
You are confusing the person with the field of study.
This confusion is more obvious if you think about the superconductor/ expert on superconduction example.
A superconductor is a material which conducts direct current with near zero resistance. You can test if something is a superconductor by aligator clipping a voltage source on it and measuring the resistance.
An expert on superconductors is a person who is knowledgeable about the phenomenon of superconduction. You can test if someone is such an expert by asking them questions about what materials are superconducting, under what circumstances they are, what phenomena can be observed during super conducting and etc etc.
If you get confused and clip the aligator clips on the expert you will measure a larger than zero resistance. If you start asking quiz questions from a superconductive material about superconductivity you will observe that it does not answer any of them.
These two things are fundamentally different. You can be good at one while miserably failing the other, or vice versa.
Similarly someone who studies evolutionary biology is someone who studies the effect of evolution on different kind of living things. They are good at predicting things which they can prove later either experimentally, or with observations about creatures and their circumstances. It has nothing to do with the act of procreation. A disembodied AI can be an expert at evolutionary biology as long as it has good theories on the topic which it can support with relevant evidence.
Through two practical examples. Someone who is good at surviving at evolutionary timescales is for example a person with a handfull of healthy, and fit children. Each of them carrying a mutation which makes their female offspring (daughters, grand-daughters and so on) have a tiny bit wider hips thus increasing their chances of having uncomplicated births, thus increasing the chances of having lots of lots of offspring a tiny bit.
Someone who is good at studying evolutionary biology for example might be able to explain why animals trapped on an island all over the world seem to change in a way that their offspring becomes smaller in stature.
Mixing up these two is as silly as measuring the resistance of your superconductivity experts.
"I have a doctorate, and equally important, 3 kids - that's how you know I am a real expert".
It means he sees the difference between a biological imperative and a moral imperative - who says he's "supposed" to pass on his genes? A strand of deoxyribonucleic acid? Is this judgement exhibited exclusively by proteins, or can a chunk of plastic also judge you for not knocking a girl up?
This to me sounds like a simple example of he understands the limitations of his work!
As for your evolutionary biologist friend. Being interested in evolutionary biology does not mean you are inherently someone that wants to be a parent. These are very very different things. Besides, evolutionary biology impacts more than just humans, it impacts every species. Being a parent comes with a great responsibility. Someone could just as easily be a really big fan of dogs, but not want one because of the responsibility or the costs, or similar.
If the economist weighs the risk to not put too much stock in these theories (no pun intended actually), why does he not likewise hesitate to teach these theories to his students? Like "I don't believe 100% that this is how the world works enough to bet my own money, but I am going to tell hundreds of students every year this is how the world works."
The biologist story is subtler. One could argue that failure to become a parent signals that you deeply, fundamentally, don't get biology - despite your superficial interest and theoretical knowledge? Like, you may talk about zygotes all day but you failed to make one...
Maybe the difference between economists and biologists vs financial advisors and engineers is that we expect the later to have skin in the game but for some reason allow the former to not have to.
Economics is complicated because at a fundamental level you're trying to understand people and their decisions. Sorry but you're really never going to "solve" that problem. Stuff will forever be a theory.
You are also assuming that the economist is teaching this and saying "this is how it works, it's 100% accurate" and not starting off with "this is a theory, and we work towards making it better over time with new data and new ideas." Just because something may not be 100% perfect does not mean you don't strive to improve what you have and you won't improve what you have if you just let it rot on the vine and not teach the next generation.
The biology one is even more convoluted. Having an _interest_ in something does not mean you have to "be" the interest. A simple example, I work to live, not live to work. I am not my work. My work is only here to support me living my life. You are claiming that the biologist is a failure because they didn't want, or couldn't, create offspring despite their interest being in evolutionary biology. That's some kind of weird argument to make there man...
Would you expect experts in criminal psychology to be serial killers?
But I see no relation whatsoever between expertise in evolutionary biology and the decision to have children.
> I don't believe 100% that this is how the world works enough to bet my own money, but I am going to tell hundreds of students every year this is how the world works
This is a fundamental misunderstanding of what a good professor does. If the economist acts in this way, they have failed as a teacher, not as an expert in economics. Likewise I think you have a fundamental misunderstanding of economics as a science - it's not one, and it sounds like the economist was making a quip at the predictive weakness of the field overall.
> The biologist story is subtler.
No, it's not. You're just having to push harder to keep it afloat.
> One could argue that failure to become a parent signals that you deeply, fundamentally, don't get biology
One would be wildly wrong to make that argument. Once again, I think this shows a deep lack of understanding on your part of the field itself and what it means to study a field. And also what it means to have a child as a human, honestly.
> economists and biologists vs financial advisors and engineers is that we expect the later to have skin in the game but for some reason allow the former to not have to
Is this not obvious? You're reaching very hard to dig at researchers in a way that indicates you don't know what research actually is. Or maybe you're defensive of the work you do? I shouldn't speculate too hard here or I risk also being this wrong.
This is complete and utter nonsense.
So farm animals understand biology better than the biologist does?
In the case of the evolutionary biologist, successful procreation does not require any knowledge of biology.
When it comes to planes, there is a high correlation between the quality of the plane and the quality of the design.
Maybe this is a good point. I would argue that a high school kid who knocks up his girlfriend has demonstrated a better intuitive grasp of biology than my PhD friend.
Not even a little. The high school students are slaves to unconscious drives in their bodies and that's not even related to having an understanding of biology. Or do you say that a world expert in biology who would rather spend their time furthering studies than raising a child actually knows less about biology than rabbits? Your arguments aren't making any sense.
A bacterium can perform cell division, but it can't explain it. The evolutionary biologist's job isn't to personally have sex, it's to explain what happens when many generations of organisms do so.
This sentiment was so elegantly expressed and struck a chord. Thank you for that.
"You do you" is the correct answer in almost every case. Evolution does not pre-select and deliberately make copies. It's a process where individuals do their thing and let the chips fall where they may. The process takes care of the rest.
I don't think they are wrong at all. That's what I would expect. In my experience, one of the marks of being an expert in a subject is being very aware of the limits of their knowledge and expertise in it.
the economist might not specialize in theories about why, when, or how much specific assets go up or down. even if he did, he might not have the skills to make actionable predictions from messy input data. doesn't mean his theories are wrong, just that someone else needs to bridge the gap between theory and application.
evolutionary biology has almost nothing to do with being a good parent. I don't think this even requires an explanation.
the financial advisor is the exact opposite. managing personal finances is the exact problem they are supposed to help you solve. if they can't do it for themselves, that's a pretty strong reason to doubt they can do it for you.
On top of that, it's not uncommon that experts understand the risks, unknowns and potential other choices better than early level practictioners.
I sat next to an Econ professor (at an Ivy) on a flight. I told him I had worked at a hedge fund, and he was like "wow, I could never put myself in a situation where my living depended on my economic theories being right."
A good friend of mine is a kinda-famous evolutionary biologist. He's in his mid-40s now, unmarried and doesn't have kids, and likely none on the horizon.
In the economist case, what does it mean that in his expert opinion, he wouldn't trust his own expert opinion! In the biologist case, what does it mean to be one of the world's leading experts on "evolutionary biology" and yet completely fail to pass your own genes?
What's most interesting to me is that neither of these scenarios strike us as "super wrong." I can imagine most people wouldn't hesitate to attend a class taught by either one of these guys, while we'd avoid analogous situations (eg: we wouldn't use a broke financial advisor or fly on an airplane whose designer refuses to set foot on it.) What's the difference?