Wednesday, December 06, 2006

Molecular biologists don't understand molecular biology, but Creationist engineers do?

Via Pharyngula I heard about these thoughts by a Creationist engineer musing on the contents of a molecular biology textbook (the link is to All-Too-Common Dissent, a pro science blog written by a scientist, where you can find the link to the original Creationist post):

"My hypothesis is that the field of molecular biology is simply not understood by the majority of biologists and thus pretty secure from rational debate by laymen. By claiming that this discipline (which they probably don't understand either) proves Darwinism and that Darwinism is vital to understanding molecular biology, the Creationists can be silenced, humiliated and put in their place by simply invoking superior knowledge. More malpractice?"

And there's this gem:

"It [this molecular biology textbook the guy was looking at] has a considerable Physical Chemistry and Organic Chemistry component which would make it intimidating for the large majority of biologists, but this subject is really foundational to understanding the molecular foundations of genetics"

Eh? The field of molecular biology is not understood by the people who are actually doing professional research on the subject, but it is understood by a fundamentalist Christian engineer?

So biologists don't know enough math, chemistry and physics to understand what they're doing? I hear comments like this every so often, like the guy who told me that his chemist friend doesn't consider biochemists real chemists. Another example is the first comment to the All-To-Common Dissent post where one guy says this:

"I'm an engineer but also did biology at university for one year. Let me say that the math and physics done at the university level by biology students nowhere approaches real math or physics; it's barely beyond grade 12 level. That said, the only biology you get in engineering is a few things about bacteria when it came to municipal water engineering, so not a whole lot, and certainly less than what biologists got in math and physics."

One year of freshman biology does not really give you an idea of the kind of quantitative training biologists get. I definitely think that biologists these days need more quantitative training to deal with some of today's most exciting research questions (and the educational trend is going in that direction). However, as Scott showed in the original post on All-To-Common Dissent, undergraduate biology curricula require plenty of math, physics, and chemistry - enough to truly grasp molecular biology as well as it's understood today, and usually much more chemistry than engineers are required to learn (chemical engineers excepted of course).

Biochemists get serious chemistry training - as an undergraduate, I had 5 semesters of chemistry (plus labs) before I took a year's worth of biochemistry; I also had 4 semesters of physics, including a class on quantum mechanics where we practiced solving the Schroedinger equation (admittedly just the easier time-independent form). Most biochemistry programs require 1-2 semsters of physical chemistry as well (I didn't major in biochem, so I didn't take p-chem). Anyone who has taken an upper-level undergrad course in physiology can vouch for the quantitative nature of that field. (The course I took involved more math than was in my chemistry classes.)

It's true that biologists generally don't go beyond two semesters of calculus and maybe introductory linear algebra, but frankly you don't need more than that to be a successful molecular biologist who understands the field. (Also, most of us learn much of our math in physics and chemistry courses, not math courses.)

At the graduate level, almost all programs require anyone in biology to take a graduate-level biochemistry course, which involves a lot of homework problems dealing with kinetics and thermodynamics (physical chemistry) and enzyme reaction mechanisms (electron-pushing organic chemistry) - maybe intimidating, as the Creationist engineer claims, but the fact is, all of us biology PhDs had to take and pass it.

And I'm not even getting into genetics, which has its own quantitative foundation.

Engineers and physicists like to pretend that biologists stop their quantitative training as soon as they finish high school. As we've seen, that's not true, but there is another important point - nobody, not even engineers and physicists, has really figured out (yet - I'm still hopeful) how to effectively, compellingly, use more sophisticated math to produce a deeper understanding of biology. Computer scientists and statisticians have contributed a lot to genome sequence analysis, but we have not yet produced very predictive theories or models of cellular behavior that are rooted in the physical behavior of the components of the cell. That may require more math than what biologists are using now. However I doubt that biology (or engineering, for that matter) will ever require the kind of math used by today's theoretical physicists. For the time being, most biologsts know enough math and chemistry to understand the discipline they work in.


Larry Moran said...

The real problem is that biology is much more difficult than math and physics because living things evolved.

You won't find too many engineers or physicists who will admit to this. On the other hand you also won't find too many physicists or engineers who have made a solid contribution to biology.

Unknown said...

And Physicists who have made big contributions (like Delbruck and Crick) really became biologists - they learned how to identify and address key biological questions, rather than just awkwardly and superficially superimposing their physics expertise onto some ill-defined or irrelevant problem.

This is a nice quote on the difficulty of quantitatively describing complex systems, from a statistical mechanics textbook:

"Indeed, even if the interactions between individual particles are rather simple, the sheer complexity arising from the interaction of a large number of them can often give rise to quite unexpected qualitative features in the behavior of a system. It may require very deep analysis to predict the occurrence of these features from a knowledge of individual particles. For example, it is a striking fact, and one which is difficult to understand in microscopic detail, that simple atoms forming a gas can condense abruptly to form a liquid with very different properties. It is a fantastically more difficult task to attain an understanding of how an assembly of certain kinds of molecules can lead to a system capable of biological growth and reproduction."

(Reif, Fundamentals of Statistical and Thermal Physics, p. 2)