A Reductionist Fallacy (in genetics)

No matter where you look in genetic science these days you will undoubtably run into this error. A new series on UK CH4 looking at the difference between Man and Animal is the latest in a growing list of genetic science blunders.

Let us examine the difference between a fish and a frog. Certainly we can sequence the DNA and look for differences. With a little knowledge of genetics we know that DNA is used to chemically code for proteins. Proteins are either the building blocks of cells, or the enzymes which direct the cells metabolism and even DNA replication. So differences in DNA will account for differences in the proteins of the cell and therefore differences in its building blocks and functioning. Thus in one sense it is sensible to say that the differences between a frog and a fish are the result of DNA.

However the problem lies in what we mean by Frog and Fish then. How did we know the difference before we did the DNA analysis? When a scientist takes specimens for analysis he carefully selects frogs and fish, puts the DNA in test tubes labelled frog and fish and looks for differences. When the differences are found he understands those differences in the light of the names on the test tubes. This is frog DNA, that is fish DNA. So he never really examines his initial decision that one is a frog and one is a fish. DNA analysis may underline that distinction, but where did it come from originally?

The reductionist fallacy is to think that once we have the building blocks we can ignore the structure they are building. We may have all the bricks that build a house, we may have all the mortar but it is useless unless it is all together in a real house. Indeed a pile of bricks and mortar IS useless until we understand it can make a house. Likewise the genetic differences between a frog and a fish ARE meaningless until we know they refer to a frog and a fish.

The great fears of a eugenics nation where people identify people according to their genes is only really founded on this misunderstanding. If I told you I have gene sequence CAAGTTGCAAAT, that is meaningless unless you are also told that it gives me blue eyes. If you find blue eyes attractive suddenly that sequence is worth something. But you can find out I've blue eyes just by looking at me! Any sequence so hidden you can't tell isn't a problem! (btw that's just 4 random proteins so won't code for anything). So all genetics can do is underline the already existing discrimination that humans express to one another. We already have CVs, interviews, psychometric tests, exams - so why not more? If we don't like it the focus of attention is on already existing society not science. Science it seems just gives society material to condense around, often showing up our weakest sides and its social undertanding and transformation we need. Positively, showing people their potential could help them find the best path through life also.

So where does the distinction between fish and frog come from? If we had never seen an animal before we might be more amazed by the fact that they move than superficial differences. Like when you see people of a particular race for the first time you only notice the general features that make them different from the ordinary, rather than individual differences. To the amateur many species of nematodes, annelids and insect larvae become grouped together as worms despite huge differences. The actual process of producing what we call "difference" depends upon the viewer then, especially the judgements behind "naming" things.

Is there a real world with real differences? How would you "distinguish" between a real world of real distinctions and an imaginary world of man-made distinctions? There is just the process of distinctions which clearly depend upon the judgements of an expert to make them. That people can agree on differences, that we can learn them and write them into books, that they are often unchanging for ages, that experts can emerge who are better than others is all part of the process. Whether that process can be reduced to building blocks (like a real independent world) is the frog and fish problem we were in the process of explaining so we can't go any down this path without a pointless loop.