nature vs nuture

All Xavier's interesting posts on evolution over on About Town has got me thinking about a debate we had in the Best Paper I Ever Took back in 1998. It was a bio anthro special topic with Vince Sarich (whose name I have no doubt spelt incorrectly) and really changed the way I think. Although he was as right wing as all get out, he respected a good argument and we had some very interesting discussions about all sorts of things, all stemming from his sometimes controversial views about evolution.

Anyway, the debate I've been thinking about ever since was one about that classic polymorphism, sickle cell anaemia, and Sarich posed the question - could anyone think of a meme equivalent, ie a polymorphic meme? He reckoned he posed this question all the time to classes and no one had ever come up with one.

One of the guys at the back of the class nervously suggested nature and nuture (Sarich was very cutting if he thought you were wrong, but it was nothing personal, just his manner). He explained himself well and I thought, wow, that sounds bang on! Sarich rubbished him, but the student stuck to his guns, and I have always remembered that and I still think the student was right.

For those unfamiliar with polymorphism, here's an explanation from an Australian HSC website:

Polymorphism is the presence of two or more distinct forms of a genetically
determined character. Humans are polymorphic for skin colour, body stature,
sickle-cell anaemia, blood groups and the epicanthic eye-fold. Polymorphic
differences occur as selective adaptations to different environments.

Let's look at sickle cell anaemia - the concept is that rather than the dominant (represented by a C) totally overuling the recessive (c), the two together (Cc) create a third form, distinct from the
CC and cc forms. In the case of sickle cell, the CC form results in normal shaped blood cells, while the cc form leads to sickle celled blood cells which generally mean an early death for those unlucky enough to be dealt those cards in the great genetic shuffle of life. But the Cc form gives a shape different from normal (but not enough to interfere with the function of the cells), and an advantage in regard to malaria.

If you think about this in terms of nature vs nuture, what the student was trying to say is that rather than one of tuther having to be dominant, as a theory to explain the personality of an individual, perhaps it is a mix, i.e. when you bring the nature (N) theory together with the nuture (n) approach, to give you Nn, you are right on the button.

I can't remember what Sarich's arguments against this were, whether he was a Nature or Nuture man. But I wish he had let the discussion develop some more.