Thursday, 10 September 2009

Meaning in biology

A tweet from Richard Dawkins:
"46% of our DNA was provided in the past by invading viruses, 1.5% from primate & animal ancestors."

led me to this piece* "Friendly viruses aided human evolution" in the Irish times. I find it fascinating the way in which life intermingles, and it is an example of why the 'tree of life' model is a misleading over-simplification.

But the specific thing I started to think about arose from things like the following:
The same is the case with HIV/Aids in humans. “HIV 1 is an acute retrovirus like the viruses in our genome,” says Ryan. “Even at its worst, we know that it is changing and selecting specific genotypes that it feels most comfortable with, while killing off others.
(My emphasis.) You get this anthropomorphism all the time, imbuing meaning and intentionality to things that are 'really' purely mechanistic. (It is in there in the phrase 'selfish gene'.) I'm sure the authors would mostly dismiss it as a figure of speech, a shorthand. But one thing I'm arguing with my layered ideas of information, is that at each layer boundary we see information/data acquire meaning. Thus high and low voltages mean 1s and 0s, a particular pattern of 1s and 0s mean the letter 'a' etc. The thing is, is the meaning I'm talking about here the same as semantic meaning? I think the usual response would be: no, it isn't. But I'm wondering, do the layers go all the way up (and down)? Is there a point where there is a qualitative change to semantics?

I think it relates to the age-old problem of how you get conscious thought through physical mechanisms - mind-matter dualism. I've no answers, of course, as ever, just flagging something of interest.

*John Holden reporting on the work of Frank Ryan. "Frank Ryan will be publishing his third paper on viral symbiosis in the Journal of the Royal Society of Medicine later this month".

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