Fact and Fiction

Thoughts about a funny old world, and what is real, and what is not. Comments are welcome, but please keep them on topic.

Sunday, February 12, 2006

The end of the Darwinian interlude

Freeman Dyson has written a fascinating article in this week's New Scientist entitled Make me a hipporoo. The theme of the article is that Darwinian evolution is merely an interlude, that was preceded and will be be followed by a different style of evolution.

Darwinian evolution operates on species. Each species has its own set of genes that carry the biochemical processing "wisdom" that has been accumulated by that species. These genes are not shared between species, so tricks that are discovered by one species cannot be shared across different species, which means that there is a lot of reinvention going on.

An alternative type of evolution, that is akin to the sharing of open source software, occurs in systems where the interspecies boundaries are dissolved. Such a situation held before cells evolved to hold small packets of biochemical processing separately from the surrounding soup, and thus prevented the free sharing of tricks that were discovered by evolution. Free sharing leads to very rapid evolution, in the same way that open source software leads to rapid software development.

When the equipment to sequence genes and to synthesise genes becomes small and cheap, and when the knowledge of how to effectively operate this type of equipment becomes widespread, the boundaries between species will dissolve away. This will lead to the end of the Darwinian interlude. This has already occurred to a limited extent with the (sometimes controversial) transfer of useful genes between species that is currently done. This requires substantial resources to implement, and it is not yet what would be called a "table top" activity, but this limitation will not hold for much longer.

Freeman Dyson is very optimistic about the possibilities for the post-Darwinian era. I wish I could convince myself that he is right. As with all technologies there is the potential for good and bad applications. With nuclear weapons technology you can't produce a weapon in your garage without a lot of outside help, but with "table top" genetic engineering a single individual could conceivably cause havoc. The scenario in the book White Plague by Frank Herbert is a frightening realisation of what could happen.


At 1 March 2006 at 04:00, Blogger jj mollo said...

If you believe Susan Blackmore, and I do, we're already post-Darwinian and have been since memes took over. Freeman Dyson is an awesome individual. I've recently reread Ring World and been re-impressed by the imagination behind the idea. But I think he's worrying too much about this. As a former computer programmer I've had experience with trying to fix terrible multiply-patched software. We call it spaghetti code. Everything is so intricately wrapped together that it's very difficult to find a good place to make a fix.

Evolution takes whatever path it can without any sense of engineering. Things, like organs, become organized perforce over the eons, but never, I'm sure, in the way a human could relate to. We have been doing reasonably well with genetic analysis, but I expect we'll reach a point of diminishing returns. The problem is that if you engineer a change, there will be 5 other things that go wrong, and when you fix them, each will lead to another five problems exponentially expanding the problem. I think it's very easy to underestimate the vast quantity of "wisdom" that really is stored in the genome, and in tradition as well.

At 3 April 2006 at 23:36, Blogger Steve said...

Freeman Dyson invented the Dyson sphere, but Larry Niven invented the Niven ring that features in Ringworld, which is halfway between a Dyson sphere and a standard planet.

Your point about messing with spaghetti code is well-taken. When I was a young researcher I was forced to develop other people's code, and I hated it. Not only could I see that the code would be better if it was completely rewritten, but I also thought that I could improve the underlying theory anyway! The first was almost certainly true, and the second was probably youthful enthusiasm.

As for whether this is a fair analogy with genetic engineering, it is not clear to me that DNA has spaghetti code in it. Sure, we don't understand lots (most?) of it, and we use giveaway phrases like "junk DNA" to describe the bits we don't understand, but we do know that there is at least some level of modular "design", where evolution has reused good ideas, which are presumably compactly coded in DNA. Surely, this reuse of good ideas is the only way that evolution could have led to such organised complexity in the limited time available?

If the design is modular, rather than like spaghetti code, then it is more amenable to analysis. This is the scenario that I assume Freeman Dyson was writing about. However, I agree that this modular assumption is not guaranteed to be true.


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