P9070060.JPG Dinner: Pasta spek e piselli, Strudel di verdure e formaggio, Verdure al vapore, Insalata & Dessert

After an afternoon catching up on email (bar a brief walk to the harbour for pictures and to buy some water) we settled into an evening lecture by John Odling-Smee on Niche Construction a key concept in modern theories of evolution. John was also my companion at the Dinner which followed (although he sensibly avoided the Grappa) and a wide ranging conversation started at lunch continued through the evening. Towards the end, the moon thankfully duplicated its behaviour of the previous night and I managed to get one photograph which at least gives and impression of its beauty. Mind you I am now convinced I need a new camera, Mine is 4 years old and these days response time and low light capability have improved. The big question – Cannon or Nikon? Once made I am committed for life ….

Either way, back to niche construction. Its something I've known about for sometime, but I hadn't realised its importance, or the fascination of the detailed examples or the implications for human evolution in the short as well as the long term. John introduces the subject with the example of an earthworm. The burrowing of an earth worm produces a partially self constructed world, in which the earthworm suborns its environment to overcome a deficiency in its own makeup. Normally terrestrial animals have kidneys that retain water, fresh water animals get rid of it and marine animals get rid of salt. The earthworm is still hanging on to the kidney function of its aquatic ancestors, hence the need to use the soil to augment its poor digestive system.

There are several other examples. Ants that use formic acid to kill off all plants other than their host in Ant Gardens. In one study the Garden was over 800 years old, so we have ecological inheritance.Organisms also modify their environment, adaption is a two way street. In consequence we have reciprocal causation in which both natural selection and ecological inheritance are in play, the result of which is something called niche inheritance. 200909080630.jpg The first picture on the left shows the traditional view of evolution based on natural selection. This shows the traditional emphasis on genetic inheritance by individuals. 200909080634.jpg In contrast with that, if we add in the idea of Niche construction we end up with something more sophisticated as show on the right.

The implications for humans are major, as here we have cultural niche construction. The example give for this is the development of lactose intolerance in a single gene in human systems (-13.910*T in case you were interested). If we look at Neolithic DNA then the gene is not present, in the modern day those of us with pastoral ancestors can drink milk, those without cannot. Interestingly lactose tolerance increases as you moth further north. Give the absence in neolithic times its is pretty self-evident that a cultural development (diary farming) resulted in a change in our genes – ecological inheritance and natural selection co-evolved.

A lovely phrase now (origin not remembered) We are hastily made over apes. One reason for this is cultural niche construction, so Darwin wins out over Lamarck. Overall the idea increases the number of feedback loops in the system.

  1. Cultural niche construction alters human history, but does not alter our genes. Here we have tools, landscape alternation etc.
  2. Environmental change modifies natural selection, for example changes consequent on our use of fire.
  3. A variation of 2, but here the genetic changes underpin culture itself. This includes the brain, cognition, language etc.

Relevance to contemporary problems

Without life the Earth would have the same atmosphere as our neighbouring planets. In the cambrian period we see Ediagaran niche construction in which early plant forms modify the environment enabling the cambrian explosion. In turn that results on a Cambrian niche construction which enables the change seen in the Ordovician age and so on.

In effect niche construction modifies the carrying capacity of our environment, it can support more life. While standard evolution seeks this limit (K) as an exogenous variable, in niche construction it is also endogenous. Economists make similar assumptions.

Now to the interesting bit, the diagram to the left indicates the way in which we can use our cultureScreen shot 2009-09-08 at 07.00.23.pngNow to the interesting bit, the diagram to the left indicates the way in which we can use our culture. By focusing on markets as the sole regulatory mechanism we either create monopoly or the tragedy of the commons A wonderful closing side, with this simple, complex and critical phrase:

Non-rivalrous, low excludability setting (low competition) have significant positive feedback effects in ecosystems facilitating rapid expansion of diversity, they change the K value.

I doubt if there is any more important message around at the moment and one wonders if any economist will have the guts to take it up. The Grameen bank is an example and there are others, but the ideology of our current cultural niche may reduce rather than increase K with catastrophic consequences. As John says Biologists can't get through to main stream economists who are talking to Government.

An hour of discussion follows, many and varied in nature. I ask about political and ideological niches and if they impact genetics, the answer is we don't know enough, but that conversation carries on over dinner looking at US and European differences, education and many other subjects. I also suggest (and gain agreement) that during periods of uncertainty the boundary between metaphor and reality blurs. I'll pick up on that in a future blog.

So what is the IBM PC link? Well its an example of the earthworm, a fundamentally flawed product suborns its ecology to satisfy its deficiencies. A few more examples like that in the history of technology, and far to many in current political orthodoxy (Baners for example are lower than earthworms).

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