Are we our bodies?

In a recent discussion on another blog somebody claimed that most people would not identify with their bodies but instead with their consciousness or (if they are inclined to give it a supernatural phrasing) with their souls*:

Alex, I can understand your perspective and there may be a considerable number who consider themselves “their whole body”, but I think most people have the conception that they are the consciousness that inhabits and wills the body.
The illusion of separateness from our body I think is rather strong. You may argue that this is just an illusion and you would be completely correct. But I would respond with the concept of soul which seems to be a popular concept throughout the world, not universal but something quite like it probably is for a majority of the human race. This concept suggests that there is a separate conscious entity that is distinct from the body. Why is this an almost universal concept, well the illusion the illusion that we are a separate homunculus is very strong. So I think those who support the idea of the self being defined as the part of the body/mind that is conscious and self aware have the stronger case.
Another thought experiment that will put this in better perspective. It we were able to perfectly record and make an exact copy of your nervous system and then simulate it in a sufficiently advanced computer-like device, I would argue that the simulation would have an experience and that experience could be labeled “you”. Conversely, If we used an extremely potent general anesthesia that precluded any awareness yet did no damage either to your brain or body would “you” still exist?

 I believe that both the assumption that most people consider themselves to be something immaterial living in the body and, to the degree that some people actually do believe that, the reasons for the belief are wrong.

Botany picture #134: Eucalyptus bicostata

Today I was lucky enough to join a tour of the Australian National Wildlife Collection, one of the country's premier biodiversity research collections. It is particularly renowned for its holdings of bird specimens and of frozen tissue that can be used for DNA extractions but it also features collections of mammal, lizard and amphibian specimens as well as bird eggs and nests.

Between the building and the car park stands this fine tree which a colleague identified as Eucalyptus bicostata (Myrtaceae).

And this is why I decided to post it: this species has the longest leaves of all Eucalypts. Quite impressive already but apparently they can get even longer.

Inevitability versus contingency in evolution

This third post on evolution will deal with the question of contingency. I will partly recycle, and partly expand upon, my recent comments at Larry Moran's blog.

The question here is this: If evolution had to start all over again, would it result in the same kinds of organisms or in very different ones? Because we cannot actually rerun evolution on this planet, it could also be rephrased as what we would expect life on other planets to look like, either very similar to that on Earth or totally different. But because we cannot see life from other planets either, for now all we have is informed speculation either way.

The discussion is often simplified as being about two sides. On one side are those who are convinced that life as it is currently developed on Earth is inevitable, either for some teleological or religious reason (with humans as a necessary aspect of divine purpose) or because of a strong confidence in the power of selection to force organisms into a few optimal shapes. On  the other are those who believe that life as it is currently developed on Earth is only one of a myriad of completely different and equally probable outcomes, either because that would make life on other worlds more interesting or because they stress the importance of random mutations and genetic drift over that of selection.

But it is obvious that there is really more of a gradient between two poles. Dividing the spectrum into four more or less arbitrary sections, we could imagine the following positions:

Botany picture #133: Tetragonia implexicoma

Tetragonia implexicoma (Aizoaceae), Tasmania, 2013. Better known from their stunning representatives in the deserts of southwestern Africa, the succulent Aizoaceae family also has a few native species on this continent, such as the one above. Like Actites megalocarpa, it is a dune stabilizer, growing across them in dense mats of tangled stems.

... except under some very specific circumstances

In my previous post I argued that evolution does not, as a whole, have any direction or goal, but I qualified that with the claim that there are some circumstances when it does, and when it even makes sense to think in terms of better and worse or more primitive and more advanced solutions to an adaptive problem. So what would those be?

Botany picture #132: Trochocarpa gunnii

Trochocarpa gunnii (Ericaceae), Tasmania, 2013. A group of shrubs standing at the shore of Lake Burbury near Queenstown. The flowers are so small and somewhat hidden between the tangled branches that at first I assumed the plants were not in bloom.

Evolution does not have direction...

After the post spent harrumphing about scala naturae thinking, I should perhaps follow up a bit to explain my understanding of evolution as it relates to questions of teleology and contingency. As so often, do not assume that evolutionary biology is my speciality, but as a phylogeneticist and systematist I cannot avoid having an opinion. Also, this is once more mainly meant to put my thoughts into a coherent form, but maybe somebody will find them helpful or controversial enough to notice.

I would like to make the following points:

1. As a whole, evolution does not have a direction or a goal. Teleological thinking is a severe misunderstanding of evolution. Consequently, there are generally no 'primitive' or 'advanced' species in biology. This one should not be particularly controversial among biologists but it is sometimes disputed among non-biologists.
2. But! There are a few special cases where I find it helpful and justified to think in terms of directionality and more primitive or more advanced solution to an adaptive problem. Again, in a few special cases only, under a set of very specific circumstances.
3. Finally, the question of inevitability versus contingency. There are those who argue that if the tape of history were rewound and played again, evolutionary history would unfold completely differently because every step is contingent on the ones that came before, and thus we would find completely different life forms in an alternate history or, for that matter, on different planets. On the other side there are those who argue that if the tape of history were rewound and played again, things would come out pretty much the same. I lean towards the latter position - to a degree.

Today, let's deal with the first point. I will expand on the other two later.