ANNOTATION:
Annotation

Here is how I propose to look at it:

1. One could state that there is no direction of evolution with regard to the increase of complexity of individual living organisms. Evolution leads mostly to equally complex, sometimes to less complex, and rarely to more complex living organisms.

2. Equal complexity is the rule: Evolution of bacteria leads to other bacterial species or other bacterial indivduals. Evolution of mammals usually leads to other mammals.

3. Evolution towards less complexity is often observed: Mitochondria can be considered as symbiontic bacteria which do not need to be as complex as the free living, more original bacteria, and indeed mitochondria are less complex. Similarly, many parasites are far less complex than their free living ancestors.

4. Evolution towards more complexity actually is statistically very unlikely. The first unicellular organisms, the origin of photosynthesis, the origin of the eukaryotic cell are only possible through long chains of unlikely events. However, since statistics is about large numbers and since evolution deals with large numbers of reproducing entities, very unlikely events may become very unlikely to unevitable. There is still another aspect about more complex organisms: they may conquer new niches, not occupied by any other organism. This is the empty niche which is always open to more complex organisms (multicellulars can feed on unicellulars, which could not feed on multicellulars. Only later, unicellulars could parasitize on multicellulars). Therefore, more complex forms should not be explained solely by the fact that they are more fit than their competitors, but especially because they always find empty niches with lots of possibilities before them. This is confirmed by the fact that we see such rapid radiations after new inventions: there is so much space, food, energy, ... available and no competition for it, that almost every concept at the new complexity level will work. Take pentaradial organisms: they represent a quite strange concept of bodily organisation, yet they exist and still are very successful (Echinodermates, like seastars etc.). Another possible confirmation of the importance of the empty niche in explaining how evolution towards more complex organisation is possible, comes from the observation that - soon after they came into existence - multicellular animals rapidly radiated into all presently known (and many already extincted) animal phyla. No new phyla arised thereafter, because very soon there was too much competition among the multicellulars. Once the niches were occupied, no new forms could arise. A similar example is maybe seen with new ways of thinking which initially lead to a rapid radiation of all possible kinds of new related ideas. Take as an example memetics in its current status of protoscience.

5. In summary, the first nucleotide encoded, cellular living organisms are still here and still crucial to any form of current life. From this complexity level onwards there is always evolution possible towards less or more complex forms of organisation. However, while less complex organisation is usually a special adaptation to some very specific niche (e.g. parasitism), the more complex forms of organisation will usually give raise to a multitude of other forms of life at this new level of complexity because of the high probability of encountering empty niches. One could say that evolution seems to be open ended towards more complexity. Once this new level of complexity is well established, high numbers of organisms exist, many new interactions have occurred (also with less complex organisms), all niches are occupied, and it becomes possible that the event of real innovation repeats itself, since at this moment highly unlikely events become almost unevitable (because of the law of numbers), giving raise to a next level of higher complexity.

6. Thus, although complexity of part of the individual systems has increased during evolution, this cannot be explained by the principle of fitness, but can be regarded at as the consequence of a 'higher order' principle.

We' better consider the process of life as a whole, instead of looking at individual subprocesses (organisms). Since evolution leads to more diversity of organisms - through multiplication of organisms in combination with mutation and recombination of the genetic code, the interactions between always more of always more diverse and possibly more complex organisms - which can be considered as the temporary subprocesses of the process of life - can possibly become more complex. The process of life becomes more complex and only now and then this leads to more complex subsystems, adding substantially to the complexity of life. Also remark that the methods of information exchange between the different organisms obviously become more diverse. From chemical interaction only at the cellular level, to additional interaction by sound and visual symbols at the animal level, to additional interaction by representative sounds (spoken words) by humans, to additional interaction by means of visual representative symbols (written words) by recent humans and science. Interaction by means of digitalized, electronically encoded information exchange between humans and computers is of course the most recent new development