[Godstud]

This sums it up completely.

[Paradigm]

So are you willing to believe that the physical form of the human body - which you have just conceded is not the image of God - might have taken its present form through a long process of evolution and adaptation by natural selection? After all, the morphological similarities between the human body and the bodies of the other higher mammals, particularly the great apes, are difficult to explain otherwise, wouldn't you agree?

I once heard that prior to Darwin, there was a Platonic theory explaining these kinds of morphological similarities in nature as a result of the emanations from ideal forms.

[Potemkin]

I once heard that prior to Darwin, there was a Platonic theory explaining these kinds of morphological similarities in nature as a result of the emanations from ideal forms.

In fact, the (neo-)Platonic concept of emanations from the pleroma is startlingly similar to the Darwinian theory of evolution by natural selection. The basic difference is that the neo-Platonists could only conceive of these emanations as being a descent from higher forms to lower forms, whereas Darwinian evolution postulates a gradual development from lower forms to higher. This meant that the neo-Platonists could not utilise their insight into the morphological similarities between humans and the higher animals into a properly scientific theory which could explain why these similarities exist. In a sense, Darwinian evolution is actually the neo-Platonic theory of emanations "turned right-way up", just as Marxist dialectical materialism is the Hegelian dialectic "turned right-way up".

[Frollein]

The whole concept of "higher" and "lower" lifeforms is anthropocentric and therefore unscientific.

[Potemkin]

The whole concept of "higher" and "lower" lifeforms is anthropocentric and therefore unscientific.

Good point, Frollein. After all, the humble earthworm is just as highly evolved as any human being. Nevertheless, we can speak of organisms which are less highly evolved, and those which are more highly evolved, in the sense of better adapted to their environment. For example, the first amphibians were not highly evolved - their legs were splayed and therefore energetically inefficient for locomotion on dry land, whereas their descendants evolved legs which are energetically more efficient. And so on. And the general trend over evolutionary time appears to favour encephalisation, which appears to allow the organism to adapt to its changing environment much more quickly and efficiently than by genetic adaptation by natural selection. It is in this restricted sense that we can (very loosely) talk about life evolving from 'lower' to 'higher' forms, in my opinion.

[mikema63]

In a very loose sense I suppose that's true, but only in animals. Even then it's perfectly possible to become less intelligent over evolutionary time. Growing and maintaining such a large and complex brain is a huge energy and time investment that puts us at a disadvantage. It's actually a testament to our luck more than anything that our intelligent ancestors survived long enough to develop language and really take off.

[Frollein]

Nevertheless, we can speak of organisms which are less highly evolved, and those which are more highly evolved, in the sense of better adapted to their environment.

Ah, but which one is evolved more highly - the one that is most perfectly adapted to its niche environment, or the one that is less specialized, but can live almost everywhere? Which one is better adapted?

[mikema63]

Well, from an extinction event standpoint the less specialized one. Anything to specialized will die out when their environment is disturbed.

That's largely the reason Rats and cockroaches have spread everywhere but every time we build a road we kill some weird species of beetle or something.

[Frollein]

And who's the higher lifeform then, the rat or the cockroach?

[Potemkin]

And who's the higher lifeform then, the rat or the cockroach?

Far be it from me to suggest that there is any teleology at work in the evolutionary process, but it does indeed seem to me that the overall evolutionary process has moved from a point of low complexity (e.g., single-celled prokaryotic organisms) to increasing complexity (e.g., metazoans with complex nervous systems). We can think of this as being merely a process of expanding into the space of possible ecological niches, rather like a gas expanding to fill the available space. No teleology is required to explain this. When I talk about 'higher' or 'lower' lifeforms, I am speaking loosely, of course. Nevertheless, even biologists use such language.

[Rich]

The whole concept of "higher" and "lower" lifeforms is anthropocentric and therefore unscientific.

No it is a measure of organismic and systemic complexity, and therefore reasonably objective. Modern society is a higher form than a hundred years ago because it is more complex, and a hundred years ago society was more complex than a hundred years before that. An ape is more complex than a reptile.

However complex systems are more vulnerable than less complex ones. The humble Cock Roach may well outlive us humans.

[mikema63]

Rice is more molecularly complex than human beings, having about 10 times more genes than we do.

We simply don't think that that sort of complexity matters, but that is entirely subjective.

[Ummon]

Good point, Frollein. After all, the humble earthworm is just as highly evolved as any human being. Nevertheless, we can speak of organisms which are less highly evolved, and those which are more highly evolved, in the sense of better adapted to their environment. For example, the first amphibians were not highly evolved - their legs were splayed and therefore energetically inefficient for locomotion on dry land, whereas their descendants evolved legs which are energetically more efficient. And so on. And the general trend over evolutionary time appears to favour encephalisation, which appears to allow the organism to adapt to its changing environment much more quickly and efficiently than by genetic adaptation by natural selection. It is in this restricted sense that we can (very loosely) talk about life evolving from 'lower' to 'higher' forms, in my opinion.

You could describe them in terms of their informational complexity, but that wouldn't exactly equate to "higher" and "lower." HUmans have fewer genes than many animals that most would consider "lower" forms.

[Ummon]

Rice is more molecularly complex than human beings, having about 10 times more genes than we do.

We simply don't think that that sort of complexity matters, but that is entirely subjective.

There are arguments right now especially coming from computer science abou minimization/maximization of entropy being correlated with intelligence. It seems that both processes are to some degree involved. Max Ent perhaps gives you more code to work with while Min Ent perhaps is a measure of efficiency. There is probably some scale below which the energy necessary for "complex" intelligence can't exist, but as you go up in scale there are tradeoffs (perhaps in humans in terms of sustaining the chemical bonds necessary for much of our biological processes). Once we run up against these limits there seems to be more utility in having genes encode for arrays of proteins that may or may not be involved in similar processes allowing us to do more with less.