Do complex life-forms in this universe automatically develop a pair of eyes?

Our eyes only operate in the human visual spectrum of infrared to ultra violet/

If we took a hypothetically long movie film reel unravel it for 2 500 miles to include the whole electromagnetic spectrum, the human visual spectrum would not take up one frame of this long reel

I do not agree with your assertion that, "Evolution is indeed not in the business of philosophical explanation." Evolutionary explanation shows us about the nature of the universe and "god" if your believe in such a concept - how is this irrelevant to philosophy? What has been "lost"? Religion?

The implications of secularism and naturalistic understanding is not that far-fetched - society should reflect order without religious affiliation or prejudice and that knowledge must be verifiable and observable. We can observe micro-evolution and have evidence of DNA and fossil records suggesting gradual diversification through mutation and the transmission methods that allows for speciation. The nature of life and the systems directing such are known. Because we do not know something, in this case the origin of the universe, we could reach for a metaphysical understanding but it does not make it correct or reality - it is merely postulation. If you can prove it, science will adopt it. Spirituality will always exist in some form.

- Minimal.

"Religion" is one word with many and diverse meanings. It ranges from tribal fetishism and animal sacrifice through to state religions and global institutions, through to esoteric spirituality and the world wisdom traditions, and a huge range of other phenomena too numerous and diverse to summarize.

My view is that evolutionary naturalism subordinates philosophy and the religious impulse itself to biology. The Origin of Species declares that the emergence of H Sapiens can be fully explained in accordance with the following principles:

1. Growth with reproduction
   
2. Inheritance
   
3. Variability
   
4. A Ratio of Increase, leading to a struggle for life
   
5. Divergence of Character, leading to the Extinction of less improved forms
   

The Origin further states that 'from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows.' Whether this actually declares that our intellectual and spiritual powers are entirely attributable to these laws and causes is, perhaps, open to debate, but I am pretty sure that most secular philosophy nowadays would declare that they are. From this arises the disciplines of evolutionary psychology and various other forms of Darwinian rationalism which propose to adopt the Darwinian principles as the only permissible principles in terms of which the development of the human species can be explained. This includes the implicit project of secularization which is to declare any religious impulse as a mechanism by which the selfish gene ensures its own survival through cunning disguised as altruism, and so on.

In effect, Darwinism and natural philosophy has replaced God, or at least the traditional religious cosmology in the modern age. This will be vigorously disputed by its proponents, who claim that their particular discipline is 'purely scientific' and subject to empirical verification, which of course no religious account of human origins ever could be (or should be). But I am skeptical that the principles as currently understood are sufficiently specific to be subject to complete observational verification. There might be principles at work in evolution, other than those which the Darwinian theory proposes. There might be teleological principles involved in the evolution of life, as pre-modern philosophy has always maintained. These would be very difficult principles to confirm or refute by scientific means, especially as they are the kind of thing which the current dogma has anathematized.

Religious philosophies of various kinds fulfill a far greater range of functions than simply serving up creationist propoganda in the American public school system. Fundamentalist creationism is in any case a completely debased form of religion. Mankind, an intelligent species, is confronted by the stark realization of his own mortality, and the fact that beyond the circle of influence within which he lives, and which he is able to expand through the application of science, the Universe is a hostile and often chaotic place, within which only death is certain and much suffering inevitable. In addition to all the things we can learn about, know about, and control, we always must reckon in the unknown, and the unknowable, which is actually an omnipresent reality, although generally suppressed from consciousness. This deeply-repressed awareness of our own mortality surfaces in modern society as a sense of lack, which in turn is sublimated to fuel the engine of unsustainable economic growth and profligate consumption by which we are eating ourselves to death and pushing the environment to ruin.

Even if the various traditional cosmologies had done no more than encode this existential situation in a symbolic or allegorical way that enable humans to at least believe that there was some overall purpose in all of this, and gave them a way to participate in this purpose, this in itself is something which should be appreciated, and which cannot simply be wished away or ignored. Current secular thinkers have very little appreciation of the real consequences of the abolition of religion which they advocate. I think Neitszche, Camus, and Sartre were far more perceptive about the real human situation in a universe devoid of creative intelligence than the current facile atheism of the consumer culture.

So, naturalism is not at all far fetched. It is perfectly reasonable, scientific, fashionable, and completely inadequate as the basis for a real philosophy of life, in my view.

---------- Post added 04-15-2010 at 11:05 PM ----------

Triablogue: The fear of religion

jeeprs, that was an insightful post and I will respond in further depth to it when I get time - need to sleep now.

However, before I bid adieu, I wish to ask of you - can you provide one substantiated metaphysical theory that is verifiable with regards to the genetic diversification and speciation of organisms on this planet? If there is no alternative theory bar this call for philosophical leeway and respect of spiritual endeavour, I think there is no discussion. Hearsay and appeals to respect of intellectual pursuit is no reason for the suspension of facts for maniacal and malevolent institutions. You can dislike the fundamentalism and purely factual nature of some scientific philosophy and preference metaphysical explanation and voodoo till your heat is content, just do not place it in this axiomatic and absolute authoritative position that many religious institutions have done in the past and present.

Evolutionary theory may vehemently reject metaphysical conjecture. However, why would a naturalistic explanation that accepts purely the physical and what is observable (that is phenomenal), accept that which transcends such parameters - the meta-physical? There is no evidence. Metaphysics is postulation and not reliant on factuality. Mechanisms are present and they are observed. Evolution gives us a fundamental bedrock to understand the nature of existence, our identity and contributes to the philosophical canon. Evolution provides a substantiated explanation for biological systems and this allows for philosophical discussion on "why" and "what this suggests" about the nature of the universe.

- Minimal.

These things operate at completely different levels of explanation. I think the entire tendency to rationalise or explain Deity with reference to 'his marvellous handiwork', which commenced in late medieval period, was fatally mistaken, and we are now reaping its fruits.

To me, the only purpose of any of the spiritual traditions is to bring about a fundamental change in your outlook on life. My 'theory of religion' is not that religion belongs to the childhood of man and should now be replaced by science. That is known as the 'Golden Bough' theory, called after a book on comparative religion by that name, by Sir James Frazer,which situates religion at essentially a primitive stage of human development. It is the implicit paradigm of nearly all scientifically-inclined thinkers when it comes to religion

But I don't believe that religion ever should have been understood as being in the business of literal explanation in the first place. It applies to a much more general, and much deeper, level of understanding. This is why it deals in myth and metaphor, in allegory and legend. It deals with the problems of existence and mortality on a completely different level to scientific theory. So I am completely uninterested in attempts by ID to 'prove' the existence of God.

My reading of the current cultural situation in the West is that Darwinian theory has been interpreted by many as being a replacement for the traditional cosmology, and even was by Darwin himself - there are many allusions to this in the Origin. And such an interpretation really makes sense if you think that the Biblical account was literally true, a view that was widely held in Western society at the time of Darwin's publications. So to put it very crudely, 'we used to believe it was all the work of God, now we understand that there are simply natural processes at work which may one day yield to scientific understanding'. But if the literalist interpretation of scripture is put to one side, then a different perspective on the scientific account may emerge also. In other words, much of the cultural impact of Darwinism itself originates from a particular, historically determined religious attitude, of which this theory appears to be a negation. It is for exactly this reason that I believe many scientifically-oriented thinkers have completely over-reached in the context of this debate. Darwinism, as a philosophy, has very much become defined by what it denies. A considerable amount of its philosophical speculation is based on the God that is not. It takes much of the preceding philosophical tradition, and tries to methodically eliminate the religious elements, which are now considered outmoded. This is how you end up with the 'protestant atheism' of a Richard Dawkins (whom, incidentally, I most admire as a science writer.) But the resulting hollowed-out and stuffed cadaver does not amount to a coherent philosophy.

Now these are obviously very weighty questions which one tries to summarize at one's peril. There have been many debates on the Forum about this, which is arguably the most significant question in practical philosophy today, in my view. It all comes down, in my mind, to the nature of intention. And my general view is that the Universe is intentional, so that does put me firmly in the religious (though not Christian) camp. But at the same time, I am agnostic in many of the particulars. I certainly don't subscribe to any kind of creationism and have never been attracted by the 'ID' school, although I don't think that their arguments can be dismissed nearly so easily as many here seem to think. But there are lot of extremely heavyweight books from neither the atheist nor creationist side to consider, for example:

Life's Solution: Inevitable Humans in a Lonely Universe - Simon Conway Morris

Why Us? How Science Re-discovered the Mystery of Ourselves - James le Fanu

Information Theory, Evolution and the Origin of Life - Hubert P. Yockey

The Anthropic Cosmological Principle - Barrow, Tipler, Wheeler

There is also a very interesting essay by Thomas Nagel called 'Evolutionary Naturalism and the Fear of Religion' which is published in a book of his essays called The Last Word.

The Conway Morris book, in particular, specifically addresses the question raised in the OP, in vast detail. He is professor of paleobiology at Cambridge.

I think our understanding of physics was completely revolutionized by relativity and quantum theory. I don't really see why the essentially 19th century outlook that underlies the 'neo-darwinian synthesis' ought not to be subject to a comparable revolution. I think one reason it appears to be so successful is that there is this subconscious awareness of the biblical literalism we think it replaced - it sure is a lot better than that. But I really think the whole paradigm of the Selfish Gene changing through random mutation and subject only to natural selection, is under a lot of strain. The le Fanu book is good on those points.

Anyway there's a lot of material the think about and consider. You're obviously a highly intelligent and very careful thinker. At this point in time, all I would say is 'keep an open mind'.

Circumstances on their planet could be different, so that having two eyes (or eyes at all) is not that much of an evolutionary advantage. Maybe for some reason vision is not very good on their planet (it is dark or cloudy), in that case they would maybe navigate the world like bats.

What are eyes ? If there was insufficient light then they may evolve to receive other wavelengths but could still be classified as eyes. The question must also be asked if there was insufficient light would life evolve at all? No life, no eyes.

I don't personally believe in other lifeforms on distant planets. However, those inhabitants of exoplanets could have sensory organs that detect any wavelength of electromagnetic radiation. Or their eyes could be merely sound detection or vibration.

How can you be so certain about the inability of life?

I agree that eyes probably have to be defined as organs for the processing of light information, any light wave.

There is some speculation about life on the moon, Europa, beneath an ice cap, where I doubt there is any available light.

We have creatures living in the depths of the sea, beyond the reach of light, now I'm wondering if they are eyeless, more research.

Some animals living in caves no longer have functioning eyes, they are de-evolving eyes, but still retain non functioning eyes.

I don't think worms have any eyes.

I checked, The life forms around undersea vents do not need sunlight to survive.

I presumed we were talking about the evolution of life and eyes being a necessity to evolve. Basic life that has no eyes and interacts with its environment through chemical contact, will not evolve without that ability to see, surely?

Not sure I understand. Are you saying that evolving from basic life form to complex life form requires ability to see?

I'm not too sure of the criteria for complex life, are worms basic or complex? I mean earthworms types.

Is complex life more than just multi-cellular?

If worms had eyes they would have evolved up the ladder of success. I cant see them evolving into more complex creatures with out the ability to see.

That sounds reasonable. They do have some sensitivity to light.
It's hard, impossible, to find a good example of anything intermediary to compare to here on earth.
Even deepsea creatures ,that don't use them,have eyes.

Im no expert , I don't know of any that appear to be developing eyes. Interesting subject though. thanks xris.

Yes there is, and we needn't go to another planet for examples of why some don't; and this discussion's example of the worm is a fine example.

The way I understand it, developing any anatomical trait on a large scale only happens when the presence of such (needs or sensitivities) enhances the organism's ability to survive. How eyes might do so for the earthworm (which needs no sight whatsoever to thrive) is beyond me. They thrive just fine as is and have no need for sight. Now, even if photonic sensitivity were to emerge (as a result of genetic change/drift/mutation or abnormality in the species), since it brings no survival-enhancing effect, there's no increased passing on (quantitatively).

I believe changes in the genome occur in virtually all species happen often (on a geologic scale), the ones which "stick" are only the ones which provide attributes which increase the chances of those characteristics being passed on. Advantages which might come as a result of light sensitivity (and subsequently, eyes) is no different.

... hoping I'm in the ballpark of the discussion's direction. And I'm still lamenting the loss of a tail; that'd be so cool

A tail, give your emotions away and knock the wine glass of the table without intending to ?:bigsmile:

Simon Conway Morris is an evolutionary biologist who has written a lot on 'convergent evolution', saying (for example) that eyes developed a number of times via different evolutionary pathways, as did photosynthesis.

Aliens are likely to look and behave like us - Telegraph

Incidentally, there has been a very interesting discovery concerning the genetics of the formation of eyes. There is a particular gene, which, if removed, results in the birth of an organism without eyes. But if scientists remove this gene from a fruit fly embryo, and replace it with the corresponding gene from a mouse, the fruit fly develops eyes. But it develops fruit-fly eyes, which are compound eyes, not mammalian-type eyes, which are built around a single lens. (1)

What this (and similar findings) does is cast serious doubt on the simple Dawkinsian-style idea of genes carrying specific instructions for the development of form (morphe) as atomic units of information. Instead the way the gene is 'expressed' is reliant upon the instructions of 'master genes' which will radically dictate the expression of the form.

(1)Nancy M. Bonini, Quang T. Bui, Gladys L. Gray-Board and John M. Warrick, "The Drosophila eyes absent gene directs ectopic eye formation in a pathway conserved between flies and vertebrates," Development (1997) 124, 4819-4826.

In my opinion, eyes would not be necessary for complex life forms - just look here on Earth, in caves. But what about life, say, deep in a gaseous planet (it might not be possible but let's assume it is). There would not be much light, but the gas would be so compact that hearing would be a much more accurate sense becuase other moving life forms and objects would displace more matter. Also, what about life forms deep in space (again, maybe not possible) that might use gravity to detect movement and size or maybe, magnetism. There are many more ways to detect things than radiative energy - it's just it's the most efficient way here on most places of Earth.

I believe that the universe is awash with life some of it so different in form compared to our reality, that we might not think they are real entities or maybe we are so remote from their dimension that we would overlook them as true living entities.

This is not too far fetched in light of the very strange life forms we see in the deepest abysses of our great oceans