The missing link?

[Formosus Viriustus]

I'm proud of both my parents, and I happen to be a second-generation atheist.

 

-- Nephele

And rightly so.

 

Sorry if I worded that somewhat unfortunately. I was certainly not trying to imply that atheists are more cowardly than religious people when it comes down to defending the things they think worthwhile. Only that you will not likely find much candidates for suicide missions in the name of atheism, while if it is in the name of religion, you are spoiled for choice.

 

BTW. It's a distinction few people will make, but while I do consider myself to be a materialist and a skeptic, I do not consider myself to be an atheist. I see no need for a supernatural reality and I have never seen the slightest proof of it. But absence of proof is not proof of absence. To me atheists are only those people who claim to have absolute certainty on the point. There are not all that many of those and I don't think either you or your parents fit that definition.

And indeed, it makes little sense to spend much time on questions to which there are no sensible answers anyway.

 

Now back to business.

 

F rmosus

[Formosus Viriustus]

But the main conclusion of this and many similar articles ("the latest fossil find is likely to ignite further the debate between evolutionists... and creationists)" is simply ludicrous; there has never been such kind of "debate". Science and faith play in different dimensions; period. This only shows the ignorance of the average media.

 

Well, they like nothing better, don't they ? At the very least they got some action going on internet discussion fora.

 

F rmosus

[Maladict]

Indeed, just doing our bit in the cycle

 

Edited May 22, 2009 by Maladict

[caldrail]

No good arguing with me on that point.

You know, Biology is not Philosophy; it's hard science.

If you don't know what evolution is, there's no way you can disguise it by circular argumentation.

 

 

What circular argument? Sylla, biology is defined as a science by convention, not some unalterable commandment. It was someones choice in previous times to determine the limits of what is or isn't part of the study of living creatures. Arguably, what is or isn't biological is a matter of philosophy. You seem to rely on labelling a great deal. You might find that the quality of an argument has little to do with the banner you display above it.

 

As it happens, I do know what evolution is and you cannot assume that you alone are the sole owner of all that is conventionally wise.

 

Well, you've chosen not to seek the second gold star. That's entirely up to you of course but I admit I'm disappointed. I'll now present the answer I was going to had you decided to expand on evolutionary erudition. I do apologise for the poor quality of the article as I hadn't the time to write anything more focused.

 

Looking Beyond Darwinian Selection

==========================

Natural Selection (Biol.). A theory of the mechanism of evolution which postulates the survival of the best-adapted forms, with the inheritance of those distinctive characteristics wherein their fitness lies, and which arise as small uncontrolled variations; it was first propounded by Charles Darwin, and is often referred to as Darwinism or the Darwinian Theory.

Chambers Dictionary of Science and Technology

 

The elegant logic of Darwins Theory of Natural Selection is impressive. He postulated that successful creatures would pass on their characterisitics to their young leading to diversity and specialisation of species. Unsuccessful creatures would naturally tend to die out.

 

An example of this is the emergence of speckled grey butterflies instead of the bright white one previously found. In the urban enviroments created by Man, the white butterfly has no camouflage and is targeted by birds, hence the speckled grey mutation becomes the survivor. This is survival of the fittest in a passive sense.

 

Perhaps two species of bird catch butterflies for food. The better hunter catches its prey easily, and reduces the chances of finding food for the other. Direct competition of this sort is survival of the fittest in an active sense.

 

In the same way that Newton was inspired to formulate his laws of physics, so Darwin was inspired by the natural world he observed in his fieldwork to find some reasoning for why animals seemd to fit their ecological niche. Darwin had no body of science to enlighten him about genetics. That science had yet to be discovered. Instead, he reasoned that small changes from one generation to the next were responsible for the drift in form. The reasoning is sound. Should a creature be unable to compete in it's enviroment, it dies and cannot pass on it's own charcteristics to another generation. The tendency to pass on 'superior' characterisitics would therefore mean that species would evolve slowly toward creatures better adapted for their enviroment.

 

His theory is by its very nature mechanistic. He proposed small changes because he observed nothing larger. Although his theory explained the variety of species in terms of random change and trial, the increment of evolution must therefore be of a very slow progression given that species tend to resemble others of their kind very closely. In Natural Selection, creatures are tested by their enviroment.

 

Enviromental Concerns

Darwin presents a somewhat simplistic picture of the evolution of species. He did so because whilst he may have been aware of changes in the enviroment from prehistoric times, he did not observe that the enviroment, be it local or global, continuously changes. His theory of Natural Selection assumes a static enviroment in which species compete.

 

Natural Selection has one essential proprty - the diversification of a species occurs over long periods of time. Under normal circumstances the change is hardly noticeable - indeed, that was the reason Darwin did not consider anything else - but modern insight and concern about enviromental issues has revealed something very important.

 

Even micro-changes in the enviroment can have a strong effect on species. Since under Natural Selection a species will tend to become more specialised, it also becomes more vulnerable to change. Arguably Natural Selection agrees with this, since the species regarded as fittest will obviously be another in different circumstances. With change, the more specialised species can no longer compete and the more generic species survive and diversify.

 

There is however an objection to this. Since the specialised species are the result of survival of the fittest, the less specialised are by definition less successful and therefore will tend to die out in competition. In other words, the diversity of the species within any enviroment is limited by the available ecological niches they can occupy.

 

Adaptive Concerns

Eyesight in human beings, or at least those born in the modern industrial societies, is getting worse. More and more people require corrective lenses. This is the Darwinistic side of things because more and more individuals are surviving to pass on poor eyesight where once this poor vision would impacted on their chances of survival.

 

With species that live in darkness, we see either of two things. Their eyes become large and very sensitive to whatever light is available, or vanish completely if there is none. Blind invertebrates are common species found in caves for instance. Under Darwinistic evolution, this was a process that happened by chance over an extended period. Since eyesight was no advantage in total darkness, successive generations had poorer vision until it declined completely.

 

There is something about this view that doesn't satisfy. Since there is no advantage whether the creature can see or not, then eyesight would persist if the creatures so blessed were successful. In other words, the eye remains whether used or not. But all too often, the eyes vanish altogether in blind species.

 

Some might argue that with the lack of one sense, the others compensate for. This doesn't mean the remaining senses are any keener, merely that the creature has no choice but to make better use of them. But even so, it seems peculiar that blind species evolve so readily in lightless conditions.

 

One suggestion is that the lack of stimulation reduces the genetic dominance of that feature. If so, then responsiveness is a factor in evolution as much as random drift. Faculties developing according to necessity and stimulus rather than mere coincidence and selection.

 

This concept has important ramifications. It would mean that a cheetah evolved to run at very fast speeds not only by the success of those ancestors who had longer legs, better lungs, and more flexible backbones, but by an implicit biological need. It does sound absurd, but the ability use limbs for walking soon vanishes in a species that takes to the water.

 

We have then the possibility that genetics is influenced indirectly by our enviroment, and that it developed in complexity to take advantage of it. Simply wishing our descendants to be faster will not produce athletes. The trend toward this biological impulse must be triggered by lifestyle. Arguably this is not the case, and we are merely discussing Darwinian selection, yet the small random shift in form over long periods of time does not in itself explain satisfactorily some of the dramatic shifts in evolution that have occured.

 

Predictive Concerns

The physical characteristics of living creatures are encoded in DNA and these complex chemical descriptions of species dictate the appearance, capability, and probably even behaviour to some degree. This is the science of Genetics, a field of study that did not exist in Darwins day.

 

Perhaps in one sense genetics provides us with the random changes required by Darwins theory. The combination of male and female genes results in characteristics passing on to the next generation. Now if Darwin is to be believed, the characteristics of creatures successful enough to consider procreation should emerge in the next generation. Unfortunately, the rules of genetics mean this isn't necessarily so.

 

Firstly, Darwin assumes that a single change is passed on. In other words, a 'changed' creaure with a superior characteristic would ordinarily mate with an ordinary specimen of standard form. In genetics, no creature is 'standard'. Although the individual may closely agree with another in appearance and capability, they are inherently unique, with dominant and recessive qualities that may be passed on.

 

In some respects, the natural world follows Darwinist principles. Social animals usually arrange for males to compete for mating rights, thus the dominant herd leader has the harem to himself, mating with the available females and passing on his own characterisitcs in preference to the lesser and somewhat frustrated males left out of the fun.

 

Nature sometimes uses this method to ensure that dominant characteristics persist. As we have already noted, it isn't 100% reliable. It is therefore, a method of creating an average new generation of persistent strength. Here already we see Darwinist theory as valid for consistent reproduction rather than the less predictable mixing of DNA found in nature.

 

Iterative Concerns

Genetics opens up another concern to laid against Darwinist theory. In Natural Selection the minute change he postulated in every generation was no more than speculation. Since individual specimens were very similar, Darwin conjectured that changes in every generation must be slight, and this is why Natural Selection is such a long term prospect.

 

In theory, the mix of characteristics allowed by genetics provides our small change, albeit less reliable than Darwins simplistic development from one generation to the next. What Darwin had not allowed for was the bigger change. The possibility of a mutation is ever present in genetics. Now this doesn't mean we need to stray into science fiction, but there will always a very small number of 'different' specimens in each generation.

 

Whereas Darwin wrote of slow gradual change, nature holds the possibility of rapid change in a short space of time. Indeed, human beings have latched onto this and for instance the selective breeding of dogs has produced over the last ten thousand years, (and the last thousand in particular) a plethora of breeds. Nature not only allows these bigger iterations but requires them for survival. In situations where the stimulus exists, these larger changes become dominant. Without this capacity for change, life would fail for one simple reason. Catastrophe.

 

Catastrophic Concerns

The stable enviroments of Darwins theory do not actually exist. We've already considered enviromental drift, but we must allow for the possibility of catastrophic change. The Earth is potentially a dangerous place. Powerful forces fed by internal tectonic movement and the volcanism it causes are known to have had far reaching effects. The Permian/Triassic Event is thought to have been largely due to a massive break-up of the Earths crust in Siberia, and whatever the cause the effect was a mass extinction of nearly all life on this planet.

 

The effects of cosmic forces are equally profound. The K/T Event which is often quoted as having killed the dinosaurs was caused by a meteorite strike in the Gulf of Mexico, and that of no great size compared to those the Earth experienced in its infancy.The survival of species in the aftermath of that event underline the concept of 'survival of the fittest'. Smaller creatures were able to hide from the worst excesses of the apocalyptic enviroment, as did those with thicker skins or those whose aquatic ability sheltered them from the effects. This doesn't mean the numbers survivng were large at all.

 

More consistently, the star that our planet orbits is responsible for periodic changes. The Sun varies the amount of heat, light, and other radiations over time. Our weather is driven by these forces and the interaction of the Earths composition has produced some startling changes in prehistory.

 

It was in fact due to one great change that life was able to develop at all. Very early on the Earth went through a 'snowball' phase, in which the planet suffered temperatures that froze it almost competely. When the thaw came, the availability of warm shallow water allowed complex life to evolve for the first time. These first creatures were very different from those we see now, and it's believed they were killed off by the second 'snowball' phase. The process repeated when the thaw finally arrived again and the resulting species eventually evolved into those we see around us.

 

Swift variations of temperature have been responsible for sweeping changes to the ecology of the northern hemisphere since the Ice Ages, and most of those within a few generations. The final thaw of eleven thousand years ago is usually mentioned as the most visible evidence of such catastrophe, but that ignores the sequence of warm and cold periods that took place within the ice ages.

 

Catastrophic changes then are not intrinsically survivable. Those species that are specialised in the former enviroments tend to die out very quickly, along with others simply unlucky enough to be in the wrong place at the wrong time.

 

The important issue here is recovery. Since the catastrophe has opened up a fresh ecology, there is a period of rapid evolution as soon as conditions are favourable. New, empty enviroments are filled with species that diversify by way of the 'big change' made possible by genetics.

 

It seems then that the iterative scale of change can vary according to enviromental pressure. As the ecology developes and stabilises, species might begin to conform and settle into what almost approaches stagnation. Survival of the fittest not only afflicts individual species, but entire ecologies as well. The stagnant population loses its sharp edge and finds it harder to compete against new arrivals. This is why isolated enviroments often produce the docile species.

 

That may be Darwinist, but the rapid evolution experienced in the fresh colonisation that follows shows us that genetic mutation is at it's most active when their are fewer pressures to seek out particular ecological niches. Because a species has found a niche and cannot utilise another without direct competition, the specimens that change the most are those exposed to the greatest competition and therefore those with a tougher time surviving. In other words, evolution responds to opportunity whereas competition suppresses it to a minimal level.

 

Behavioural Concerns

The concept of survival of the fittest must be extended beyond mere physical characteristics. Although having the right 'tools' for the job of survival, the manner in which the job of survival is carried out

 

Without doubt, the behaviour of a species directly affects its fitness. Aggressive species can ward off competition, and nervous species watch out for them. The development of social behaviour brings co-operation into the mix. Safety in numbers is a principle that many herbivores adopt. Some carnivorous species adopt a tactical approach to pick off individual members of such a group.

 

We run into an old debate here about instinct, learned behaviour, and intelligence. Instinct isn't really a behaviour pattern as such, but an urge toward it. Learned behaviour has been shown to be vital in the wild. Without parental guidance, many creatures find survival difficult if not impossible simply because they don't know how.

 

Rescue centers for wild animals often train them in survival techniques as a prelude to release into the wild, but sadly, the learned behaviour required for succesful adaption to the wild enviroment is often lacking, especially in the interaction with other members of their species.

 

Intelligence becomes a useful characteristic when all else is equal. It also seems to occur in species that have a hard time surviving, especially those linked to cold climates. The need to remember food and water sources, the need to co-ordinate survival, and even the need to find new ways of exploiting the enviroment are all stimuli to mental capacity.

 

How does this all diverge from Darwins theory? Behaviour is partially genetic, formed by the biological needs of the animal and available as instinct, or something gained from experience. The more complex the animal, the more it must learn to be the creature it is and how to survive. It isn't a system of small inherited changes, but very much something an animal has learned for itself, either by watching others or direct experience. Most importantly, even on a very basic level, an animal may make a decision, rational or impetuous, with the thought processes available to it. It does not neccesarily act on accumulated instinct as Darwinian theory would demand.

 

Technological Concerns

The arrival of genetic science has the potential of creating directed evolution. Already scientists are capable of cloning as Dolly the Sheep demonstrated. The science isn't perfect however, and whilst the possibility of making copies of individual animals is now possible, at this stage the genetic age of the clone is unchanged from its donor. Dolly was old when she was born.

 

The recent discovery of near-perfect frozen mammoth remains has brought the 'Jurassic Park' scenario a step closer. The recreation of extinct forms is something of a scientific novelty. Although we might potentially learn about primeval life, we must understand that these creatures will not have the benefit of being brought up in their natural enviroment or have the opportunity to learn appropriate behaviour from their parent.

 

The nightmarish visions of science fiction of course go much further than that. The concept of designer babies, infants modified genetically to be what the parents require, brings with it a moral choice about the spiritual and aspirational aspects of applying a pre-destined fate upon a child. Worst still are the exploitive visions whereby human beings are grown for the benefit of a few.

 

Rather than rely on genetic trends and Natural Selection, we are close to creating an artificial enviroment removed from that of the wild, where we strive to control our own evolution and be what we desire to be. Unfortunately, human nature is rarely so benign and inevitably, the spread of such technology may well one day produce a 'biological arms race' in which humans of opposing factions are improved in a forced analogy of real Natural Selection. This mindset is with us already - we see it in our armed forces, our very own replacement for the teeth and claws we lack. It is an instinct.

 

Conclusions

Logic dictates that Darwins Theory of Natural Selection must be a factor in the evolution of life on Earth, no question of it. The parameters of the theory are somewhat static however, and do not account for the dynamic interaction of enviroment, genetics, and behaviour. Darwin invented a mechanisn that he thought was responsible for evolution as opposed to something more along the lines of divine intervention that was generally accepted in his day.

 

Life on Earth is a remarkable thing but one that is ultimately and entirely dependent on a suitable enviroment in which to thrive. The composition of that enviroment is not only the local conditions, but the interior and exterior forces that mould it. Life is linked by its very own substance to the universe from which it developed. As our study of the physical world has opened up more detailed layers, should we really be suprised that these underlying principles haven't in some way produced similar layers of understanding of the natural world?

 

Time then to put Darwins Theory of Natural Selection in its place, as an early step on the road to discoverng what life on Earth actually is and how it works.

 

[Formosus Viriustus]

That's because you think that evolution goes there jumping from step to step; wrong. Mama ape didn't give birth to a baby human one day.

Evolution is happening all the time; the change of one species into another is a looong gradual transition. We're little different from our parents and offspring.

 

IMHO that is actually how evolution works, I think. I does happen in bursts and spouts, not at a less or more uniform pace. Environmental conditions are no doubt the major factor. You have large scale extinctions due to catastrophic events which creates opportunities for new species. Mutation does the rest.

 

Darwin's theory of natural selection doesn't take mutation into account. In fact his idea of how evolution works has been proven wrong : he thought indeed that evolution happenend very gradually, with each generation being minutely different from the previous one, slighty more adapted to the reigning environmental conditions. That's quite different from how we think it goes today.

 

My initial post here was not meant all that seriously, and I should look things up to be a bit more precise, but there doesn't have to be anything contradictory in an 18 million year period with big steps in evolution being made, being followed by a period over twice as long with much less evolution comparatively. Since I was not being serious I probably also somewhat overstated the 'primitive' form of the mamals that were around 65 million years ago.

 

Formosus

Edited May 22, 2009 by Formosus Viriustus

[Ursus]

Well, I wasn't expecting the Spanish inquisition with this thread.

 

I happen to be one of the religious people who do believe in evolution. But then I was never one to take mythology literally. The only religious people who are automatically opposed to evolution are the ones that do take their creation myths at face value. And I'm perfectly fine with them teaching their beliefs to their crowd within the four walls of their own temple, church or mosque - just not in a public science classroom, since their beliefs should not be construed as either public or science.

 

Also, on another point: I'm not here to babysit anyone, and I do appreciate people who contribute to discussion. But I have to say for the record this place is not a debating club. Every thread I walk into I see the same people trying to score points off each other with alleged lack of knowledge or alleged faulty reasoning. Guess what: no one really cares. Not the moderators, not the site regulars, not the odd passers-by. Not every thread is or should be a debate. It gets ridiculous at times. Especially when we start making snotty comments about elementary school analogies. If we want to go down that road, then the moderators can certainly start sending people to stand in the metaphorical corner with their noses against the wall while the rest of the kids get to play nicely outside.

 

So I am locking this thread as a statement. Cheers.