Darwin's Finches Demonstrate Evolution

[Bobblehead]

Originally Posted by Calgaryborn

Imagine what it would take by chance to create an eye. The end result is quite complexed and needful for many species. How could an eyeball be produced over time. Are we to believe that this was the cause of small progressive mutations that dispite all odds endured for millions of years until it became useful? I don't believe it.

That's too bad.

But in research reported this week in Current Biology, the evolutionary history of a critical eye protein has revealed a previously unrecognized link between certain components of sophisticated vertebrate eyes - like those found in humans - and those of the primitive light-sensing systems of invertebrates. The findings, from researchers at the University of Oxford, the University of London and Radboud University in The Netherlands, put in place a conceptual framework for understanding how the vertebrate eye, as we know it, has emerged over evolutionary time.

link

Also, Wikipedia has a good summary of the Evolution of the Eye

Although the eye remains a common and popular example of complexity in arguments against evolution, some intelligent design and creationism advocates have abandoned the eye as an example of "irreducible complexity". As the detail and history of eye evolution have become better understood, its role in these circles has declined and been replaced by molecular and microscopic structures such as the flagellum. However, much as with the eye, research into these smaller-scale structures has also uncovered details of their evolution[

[icarus]

Originally Posted by Calgaryborn

Are we to believe that this was the cause of small progressive mutations that dispite all odds endured for millions of years until it became useful?

No, you are not meant to believe that because that is not what evolutionary biologists believe. They believe that the eye developed gradually from light sensitive cells that were useful at every point in the course of history. Eyes have evolved at least twice independently, once in vertebrates and once in invertebrates. The eyes of humans and squid are comparable in many ways but differ in other ways--such as the location of the photoreceptive layer within the retina--that betray an entirely separate evolutionary history.

Some photosensitive cells have not evolved into an eye. The pineal gland in vertebrates has light-sensitivity but it has not developed into an eye, yet it still remains useful enough to be maintained. Perhaps millions of years in the future it will evolve to form an eye.

[Daradon]

Calgaryborn:

Thank you for the personal response. I'll try to sum up both here.

I agree with you on the variation thing. Environmental nature and/or nurture stimuli (such as how well I am fed or what I eat) could indeed be responsible for me growing taller than my parents as in your example, and would have nothing to do with a genetic mutiation.

But we are not talking about general variations. We are talking about physilogical differences. Perhaps if we had pictures of these birds we could better debate this, and see if there is enough of a size difference to indicate an actual physiological difference or just a variation. However, mutations DO occur regularly. Going back to the finches, there is also a quote near the bottom of the page of the article that is very telling, showing how they recorded the variations in population of the short beaked and long beaked finches and how the shorter ones over took the population of the longer ones after their environment changed. A perfect example of microevolution. The mutation was always there, however, after the drought, the short beaked ones reproduced with more success, because they had better access to food. If you wish to find any flaw in the study, you are free to look it up.

As for mutations that show up in the genes, I would know, I am on the losing scale of such a mutation. I was born with a three valved heart. The more we learn about it, the more we have discovered that it is a genetic flaw (or possibly advantage, though doubtful) rather than any varitation (it is a true physilogical difference) or anything cause by outside stimuli (my mother took no drugs, prescribed or otherwise, and had no problems with the pregnancy). As further proof, her mother lost a son early in his life to a heart realted problem, showing it is probably an X chromosome trait, or GENETIC) Further tests have proven throughout my life that this is a genetic mutation, and not a just a coincedence or random occurance. It's because of modern medicine (and a very strong will to survive) that I am alive today. Almost no one exists with this condition anymore, they transplant the heart as soon as they can (or the patient dies, like in the natural world) with the advances in surgery they have made since I was born.

We can further debate the finches if you like, but you can't deny that random (or non random) mutations happen all the time in all species. There are examples everywhere. I myself am living proof of that. The ones that are advantageous become part of the species over time and they slowly change into something different, (over a very long time). The ones disadvantageous (excluding humans cause we are creating our own destiny lately) die out sooner then they can reproduce, therefore eliminating tha mutation.

As far as your 'suggestion' on what books I should read about space and science, I would like to alert you I read from a variety of different sources. If you would like to quote or link some things I might find useful then by all means. But to sit and tell me I might not have read different authors or know about different studies is a bit of a blindside with no real merit.

I am well aware of flaws in certain theories. I do not proclaim that any one answer is ultimately correct, as we understand it today. However most of these theories and accompaning laws work very well with each other, with the exception of 'creationism'. So either we have 30+ interlocking theories with some truth that support each other to some extent leading us to a greater path of knowledge and truth. Or we have one stand alone theory with no real proof, that flies in the face of much we know scientifically.

I know much about space and light and time, at least conceptually, but do not subscribe completely to the big bang theory. Even if I did, I would still have to ask myself the question, 'what happened before that?' It's a question you can always ask. On the other side of the coin, you can ask. 'Where did God come from?' or 'What was before God?' These are spiritual questions that people have been asking since the beginning of time and answer differently. Saying 'God always existed' is no more truthful than asserting 'Space dust always existed'. Both could be right, both could be wrong, and shoot, no one really knows. Maybe 'God' is space dust. A amalgamation of living loving energy. WHO KNOWS? I do not ever claim that big bang theory or even evolution theory are completely rock solid.

But to tell me there is NO truth behind evolution and or astrophysics and math is burying your head like an ostrich in the sand because you either can't comprehend the truth, or it damages your belief system and you're not open minded enough to learn and change. They have many provable and observeable aspects. Many more so than 'creationism' and a 2000 year old book written by men to control the thinking of their people after a revolution.

I do believe in a higher power, I do believe in Jesus, his teachings and his importance. But I am not so ignorant or self important to think I know more than the leading scientists and mathmaticians of our day. I take what they say with a grain of salt, but I work towards learning more about it, then dismissing it because I can't understand it following an ancient story.

Einstein once said (and you seem to be well read and argue well so I'm sure you know this) 'God does not play dice with the universe.' Even with all he taught us and the mind bending aspects of light and time he brought to us (which we have since recorded and observed to be true) he believed in a Christian type god. Stephen Hawking, the best physist we have today, is also a spiritual person. No one is arguing against a higher power or a benevolent force.

However one can not and should not dismiss the advancements and ideas our great minds have brought us, including the observable and logical theory of eveolution.

[FlamesAddiction]

Originally Posted by Calgaryborn

Daradon

If you are taller than your parents or have bigger feet it doesn't mean you are a mutant.

Actually, by definition, we are all mutants. Everytime DNA replication takes place in an organism, and chromosomes are duplicated, there are always some changes in the coding. This can happen in many ways; insertion or deletian of amino acids, or uneven breaking when the duplicates are pulled away.

Most of the time, there is no noticable change in phenotypes, but they are still mutations. Occasionally, these changes do manifest themselves as physical characteristics if the mutations are at important parts of the genetic code.

(And yes, this process has been observed and manipulated in laboratories. Today, we genetically modify organisms by purposely causing insertions and deletians in DNA.)