Question on evolution and the idea of "natural selection"...?

>"how does science explain the emergence of complex organic structures?"

You are pretty much on the answer ... by slow, incremental improvement ... small change after small change ... for millions of years piled on millions of years.

>"For example, for a species to evolve from one without eyes to one with eyes. Well eyes couldn't be the result of a single mutation, could they?"

No they couldn't.

>"Logically, many steps would have to be involved in the creation of something so complex. "

You are correct. Eyes would take thousands of mutations on thousands of mutations ... millions of years.

>"Yet, what benefits could those intermediary mutations possibly have provided for the animals that had them?"

To start with, the ability to detect light *AT ALL* has benefits. For example, jellyfish have light sensitive cells on the tops of their bodies that help them know (a) which way is towards the surface; and (b) when it is dark up top so that they can safely move closer to the surface for food.

Heck, even plants benefit from cells that detect light so that they can change the orientation of leaves to maximize the amount of light they receive. So photosensitive light cells are *very* common in nature.

There are many many examples in nature of organism with all ranges of eye designs ... from primitive collections of these photosensitive cells which are more correctly called "eyespot" than eyes ... to slightly cup-shaped indentations that provide better and better information about the *location * of the light source ... to cupshaped eyes with a small opening for controlling the *amount* of light ... to cupshaped eyes closed off with a primitive lens ... and on and on. Each of these point to intermediate stages by which an eye can develop in a long succession of ancestors via small mutations at each stage. Each stage, each small mutation, providing *slightly* better eyesight than its ancestors ... constant *relentless* improvement.

It is always natural selection at work ... slight improvements lead to slightly better survivors ... which leave slightly more offspring ... repeat, repeat, repeat over generations ... for hundreds of thousands of generations ... hundreds of millions of years.

The power of natural selection to achieve *incredible* changes, and incredible complexity ... is its relentlessness ... coupled with deep, inimaginable amounts of TIME.

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Because Chuck B chooses to insult the overwhelming consensus of the world's scientists who support evolution, by calling them "scientists" in quotes (as if he, or some preacher-turned-self-proclaimed biology researcher, are the "real" scientists), I have to respond.

Problems like the eye, or any of the dozen or so other examples of "irreducible complexity" raised by ID advocates, are absolutely NOT "very problematic" for evolutionary biologists to explain AT ALL. Many have cited Dawkins' "Climbing Mount Improbable" and I recommend it as well, as going through many of these cases one-by-one to show that they are not much of a problem at all ... in other words, every example of "irreducible complexity" raised so far has been shown to be quite reducible after all.

The evolution of the eye is fairly well understood (not "problematic" as someone below stated). Many types of cells can react to light, and a simple patch of light-sensitive cells can tell a creature whether it is in a light or dark place. If this patch becomes concave, it can tell which direction the light is coming from -- a definite advantage. If it becomes deeper and a clear mucus plug forms at the top, you have a crude lens. A muscular ring around it can focus the lens, making a clearer image, and so on. If you just keep adding mutations like that, you get an ever-more complex eye. Looking at various creatures today, we can see that all these "intermediate" eye types actually exist, from very simple to very complex, and they're all useful -- they serve their respective creatures as well as they need to (for example, a slug doesn't need a complex eye like a human's). Any number of complex features can evolve in this way, just by building on previous mutations.

Evolution of our species to where we are at this time is related to the influence of how the creation of languages, resulting in lingual communication, resulting in ability for the member of the language group to interpret meaning and to offer individual suggestion, resulting the ability for abstraction, resulting in the growth of our brain, resulting in how our species computed the variables existing and addressed these issues in a manner that, not without victims, provided the comprehension necessary for continued survival of the group (tribe). OK, the four major constituants of organic chemistry are: Hydrogen, Oxygen, Nitrogen, Carbon. The vagaries involved in how these elements are combined and the molecule resulting are limitless. Your question seeks many answers. So, I'll begin with your first one:

1. Natural selection is how an organism provides itself with the necessities available from the variables for its continued life.

2. Extinction of a species results as the inability for that species to continue to reproduce in a number that will secure its existance.

3. Mutations occur as a result of the random opportunity. The combination of the DNA of all species that will result in continuity has its own individual pattern. If this pattern is compromised, then the liklihood for mutation is strong. If, the DNA helix of any of the species that contain this mutation combine, with the mutation in alignment, then this will become a dominant "gene", and will have a greater than average potential to produce and aberrant member of the species. You must understand that the building blocks of organic structure must contain the initial four elements. There are several other organic elements involved, which are necessary for the evolution of a sophisticated species. If you are really interested, focus on biology, physiology, organic chemistry, and anthropology. Good luck.

I know that there are two kinds of mutations that affect only the nucleotide such as point mutation.. for example the sentence THE DOG BIT THE CAT the point mutation would be if i changed one letter making it THE DOC BIT THE CAT. a frameshift would affect everything after because of a deletion of a base pair or an insertion such as THE DOB ITT HEC AT. the G was deleted making it totally different. I can't tell you much more though it may just take a long time

Awesome question...here's my theory.

You are making an assumption that on a micro level that simple multi-cell organisms don't have "eyes" or other input organs. Which they probably don't, but they do have apperatuses for electro-chemical messengers that are sensitive to certian types of input. Vibration, Light, and chemical molecules.

So to begin, lets just say touch was the first evolutionary sense. It's based on electrical fields a nano level. Once organisms began eating other things besides plants, touch develped into hearing as the second evolutionary sense that an organism developed (I'm guessing here). Hearing is just another word for sensing vibration on a more accute level.

It's difficult to say whether hearing or locomotion came first.

As the organism grows it begins to adapt to the environment it has the preprogramed intention to develop defensive and offensive genetic/physical changes.

UV light, chemicals, and viruses also randomly change DNA adding to and switching genes on and off. The programing becomes more and more complex over time.

There are some recent theroies that space is the carrier and fertilizer for genetic material through comets and asteroids. What physical manifestations of the senses a complex organism develops is based on the environment.

From a religious point of view, people are assuming that genetic material is only unique to developing on Earth. We will find in the next 25 years that genetic material is found outside this planet, even if it is in the simplest of forms. That is going to be a tough pill to swallow for some folks.

Eyes are more difficult to see as an adaptation, but I am sure they started off as a simple-celled organism's chemical reaction to light. Probably garnered from a non-seeing organism who ate plants high in a photosenstive chemical. The organism adapted by first developing an organ to process this chemical then some of it's cells being exposed to infrared started to "see" this radiation on its food source. Infrared vision became rudimentry vision that could sense movement. Over time the predatory intention in the organism developed into sharper and sharper vision allowing it to be better suited for gathering food. I.e. survival of the fittest.

This has already been answered accurately and well - it may just be helpful to point out something that many people seem a bit confused about: natural selection and evolution are different things, yes - evolution is the change in the organism and natural selection is one of the primary drivers of that change. How selection pushes change in any particular direction is where the fun is. Different forces can act in different (even opposing) 'directions'. There's no "guiding plan" to it, and it's not any sort of 'progress' from "bad" to "good". It's a simply a constant effort to adapt better to a changing world. It never ends, unless your world stops changing.

Really good question.

Richard Dawkins, recently voted as one of the top three intellectuals in the world (he of 'The God Delusion') has written a book on the eye question (Climbing Mount Improbable). You could equally well have asked the 'flight' question - how could wings develop incrementally when the "flier" would crash and die with only a partial wing, and therefore not pass on his wing genes.

Little steps is the answer. The eye has evolved independently at least 40 times in nature, and they range from a cluster of light sensitive cells found in worms to the acute vision of raptors.

If you are still bored, find a copy of Dawkin's 'Improbable'. It's worth it, even if only for his brilliant writing style.

First of all the oft cited number of 4.5 billion years is all wrong . The oldest life bearing rock in the Grand Canyon are the stromatolites found in the 1,250 m.y.a .Bass Formation >which of course is PC The Cambrian rocks of GCNP are considerably younger and begin w/ the Tapeats Sandstone @550 m.y.a. > see Cambrian explosion What you're not getting is that all evolution be it biological , astronomical, cultural or mechanical follows the exact same five step pattern >>>) Step one is the longest part >Getting it to work at all >>>) Step two is the crazy permutation phase that happens in a relatively very short period time whereupon the stuff that works lasts and the stuff that doesn't is a foot note of history . >>>) Step three is the establishment of the basic form that all future designs will follow >>) Step four is the perfection of that form according to the environment >>) Step five is if the environment changes repeat steps 2-4 or become extinct >> If you're really interested you can try out that hypothesis on all sorts of neat and unrelated things.

Wow, there is an entire book on the subject called the Blind Watchmaker written by Richard Dawkins. You can't get a more informed well thought out answer than the one he provides. And given that you are bored, you have a good reason to go to the library and pick the book up and read. If his answerr doesn't satisfy you, nobodies will.

Natural selection and evolution are not the same thing, even though many people think so. Natural selection, which you have described, a random mutation (or adaptation) that has some beneficial result, can be demonstrated in nature. For instance, faster animals will outlive slower ones in the wild, due to being able to escape from predators, so it is likely that future generations will tend to be faster, rather than slower.

The type of evolution that you describe, concerning the eye, is very problematic for "scientists" who hold to the theory that all life evolved without the intervention of a creator. One would expect the fossil record to show evidence of a multitude of species with partial eyes, but none can readily be found. One could argue that we just haven't found them YET, but some of us believe that this is evidence of an "intelligent design" in nature. Darwin himself stated that if no evidence could be shown that a complex organ (such as the eye) developed in a multitude of tiny steps, that his theory of evolution could and should be called into question. The eye is one of many systems found in nature which is "irreducibly complex", that is, that could really serve no purpose without being fully developed.

Unfortunately, there are many who quiver at the thought that there is an intelligent designer (God), and so continue to espouse and believe theories that should have been either discarded by now, or at least have some more thought put into them. The only real solution offered is the "billions of years" that science throws into the cycle to make the theory work. What is completely disregarded is that some modern theories say that it is unlikely that the world can even be billions of years old.

I readily admit that there are many things that I cannot comprehend, and trust, in faith, that God has His hand in much more than we give Him credit for. Let others place their blind faith in so-called science.

check out the following book for a bettter explanation that I can offer in such a concise way:

The Making of the Fittest: DNA and the Ultimate Forensic Record of Evolution by Sean B. Carroll