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Natural Selection: Who selects?


LeeCollins
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LeeCollins: What i don't understand is this; was there a biological change involved in all this or (as Tormod said) did the moths that were less visible get eaten less and so had a greater reproduction rate therefore producing more less visible moths or both?

 

Simply put, there was no biological change: that is, nothing new arose. There was preexisting biological variation ("dark" and "light" moths) and changes in the environment changed which one of those was the more easily seen. Consequently, the ratio of dark to light moths changed as the birds preferentially ate the more easily seen moths. When the environment changed again, the ratio of dark to light moths changed accordingly again (because of differential predation).

 

How is this evolution? After all, no new organ - or anything - was involved. It's evolution because evolution can be defined as a change in the allelic frequency of a population over generations. And this occurred.

 

The coloration of the moths is genetically controlled: basically, one allele codes for 'dark' and another allele codes for 'light'. As the birds ate more of one of those types of moths, the survivors (most of which were either dark or light) reproduced and spread their cryptic coloration advantage through the population. And over some generations, the allelic frequency (ratio of dark to light alleles) changed in the population. Evolution.

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So how then is evolution responsible for the all the changes required to go from reptiles to birds? These transitions require massive biological change. How would evolution account for the development of a lung? How would an organism wean itself off the old respiratory system?

 

This seems to be more than just "a change in the allelic frequency of a population over generations". Is there some more powerful mechanism at work in evolution?

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Originally posted by: Freethinker

Some will emerge from the chrysalis to become adult moths......, If a moth while emerging from the chrysalis.....

Just a nitpick here to assure accurate information. The pupal stage of a moth is usually refered to as a caccoon, a chrysalis is that of a butterfly. Very different mechanisms are used in creating/becoming one of these two very different things.

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Lee Collins: So how then is evolution responsible for the all the changes required to go from reptiles to birds? These transitions require massive biological change.

 

Essentially, taking a step involves shifting balance to one side, advancing the opposite leg, and then returning to a balanced position. Big whoop! How can such an insignificant process account for humans spreading out all across the African continent? By the accumulation of many many of the individual, small advances over a long span of time.

 

The same general logic applies to evolution. Scientists can observe bacteria mutate in a petri dish and see that this affects their ability to survive and reproduce. Yes, the bacteria started as bacteria and ended as bacteria, but a person taking a single step starting in his living room ends up in his living room too.

 

Lee Collins: How would evolution account for the development of a lung? How would an organism wean itself off the old respiratory system?

 

You are aware that there a different types of lungs of varying complexity/simplicity. A salamander lung is very simple, and that of a lungfish is even simpler. Note also that lungfish have both lungs and gills: they could theoretically be weaned off of either one and still survive. And even simpler are the "lungs" of invertebrates such as some spiders and and certain snails.

 

 

Lee Collins: This seems to be more than just "a change in the allelic frequency of a population over generations".

 

Doesn't seem that way to me. It's just a matter of accumulating individually minute benefits, over great spans of time, through the action of natural selection.

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I know that there are different types of lungs. However, I am asking about how the simplest one was formed by evolutionary processes. I know that there are alot of possibilities but nothing seems to be certain. Is there any lab experiment that would show that enough small change could actually equal a massive change as required to go from reptiles to birds? There seems to be the idea that this is probable what happened but does anyone know how it could have happened?

Don't get me wrong, it is a reasonable hypothesis ... until we get to the specifics.

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Originally posted by: LeeCollins

So how then is evolution responsible for the all the changes required to go from reptiles to birds?

Lee, just as Telemad had posted. This is a "natural" process. Nothing needed to be turned on or later turned off. Each new member of a species has a unique DNA structure. Mutations happen each time. Some mutations are so extreme the initial cells are rejected by the host (think "mother") or not able to establish itself to develop into a life. Some are very minor, slight colors or paterns, lengths of parts, ...

These transitions require massive biological change.

Only when viewed over long periods of time. Though "punctuated equilibrium" states that some of the perhaps more radical mutations happened in short spurts.

 

Such as the 5 legged frog situation a few years ago. Suddenly there was a large number of frogs being born with 5 legs. This may have been human polution related, but mutations are mutations.

 

If having 5 legs had given a leg up (lol) to those frogs in mating, then 5 legs might have become a new genetic path. But it obviously was not an advantage, but a disadvantage. The 5 leggers died off (perhaps harvested more rapidly by suppliers of frog legs for restaurants?) and did not reproduce to pass this mutation along.

 

Imagine a mass of cells in water on primoridal earth. If the coloring of some started to mutate into a redish tint, they would respond to light more than other colors/ no color. THis might then act as a receptor of sunlight and the discomfort of the light hitting the red cells might cause them to move away from the light source and perhaps this would give that mass of cells an advantage over other non red ones. Then if this red "spot" became localized, the other cells doing their job, then just a smaller red area in the mass will accomplish the same task more efficiently.

 

This type symbiotic relationship is very evident in even the most basic of life forms. Just recently (the last few years) because of technology, we have been able to visit the bottom of the ocean and it's sulphur vents. Jets of superheated water and concentrated sulphur which, besides the extreme pressure already there, would kill all life forms we had known. But we found a bacteria that lived off of the suphur from the vents. Then more amazingly we found another life form that assembled itself into tubular shape around collections of the bacteria. This life form lived off of the by products released by the suphur eating bacteria. The tubes provided a way to concentrate the sulphur flow and maximize the concentration of byproducts from the bacteria for better feeding to the tube life.

 

There was obviously no intellectual desicion made at any point by these various single celled organisms or anything connected to their existence. But a basic symbiotic relationship developed strictly from Evolutionary advantage. A basic digestive system was being Evolved by simple natural processes.

 

So it is not hard to see the actual development of task specific cells that develop strickly from natural evolutionary advantage. A few red cells in the mass give that mass an evolutionary advantage. A protective layer of transparent cells becomes an evolutionary advantage. And the begining strucure of the eye is formed. No need for a fully formed eye to pop into existence. Each individual step has it's own functional advantage. Each comes about by simple natural mutation.

 

Computer simulations show that a fully formed and functional eye can evolve thru simple single stage mutations with each stage having it's own functional advantage, in less than 10,000 generations. If each generation was 1,000 years (an extremely conservative estimate), we could go from a simple red celled advantage to a fully formed eye in 1 M years. A short time in the overall history of nature on Earth.

How would evolution account for

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Evolution is a well proven and logically identifyable process. We see it happening all around us. We can understand why it happens. It gives us extremely accurate predictability.

The evolution we see all around us does not create new species. We see species genetically mutate in certain ways that may or may not be advantageous. We extrapolate fromwhat was observed and hypothesizethat this same process produced the species.

 

example: If I work out every other day for a month and observe an increase in my strength by 20 lbs.( I can lift 20 lbs more than when started). Can I use this fact to say that if I do this continually for 5 years thatI will be lifting 1200 lbs ?At a glance ... yes.But ofcourse this is false.

 

This is why I asked: Is there any lab experiment that would show that enough small change could actually equal a massive change as required to go from reptiles to birds?

 

If there were such an experiment then evolution would be the most viable possibility. But, lacking that, what do we have as evidence?

 

In fact the very concept of our Medical Science is based on the factual nature of Evolution.

What can be done medically because of a belief in evolution that could not be done without it? Is it not true that medical science is based on observation?

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Originally posted by: LeeCollins

Evolution is a well proven and logically identifyable process. We see it happening all around us. We can understand why it happens. It gives us extremely accurate predictability.

The evolution we see all around us does not create new species. We see species genetically mutate in certain ways that may or may not be advantageous. We extrapolate from what was observed and hypothesize that this same process produced the species. ... Is there any lab experiment that would show that enough small change could actually equal a massive change as required to go from reptiles to birds?

 

If there were such an experiment then evolution would be the most viable possibility. But, lacking that, what do we have as evidence?

Perhaps you've heard of "fossiles"?

 

The basic Theory of Evolution as we currently understand it was first developed about 150 years ago. If specific experiments to prove speciation (change of species thru evolution) were started at that time, we would only have perhaps a few tens to hundreds of thousands of years to wait for the level of change you are asking about to happen.

 

Meanwhile EVERY ASPECT of Evolution has been proven over and over. We have even PROVEN speciation in lab experiments. That is we have, under controlled lab conditions, evolved from one common species, two species, in that one species can not procreate with the other. That IS the defintion of speciation.

 

Did a fruit fly evolve into a bird in one path and mouse in another? Of coourse not. Such expectations are stupid. Simple obfuscation of the issue.

 

We have also traced fossiles thru any number of transitions from common ancestry to two different evolutionary species paths.

 

But those wishing to ignore the overwhelming amount of factual data we have collected showing transitional speciation will always ask for more. They do not wish to review factual data for truth. They are desperately scraping for anything they can find to claim a gap. As if we should expect a complete set of fossiles laid out in a neat linear evolutionary sequence in one location. Preferably with lables attached to each fossile giving time and date of each with arrows and diagrams. Perhaps with a large "X" painted over the spot we should start digging. Anything less will continue to be rejected as having GAPS.

In fact the very concept of our Medical Science is based on the factual nature of Evolution.

What can be done medically because of a belief in evolution that could not be done without it? Is it not true that medical science is based on observation?

Yes, both medical science and evolution are based on Observation, and the same ones!

 

Pig parts can be used as replacements in humans because of Evolutionary commonality. Vaccinations can be manufactured in chicken eggs because of Evolutionary commonality. New medicines are tested on various other animal species becuase of Evolutionary commonality. And the Evolutionary differences help us find ways of fighting diseases by learning how other species evolved immunities. In fact:

 

"Nothing in biology makes sense except in the light of evolution" the title of a 1973 essay by Theodosius Dobzhansky ( January 25 , 1900 - November 11 , 1975 ) a noted geneticist and evolutionary biologist.

 

"INTRODUCTION: THE NATURE OF SCIENCE AND BIOLOGY

Theories Contributing to Modern Biology

 

Modern biology is based on several great ideas, or theories:

 

1. The Cell Theory

2. The Theory of Evolution by Natural Selection"

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookintro.html

 

"Whereas medicine is historically rooted fir

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Pig parts can be used as replacements in humans because of Evolutionary commonality. Vaccinations can be manufactured in chicken eggs because of Evolutionary commonality. New medicines are tested on various other animal species becuase of Evolutionary commonality.

 

Could it not be stated that:

 

Pig parts can be used as replacements in humans because ofbiological commonality. Vaccinations can be manufactured in chicken eggs because of biological commonality. New medicines are tested on various other animal species becuase of biological commonality.

 

We have also traced fossiles thru any number of transitions from common ancestry to two different evolutionary species paths.

Again, all we have here is "This looks like that so they have common ancestry".

 

Evolutionary differences help us find ways of fighting diseases by learning how other species evolved immunities.

This is the information I am looking for: How did species evolve immunities? Is there a step-by-step account of the process? And I don't mean bacteria and viruses. What have we learned so far about the process that helps us cure disease today?

 

and again...

What can be done medically because of a belief in evolution that could not be done without it?

 

"Nothing in biology makes sense except in the light of evolution" the title of a 1973 essay by Theodosius Dobzhansky ( January 25 , 1900 - November 11 , 1975 ) a noted geneticist and evolutionary biologist.

 

I like a good quote but what about these?

 

Dr. Colin Patterson, Senior Paleontologist at the British Museum of Natural History said this about evolution: "positively anti-knowledge," and that "all my life I had been duped into taking evolutionism as revealed truth."

 

Also on BBC, Dr. Patterson says:

"Imean the stories, the narratives about change over time. How the dinosaurs became extinct, how the mammals evolved, where man came from. These seem to me to be little more than story-telling. And this is the result about cladistics because as it turns out, as it seems to me, all one can learn about the history of life is learned from systematics, from groupings one finds in nature. The rest of it is story-telling of one sort or another. We have access to the tips of a tree, the tree itself is a theory and people who pretended to know about the tree and to describe what went on with it, how the branches came off and the twigs came off are, I think, telling stories."

 

 

 

 

H.S. Lipson, Physicist, said this:

 

"In fact, evolution became in a sense a scientific religion; almost all scientists have accepted it and many are prepared to 'bend' their observations to fit in with it."

H.S. Lipson "A Physicist Looks at Evolution." _Physics Bulletin_ 31, n.d., 1980

 

 

Do these scientific opinions have any weight?

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Originally posted by: LeeCollins

Could it not be stated that:

 

Pig parts can be used as replacements in humans because of biological commonality. Vaccinations can be manufactured in chicken eggs because of biological commonality. New medicines are tested on various other animal species becuase of biological commonality.

Yes absolutely. And the most accurate explanation we have to explain this biological commonality is Evolution. Nothing else even comes close to explaining WHY there is the biological commonality we find in everything from pigs to fungus.

 

This seems to be perhaps part of your sticking point. You seem to want some "absolute". You want Evolution to be the ONLY answer. Some mythical wave of the wand and POOF, Evolution and that is that!

 

Science does not work that way. Scientific process took all of the observations we have ever made concerning how life functions, what it does, how it works, commonalities, differences, historical evidence, lab tests, .... and developed a theory to explain it as accurately as possible. The name that was given to the Theory that best fits everything we know about the diversity of life is "Evolution". Then science further tests the Theory by using it to make predictions. An accurate Theory makes accurate predictions.

 

As I said, there is not any other explanation that even gets close to explaining the observations and existence of the variety of life. And nothing offers the accuracy of predictions the way the Theory of Evolution does.

We have also traced fossiles thru any number of transitions from common ancestry to two different evolutionary species paths.

Again, all we have here is "This looks like that so they have common ancestry".

Yes, exactly, cross species medical applications and transitional fossiles are but two of the many observations and accurate predictions which support the Theory of Evolution.

 

Each in and of themselves is a curiousity. We could develop any number of propositions to support one or the other. Perhaps someone planted the fossiles to intentionally confuse us. But then we need to prove a "someone". Maybe little gnomes climb into our bodies when animal transplants are used and makes the needed corrections? Prove otherwise! :-) But what predictive value does this have? How does it fit with the guy digging up dirt to plant fossiles? The two are in conflict and can't fit in at all with other observations.

Evolutionary differences help us find ways of fighting diseases by learning how other species evolved immunities.

This is the information I am looking for: How did species evolve immunities?

Once more, mutations. Say there are 1,000 rabbits in a room. One has a potentially mortal disease. Because of genetic mutations, each has various immunities or lack there of. Say 990 of them do not have immune mutations. They die. They don't have babies. Thus there immune lacking genes do not get passed on. However the remaining 10 rabbits, hopefully at least one of each species, do have the immune gene. Thus they do there thing, multiplying like rabbits. The immune gene gets passed to the next generation.

 

But if through mutation, one of the ofspring's gene changes to the non-immune type, that rabbit will die off and not pass the non-immune gene.

What have we learned so far about the process that helps us cure disease today?

Genetics, like biological commonality and common ancestry adds to the pile of support for Evolution. Using genetics, we understand that if we can isolate the immunity organism, we can reproduce it genetically and use it to mutate the body into fighting off the desease. We can also identify genetic tendencies to allow us to know which d

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Sorry that I edited my post after you responded. I didn't mean to do that. But, I would like to know what you think about the opinions of people making the quotes that I posted.

 

Yes absolutely. And the most accurate explanation we have to explain this biological commonality is Evolution. Nothing else even comes close to explaining WHY there is the biological commonality we find in everything from pigs to fungus.

 

So, let me get this straight:

Biological commonality is observed and evolution is the best guess as to why. Is that it?

 

Is it unreasonable that someone could have created fungus and pigs using the same basic parts?

I know this does not sound scientific, however, as a software developer, I write many applications from communication systems to accounting apps. Some of the applications, if analyzed, would yield the exact same machine-code in some places. These places are where a generic function is required. If I create an object that doescertain computations, I will use it everywhere that I need that kind of computation. Sometimes I may need to modify to object to perform on a certain platform so the object I created will vary but it will have the same function.

 

I don't want to get Occam and his razor upset but is this possibility ruled out by known science?

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FreeThinker: "Nothing in biology makes sense except in the light of evolution" the title of a 1973 essay by Theodosius Dobzhansky ( January 25 , 1900 - November 11 , 1975 ) a noted geneticist and evolutionary biologist.

 

A silly statement that is easily shown to be very wrong.

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Originally posted by: LeeCollins

The evolution we see all around us does not create new species.

 

Yes it does. I gave you examples.

 

We see species genetically mutate in certain ways that may or may not be advantageous. We extrapolate from what was observed and hypothesize that this same process produced the species.

 

In most cases, yes. This is usually how evolution works. There are few creatures on this planet which can be called "shapeshifters" - I am not aware of any, at least.

 

example: If I work out every other day for a month and observe an increase in my strength by 20 lbs.( I can lift 20 lbs more than when started). Can I use this fact to say that if I do this continually for 5 years that I will be lifting 1200 lbs ? At a glance ... yes. But of course this is false.

 

It makes me wonder - do you really know what the definition of evolution is? This example has absolutely nothing to with evolution.

 

This is why I asked: Is there any lab experiment that would show that enough small change could actually equal a massive change as required to go from reptiles to birds?

 

Where do you draw the line for "enough small change"? In nature it takes thousands, if not millions of years for this to happen. To instantly create on species out of another is easy with very small creatures like banana flies, algae, and bacteria, but not animals of this size. The more complex the DNA, the longer it will take. But the nature of evolution allows things to go faster when it is required - say, after a big rock hits the earth and wipes out entire races. Then suddenly there will be large gaps in the food chain which will rapidly be filled.

 

If there were such an experiment then evolution would be the most viable possibility. But, lacking that, what do we have as evidence?

 

I don't know how many times we will tell you and how many times you will ignore what we say, but you are going into an endless loop here.

 

Is it not true that medical science is based on observation?

 

Hm. No. Observation is important, as it is in every science. But medical science is based on tried and tested hypothesis. There is a reason why human trials is not allowed until a drug has been tested in any other conceivable way. Aspirin was found when people ate the bark of a Peruvian tree. Most of our medical science is based on the scientific method of observation, testing, falsification, new observations, new theories, etc etc.

 

I don't agree with Freethinker that medical science is wholly based on the nature of evolution, though. But that is a different discussion for another thread.

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Originally posted by: TeleMad

FreeThinker: "Nothing in biology makes sense except in the light of evolution" the title of a 1973 essay by Theodosius Dobzhansky ( January 25 , 1900 - November 11 , 1975 ) a noted geneticist and evolutionary biologist.

 

A silly statement that is easily shown to be very wrong.

 

Moderator warning: Please don't post one-line replies like this. If you can show it to be wrong, do so.

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Originally posted by: LeeCollins

What is Natural Selection?

Who is the selector in "Natural Selection"? ?

Perhaps the term "natural selection" is a bit of a misnomer, or at least misleading to some. Science is filled with less than adequate terms for defining complex ideas. For example; black holes are not holes, the big bang was not an explosion in the typical sense, etc.. Natural selection is not a selection, but rather a dynamic process that happens independent of any conscious or intelligent selector. No one selects. It just happens. The terminology is not always perfectly descriptive of the process it is designed to describe. Our languages have limitations. Most people understand this and take it into consideration when learning about a subject.

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