natural selection

[Agent007]

I mentioned an individual diet. Although a population might generally consume only twigs in its own niche, an individual organism may eat not only twigs but also leaves. However, heredity does not necessarily ensue in the organism's offspring eating both twigs and leaves.

[Pooeypants]

Quote by: Agent007 I mentioned an individual diet. Although a population might generally consume only twigs in its own niche, an individual organism may eat not only twigs but also leaves. However, heredity does not necessarily ensue in the organism's offspring eating both twigs and leaves.

Why not? We know that behaviour can be hard-wired, aka Instinctive. The individual may also have some "freakish" mutations which allows it to eat more than twigs and therefore gain an upper hand on the others; ergo it can reproduce more successfully.
Do you have any idea about natural selection at all? It seems to me you don't even understand the rudiments of it.

[jeafl]

Quote by: belverron That's a foolish statement to make. Speciation would prove macroevolution irrefutably.

How so? Give me your defition of speciation and macro-evolution.

[jeafl]

Quote by: belverron No taxon is really "higher," per se.

No? Are you saying that a family does not contain a greater range variation than a genus does?

[belverron]

How can you admit to speciation without admitting to macroevolution?

According to Meriam-Webster, speciation is "the process of biological species formation" and macroevolution is "evolution that results in relatively large and complex changes (as in species formation)." I think that's pretty clear.

Quote by: jeafl No? Are you saying that a family does not contain a greater range variation than a genus does?

I misunderstood.

[jeafl]

Quote by: Pooeypants No, most mutations are silent because we have a degenerate code. I thought you had a degree in biology?

http://scienceweek.com/2004/sc040806-5.htm

“The genomic mutation rate is a fundamental evolutionary parameter of any population, determining the rate of influx of new deleterious and beneficial alleles. Because most mutations are likely to be harmful to fitness, DNA repair and proofreading systems have probably evolved so as to minimize rates of mutation”.

Note the added emphasis.


http://www.colband.com.br/ativ/nete/.../geral/007.htm

“The number of harmful mutations that arise in each generation has been measured, and it is surprisingly high.”

Note the added emphasis.

http://bioweb.wku.edu/faculty/McElro...4lects5.htm#p4

“Most mutations are deleterious under any scheme and are quickly removed by selection.”

Note the added emphasis.

And also note that these statments are made by evolutionists, not creationists.

My biology degree came from Emory University. Where did yours come from?

[jeafl]

Since no one here has been able to answer my question, I will answer them for you.

According to Richard Milner, author of Encyclopedia of Evolution Humanity’s Search for Its Origins (Henry Holt and Company, 1990), Bumpus’ sparrows was the first and until the peppered moth in the 1950s the only major sources for experimental data available to explain natural selection. Bumpus’ work was cited in textbooks until the 1950s when H. B. D. Kettlewell’s work with England’s peppered moth became the standard example of natural selection.

Following a severe winter storm in 1898 Brown University zoologist Hermon Carey Bumpus found 136 wind-blown sparrows lying on the ground in Providence, RI. Bumpus collected the birds and took them to his laboratory. Sixty-four of the sparrows died, while seventy-two recovered.

Bumpus took an assortment of measurements- wingspan, beak, head et cetera- for both the living and the dead. Bumpus found that the survivors had measurements that were closer to the average measurements for the entire group of 136.

What Bumpus had observed was a balanced phenotype, or stabilizing selection. The extreme characteristics found in this population were eliminated.

If Bumpus’ sparrows are any guide, then we must conclude that natural selection acts only to preserve the average genome. Selection pressures generally kill off the extreme phenotypes.

Now consider the peppered moth. According to Darwinists this species of moth has two phenotypes- a light and a dark. Before the Industrial Revolution the light moths were the dominant variety. But, then air pollution from coal smoke darkened the lichens on the trees where the moth lived. Predators could more easily identify the light moths so their number was reduced and the dark moth became dominant.

Then air-pollution laws in the 1950s cleaned the air and allowed the tree lichen to return to their natural light color. Now the dark moths can be more easily found by predators and the light moths have once again returned to dominance.

But, this does not explain why the dark moths were able to survive before the Industrial Revolution darkened the trees. Neither does it explain how light moths were not driven to extinction in areas that did have darkened trees.

So again we see natural selection acting as a conservative force. If the dark genes had been eliminated before the Industrial Revolution, when they had lower fitness, they would not have been available to “save” the species when the air pollution came. And if the light moths had been driven to extinction because of the air pollution, the light genes would not have been around to “save” the species when the air pollution was gone.

So apparently natural selection can preserve genes that are detrimental to fitness just in case those genes will be needed in the future.

So can anyone here tell me of any experimental confirmation of natural selection’s ability to perpetuate innovative genetic traits- the type needed to allow scales to turn into feathers or paws to turn into hands? Or has natural selection been documented to do nothing more than eliminate genes that strongly impair fitness or preserve genes that may grant greater fitness in the future?

[Starboy]

Quote by: jeafl So can anyone here tell me of any experimental confirmation of natural selection’s ability to perpetuate innovative genetic traits- the type needed to allow scales to turn into feathers or paws to turn into hands? Or has natural selection been documented to do nothing more than eliminate genes that strongly impair fitness or preserve genes that may grant greater fitness in the future?

Natural selection only selects for traits that provide a species an advantage in a particular environment. Selecting for traits doesn't necessarily mean the loss of other traits, even if the expression of that trait may be reduced. Not all genes work the same way within the genome. Some traits depend on the frequency of that gene, some on the mirror transpose of an existing gene along with the un-transposed version, some are dependent on the behavior of other genes. Some depend on the position of genes WRT other genes. It is a very complicated mess that people are still trying to figure out. It is not all that easy for some traits to just completely go away. Besides there is no telling what the future environment of any species will be. Those species that had the ability to retain some of their prior variations, especially for environments that undergo very long period cyclical variations will have an advantage over those species that can't.

Starboy

[belverron]

Would you clarify your position on extinction, jeafl? Your last point seems to indicate that you have some interesting ideas there. If speciation does not occur, how can the balance be maintained when extinction occurs?

[Pooeypants]

Quote by: jeafl So again we see natural selection acting as a conservative force. If the dark genes had been eliminated before the Industrial Revolution, when they had lower fitness, they would not have been available to “save” the species when the air pollution came. And if the light moths had been driven to extinction because of the air pollution, the light genes would not have been around to “save” the species when the air pollution was gone. So apparently natural selection can preserve genes that are detrimental to fitness just in case those genes will be needed in the future. So can anyone here tell me of any experimental confirmation of natural selection’s ability to perpetuate innovative genetic traits- the type needed to allow scales to turn into feathers or paws to turn into hands? Or has natural selection been documented to do nothing more than eliminate genes that strongly impair fitness or preserve genes that may grant greater fitness in the future?

This reminds me of Sickle Cell anaemia. Can you tell me why it shows convergent evolution amongst humans? Because it does.

[Pooeypants]

Quote by: jeafl “Most mutations are deleterious under any scheme and are quickly removed by selection.” Note the added emphasis. And also note that these statments are made by evolutionists, not creationists. My biology degree came from Emory University. Where did yours come from?

My bad, but I read this

Silent base changes are mutations which do not alter the amino acid. (Those which do are called replacement mutations.) Since they are less constrained than replacement sites, the geneticist Kimura had predicted, before DNA sequences were available, that silent changes would evolve more rapidly. It has now been well confirmed that they do; the table shows that evolution in silent sites runs at about five times the rate in replacement sites.

source

This does not invalidate your quoted statements however, because they're talking about replacement mutations, not total mutation including silent ones.

[MerlinsByte]

This reminds me of Sickle Cell anaemia. Can you tell me why it shows convergent evolution amongst humans? Because it does.

We have come full circle to sickle anemia again, Its a straw and evolution of the species is the drowning man, I hope even evolution of the species by natural selection doesn't suffer too much longer...

And jeafl I like your style, you have taught me in a few posts that is much better to be on the offensive side rather than on the defensive side that I so often find myself in here at Volconvo.

mb

[Pooeypants]

Quote by: MerlinsByte We have come full circle to sickle anemia again, Its a straw and evolution of the species is the drowning man, I hope even evolution of the species by natural selection doesn't suffer too much longer... And jeafl I like your style, you have taught me in a few posts that is much better to be on the offensive side rather than on the defensive side that I so often find myself in here at Volconvo. mb

Do you have any idea what I was talking about? 'cause I don't have any of what you're rambling.

[jeafl]

Quote by: Starboy Natural selection only selects for traits that provide a species an advantage in a particular environment.

Are you saying that natural selection does not work against detrimental traits as well? Isn't this what Bumpus showed with his sparrows?

Selecting for traits doesn't necessarily mean the loss of other traits, even if the expression of that trait may be reduced.

Take it up with Darwin. About a year ago I ran across a quote that appeared in one of Charles Darwin's books or letters in which he made the declaration to the effect that natural selection would remove any detrimental trait from a population. I cannot remember now where I found this information, but I think it is in one of the various editions of Origin

I fail to see why, in a Darwinian universe, natural selection would allow any trait that is completely detrimental to persist in a population. Can you document how a light color is beneficial to a population of moths that live among trees that are darkened by air pollution.

[jeafl]

Quote by: belverron Would you clarify your position on extinction, jeafl? Your last point seems to indicate that you have some interesting ideas there. If speciation does not occur, how can the balance be maintained when extinction occurs?

I have not said that speciation does not occur. I have only said that speciation is possible only within the genetic limits inherent in the original "kinds" of organisms that God created. And by kind, many Creationists mean genus, but I am not convinced that kind is not a yet higher taxa.

I also have never said that extinction is impossible. But the natural selection shown by Bumpus' sparrows and the peppered moth may reflect a design meant to stabilize population while preserving as many normal genes as possible so extinction may be delayed as much as possible.

[jeafl]

Quote by: Pooeypants This reminds me of Sickle Cell anaemia. Can you tell me why it shows convergent evolution amongst humans? Because it does.

Based on what I know about sickle cell anemia, it does not match the definition of convergent evolution:

Evolution
Philip Whitfield
Macmillan Reference USA/Gale Group
New York
1993, 2000
0028655931

convergent evolution
The process by which two or more independent lines of evolutionary development bring about superficially similar end-points. When different groups of organisms are subjected to the same selection pressure they tend to evolve a similar design feature. Streamlining, for instance, gives great energy—efficient benefits to any animal that swims underwater. As a result, sharks, dolphins, and the now-extinct marine reptiles, ichthyosaurs, although unrelated, all converged on a similar streamlined body form.

Teach Yourself Evolution
Morton Jenkins
NTC/Contempory Publishing
Chicago, IL.
1999

Convergent evolution If two forms are descended from very different ancestors but show a superficial similarity to each other through adaptation to similar niches, they are said to show convergent evolution. Examples are whales and fishes.

What other species have the sickle cell trait?

[jeafl]

Quote by: Pooeypants My bad, but I read thissource This does not invalidate your quoted statements however, because they're talking about replacement mutations, not total mutation including silent ones.

Do you concede that nature produces more deleterious mutations than it does beneficial ones and that silent or neutral mutations have no bearing on natural selection and therefore little to do with evolution?

[Starboy]

Quote by: jeafl Are you saying that natural selection does not work against detrimental traits as well? Isn't this what Bumpus showed with his sparrows?

I think you are playing semantics here. A change in a "detrimental" trait that benefits a species is still a change.

Take it up with Darwin. About a year ago I ran across a quote that appeared in one of Charles Darwin's books or letters in which he made the declaration to the effect that natural selection would remove any detrimental trait from a population. I cannot remember now where I found this information, but I think it is in one of the various editions of Origin

So you think that Darwin’s theory represents the current understand of evolution? Do you also think that Newton's theory also represents the current understanding of motion? You may not be aware of this but scientific explanations change over time. Also explanations based on purely evolutionary constructs are being replaced by explanations based on molecular biophysics explanations as well. You could say that ToE as it currently exists is the phenomenological explanation vs. reductionist explanation. Like say thermodynamics vs. statistical mechanics. Evolution is not some holy revelation. It is a scientific explanation and like all scientific explanations it changes over time as more is learned.

I fail to see why, in a Darwinian universe, natural selection would allow any trait that is completely detrimental to persist in a population. Can you document how a light color is beneficial to a population of moths that live among trees that are darkened by air pollution.

Darwinian universe? Is that like a Newtonian universe? You appear to be stuck in the 1800's. You are just playing with words. Any set of traits that doesn't allow a species to survive could be seen as detrimental. However you want to label it, it just doesn't matter. The changes that occur over time allow the species to survive or flourish. If they don't then it is just too bad for the species. What would be interesting is a species that never changed and persisted through radical changes in environment and did just fine for many millions of years. That might be difficult for ToE to explain.

Starboy

[Pooeypants]

Quote by: jeafl Based on what I know about sickle cell anemia, it does not match the definition of convergent evolution: Evolution Philip Whitfield Macmillan Reference USA/Gale Group New York 1993, 2000 0028655931 convergent evolution The process by which two or more independent lines of evolutionary development bring about superficially similar end-points. When different groups of organisms are subjected to the same selection pressure they tend to evolve a similar design feature. Streamlining, for instance, gives great energy—efficient benefits to any animal that swims underwater. As a result, sharks, dolphins, and the now-extinct marine reptiles, ichthyosaurs, although unrelated, all converged on a similar streamlined body form.

Sickle cell anaemia occurs in West Africa and India. However, the mutations which causes the same phenotype in both set of populations is identical but the replacement mutation is at a different location.
Although we're talking about same species, I'm pretty confident these two populations don't readily interbreed and even if they did, it wouldn't explain why two genotypes of HbS exists.
What links them together though, is the threat of Malaria and I'm sure you're well aware that heterozygous HbS have increase resistance to the Plasmodium parasite.

[Agent007]

Pooeypants, do not belittle me. Behavior is instinctive, but you did not understand what I wrote in my post. Truly, if a twig-eating population's environment changed from a place with only twigs to one with twigs and caterpillars, then it is possible for a mutated organism to adapt in order to eat both twigs and caterpillars. If its offspring get the trait to eat both foods through heredity and they live in the same environment, then their food would be both as well. However, if a mutation occurred so that the organism can eat only mushrooms, and there were no mushrooms in the environment, then it would die, and all other organims mutated like so would perish as well in that environment. Heredity does not necessarily ensue in organisms' offspring from eating twigs and leaves because environments change over time. Populations that do not adapt properly are those that are wiped out like the organisms that eat only mushrooms.