Discussion of everything related to the Theory of Evolution.
Okay, so your source claims to cite a legit journal, even though it links to the journal's home page and not to the article in question (which still casts suspicion, but oh well). That still doesn't resolve the problem that this article of yours has nothing to do with the topic of discussion, natural selection.
#2 Total Post Count
it shows harmful genes are common
which should not be the case for natural selection cliams harmful genes should be rare
thus NS is wrong
you want more evidence
http://www.accessmylibrary.com/coms2/su ... 738782_ITM
http://www.libraryindex.com/pages/270/G ... rders.html
Hello again gamila,
I've been trying to figure out why your last quote from an article on cancer research is at all relevant to your argument, but in light of some of your other comments, I think the title of the article "Researchers find new breast cancer genes" is causing the problem. New genes. You seem to be under the impression that speciation is caused by, or at least requires, the appearance of new genes. Before talking about how new genes develop, I'd like to clear up a common misconception that may or may not be contributing to your misunderstanding of the issues here.
This news article talks about new cancer genes. These genes are not new genes, they are just known genes that have been newly linked to some forms of cancer. And their function is not to cause cancer, but to perform some normal biological function that is probably described in the research article but is not mentioned in the news article. Some alleles of these genes (an allele is a variant of a gene - most genes have many variants in a population, but any one person can have at most two alleles for any gene, one from the mother and one from the father) possess polymorphisms (differences) that disrupt the normal function of the proteins encoded by the genes. Cancer is caused by the unfortunate co-existence of mutations in multiple genes, not by single mutations in only one gene. There are no genes whose function is to cause cancer.
Now, new genes. New genes arise from old genes (no spontaneous generation at the genetic level either). Genomes are not static things, particularly at the population level. We talk about "the human genome" or the genome of this or that species. If the genomes from all humans (or all individuals of any species) were completely sequenced and compared, you would be amazed at the differences that exist between individuals. And not just differences in alleles of genes, but differences in the numbers and locations of genes within "the" human genome. Genes get duplicated, small or large bits of chromosomes get duplicated, or deleted, or inverted, or transferred from one part of a chromosome to another or to a different chromosome. Some small bits of chromosomes can get duplicated, which then form small, independently reproduced circles. There's plenty of weird stuff happening in the genomes of species. Sometimes entire genomes get duplicated, leading to polyploid organisms (we are diploid).
When a gene is duplicated, you now have two copies of the same gene, so the copy is not actually needed. If a mutation occurs in the copy that would normally cause a complete loss of function, no worries, the original is still there to perform that function. The copy is essentially a renegade and can continue to accumulate mutations without having any effect on the species' fitness. If the copy still has its control sequences or finds itself embedded in another part of the genome where a protein can be produced from it, maybe (probably not, but maybe) it could some day a thousand years hence produce a protein that ends up with a different function. Try not to picture this happening as a single event within a single individual or lineage, but as multiple events accumulating within populations over very, very long periods of time. Sometime, somewhere one of these renegades is going to end up as a "new gene". Most of the trash is trash and will get tossed out eventually, but sometimes trash can be useful.
You don't need new genes to get a new species. The genomes of humans and chimps are virtually identical in the genes that they contain, and there are no "chimp genes" that make a chimp a chimp. The difference between humans and chimps is determined by different alleles of common genes and by how and when our common genes are expressed (the production of the proteins that the genes encode). Imagine that. Two closely related species could even have the same genes and the same range of alleles of these genes yet be unable to interbreed due to something as trivial as a behavioural difference in the mating ritual.
The biological world is in a constant state of change. What we call species are discontinuities that we can recognize by morphology or genetics (or behaviour). What we choose to call a species is indeed a human construct, but these constructs are based on observation and are just our attempt at categorizing the biological world. You are right in stating that there is no agreed definition of what a species is. Few biologists will argue this point. The lack of a universal definition, however, in no way negates that speciation has occurred, is occurring, and will continue to occur. What it does illustrate, though, is the richness of the biological world. We try to digitize organisms into discreet groupings as best we can, but the biological world is better viewed as an analogue continuum in constant flux with smaller or larger gaps here and there that we choose to call species (with varying levels of success or justification).
Natural selection does not need new genes to operate. It operates in every gene of every individual of every population of every species every day. Given enough individuals with enough genetic variation in enough environments over a long enough time, natural selection will lead to the formation of new species.
As far as the presence of so many harmful "genes" in the human genome is concerned, you (and the popular press) are confusing the terms "genes" and "alleles". I think the last guestimate of how many genes we have stands at about 35,000 (someone give me an update if there is one). And there are roughly 6,000 single-gene disorders. My, but we're in trouble. Why are only 1 in 200 births affected? My math is not particularly good, but shouldn't there be more than 1 in 200 births affected? This discrepancy is due to there not being 6,000 bad genes in our genome, but 6,000 genes that have bad alleles in the population. Some genes can have hundeds of alleles, some of which may not work very well and can cause disease. Most alleles do just fine. New alleles arise all the time. They can arise by new mutations, but they can also arise by recombination during meiosis that ensures that no two individuals will ever be genetically identical (except monozygotic twins). So, bad alleles, over time, tend to be slowly (sometimes quickly if they are fatal or prevent reproduction) removed from populations by means of natural selection. New alleles are arising all the time, some of which may cause problems. I suspect that modern medicine and reproductive technologies will tend to increase the frequenccies of bad alleles in us. The presence of so many bad alleles in our species is, though, quite normal. Alleles come and go. Evolution, in part, is the change in frequencies of alleles over time.
there i am talking about traits not genes
and as such NS is invalidated ny speciation
and they are harmful as such
you dont even know what a species is
and you talk all this scientific bumbo jumbo about speciation genome mutations - and none of you can agree on a definition of species
OK. I'm considering calling it quits on this thread. I don't know why I've tried so hard to explain some of the basics behind natural selectiion. My wife's been away for the last week, and maybe I'm just getting bored. Sometimes, though, I feel like a missionary, willing to strive to save even a single poor soul lost in the wilderness. But if that soul has no desire to be saved, then what's the point?
gamila, I'm not a moderator and have no authority for saying this, but this forum is for discussions about evolution. Nonbiologists are more than welcome here. Many laypeople have questions they want help with, and we are willing to help. Sometimes we get an occassional creationist who beats their head against the wall of science. It seems to me that you are not here to learn or to rationally discuss specifics but only to state that natural selection does not happen, for whatever agenda you have. Well, you've come to the wrong place for that. You will get no converts here. There are plenty of forums available to you where you can happily exchange dubious quotes.
Confrontation is not a good strategy for fruitful discussion. I, at least, would be more tolerant if you were willing to discuss why you hold the beliefs you do. I realize that you're not a biologist and so don't have much knowledge of the subjects discussed here, but that's OK. You're not discussing anything, though. Tell us why you believe the sources you have quoted, not necessarily in scientific mumbo jumbo, but just discuss something, anything. This is a discussion forum. Give us one of your quotes and then tell us why you think they are right. Don't just give them to us and say "There. I'm right and you're wrong". This doesn't get us too far. Evolutionists believe they are right because they have a wealth of evidence in support of their beliefs. Give us your evidence and we'll talk. Some thought is required, preferrably of the rational variety. But as I said before, an open mind is required. I believe what I believe for good resaons. I KNOW very little of any consequence beyond a shadow of a doubt, but probability is good enough for me to be a missionary.
look its quite simple NS is
1)darwin noted that the cambrian explosion made his theory wrong
it is noted
2) speciation makes NS wrong- i am talking about traits not genes and mutations are not what NS deals with
3* i have given evidence that harmful genes can be common thus invalidating NS which says they should rare
i think i have presented a sound case
I have already addressed this question, and you have refused to answer it. Would you mind finally explaining what was wrong with my previous analysis of why oncogenic genes might be considered beneficial from an evolutionary standpoint? For that matter, you have also declined to answer my question of what sort of theory you propose in place of natural selection.
This has also been answered previously, by myself and others. You have also never explained what was wrong with those explanations, either. In fact your habit of refusing to answer questions presented to you is beginning to convince me that wbla3335 is right. You are clearly not interested in a reasonable discussion; you are here to push whatever agenda you have, without any desire to keep an open mind to other possibilities and without any regard for the fact that your claims have been proven wrong time and again. If I am wrong and you really are interested in an intelligent, reasonable discussion, then you can begin by answering the questions presented to you.
#2 Total Post Count
more evidence that NS is wrong due to genes for breast cancer
some of these genes are common
these genes are harmful as they can lead to the death of the person
more evidence that the cambrian explosion makes NS wrong
even steven J Gould notes the problem
"The case at present must remain inexplicable; and may be truly urged as a valid argument against the views here entertained." (Darwin, C., The Origin of Species, 1872, pp. 316-317.) Today, Gould writes, "The Cambrian Explosion occurred in a geological moment, and we have reason to think that all major anatomical designs may have made their evolutionary appearance at that time. ...not only the phylum Chordata itself, but also all its major divisions, arose within the Cambrian Explosion. So much for chordate uniqueness... Contrary to Darwin's expectation that new data would reveal gradualistic continuity with slow and steady expansion, all major discoveries of the past century have only heightened the massiveness and geological abruptness of this formative event..." (Gould, Stephen J., Nature, vol. 377, October 1995, p.682.)
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