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Brian:
You are asking me to explain simple concepts to you that you should have learned in the fifth grade:
can: past singular 1st person COULD.
can: to be able to; have the ability, power, or skill to.
In the case of jumping genes, it appears that not only can they cause irreparable damage to genes, apparently they usually do:
Transposons causing diseases
Transposons are mutagens. They can damage the genome of their host cell in different ways:
A transposon or a retroposon that inserts itself into a functional gene will MOST LIKELY disable that gene.
After a transposon leaves a gene, the resulting gap will PROBABLY NOT be repaired correctly.
Multiple copies of the same sequence, such as Alu sequences can hinder precise chromosomal pairing during mitosis, resulting in unequal crossovers, one of the main reasons for chromosome duplication.
Diseases that are often caused by transposons include hemophilia A and B, severe combined immunodeficiency, porphyria, predisposition to cancer, and Duchenne muscular dystrophy.
Additionally, many transposons contain promoters which drive transcription of their own transposase. These promoters can cause aberrant expression of linked genes, causing disease or mutant phenotypes.
-Wiki, under Transposons (caps mine)
Do I need to explain what "most likely" and "probably not" mean?
Your vaunted jumping genes, which you present as carriers of superior genetic material, and which in your imagination quite blindly insert themselves into gene sequences to turn monkeys into men, as it were, are not turning out to be your white knights of evolution after all. Upon insertion they disable the gene, and when they leave like an unwanted house guest, they leave a damaged gene that probably can't be repaired properly.
Sounds like the genetic equivalent of the visiting relative from hell to me.--- --- --- --- --- --- --- --- --- Replying to: Listen, I'm waiting for a real challenge. Why don't you ask me how an inferior brain like that of John could evolve into a far superior brain, like that of Brian?
Answer: the theory of evolution does not claim that my brain evolved from John's, it simply claims that we have a common ancestor. Hehehe.
Now, you once again have made me very proud, John, I can see that you are learning. Really, this pleases me greatly. Wikipedia, while not truly peer-reviewed per se, is a good start for many of the topics we are discussing.
I just want to make sure we agree on a couple of points. First, transposition of pieces of DNA code occurs in all major branches of life. In other words, pieces of DNA in an organism's genetic code occasionally pick up and leave and replant themselves in a different position in that organism's genome. Are we in agreement on that?
Second point: you say "[transposons] CAN cause irreparable damage to the genome." (my caps) I don't want you to spend another 250 words on the definition of CAN, so I'll just ask, do transposons ALWAYS cause irreparable damage? Or can I assume that by "can", you really do mean that they SOMETIMES cause irreparable damage, and sometimes they don't? When they don't cause irreparable damage, what do they do? Do they EVER do anything good for an organism?
Finally, I'm wondering where exactly I said that "jumping genes caused favorable mutations....conferring large, superior brains..". I just can't seem to find where I wrote that, could you point it out to me? Thanks. |
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