[b said:
Quote[/b] ]Corn and maize are very much mutants.
I see what you are saying but I disagree. Using your argument every domesticated veggie/fruit/animal is a mutant. I call it selective breeding for desirable traits. Semantics I guess.
[b said:
Quote[/b] ]When they first entered cultivation thousands of years ago, each head only had 2 kernals on it.
Again, it has been a while for me but I believe that wild maize actually had 4-6 kernnels that grew on only one side of the "cob" and the kernnels were about 2-3 times larger than what we see on traditional corn. And wild maize still exists. there was talk a while back about crossind commercial corn/maize back with ancestral stock to regain some of the disease resistance lost. The farm industry shot the idea down though as it reduced yeild per cob.
[b said:
Quote[/b] ]Just because that is the mechanism in corn/maize does not mean it will be the same for nepenthes.
Actually yes it does. The mechanism for TE excision/insertion is pretty much universal so it does not matter what the TE is in be it bacterium, maize, Nep or human. All that really matters is where the TE jumps into/out of. In this case, discussing the possibility of a TE inserted into the pigment gene for peristomes, the mechanism would be probably be almost identical to that of maize. So the only factor you really have to take into account is the transposition rate which is higher than the mutation rate of DNA by 3-6 orders of magnitude. And personally I feel that covers the "TOO random" part.
[b said:
Quote[/b] ]Consider the orders of magnitude of complexity that nepenthes genetics has over corn/maize genetics. Though it MAY work by the same mechanism, you are assuming that since it works in an organism with n=10, it must be the same in an organism where n=40
The magnitude of genetic complexity make little or no difference (actually that is not quite correct, the more genetic material then ususally the more TEs are present. But that is beside the point). The point is that the mechanism is constant through out. It is simple: a TE inserts into a region of a gene, any gene, and alters the expression (either up or down). At some point in the future that TE jumps and the gene reverts to its normal expression pattern. It make zero difference if the gene is one for colour or one for cytochrome C production, the mechanism of TE insertion/excision is always the same.
[b said:
Quote[/b] ]well, maybe shrivel isn't the best word. but they condense to form little blobs called Barr bodies. they definitely separate from the rest of the chromosomes.
Yes, the Barr bodies.
But they are not seperated from the other chromosomes and they are minimally active. They are just mostly permanently condensed as opposed to the other chromosomes which are partially/temporally condensed.
[b said:
Quote[/b] ]
[b said:
Quote[/b] ]
...since a major part of every genome is composed of TEs...
whoa, slow down there. TEs have been discovered in some eukaryotes...but they're not a MAJOR part of ANY genome, let alone EVERY genome.
At the risk of sounding like a pompus arse, be careful when arguing genetics with a geneticist
But you are partially correct and I was rash saying that TEs are a major part of every genome. However, to date, every sequenced organism has had at least some type of TE present so I was correct in saying they are in every organism. And typically as the size of the genome increases so to does the persentage of the genome that is TEs (with a few exceptions such as the honey bee). So if you look at it in order of increasing size, in
E. coli TEs compose 0.3% of the genome, in
C. elegans it is 12%, in
D. melanogaster it is 15-22%, in humans it is 45%, in maize it is 60% and the frog
R. esculenta it is 77%! Now I guess it comes down to personal definition but in my book 12%+ is a pretty "major" fraction of the genome. But even if you do not agree with me on that point you have to admit that 45%-77% of the genome is major.
[b said:
Quote[/b] ]In actuality, a "mutation" is a change in the DNA sequence, through any one of several means. It actually occurs quite commonly. So basically, every organism on Earth that evolved from the earliest primordial life is a result of mutation.
And by that same token every individual of any species is a mutant because no two individuals are truely genetically identical what with SNPs and alleles and all
And that is why I say maize is not a mutant any more than a dog is a mutant. But to each their own...