You may have heard about that odd hothead mutation in Arabidopsis that seemed to be violating a few principles of basic genetics—there was an unexpectedly high frequency of revertants that suggested there might be a reservoir of conserved genetic information outside the genome. Reed Cartwright proposed an alternative explanation, that gamete selection could skew the results. Now the latest reports suggest that the bias was an artifact of foreign pollenization (which I think is interesting in itself. Life is damned good at sneaking its genes in wherever it can.)
Anyway, if that's all gobbledygook to you, Scientific American has put up a lucid summary of the hothead affair. It's an example of good science, where the observations and hypotheses are hammered out and refined to get a best explanation.
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Bah. All this really proves is that all you Evilutionists don't have a clue how genes and mutations work, and refuse to see the Designer's hand at work in repairing these poor, afflicted plants.
Until, of course, you do solve the problem. But don't worry. We'll have latched onto the next gap by then.
(just getting the obligatory blather out of the way.)
"Arabidopsis does seem to have a proclivity for mutating. My colleague David Biello recently wrote about a finding that the plant kicks up its mutation rate when stressed and passes down the trait for several generations."
I don`t think this is an outstanding claim, given that we know for quite some time now that epigenetics - so more or less the histone modifications plays a major role in most of eukarya.
From an evolutionary standpoint i don`t like the cache hypothetisis, there is a good reason why nature hasn`t introduced caches but rather only outsourced functionality - just like software engineers do, nature uses plasmids, microcircles or heck one might even say virions.
Transposons could account for this phenomenon as well if there are some special transcription factors that act specifically on the transposons in such a way that they are in fact silenced and switched back in such a way that it would mimic a cache like system....hmmm....but given that the A. thaliana genome is fully sequenced one could actually check this out at BLAST level, which of course certainly has already been done.....and i should have come to that conclusion before i wrote all that :(
But the simplest explanation was already given and as we all know the simplest logical explanation is often the right one.
I felt the response to the Communication arising was pretty strong arguing against the foreign pollenization, but we'll see....
Life is damned good at sneaking its genes in wherever it can.
PZ, this sounds like something from panspermia. Is your belief waning?
There was a link in the SciAm story about bacteria thought to be similar.
It seems they should be able to show this duplication with the technology today. The article this story points to is hard to read. Does this say whether they've actually seen this? That would be pretty compelling.
It seems they should be able to show this duplication with the technology today. The article this story points to is hard to read. Does this say whether they've actually seen this? That would be pretty compelling.
Certainly.
The article says
Looking at reference number 2, we find:
Andersson, D. I., E. S. Slechta, and J. R. Roth. 1998. Evidence that gene amplification underlies adaptive mutability of the bacterial lac operon. Science 282:1133-1135.
http://www.sciencemag.org/cgi/content/abstract/282/5391/1133?ijkey=f29e…
and this article delivers the evidence, as the title promises:
Thanks, windy.