Moss Has Cloned Itself for 50,000 Years

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edfrank
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Moss Has Cloned Itself for 50,000 Years

Post by edfrank » Sun Jan 01, 2012 6:17 pm

Moss Has Cloned Itself for 50,000 Years, Study Says
Hawaiian plant may be one of oldest multicellular organisms.
http://news.nationalgeographic.com/news ... waiianmoss


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Ker Than
for National Geographic News
Published December 30, 2011

A moss spreading throughout the Hawaiian Islands (map) appears to be an ancient clone that has copied itself for some 50,000 years—and may be one of the oldest multicellular organisms on Earth, a new study suggests.

The peat moss Sphagnum palustre is found throughout the Northern Hemisphere, but the moss living in Hawaii appears to reproduce only through cloning, without the need for sex or production of spores.

All the moss populations sampled share a rare genetic marker, which suggests they're descended from a single founder plant that was carried via wind to Hawaii tens of thousands of years ago.
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"I love science and it pains me to think that so many are terrified of the subject or feel that choosing science means you cannot also choose compassion, or the arts, or be awe by nature. Science is not meant to cure us of mystery, but to reinvent and revigorate it." by Robert M. Sapolsky

TN_Tree_Man
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Re: Moss Has Cloned Itself for 50,000 Years

Post by TN_Tree_Man » Sun Jan 01, 2012 9:18 pm

I can almost believe it. When I was a single man, I thought this might be occuring with moss over much of my leftovers in the refrigerator...

Steve Springer
"One can always identify a dogwood tree by it's bark."

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Lee Frelich
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Re: Moss Has Cloned Itself for 50,000 Years

Post by Lee Frelich » Fri Jan 06, 2012 2:22 pm

I am always doubtful about peoples claims that a given organism is a clone that hasn't reproduced for thousands of years. Such claims have been made for aspen, various fungi, mosses, etc., over the years.

What I find more interesting is that Sphagnum can grow in Hawaii--this lends support to the hypothesis that Sphagnum moss is the ultimate climax vegetation for the terrestrial earth. According to this hypothesis that I heard about in a lecture in Minneapolis in 1989 (I never seem to forget these sorts of things), without disturbance, the entire landscape of the earth would be covered by sphagnum, like northern Scotland. Of course, that would suck a lot of CO2 out of the atmosphere, and make the whole earth very cool, which would make the moss happier, I suppose, than a tropical climate, and reinforce the moss dominance.

I wonder if anyone has studied the evolution of these mosses by epigenetic processes and somatic mutations?

Lee

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edfrank
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Re: Moss Has Cloned Itself for 50,000 Years

Post by edfrank » Fri Jan 06, 2012 9:23 pm

Lee,

The age of most of these clonal colonies are estimates based upon extrapolations of their measured rates of growth. I know there is potentially a large amount of error in doing these types of extrapolations, but the alternative would be to simply not try do do any age estimate at all. I think a reasoned guess is better than nothing at all. How would you approach this type of a problem - i.e. estimating the ages of these clonal colonies, or would you opt not to do so at all?

Ed
"I love science and it pains me to think that so many are terrified of the subject or feel that choosing science means you cannot also choose compassion, or the arts, or be awe by nature. Science is not meant to cure us of mystery, but to reinvent and revigorate it." by Robert M. Sapolsky

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Lee Frelich
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Re: Moss Has Cloned Itself for 50,000 Years

Post by Lee Frelich » Sat Jan 07, 2012 10:21 am

Ed:

I suppose I would try the so-called molecular clocks that look at DNA in various organelle (chloroplasts, mitochondria, etc.).

Looking at C14 at various depths in the moss carpet might be interesting, and may or may not tell us much, depending on the rate of decay and how the oldest organic carbon at the bottom of the sedimentary sequence is. There might also be a signal in the sedimentary sequence of ponds of lakes, or even cave deposits or speleothems. This would be because when the moss took over the forest floor, it would have changed the chemistry of water percolating through and into the ground (because of the organic acids the moss produces), and probably changed the species of algae and diatoms in the water, and also for speleothems, the change in water chemistry could change the mineral deposits--given your background, I am sure you know a lot more about this than I do.

Anyways, if a date that the moss started to dominate ecological processes could be obtained from sediments/caves, and there was also a good molecular clock based on mitochondrial DNA, then there would be good reason to make the claim that its so old, a better basis than extrapolating from the last few thousand years.

Lee

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Rand
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Re: Moss Has Cloned Itself for 50,000 Years

Post by Rand » Sat Jan 07, 2012 11:25 am

Lee Frelich wrote: What I find more interesting is that Sphagnum can grow in Hawaii--this lends support to the hypothesis that Sphagnum moss is the ultimate climax vegetation for the terrestrial earth. According to this hypothesis that I heard about in a lecture in Minneapolis in 1989 (I never seem to forget these sorts of things), without disturbance, the entire landscape of the earth would be covered by sphagnum, like northern Scotland.
Lee
Discover Magazine ran an article similar to this, where accumulating spagnum moss makes the soil acid, similar to the forest death caused by acid rain. In this case they were saying that clear cutting the tongas NF might not be as bad an idea as we think as the clearcut resets the accumulating spagnum moss. The were basing this on an aleutian island were a large volcanic eruption cleared the island, the forest grew back but was gradually overwhelmed by the moss.

To be far I don't think they were advocating clearing the whole thing in human lifetime like we've done everywhere else.

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edfrank
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Re: Moss Has Cloned Itself for 50,000 Years

Post by edfrank » Sat Jan 07, 2012 12:07 pm

Lee,

You are suggesting that genetic variations would have taken place within the organelles between different areas within this clonal colony or that there would be genetic differences between this colony and colonies in other areas? How would the rate of genetic drift be established? Through dating changes in the environment? Dating the effects of the moss on the ecosystem based upon sediment or cave deposits seems a reasonable option. Calcite speleothems are limited in number the basic volcanic settings in Hawaii, but there are some. Perhaps.

Ed

Molecular drift: http://www.nature.com/scitable/topicpag ... ence-41971
"I love science and it pains me to think that so many are terrified of the subject or feel that choosing science means you cannot also choose compassion, or the arts, or be awe by nature. Science is not meant to cure us of mystery, but to reinvent and revigorate it." by Robert M. Sapolsky

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Lee Frelich
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Re: Moss Has Cloned Itself for 50,000 Years

Post by Lee Frelich » Sat Jan 07, 2012 3:01 pm

Ed:

I would sample a whole bunch of different parts of the moss, since there might be different patches of the moss that had different mutations, so that the development and then flow across the landscape of each mutation could be followed. If not, it might be hard or impossible to tell how much time had gone by, since there wouldn't be a reference, unless such a reference exists in the place where the moss originally dispersed from, in which case we would be comparing two divergent paths of mutations starting from the time that the moss reached Hawaii.

This is interesting to think about, but would be really hard to carry out.

Lee

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