Here's something cool. Norway spruce trees sprout from subterranean root systems, and though the actual trees come and go, the roots are extremely long-lived. In this they're actually a lot like mushrooms.
New research by Leif Kullman at the University of Umeå is just being reported on by the media. His team has studied spruce trees on the treeline of Mount Härjehogna in Dalecarlia, central Sweden, and found no standing trees older than 600 years when wood samples were dated. But below ground, the living roots of three trees gave radiocarbon dates at 5,000, 6,000 and 8,000 years BP! The oldest root system thus dates back from the end of the latest glaciation. It's been supporting varying types of spruce, from little bushes to tall trees, as conditions have varied through the millennia.
(The only bits that are actually alive and metabolising in trees are the surface layer. Every year-ring gives a progressively older radiocarbon date as you move toward the centre of the trunk. That's how it's possible to use dendrochronology to calibrate radiocarbon dates.)
This offers a number of interesting new perspectives. Firstly, though the Norway spruce is a recent immigrant to much of Sweden, it is now in fact the oldest known tree species in the mountains of Dalecarlia. Secondly, if we want to know what the Norway spruce genome was like 8,000 years ago, we needn't look for deadwood in bogs. We can sample living individuals on Mount Härjehogna and elsewhere.
[More blog entries about trees, spruce, Sweden; träd, gran, Dalarna.]
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I am surprised that you can carbon date something that is still alive, I was always under the impression things stopped taking on carbon at death (or end of eating etc).
The only bits that are actually alive and metabolising in trees is the surface layer. Every year-ring gives a progressively older radiocarbon date as you move toward the centre of the trunk. That's how it's possible to use dendrochronology to calibrate radiocarbon dates.
8000 years old? That's impossible. The Earth is only 6000 years old.
:-D
Fine. But the article says that they dated the roots, not the trunk. Or do roots also put on yearly rings like the trunk does?
While the Norway Spruce is a fine tree, its clonal colonies have nothing on the Quaking Aspen (Populus tremuloides.) There's Pando in Utah, a single clonal colony that is thought to weigh 6,000 tonnes and perhaps as old as 80,000 years.
As far as the genome goes, it would be interesting to do comparisons between the genome of various areas of the root structure and areas on the actual trees. Given enough time and changing conditions you could have vast amounts of genetic variation within a single organism, possibly even comparable to variation between species.
I may just be exposing arts-student ignorance here, but if a lifeform has been going for that long, is the genome still going to be the same? That's an evolutionary timespan, surely. You say it's produced widely differing sorts of spruce plant up top in this time; presumably it's also been replacing itself down below. As the previous commentator asks, is the living root still going to be the same as the 8000-year-old one? Not that that stops you taking 8000-year-old samples, obviously. How far can one go from such a sample to what the actual plant would have been like, though?
The six year old thought this was just too cool. Then, when we looked up Reed E's comment, his head just about exploded. We just finished the BBC's Prehistoric America about five days ago and have been discussing the time line (this would actually be the planetary timeline in our Atlas of Life on Earth).
I would also note that one of the articles I read about Pando, mentioned that it might be as much as a million years old.
Hej, Martin! Long time no seen :-)
Snygg blog. Ãlskar namnet LOL
Kram,
Ketutar
Of course! All woody parts of the plant do that!
8000 years is nothing, however. Look at how we changed in the last 8000 years -- blue eyes, lactose tolerance, and that basically is it.
"Given enough time and changing conditions you could have vast amounts of genetic variation within a single organism, possibly even comparable to variation between species."
Unlikely. No sexual reproduction means even less variation than found within a single species. And no germline mutations means a mutation within a single cell isn't going to be reproduced throughout the organism.
Brand new cells will be highly similar to 8k year old ones, genetically, AFAIK.
David MarjanoviÄ -
I have to say, I really appreciate your comments. Have you ever considered your own blog? Seriously, you provide a lot of interesting information that I have really enjoyed being privy to. I for one, would love to see you at a blog of your own.
Brian S.:
"Unlikely. No sexual reproduction means even less variation than found within a single species. And no germline mutations means a mutation within a single cell isn't going to be reproduced throughout the organism."
what about in the case of polyploidy? can't new buds shoot off with double or triple the chromosomes of the "parent"? just a thought.
A late comment, since this came up at talk.origins now... The National Geographic article on this says:
So looks like insides of living roots were not carbon dated. Some people have also got the impression that genetic testing was done on the ancient material, but I can't find any account of that either.
Hmmm. That puts the whole thing in a different light. I wonder how confident they are that the material they've dated is actually earlier parts of the living clones.
I think they seem to be very confident, but I don't know why :) The individual trees/bushes seem to be very isolated, judging from this pic, so it's sort of justified to assume that all the material comes from the same tree. But if a tree dies, couldn't the same spot be recolonized so 'quickly' that it would be hard to tell the difference on the 9,500-year scale?
DNA?
Spruces are not known to sprout from root systems. Other reports suggest that layering occurs (rooting of prostrate branches), but too few details have been provided in the news reports to really understand the specifics. I think layering is by far the most likely origin.
The dated root material cannot have been alive. If so, one could have counted rings on it, and that would surely have been done early on. I'm afraid these fragmentary news reports are almost worthless and only a scientific report by qualified conifer morphologists or anatomists can clear up the confusion.
BTW, the old aspen clone is kid stuff. Read about the 43,000 + yrs. Kings Holly clone in Tasmania in my 2007 book "The Bristlecone Book: A Natural History of the World's Oldest Trees"(Mountain Press).