When talking about megafauna resurrection, it is often said that it's not possible because DNA degrades too much after a few thousand years. Yet apparently the DNA of this plant was still viable. What am I missing?
A seed is a living organism essentially in suspended animation. Cells in the embryo have intact plasma membranes, DNA repair mechanisms are present (although working very slowly), each cell is surrounded by a cell wall, and the entire seed has an outer protective seed coat.
When people talk about DNA degrading, they are usually referring to DNA that is no longer inside living cells, and that doesn't have these multiple levels of protection.
Basically just time scale. When people talk about DNA having degraded too much, it's generally in the context of bringing back dinosaurs. Dinosaurs went extinct about 65 million years ago, which is (obviously) much longer than 30,000.
Until recently it was thought that DNA degraded more quickly, indeed making it un-viable after only a few thousand years, but a relatively recent study put the half life of DNA at 521 years, meaning that it would take several million years to degrade fully, under ideal conditions.[1]
Therefore, bringing back animals like the woolly mammoth should be quite feasible, but probably not dinosaurs.
I guess that even if the DNA breaks down into smaller strands, you can still computationally assemble the DNA back into its original form (just search for overlaps in the sequences, and stick these together).
(Remember that if you have multiple cells, you have lots of strands of the same DNA, all broken in different places.)
Not an expert, but I would think it depends how broken down they are. Assuming you have the tech to examine millions of fragments, you would still need long enough sequences for the overlaps to be unique. For instance, you probably couldn't put a book back together with nothing but ten character phrases, but you probably could with 100 characters. It would be interesting to run a simulation to see where the cutoff lies.
Also not an expert, but since a very large percentage of a given dino's genes should be common in other organisms, there's at least a large corpus to compare (most) fragments to.
Imagine taking a thousand copies of War and Peace, cutting them into strings of less than 10 characters, and mixing them all up. Even with the entire corpus of human literature to compare to, I doubt you'd be able to reassemble the scraps back to something even close to War and Peace. In fact, you could probably take those scraps and turn them into any number of completely different novels, because your building blocks are so small you've got essentially no constraints to work with. You don't have complex ideas, you just have the basic building blocks of language.
Now, I'm not saying this is the case for dinosaurs, just that, given enough time to decay, it makes sense that eventually DNA would reach a point where it isn't possible to reconstruct, because the information just isn't there any more. I'd be curious to know how long it would take to reach this point.
DNA that's hundreds of thousands of years old has been recovered [1]. Sorry for the non academic link but the number I've always been told was just under a million years, this seems reasonable at first blush.
The tundra is primarily always frozen. As you point out freeze/thaw cycles are terrible for biochemical stability, but at the tundra below the surface (where earth acts as an heat insulator) I believe this effect is minimized
DNA has some remarkable stability properties when it comes to preservation. This is one of the reasons people are so interested in DNA storage technologies.
DNA chemistry allows for information to be preserved for millenia at sub-zero centigrade temperatures.
Robert N. Grass, Reinhard Heckel, Michela Puddu, Daniela Paunescu, Wendelin J. Stark. Robust Chemical Preservation of Digital Information on DNA in Silica with Error-Correcting Codes. Angewandte Chemie International Edition, 2015; DOI: 10.1002/anie.201411378
It depends of the species, but polyploidy is common in plants because plants often can work as colonial organisms that can clone itselves.
Is the same problem as to restore a file that is partially distroyed in four or five points. You can still recover the original file if you have five copies, each one with the damage in a different area. Polyploid organisms have several identical security copies of each chromosome. If something in a chromosome is damaged, they can quickly fix the damaged areas using the safety copy saved in his 'twin' chromosome.
Nice to read about a new breakthrough in botany. The field doesn't get much attention at all. Maybe now it will benefit from the popularity of Martian, the movie.
As is true in many areas of organismal biology, botany is a field in decline. There are not a lot of jobs anymore, and in academia, not a lot of grant money. In spite of this, every year universities continue to pump out more and more graduates trained for careers that no longer exist. Some of the best botanists these days are citizen scientists who have day jobs at the Cheesecake Factory or driving limos in Las Vegas.
I've recently read a (German-language) article, that botanical gardens in Germany are an endangered species.
That's because they are expensive to maintain, professorships have been faded out and biology students and post-grads are usually not so much interested in real plants and systematics anymore, but more in genetics and laboratory work.
The small state of Saarland doesn't have a single publically accessible botanical garden anymore. Across Germany the outlook is dim.
Reminds me of an episode of Futurama where they revive xmas trees which were accidentally were cross contaminated with bio-weapons. Spoiler, the Christmas trees shoot exploding pine cones that multiply until the entire earth is covered in pine trees.
Amy: "What's that splork on them? It's not germs, is it?"
Please tell me that virusses and bacteria can't be revived after 30k years in ice, or that our imune system is able to remember its defenses against virusses and bacteria it hasn't seen for 30k years.
Our immune system is pretty good at identifying all kinds of foreign proteins. Unless a virus or bacterium has specifically evolved to evade our immune system, its chances are pretty bad. I wouldn't be too worried.
tdy721 has been downvoted, but as far as I'm aware he's got the right idea. Viruses don't die. When outside a host, they basically just crystallize. If a plant can be viable after 30k years, a virus can definitely also be viable after the same 30k years.
> (PS: I know what you want to say, but it's your own fault for arguing that way.)
If that's the game you're going to play, what was the point of your original comment? You're claiming to have known when you posted it that it was nonsense.
Nothing. But, Panspermia is not meant to address how life began, just the method that may cause its distribution in the Universe. - from the Panspermia Wikipedia article
If the DNA in a seed is still in good enough shape to support blooming after being frozen 30,000 years, perhaps a seed frozen in a meteorite [1] could also survive long enough to be spread between solar systems.
[1] maybe after glancing off a planet or created by the collision of two large objects
I'm not an expert on comets, so I might be wrong, but I guess that we talk about recycled ice; that would be sterilized each time the comet orbit pass closest to the sun and the water is (partially?) boiled, to become frozen again later.
There would be probably other consequences if a such large comet will fall in a planet. I can't see any happy ending for this organism to surviving its travel just by chance. If the comet is small or disintegrates in smaller pieces the plant is roasted and dead. Otherwise if fallen in one piece, all the life in the impact area of such large comet should be crushed by the pressure wave and vaporized also, including our plant
I guess it's all about freeze/thaw cycles, if the plant can handle one 6 month freeze, it can probably handle one 30,000 year freeze. The freezing is what causes damage, not the being-frozen. I guess.
The flower itself didn't so much bloom after being frozen, as cultivated tissue was worked in vitro to produce a viable flower. It's not exactly clickbait given the payoff, but it's still less than truthful IMO.
I guess I automatically assumed it was a human-assisted process since the link was to nature.com, although in hindsight it would have been equally publishable, if not more so, if the flower bloomed on its own.
