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Comment by FooBarBizBazz | Hacker News Reader

I hope they are able to bring back the American Chestnut too.

That tree isn't completely dead -- some stumps and shoots remain -- but adult trees never survive, due to a fungus that didn't used to exist in North America.

There are now two programs to bring it back. One, by hybridizing with Japanese Chestnut and breeding to (hopefully) keep not much more than the Japanese tree's blight resistance. And another -- more controversially but maybe actually better -- that adds to the American Chestnut genome a single gene, from wheat, that confers resistance to the fungus. These latter trees would be even more like the originals.

The hybrid program has some test sites now in the wild. The GMO version has not been approved, but I hope it will be.

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The Wikipedia article suggests there are not just a few, but many known living examples of the American Chestnut. Not to say it doesn't need saving, but this seems better than just some stumps and shoots.

https://en.wikipedia.org/wiki/American_chestnut#Surviving_sp...

It is quite common to see American Chestnuts in the northeast US, in the Hudson Valley, for example. Growing up in that area, I saw many with their big beautiful serrated leaves. The problem is that they never grow very tall or big before being attacked and killed by the blight. I believe some can even bear fruit though I do not personally recall this. There have been a number of really good articles in publications like the nytimes on bringing back the American chestnut to health via parallel tracks of cross-hybridization and GMO. I don't have the references right now, but a quick Internet search will reveal them.

I'm a bit late to this conversation but I wanted to drop in and support this comment. I live in North Carolina and have personally seen dozens of adolescent American Chestnut trees in the Appalachians in the western part of the state. They love the high ridge lines out there. Most of the chestnuts I've seen look like shrubs due to how they develop and can easily be missed of you're not looking carefully for them. From what I've read elsewhere most American Chestnuts only make it to 5-10 years old before the blight gets them. I've only seen a couple of trees taller than 10-15' tall in the wild (and have seen several infected with the blight).

The American Chestnut is "functionally extinct", because despite the fact that they are somewhat prominent throughout their native habitat as adolescents, they rarely (if ever) are able reach maturity and develop fruit (and therefore can't reproduce).

Here are a few pics of some adolescent chestnuts if anyone is curious:

- https://unsplash.com/photos/O9q1p_9bji0

- https://unsplash.com/photos/0s7_4fm8y-g

- https://unsplash.com/photos/WKl-XtkAnXM

- https://unsplash.com/photos/fESmwiRQf_c

Beautiful pictures. Thanks for sharing. I am really fond of the shape of the leaves. Since this is HackerNews, I believe there is also an entrepreneurial angle for the reemergence of American Chestnuts for carbon offset markets and to produce food (roasted chestnuts are delicious!). If the GMO version of the American Chestnut is approved by the US government, it will be the first GMO tree.

Some do still bear fruit even inside blight range. I live in NJ and have a survivor that's stressed but able to produce. Got a few handfuls out last year and was able to try some for the first time. This yield is compared to the few truckloads I get off the 2 chinese chestnuts here, but it's something.

Basically, there's 2 ways to bring these trees back to blight range (or something approximating them). Method 1 is hybridization route with Chinese chestnut, method 2 is genetically modified route using a single wheat protein gene to confer resistance. Method 2 needs approval and there was a request for comment open a couple years about it.

I watched this video from a guy named Mark Shepard who's approach is hybridization and natural selection. It sounds like he has American-Chinese chestnut hybrids in his farm: https://m.youtube.com/watch?v=RePJ3rJa1Wg

We're likely going to need such programs to save thre North American ash species from the Emerald Ash Borer as well.

Releasing GMO chestnuts will contaminant the gene pool forever, it's a bad idea.

Two things about the American chestnut are relevant: 1) the percentage of forest it occupied is widely overstated, seemingly due to exageration thru retelling of the story. It was usually a top ten tree at most sites, far from the numbers you usually see in articles. The these numbers are from ideal sites for its colonization or areas where it was planted by humans. This is widely known and studied, but people who write about it to lay audiences tend to use exaggerated figures out of context.

2) many specimens survived the blight due to partial resistance, not all were wiped out.

All we need to do is wait and they'll do just fine. Even a traditional breeding program would work in a few generations, there's really no good reason to rush this stuff.

All we need to do to fix climate change is wait as well ;)

I dont know why the poster is being downvoted, I have heard the same about the Chestnut coming back from foresters and others in the know for a decent amount of time.

Pretty sure you'll find https://www.youtube.com/watch?v=Vi12xaJxA5U saying the same thing about the Chestnut.

What are you winking at? Cheeky comment, but thread was about trees... You just trying to flame war?

>Releasing GMO chestnuts will contaminant the gene pool forever

So what?

Whomever downvoted this care to comment with evidence?

American Chestnuts that have gained resistance to blight via selective breeding, hybridization with a different species, or insertion of a different gene are all genetically modified. The only difference is the source of the modification. Starting a comment with the inflammatory statement "Releasing GMO chestnuts will contaminant the gene pool forever, it's a bad idea" doesn't serve the discussion well.

Humans are really good at throwing environmental pressure (logging) after environmental pressure (chestnut blight) after environmental pressure (urban air pollution) after environmental pressure (global warming) at species. The speed with which these pressures arise is faster than natural selection can deal with for most species, and are leading to an extinction event rather than species just learning to adapt. If we can make minor direct genetic modifications to help species cope, I think it's an unqualified win.

I didn’t downvote, but my guess is that it has to do with the first sentence as sounding like something an anti-GMO nut would say.

Right. "contaminant " or even "contaminate" is a "press the emotional button" kind of word. The kind of disgust-trigger than inhibits rational thought.

Stripped of that, it says "the new gene will be in the tree's the gene pool forever, so it's a bad idea" which is a non-sequitur. Putting the gene in permanently, for permanent fungus resistance, is the point, isn't it?

The emotional appeal is the entire argument. It seems to imply that gene editing is always "bad and dirty". There might be a case to be made that putting this particular gene in this tree is a bad idea, but this sentence is really not it (1). I think that I had an emotional reaction against it ;)

IMHO Gene editing is too broad a category to judge like that. Comments on the internet - good, bad or useless? It depends on what you write, and where.

If someone is going to ask for "comment with evidence", then do not reverse the burden of proof (1) and put that on "downvoters", instead ask for "sources" that all gene editing is "contamination", rather than giving a free pass to sneaking in the conclusion via loaded language, without supporting evidence.

I think that I gave this topic more in-depth examination than it deserved, but there you go.

1) https://en.wikipedia.org/wiki/Argument_from_fallacy

2) https://en.wikipedia.org/wiki/Burden_of_proof_(philosophy)

Two points:

1) resistance genes are already in the genome, they don't need to be added. This means the entire endeavor is unnecessary

2) this is an internationally recognized definition of genetic pollution, it's controversial only with a few hardliners.

1. Resistance genes are already in the genome, but they have so far proven inadequate. Experiments in interbreeding and crossbreeding have been going on for 60 years from the USDA, the American Chestnut Foundation, the American Chestnut Cooperators Foundation, etc - and none of them have declared "victory" yet. There's no reason to assume there'll be blight-resistant chestnut seedlings available anytime soon. Or anytime late, to be honest.

2. If you read the wikipedia article [1], it has an entire section on why it's controversial. It also has links to an article on genetic rescue[2], which I think is more relevant.

[1] https://en.wikipedia.org/wiki/Genetic_pollution#Controversy

[2] https://en.wikipedia.org/wiki/Genetic_rescue

Yes! Also the Dutch Elm.

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