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Comment by pazimzadeh | Hacker News Reader

It's too bad that the cost to sequence a human genome was above $100 million dollars in 1997. Of course, by the time Jeanne Calment was 122 years old her genome would have accumulated thousands of mutations, so what we would have needed is to sequence her in 1875, the year that she was born (someone correct me if I'm wrong).

Now that the price of sequencing the human genome is ~$1000, is it worthwhile to sequence all newborns, so that on the off chance that a person is a long lived anomaly we can study what made them so?

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The genetic basis of longevity is highly debatable. But anyways, just sequence her kids. Not that it matters so much, since even if we had that information we wouldn't know what to do with it. Longevity is a highly polygenic trait, and as it stands we barely understand the genetic architecture of even much simpler ones like height.

No it isn't. Lobsters have no known biological senescence. The difference between a lobster and a person is genetics.

Does that difference preclude senescence in humans being polygenic?

The difference between a person and a lobster, is a lobster is delicious.

So you know with absolute certainty that a human isn't?

But so are humans, so I'm failing to see your point.

Assuming humans taste somewhat like pigs, humans are every bit as delicious as lobsters.

> The difference between a lobster and a person is genetics.

A difference. There are others.

The only other differences are environmental. Since other animals that do exhibit senescence share the environment of the lobster, we can conclude that the lobster's environment does not confer this property.

> The only other differences are environmental.

That's true.

> Since other animals that do exhibit senescence share the environment of the lobster

Not entirely -- the environment through the whole lifecycle, including at the microscopic level, matters, and things that aren't lobsters differ in the environment in which the genes are embedded from a microscopic level from lobsters as well (there is, of course, a complex two-way cause-and-effect interaction between this environment and genetics, but that doesn't change that it is a different thing than genetics.)

> we can conclude that the lobster's environment does not confer this property.

It may, perhaps, be a reasonable conclusion that the environment (at any level) alone does not confer the property, but it is certainly less reasonable to conclude that the environment is not relevant to the property and it results from genetics alone.

>It may, perhaps, be a reasonable conclusion that the environment (at any level) alone does not confer the property, but it is certainly less reasonable to conclude that the environment is not relevant to the property and it results from genetics alone.

We can, however, rule out the environment as a sole causal factor. Since the only other possible factor is genetics, we must conclude that genetics plays some role in longevity.

Hence,

> The genetic basis of longevity is highly debatable

is false. Its basis is not debatable.

Actually, it is. I can tell by the way you argue that you are not (successfully) in science, so this is probably a futile gesture, but here is a paper which touches on what I am saying:

http://biomedgerontology.oxfordjournals.org/content/53A/6/M4...

The paper looks at twins in Sweden. Hence, everyone in the study was subject to more or less the same environmental conditions, while only a portion (the monozygotic cohort) are genetically identical. You can use this design to isolate the portion of variance in longevity attributable solely to genetics, while making no other structural assumptions about the possible mechanism. At the extremes of the age distribution (this includes your lobster people) they essentially found no such component. Over the entire age range you can explain perhaps a third of variability in longevity by genetics.

Also, you seem to be under the impression that lobsters and humans are completely different at a genetic level. This is again false. I don't know offhand what the number is for crustaceans, but humans and frogs share about 80% of disease-causing genes, for example (http://www.nature.com/news/2010/100429/full/news.2010.211.ht...). A great deal of the animal genome evolved a very long time ago and is conserved throughout the entire kingdom.

> The paper looks at twins in Sweden. Hence, everyone in the study was subject to more or less the same environmental conditions, while only a portion (the monozygotic cohort) are genetically identical. You can use this design to isolate the portion of variance in longevity attributable solely to genetics, while making no other structural assumptions about the possible mechanism.

You seem to be completely missing my point. Twin studies do not prove that genetics are not a component of longevity. All it shows is that among the genes the commonly vary between human twins there is little influence on longevity. A far narrower statement than genetics does not influence longevity.

> At the extremes of the age distribution (this includes your lobster people) they essentially found no such component. Over the entire age range you can explain perhaps a third of variability in longevity by genetics.

My lobster people are not captured by any distribution. They do not exist. You cannot simply extrapolate the curve of Swedish twins out to lobster people. That isn't how statistics works - that isn't how anything works.

>Also, you seem to be under the impression that lobsters and humans are completely different at a genetic level.

I am not at all under that impression. What I am under the impression of is that lobsters have extreme longevity relative to humans, and that that can be explained by the ways in which their genome differs from ours (primarily, at least).

> My lobster people are not captured by any distribution. They do not exist.

Well then, at least we agree that the point you trying to make, successfully or not, is pointless.

I could nitpick your statement to death, starting with the fact that the implicit definition of "environment" in your statement makes it tautologically true that no other animals share the environment of the lobster.

But, really, that's not the reason you're wrong. There are two major reasons that you're wrong:

1. The idea that lobsters experience no senescence is, at best, unproven.

2. Even if we assume that lobsters experience no senescence or vastly less than humans, there is no particular reason to believe that the source of their longevity does not depend on things that are vastly incompatible with humans. If "the only difference" between humans and lobsters is genetics (it's sort of not, see below) it can still be the case that the only way to get the longevity of lobsters into humans is to turn humans more-or-less entirely into lobsters.

Bonus third thing: Understand that genetics and environment aren't two ingredients that you pour together at the last minute and out comes an organism: they're a many layered system of feedback loops. A portion of an environment triggers a genetic expression which then alters the environment which then alters more genetic expression and so forth. You can reductively call that "genetics + environment," but when you actually try to turn "genetics + environment" into a result, you have to deal with the extreme complexity here.

> 1. The idea that lobsters experience no senescence is, at best, unproven.

True, but irrelevant. They have extraordinary longevity. That much is proven.

> 2. Even if we assume that lobsters experience no senescence or vastly less than humans, there is no particular reason to believe that the source of their longevity does not depend on things that are vastly incompatible with humans. If "the only difference" between humans and lobsters is genetics (it's sort of not, see below) it can still be the case that the only way to get the longevity of lobsters into humans is to turn humans more-or-less entirely into lobsters.

Also true, but irrelevant. It may be the case that we have to have the exact genome of a lobster in order to obtain this benefit. However, this fact has no bearing on my point: Genetics and longevity are deeply related.

I've heard this a lot and looked it up. There are some other sources I found, but most seem to be referenced in this wiki:

https://en.wikipedia.org/wiki/Biological_immortality#Organis...

Looks like they're not immortal. Eventually they run out of energy to regenerate their shell or their shell stops moulting and it rots.

Consider she saw two world wars in an ever changing century, I'd be surprised if her age record was contextual. Asian elders I can understand (climate; food; social structures; philosophy) .. but here.

Not every cell changes the same way. So if you have a large enough set of DNA samples from distinct cells, you could probably reconstruct the original.

Good point. I thought have thought of that - otherwise how are we able to reconstruct the genetic makeup of Neanderthals or any other extinct species?

The oldest person, and the person whose DNA maximizes lifespan are very likely to be different.

Further, DNA sequencing is only part of the issue. The state her cells where in over time is also critical information.

PS: Basically, an identical clone of her would have very low odds of living to 122. Though likely better odds of hitting 100 than the average person.

It could be that those mutations were what kept her alive so long.

I don't think most cells would have accumulated mutations. Sequencing DNA from several samples should still give a pretty clear result.

This is pretty much what our sex cells are. It's part of why newborns are so healthy, genetically. And they only use two cells.

To start sequencing everyone's genome as they're born seems a little Gattaca. We might as well fingerprint everyone and submit them to a national database while we're at it.

Seems pretty likely to me that if we stick around long enough we will definitely sequence everyone's DNA as a matter of course. What we'll want is to have a decent ethical and legal framework around that by the time it happens.

In the US it is actually quite common (if not consistent) that newborns have blood samples taken for screening. I would be surprised if those samples are destroyed after, so we are certainly well on our way.

Couldn't samples have been taken and stored to be sequenced later, when it was cheaper?

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