
Greenland shark found to be at least 272 years old - okket
http://www.nature.com/news/near-blind-shark-is-world-s-longest-lived-vertebrate-1.20406
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bgentry
_The study also shows that Greenland shark females don’t reach sexual maturity
until around 150 years old — suggesting that a century of heavy fishing could
wipe out the entire species, says Bushnell. But climate change is a greater
threat, says Aaron MacNeil, a marine biologist at the Australian Institute of
Marine Science near Townsville, Queensland._

Fascinating that the reproductive timeline can be so long. I'd always thought
evolution was heavily biased in favor of rapid reproduction.

~~~
madsushi
r/K selection theory[1] can help explain why some creatures favor longer
reproductive timelines.

[1] -
[https://en.wikipedia.org/wiki/R/K_selection_theory](https://en.wikipedia.org/wiki/R/K_selection_theory)

~~~
ralfd
Yes, but even the blue whale, the largest animal ever existed (as far as we
know), reaches sexual maturity after 5-10 years. Elephants need 10-13 years.
Humans are roughly the same. An age for reaching puberty of ten times that,
over a century, is a whole other definition of "long".

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paws
The Greenland shark is pretty unusual.

* Eating it has a deleterious effect on sobriety [1].

* It's also the most toxic shark meat out there. [ibid]

* Female Greenland sharks take 150 years to reach sexual maturity (no word on the gestation period).

 _The study also shows that Greenland shark females don’t reach sexual
maturity until around 150 years old — suggesting that a century of heavy
fishing could wipe out the entire species, says Bushnell._

[1]
[https://en.wikipedia.org/wiki/Greenland_shark#Greenland_shar...](https://en.wikipedia.org/wiki/Greenland_shark#Greenland_sharks_as_food)

~~~
flukus
> It's also the most toxic shark meat out there.

Is that innate or related to the longevity? Other species could just die for
they get to that level of toxicity.

~~~
grawlinson
Some turtles can live in excess of a hundred years. If they were toxic, surely
some tribal community in the South Pacific would've figured that out by now.

~~~
flukus
Some quick googling didn't turn up much on turtle toxicity other than we seem
to be more concerned about us poisoning turtles than them poisoning us.
Probably with good reason.

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ajeet_dhaliwal
Amazing that there are animals as complex as this living out there today born
in 1744 or earlier. Older than the United States.

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greggyb
I like that the number in the headline is the bottom range of their estimate.

~~~
rusanu
"Because radiocarbon dating does not produce exact dates, they believe that
she could have been as "young" as 272 or as old as 512. But she was most
likely somewhere in the middle, so about 400 years old."

BBC went with 400 in the title :) [0]

[0] [http://www.bbc.com/news/science-
environment-37047168](http://www.bbc.com/news/science-environment-37047168)

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chrisbennet
The test is performed on a dead shark - a little sad that something so old is
no longer with us.

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runeks

        > The shark's longevity probably arises because 
        > it expends very little energy, owing to its cold 
        > body temperature and enormous size, Bushnell says.
    

Why would either a low body temperature or a large body size contribute to
expanding less energy?

~~~
protomyth
Bergmann's rule
[https://en.wikipedia.org/wiki/Bergmann%27s_rule](https://en.wikipedia.org/wiki/Bergmann%27s_rule)

 _The earliest explanation, given by Bergmann when originally formulating the
rule, is that larger animals have a lower surface area to volume ratio than
smaller animals, so they radiate less body heat per unit of mass, and
therefore stay warmer in cold climates. Warmer climates impose the opposite
problem: body heat generated by metabolism needs to be dissipated quickly
rather than stored within._

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dingo_bat
> Instead, the team decided to measure levels of radioactive carbon-14 in
> fibres in the centre of the shark’s eye lens. Such measurements reflect
> levels of radiocarbon in the ocean when the lens was first formed.
> Measurements of 28 female Greenland sharks, made during surveys in 2010–13,
> suggested that the largest of them (at 5.02 metres long) must have been
> between 272 and 512 years old at the time.

>levels of radiocarbon in the ocean when the lens was first formed

But wouldn't that tell you the age of the rocks/minerals that were used to
make the lens? Or is the lens living tissue that dies after formation?

~~~
CamperBob2
It's a pretty cool experiment. C14 is formed continuously in the upper
atmosphere and enters the carbon cycle via CO2 absorption by plants. Since the
ratio of C12 to C14 in the environment is known to be reasonably stable over
time, the C12:C14 ratio in a given biological sample can be used to infer how
long it's been since the organism stopped participating in the carbon cycle
(i.e., died.)

The basic idea is simple enough, but the dating process is complicated by
various factors that have to be calibrated out. The environmental C14:C12
ratio got a lot lower when we started burning fossil fuels in the 1800s.
Later, setting off a bunch of massive nukes in the 1950s had the opposite
effect.

The lens of the eye is living tissue, so it can be carbon-dated. In this
study, the researchers actually took advantage of the nuclear contamination
problem. They noted that only the smallest, most immature specimens exhibited
the unnaturally high C14:C12 ratio characteristic of items from the period
before the test ban treaties took effect. Bigger sharks had clearly absorbed
most of the carbon in their lenses over a much longer period of time[1]. Since
they have a good idea of the rate at which the sharks grow, they could infer
that the larger specimens must have been growing for hundreds of years before
the nuclear tests.

[1] Things get a bit hand-wavy here; the article suggests that the shark lens
stops absorbing carbon after it's formed. Meanwhile, Wikipedia says that the
human lens continues to grow.

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ars
They need a control to make sure their science is good.

Measure C-14 in other aquatic animals with known ages to make sure the
technique actually works.

(Maybe they actually did it.)

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matteuan
interesting, maybe by studying these animals we will discover new tricks to
live longer

~~~
exclusiv
Definitely. Some say lobsters can live forever since they don't age, others up
to about 500 years due to telomerase and jelly fish potentially forever from
being able to rejuvenate.

If we can slow down our aging we could live much longer and better lives.

I'm a firm believer that nature has the secret answers to everything.

Relevant discussion:
[https://news.ycombinator.com/item?id=12271109](https://news.ycombinator.com/item?id=12271109)

~~~
Joof
Live like a jellyfish.

 _bloop_ _bloop_

~~~
piaste
Right? What a pointless life. Who could possibly enjoy it?

Now excuse me for the brevity, I have an awesome game of Candy Crush to
finish. I think I'll get a new high score. _Bloop bloop_!

