Comments on: The olm: the blind cave salamander that lives to 100

By: Chris

Chris — Mon, 14 Mar 2011 21:30:36 +0000

“As a group, salamanders are hardly go-getters, but the olm’s metabolic rate isn’t any lower than that of its much shorter-lived cousins” – Actually the olm can live for several YEARS without food which would indicate it has a very low metabolism.

By: GuitarFish2760

GuitarFish2760 — Mon, 26 Jul 2010 12:28:38 +0000

Do you think perhaps the reason for the Olm having such a long lifespan is because it is a cave-dweller and therefore lives in complete darkness, so isn’t exposed to sunlight? The UV element of the suns’ rays are well known for generating free radicals.
More free radicals= more damage= a shorter lifespan.

Has this justification been explored?

Brilliantly- written article by the way, it was a pleasure to read

By: Emp

Emp — Thu, 22 Jul 2010 21:21:00 +0000

Dosed, it’s true that there is typically little selective pressure to weed out diseases past the age of breeding (or child-rearing, if applicable) in most animals. Some of those late-onset diseases, such as most types of cancer, are common killers of animals that often manage to survive beyond their breeding years, humans being a good example. But what diseases plague other salamanders that mange to avoid predation, and do they really affect the olm at a different rate? I don’t know the answer to that, and I don’t know if scientists studying the olm do, either. The olm happens to be an interesting case because it actually lives much longer than its kin (and humans!) on average, and yet we know little about how it actually achieves this. Of course, there are likely other creatures with similarly unexplained long lifespans; maybe they’ll be the topic of a future blog post.

By: Aurora

Aurora — Thu, 22 Jul 2010 19:29:44 +0000

I made sure my Inter-rail trip included Slovenia to go see the olms, and this just makes them even more fascinating! Had been mildly disappointed by coverage elsewhere, but you actually explained what Voituron & colleagues did and the significance of the whole issue – thanks, Ed!

By: dosed

dosed — Thu, 22 Jul 2010 13:16:50 +0000

@Emp, So, we agree there is no mystery(it is expected to)/(mass isn’t the valid criteria but habitat and lifestyle) in finding that a small organism like the Olm has a longer lifespan. But how he achieves it is, a mystery. But aging is just as mysterious for all organisms.

“we don’t know the exact biochemical mechanism that causes the increase in lifespan. Ultimately, knowing that mechanism may prove useful in the study of human aging as well.”

I would say we don’t even know the general mechanism that causes an increase in lifespan but only have some clues.
I was asking if we should really expect to see a clear difference in antioxidant capabilities of two related species, with different lifespans…I don’t know the answer.

The “only two” known ways of increasing lifespan, that Ed Young has covered above, are missing the most facile and obvious way: selection on fitness for longer time, which is not reflected in antioxidant capabilities. All the systemic diseases and not only, that creep in after an organism passed the “optimal age”(for his lifestyle and habitat) are not enough to explain his increase of lifespan?
Sure, if the olm lived for a couple of hundred years we would be entitled to expect some sort of novel mechanism that increases lifespan. But the olm fits right in with most other species living in hazard- and predator-free environments.

Sorry to bore you so much with my doubts but, when we see two men, one having a lifespan of 93 and the other of 71. Do we expect to see relevant differences in antioxidant capabilities? Or the genetic makeup for increased fitness is enough to explained it?
My example is not so misplaced. The olm faced selection in a hazard- and predator-free environment for 20 my.

By: Emp

Emp — Thu, 22 Jul 2010 01:28:50 +0000

Dosed, I think the point is that while we know longer lifespans can result from relatively hazard- and predator-free environments, we don’t know the exact biochemical mechanism that causes the increase in lifespan. Ultimately, knowing that mechanism may prove useful in the study of human aging as well. Just because we know something (long lifespan) is selected for does not mean we know the exact gene(s) that generate the trait, or the exact processes that have an impact on the trait in the organism in question. Thus, Ed’s mention of the normal metabolic rate and antioxidant capabilities of the olm is relevant, because it demonstrates that the mechanisms for delayed aging that many might suggest (and indeed, that many people are researching in other organisms) do not seem to apply to the olm.

By: BethSkw

BethSkw — Wed, 21 Jul 2010 20:27:56 +0000

I’d venture that we don’t know enough about other salamander species to make a fair comparison with the olm. Whenever I’ve looked up longevity information about newt or salamander species, the reports are spotty – “maybe 20 or 30 years, but so-and-so zoo had one that lived to 50″ kind of stuff. Very few data points.

I suspect that many amphibian species live a lot longer than we give them credit for. This study of the olms is impressively long-ranging and detailed. Are there comparable studies of related amphibian populations?

Also, even though some animals live longer in captivity, many are hard to keep alive because we just don’t know a whole lot about them. While I’m speculating, I’m going to say that most of our amphibian lifespan data falls into this category – so a salamander can live 50 years in a zoo cage eating crickets. Does that really tell us the maximum lifespan of its species?

By: dosed

dosed — Wed, 21 Jul 2010 20:17:30 +0000

Sorry guys but this really isn’t about proximal and ultimate explanations, which are really basic concepts and there is no special merit in making the distinction.

From knowing the olm’s environment, we should expect it to have a longer lifespan.
I’ll try to express my “ojection” from a different angle:
Ed Young: “…the olm’s metabolic rate isn’t any lower than that of its much shorter-lived cousins…………the olm’s antioxidant abilities aren’t anything to shout about.”

Here you express this observations relative to the olm’s cousins.
Why should we expect to see a difference?
Oxidative stress is counteracted by the cell. But there is evidence of a direct correlation (unlike the correlation between mass and lifespan) between antioxidant capabilities and lifespan? Or is it more specific to different groups?
Can you see the difference between antioxidant capabilities of a turtle with a long lifespan and another one with a shorter lifespan? Or are they more or less the same in this respect? Same question about organisms with higher metabolic rates.
If I am wrong I’m sure u can easily correct me.

By: jdmimic

jdmimic — Wed, 21 Jul 2010 18:14:42 +0000

Great article, thanks for posting about it. It is interesting on multiple interrelated levels.

Oh, and I am glad to see someone who not only knows the difference between proximal and ultimate causes, but actually makes a distinction between them.

By: Chris M.

Chris M. — Wed, 21 Jul 2010 15:34:31 +0000

@dosed, the comparison is likely to be based partly on the lifespan of captive animals, which tend to avoid predation and (to a degree) accidental death. “Maximum” lifespan does attempt to take these factors into account.

What’s interesting is that it doesn’t use the known mechanisms of avoiding aging. Clearly, we have an example of something that has improved its longevity relative to its peers, but not done so with any genetic mechanisms that we understand. It really isn’t a big surprise that it has evolved toward a longer lifespan, but to have done so very successfully without using mechanisms that we know of? Clearly it’s done something different; it seems odd to dismiss that, simply because a longer lifespan is expected for its evolutionary history.

Anyway! Really great animals, and what may turn out to be interesting is comparing the typical olms with the black olm subspecies, which appears to be significantly less specialized for underground living, or with the other Proteidae. Since the mudpuppies are so common in the United States, it’s likely that they make up at least one of the samples in the graph, and may provide a good genetic comparison.