I remember seeing a shark documentary as a kid, hosted by Burgess Meredith, if I remember correctly. It made the same basic claim about great white sharks: too big to have predators, nobody had ever seen them die except by accident or by human hands, blah blah blah, therefore “some have suggested” they are immortal.
That I can remember the end of the show all these years later shows you what a terrific close the “immortal” idea makes. But it only sounds plausible because of our disconnect with that natural environment. It plays on our lack of knowledge about the natural world, and that we have a hard time tracking these sorts of things. It’s like asking most city dwellers, “Have you ever seen a baby pigeon?” “No, I haven’t. And you know what, I’ve never seen a dead pigeon, either! Oh my goodness, pigeons must be immortal!”
Sharks and lobsters have a few things in common, too, that makes the “immortality” claim easy to make. They live in the oceans, which means they are hard to track, and few people have first hand experience with them. They are long lived species, and it’s not easy to look at one and know how old it is. Wolff (1978) says of lobsters:
The scanty data presented above demonstrate the great difficulty in estimating the age of the very large lobsters.
When you add in “they only die from external causes,” you have a huge out. Most animals, including humans, die from external causes, broadly construed. Sure, a predator is an external cause. A bacterial or viral infection is an external cause. What would not count as an “external cause”? The definition is so loose that you can make exceptions for almost every possible counter-example.
And, of course, it links out, not to an actual scientific paper, which would be the sort of action you might expect from a group that proclaims to love science, but to a radio interview.
This is not a slap against the participants in the interview. Jelle Atema is a good scientist with real bona fides. But this radio interview is a long way from the sort of careful science you would need to do to show lobsters are “functionally immortal.”
There is some interesting science to this. Many decapod crustaceans have indeterminate growth (mentioned by Vogt 2008, 2010, who cites others). This means that they keep growing throughout their life, and do not have a set upper limit for size. It’s not just lobsters that do this, as far as I know; crayfish do, too. Lobsters are probably in this meme because they get so much larger than crayfish. It’s easier to people to believe a big animal like a lobster could be so much older than a small animal like a crayfish.
There is about one paper that I have been able to find on lobster longevity by Klapper and colleagues (1998). The introduction says:
Lobsters grow continuously throughout their lifespan, only decreasing growth rates with age. Furthermore, and again in contrast to humans, they are able to regenerate whole limbs even at a high age.
This cites a book chapter by Govind, on... muscle innervation?! The chapter talks a little bit about sarcomeres being added throughout life, but that’s about it. It’s not a chapter on aging and senescence.
More provocatively, the abstract of the Klapper and colleagues says (my emphasis):
Lobsters (Homarus americanus) grow throughout their life and the occurrence of senescence is slow.
But there is no citation for the “slow senescence” claim. And there is no original empirical data supporting that in the Klapper paper (e.g., longevity and activity and health and mortality data). The paper shows that adult lobsters still make an enzyme called telomerase, but it does not show that lobsters are long lived because of it.
How old does this “functionally immortal” lobster get? If lobsters really were “functionally immortal,” why would you note expect them to live for centuries?
Wolff (1978) wrote:
I also believe that Herrick gets pretty close to the truth in his poetic conclusion (1911: 199): “Giants weighing from 25 to 35 pounds [11.5-16 kg] have possibly weathered the storms of life half a century or more”.
More recently, Sheehy and colleagues wrote (1999; my emphasis):
The exceptional ages attained by some of the largest lobsters (males: average 31 years, maximum 42 ± 5 years; females: average 54 years, maximum 72 ± 9 years) are explained by ageing theory, indicate natural mortality rates, M, of 0.15 and 0.08 for males and females, respectively, and point to the existence of an offshore refuge.
Bodnar (2009) has a table that puts the oldest lobster on record in the 50-100 range; a bit more liberal than Wolff or Sheehy and company. Bodnar cites Finch (1990), which again does not seem to have much more than a table with an estimated maximum lifespan, connected to another reference I haven’t been able to track down. Nobody seems to define what “slow senescence” is, or how it has been measured in lobsters.
Regardless, a “functionally immortal” animal that has a shorter recorded maximum lifespan than a human? Colour me unimpressed.
For such a bold claim, it has been disappointingly hard to track down the real science. It’s also disappointing to see such a credulous claim come from a source that contends it fucking loves science. I think it is fair to call this one:
Sadly, I suspect this myth might have a longer lifespan than many lobsters.
Additional, 24 May 2013: Fighting fire with fire. Fire, and frickin’ awesome big crustaceans.
Additional, 26 May 2013: Welcome Redditors who found this post though this thread.
I also found this meme, made three days ago, apparently in response to the I Fucking Love Science post.
I got criticized a bit on I Fucking Love Science for promoting this post by characterizing the original IFLS picture as saying lobsters “live forever,” when the original picture said, “functionally immortal.” This meme shows that people are not picking up on the nuance. “Functionally immortal” became “biologically immortal,” which, I think, shows people are just going to remember “immortal.”
So, at this point, the original picture on I Fucking Love Science was probably seen by a few million people (over five million have liked it, and over four million are talking about it, says Facebook). The meme above has 689,321 views to far. This post has about 5,000 views so far.
I am going to have to put up with people asking me about immortal lobsters for years, aren’t I?
Additional, 27 May 2013: More evidence that people are seeing lobsters as pretty much straight-up immortal:
Is it true Lobsters can’t die from old age, are they immortal apart from sickness and injury?
I also finally turned to what may have been the source of the claim. Wikipedia. A section on biological immortality contained (until I edited):
Some scientists have claimed that (lobsters) could effectively live indefinitely, barring injury, disease, or capture.
The good bit was that it had a reference. To a journal article. With a relevant looking title:
Guerin JC. 2004. Emerging area of aging research: long-lived animals with “negligible senescence”. Annals of the New York Academy of Sciences 1019(1): 518-520. http://dx.doi.org/10.1196/annals.1297.096
Aha! Maybe this would be the source of the claim that lobsters are slow to undergo senescence! Maybe there is actual data!
I got it, and searched for “lobster.” It was fast; there are only two pages in the paper besides the references. It cites Finch (1990), again, with the reference that I haven’t yet been able to track down. Guerin notes that Finch listed several animals that might have negligible senescence, “including rockfish, sturgeon, turtles, bivalves, and possibly lobsters.” My emphasis: possibly.
That’s all. That’s weak stuff compared to “some scientist claim” lobsters could live indefinitely. Instead, lobsters might have little senescence. Maybe.
It seems that the source of all these “immortal lobsters” factoids are whatever research Finch is citing. I’ll continue to try to track it down, and report back on what I find.
Additional, 3 June 2013: The Surprising Science blog also tackles this story. That post is not just a repeat of information here (though this post does make a cameo). There are excellent comments from several other lobster biologists. For instance:
According to Carl Wilson, lead lobster biologist with the Maine Department of Marine Resources, between 10 and 15 percent of lobsters die naturally each year as they shed their exoskeletons because the exertion proves to be too much. Each molting process requires more and more energy than the one before it as lobsters grow in size.
Finally, older crustaceans stop shedding their exoskeletons altogether—a clue that they’re near the end of their lifespans. They run out of metabolic energy to molt, and their worn-and-torn shells contract bacterial infections that weaken them. Shell disease, in which bacteria seeps into lobster shells and forms scar tissue, adheres the crustaceans’ bodies to their shells. The lobster, attempting to molt, gets stuck and dies. The disease also makes lobsters susceptible to other ailments, and in extreme cases, the entire shell can rot, killing the animal inside.
Additional, 30 June 2013: Discovered this version of the meme circulating on Google Plus:
As someone pointed out in the response thread, it’s ironic that a picture of a cooked lobster is used to support the idea of their longevity.
Additional, 4 August 2013: David Shiffman informs me that this claim has resurfaced again on Discovery Channel’s Shark Week programming. Argh... I’ll take this moment to plug the Science... Sort Of podcast, where I will be discussing the “immortal lobsters” claim soon (episode 178, I think).
Additional, 9 August 2013: The Science... Sort Of podcast is now available!
Additional, 25 August 2013: Buzzfeed perpetuates the lobster myth with a video “6 almost immortal animals” (spotted by David Shiffman). Of lobsters, it claims:
They don’t age. They just continue to grow until they are killed. Yum.
Additional, 13 November 2013: Buzzfeed repeats this myth yet again, linking out to the National Public Radio story, via Quora.
Bodnar AG. 2009. Marine invertebrates as models for aging research. Experimental Gerontology 44(8): 477-484. DOI: 10.1016/j.exger.2009.05.001
Govind CK. 1995. Muscles and their innervation. In: Factor, J.R. (Ed.), Biology of the Lobster Homarus americanus, pp. 291–312, Academic Press, San Diego, CA.
Klapper W, Kühne K, Singh KK, Heidorn K, Parwaresch R, Krupp G. 1998. Longevity of lobsters is linked to ubiquitous telomerase expression. FEBS Letters 439(1-2): 143-146. DOI: 10.1016/S0014-5793(98)01357-X
Sheehy MRJ, Bannister RCA, Wickins JF, Shelton PMJ. 1999. New perspectives on the growth and longevity of the European lobster (Homarus gammarus). Canadian Journal of Fisheries and Aquatic Sciences 56: 1904-1915. DOI: 10.1139/f99-116
Vogt G. 2008. How to minimize formation and growth of tumours: Potential benefits of decapod crustaceans for cancer research. International Journal of Cancer 123: 2727-2734. DOI: 10.1002/ijc.23947
Vogt G. 2008. The marbled crayfish: a new model organism for research on development, epigenetics and evolutionary biology. Journal of Zoology 276: 1-13. DOI: 10.1111/j.1469-7998.2008.00473.x
Vogt G. 2010. Suitability of the clonal marbled crayfish for biogerontological research: A review and perspective, with remarks on some further crustaceans. Biogerontology 11: 643-669. DOI: 10.1007/s10522-010-9291-6
Wolff T. 1978. Maximum size of lobsters (Homarus) (Decapoda, Nephropidae). Crustaceana 34: 1-14. DOI: 10.2307/20103244
Hat tip to Chris Vitek for “Someone is wrong” picture.