Monday, August 23, 2010

The Bowhead whale can live how long?!!

A graphic in Why Can't We Live Forever? (Scientific American) lists maximal lifespan of various familiar species.

The Jellyfish and Hydra are "immortal". The Galapagos tortoise can live 150 years. Humans 122, Dogs 39, Cats 36, Horse 62(!), Chimp 59(!).

There are a couple of surprises there. I didn't dream a horse could live that long. I imagine that's a bit of a problem for many horse owners. I wonder how many horses ever die a natural death, even if the average lifespan is only half that.

And, of course, the Bowhead whale can live up to 211 years.

WTF?! Where did that come from?

I found this 1999 reference, it's apparently the source for the 211 year estimate ...
... Based on these data, growth appears faster for females than males, and age at sexual maturity (age at length 12-13 m for males and 13-13.5 m for females) occurs at around 25 years of age. Growth slows markedly for both sexes at roughly 40-50 years of age. Four individuals (all males) exceed 100 years of age. Standard error increased with estimated age, but the age estimates had lower coefficients of variation for older animals. Recoveries of traditional whale-hunting tools from five recently harvested whales also suggest life-spans in excess of 100 years of age in some cases.
It turns out Bowhead Whales and Naked Mole Rats both have weirdly long lifespans  ...
... Mitoptosis can be also activated in adult postmitotic somatic cells by evolutionary conserved phenotypic adaptations to intermittent oxygen restriction (IOR) and synergistically acting intermittent caloric restriction (ICR). IOR and ICR are common in mammals and seem to underlie extraordinary longevity and augmented cancer resistance in bowhead whales (Balaena mysticetus) and naked mole rats (Heterocephalus glaber)...
So to live long and prosper spend mealtimes holding your breath rather than eating?

Not surprisingly a 2007 article advocating genome sequencing of mammals with atypical longevity ...
... we propose the sequencing of three organisms of unique interest for aging research: the naked mole-rat (Heterocephalus glaber) whose record longevity of 28.3 years makes it the longest-lived rodent (2), the white-faced capuchin monkey (Cebus capucinus) which can live 50 years (3), and the bowhead whale (Balaena mysticetus), the longest-lived mammal with estimates suggesting that it may live 200 years (4).
Hmm. Maybe we should do this sequencing before we drive all whales to extinction?

Even if the 211 year estimate is an exaggeration these whales live much longer than I'd imagined. I'd have guessed 40 years, but they're still young adults at that point.

Until this minute I was skeptical that there was really much room to slow the human aging process. Now it feels inevitable. Not likely in my lifespan, but maybe the future of my children or their children.

1 comment:

cathy said...

I was most surprised by dogs. The oldest one I can recall reading about died in his 20's (after a lifetime of eating table scraps).