Don’t yawn too soon. Please bear in mind that bowheads DON’T hibernate, and are fully awake and functional and at normal body temperature all year round. And they are mammals. Therefore, they might have a secret for reducing metabolic rate that we can borrow. Blubber is not their secret, something else is going on. And metabolic rate or no metabolic rate, being free of cancer for 200 years seems like a good achievement. As one aspect of this, cell division is considered risky for carcinogenesis, yet how many cell divisions does the Bowhead go through compared to us? Not too shabby.
And incidentally, the rate of living theory has been disproven. Yes, it provides
interesitng rules of thumb, but it is not a true theory of aging, it is more of a way of making rough predictions and does not provide any mechanistic insights to speak of, so you should not put all your bets on it.
As for Mcaws: of course! By all means! Let’s learn from them too.
On Sunday, February 1, 2015 7:58 AM, David Gobel wrote:
you would be interested in leading a crowdfunding effort to sequence the Macaw? I for one would love that!
DaveOn Saturday, January 31, 2015, sbharris1 wrote:
Greg, et al.
Bowheads don’t excite me for the same reason that naked mole
rats don’t. Large animals have slow metabolic rates. Bowheads have only 1/3rd
the metabolic rate you’d expect for an animal of their size, possibly because
they keep their heat losses so low from all that blubber.
Bowheads are the second largest whale (only blue whales are
larger) and can get up to 50 to 100 tons. So let’s say they weigh 1000 times
what a human does. We’d expect them to have a specific metabolic rate
1000^-(.25) = .178 that of a human. If it’s really only 1/3 of what you’d expect
from the Kleiber equation that’s only 0.044 that of a human– down in the
reptilian range. Multiply that by 200 years and you get only 9 years. Over a 200
year old lifespan a kg of bowhead muscle burns only 10% of what kg of
human muscle does.
Even using Kleiber, the bowhead MLS comes out only 36 years.
These are just really gigantic cows, like elephants but bigger and longer
lasting. The excitement of scientists at their long life really mystifies me.
Nobody gets that excited over 200 year old tortoises, but the whales are just as
slow-motion when it comes to making calories.
I can’t grow to a size of 100 tons, or put on that much
blubber (though I admit I do find it chasing me). The bowhead is not likely to
have anything really interesting in its slow cells. And if they can’t find any
cancer in bowheads, it’s because the ones they’ve seen are only 9 to 36 years
old in human terms.
Sorry, it’s still the 100 year-old macaws that
interest me. Their cells have some trick that you’re not likely to
find in a whale, a mole rat, or even a bat. I hope the simple math I’ve
given has shown this.