Lifespans
I was listening to NPR this morning and a scientist was talking about why small animals like mice have such short lifespans while elephants and whales have long ones. He says they all have the same number of heartbeats in their lives. The mice hearts beat really fast and the whales really slow. Humans for some reason do not conform to this theory, however. We should actually have shorter lifespans according to our heart rhythms.
posted by Flimsy Sanity @ 5:50 AM
2 Comments:
At 1:10 PM,
Anonymous said…
Yes, about one billion heartbeats per lifetime in mammals. Humans can more than double that, probably because we live relatively stress-free lives. Human lives were much shorter a few hundred years ago, and even today in many third world countries where people live stressful lives and eat poor food, the one billion rule would probably apply. Interestingly, there is also a relationship between metabolism and size, with smaller mammals having a much faster metabolic rate than larger ones. For instance, a mouse has to eat half its weight in food per day to avoid starvation, a human only needs 2% of its bodyweight.
At 8:28 AM,
Flimsy Sanity said…
Emerson said that all things were equal - that the anteater had a long snout to compensate for his short legs etc. Makes one believe that there may be some sort of order - not a god that looks like man, but something.
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