Marcus G. Daniels wrote circa 11-10-23 01:16 PM: > On 10/23/2011 1:48 PM, Edward Angel wrote: >> On the face of it, it's pretty absurd. If a human has an average heart >> rate of 70 beats per second and an average lifetime that is 10 times >> that of a dog, the dog's average heart rate would be 700 beats/sec. >> Don't think so. > And it is inverted within the species -- small dogs live longer than > large dogs (large dogs having heart rates of 60-100 bps), yet have > higher heart rates (100-140 bps). > > http://biomedgerontology.oxfordjournals.org/content/51A/6/B403.abstract > > Anyway, how do you pin down this invariant unless you know the cause of > death was heart failure?
Well, this is as far back as I can get until I get my hands on some physical paper: Scaling, why is animal size so important? By Knut Schmidt-Nielsen I'd like to get my hands on this one, though: Life History Invariants Some Explorations of Symmetry in Evolutionary Ecology Eric L. Charnov It's odd that they're _books_ instead of journal articles. I'm hoping that if I do get my hands on them, they'll cite some peer-reviewed articles and show the actual data. The google preview for Knut's book shows straight line models for the heart rate to mass relationship, but no the data. The preview did show one observed/model comparison for the shrew: observed: 600(rest)/1320(max) in min^-1 expected: 1029 observed/expected 0.6 0.6*1029 => 617.4 ..., so I assume he used 600/1029. As far as I can tell, the _derivation_ of the "approximately invariant" heart beats is only implied by West et al: Allometric scaling of metabolic rate from molecules and mitochondria to cells and mammals, PNAS 99, 2473–2478. "This value follows from the empirical observation (2) that heart rate scales as MϪ1/4, ..." That seems pretty flimsy to me. So, I'm still looking. -- glen e. p. ropella, 971-222-9095, http://tempusdictum.com ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
