From: Gordon Getty <IIMI >
To: Robert Trivers
Cc: Gerry Ohrstrom , Jevin West , Sam Arbesman
, Geoffrey Miller , awe ill
, Andrew Torrance <torrance outer
, Reese Jones William Casebeer
,Jeanne Eicks , Jennifer Kubota
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, John Chisholm <johnc .edu>. Erin O'Hara
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>, Sarah Brosnan Harry Surden
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< >, Marshall Van Alstyne skil Ullberg
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>, Jero , Don
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, Mike Dooley , "John R.
SEARLE" , Jeffrey Epstein <jeevacation@gmail.com>, Yvette Robbins
Subject: M.
Date: Fri, 16 Sep 2016 17:08:31 +0000
Dear Bob,
Right now my total immersion is in composing. Just as much fun as econ or ev bio, though considerably harder
work.
Your last got me thinking again.. a fan of W. D., but contest him to two points. His rule goes too far and flubs
the math. My new thought is that maybe I see how to fix the math.
My book already says that capital and fitness are two words for the same thing. Depreciation is decapitalization
caused by the time alone. What I and others call human depreciation can be generalized to all species including
us as "biodepreciation". R. A. Fisher's reproductive value model shows how it might work; fitness (capital)
declines as reproductive potential does.
My suggested retouch of Hamilton's rule, under simplifying assumptions, is that creatures maximize r b. Zero is
the only minimum or hurdle level ( b must not be negative). Since biodepreciation continues inexorably, and is
deadweight loss if left uninvested, we maximize r b as readily to minimize loss as to maximize gain.
An exception arises if fitness can be banked or stored. Your reciprocal altruism, or Alexander's indirect variant,
are classical ways to store fitness. When r b prospects are slim, banking fitness is a way to gamble that future
ones will be better.
EFTA00817764
Fitness (capital) once banked is then invested to maximize genic return over the banking period, just as with
reciprocal altruism or Alexander's variant. The maximand is r b compounded at the generation rate (one over the
generation length).
Another qualifier covers voluntary decapitalizations (fitness transfers), as with Haldane's parable of giving one's
life for so many sibs or cousins or nephews. Here I think WD's r b — c hurdle rate is correct. But voluntary
fitness transfers look to be exceptional. My reductio ad absurdum does not foreclose them if they are rare
enough to do no more than make up deficits in the usual transfer through biodepreciation.
I haven't really thought this through, and welcome your critiques or anyone's. It fixes the math of Hamilton's
rule, if right, but still leaves my other reservation. His rule is over-committed to kin selection. I think it fights
his own parasite theory of 1982, where histocompatibility alleles that compete today are teammates in the long
run. The loser goes to the bench, not the cemetery, and stays there until needed again.
Best, Gordon
EFTA00817765