April 10, 1951.

\

Dear Kin-

I just saw your paper on perlodic selection in print, where it reads
better somehow than in typrecript. I hope you'll forget about most of
my earlisr coments.

Jim (Crow) and I are still somewhat confused on the main questidi we
were batting around in our letters: the effecb of periodico selection on
populational equilibria, If the sampling 1s not abrupt, but instead
rather continuous and quantitative, then I would foresee this of
(smoothed out) evolution of cultures: ,

 

I etill can't see you you can escape the nesesalty that the areas
under the two curves mist be substantially equal by the time the hypothetical
culture without P.S. would have approached its asymptote. If the P3's are
numerous and overlap, then of course, you are right in suggesting that the
variances will be diminshed rather than broadshed, but it seens to me
that the peeudo-equilibrius will appreach the trusmitational equilibrium
at about the sane rate as if P3 did not operate. The discrepancy will depend
on the frequency of PS} if this is very high, with numerous overlaps, there
would obviously be little effect. Have you worked cut the theory yet in any
detail- I'd be greatly interested to see it, :

All this supposes that the Army has released its grip- Have I been |
entitled to assum that no news was good?

Esther and I might like to spend about a week at Woods Hole after the
CSH meetings.Do you know any one who might be willing to rent an apt. or
room with kitchen facilities for that time? See you in June, and best to
all the Atwoods,

Joshua,