Article,
Genetics of Natural Populations. X. Dispersion Rates in Drosophila Pseudoobscura
Genetics, 28 (4): 304-340 (July 1943)
Abstract
TH E breeding structure of a population is determined, among other factors,
by its effective size (N) and by the migration index (m). The latter con-
stant measures the extent to which the population of a given territory is re-
placed in each generation by immigrants from the rest of the species or from a
territory large enough to have all the genetic variants of a given class a t their
equilibrium frequencies. The value of the migration index, in turn, is a function
of the mobility of the organism. Joint estimates of N and m have been arrived
a t for certain populations of Drosophila pseudoobscura, and some attempt has
been made to make separate estimates (DOBZHANSKY
and WRIGHT 1941;
WRIGHT, DOBZHANSKY,
and HOVANITZ
1942). The data reported in the present
article were collected in order to test the validity of these estimates.
The experimental work was done in the summers of 1941 and 1942 on Mount
San Jacinto, California. This work was made possible by a grant from the
CARNEGIE
INSTITUTION
OF WASHINGTON
and by the devoted and conscientious
collaboration of MR. BRUCE WALLACE,
MRS. N. P. DOBZHANSKY,
MISS R.
MIRSKY, MR. ALEXANDER
SOKOLOFF, MR. H. LEWIS, PROFESSOR
C. C.
EPLING, and MR. W. HOVANITZ.
Acknowledgment is also made to the DR.
WALLACE
C. AND CLARA A. A B B ~ T MEMORIAL
T
FUND
of the UNIVERSITY
OF
CHICAGO
for assistance in connection with the calculations.
