SFI News:

John Martin will present the talk, Sex Ratios at Birth Vary with Maternal Residence, Age, Parity and Their Interactions, at 12:15 p.m., Wednesday May 23 in the medium conference room at the Santa Fe Institute.

Martin is a Visiting Research Associate, School of Advanced Research; Professor Emeritus, Department of Anthropology, Arizona State University.

Abstract: The ratio of male to female births [(m/f) x 100] is reported to vary from 100 or less among national populations in southern Africa to 105-6 among national populations in Europe, Asia, and in the United States.

In northern sub-Saharan Africa sex ratios at birth (SRb) are reported to be high as 108 to 110. Differences this large between national and regional populations are not likely to result from chance.

Such variations have been attributed to genetic differences and to such biological and social/behavioral factors as maternal age, parity (the number of mother’s previous births), polygyny as against monogamy, the presence or absence of a male partner in the household, and the frequency of unprotected sexual intercourse in the woman’s fertile period.

SFI Host: Linda Cordell

http://www.santafe.edu/gevent/detail/science/904/