Genetic drift in present human populations: Survey of a Mediterranean region (La Alpujarra, south-east Spain)

This paper presents information on the opportunity for genetic drift in La Alpujarra, a rural population of the Spanish Mediterranean. This region is characterized by its historical isolation. The analyses were based on a survey of 45% of the population. The Effective Population Size (N-E=1986), the Effective Migration Rate (M-E = 12.4) and the Coefficient of Breeding Isolation (CBI=246.2) of Lasker & Kaplan (1964) were calculated. The value of the latter index indicates that genetic drift in the Alpujarrenian population is negligible at present because of the cessation of reproductive isolation due to the development of communication networks.