BIOCHEMICAL HETEROZYGOSITY AND MORPHOLOGIC VARIATION IN A COLONY OF PAPIO-HAMADRYAS HAMADRYAS BABOONS

This analysis examines the association between genetic heterozygosity and individual morphologic variation in a captive population of Papio hamadryas hamadryas consisting of 403 juveniles and adults. The popula tion structure of the colony was artificially generated and maintained and is thus rigorously defined. Subpopulations delimited by age, sex, and degree of inbreeding are also explored. Heterozygosity, as enumer ated from six simple Mendelian biochemical loci, is compared with the residual morphologic variation of each individual for each of 20 quant itative traits. Use of a sequential Bonferroni technique nullifies all significant correlations. Principal-components analysis reduces the m orphometrics to a single or few significant axes in each population. T he first axis of the total population contains 86.07% of the variation in the sample and the absolute values of the factor scores exhibit a significant positive correlation with heterozygosity at P < 0.05. Corr ecting for age- and sex-related variation in the total population with a linear model subsequently demonstrates that no significant correlat ion between heterozygosity and morphologic variation exists. No signif icant relationship is found in the inbred animals or subpopulations wh en age and sex are controlled. Previous studies have indicated that in dividuals proximal to the population mean for a specific polygenic tra it exhibit a higher biochemical heterozygosity than individuals distan t from the mean. The results presented here, which are based on more l oci than many studies and a well-defined population, do not support th is relationship. Substructuring of a population by age and sex can lea d to spurious correlations with univariate or multivariate techniques. Comprehensive indices of genetic variation and rigorous statistical t echniques should be used in future analyses. Studies that fail to reco gnize these design elements should be interpreted with caution.