A model for the evolution of senescence known as "antagonistic pleiotropy" makes 
the specific prediction that there should be a negative genetic correlation 
between early- and late-age traits associated with fitness. This model has 
previously been tested by classical quantitative-genetic means including 
sib-analysis and artificial selection. We used the approach of chromosome 
extraction, which has both advantages and disadvantages compared to classical 
techniques, to test the model further. From four isogenic lines of Drosophila 
melanogaster, four sets of recombinant extracted lines were constructed using 
standard balancer-chromosome techniques. The four parental lines and 53 
recombinants were reared under controlled laboratory conditions and isolated as 
pairs for scoring daily fecundity and longevity. Even though the design is not 
optimal for estimating classical components of genetic variance, it afforded a 
uniquely direct test of the magnitude of environmental covariances, while giving 
a detailed genetic picture of part of the genome. There were clear differences 
among the recombinant series in the distribution of mean longevity and early 
fecundity. The genetic correlation between early fecundity (sum of egg 
production for the first five days posteclosion) and female longevity was 
significantly negative in only one of the recombinant series. When all lines 
were considered together, the phenotypic correlation between these traits was 
significantly negative (P < 0.02), while the broad-sense genetic correlation was 
-0.219 (P < 0.11). This result may be viewed as weakly consistent with the model 
of antagonistic pleiotropy, but other aspects of the data are at odds with the 
model.