Figure 1.—

Marey maps of chromosome arms (a) 2L, (b) 2R, (c) 3L, and (d) 3R of the D. melanogaster genome, based on the 615 genes in Release 3 of the genome sequence, which have been localized on both genetic and physical maps. A third-order polynomial curve mapping the genetic location onto the physical location is also represented. N, the numbers of genes from which the curve was derived; outliers, the number of genes excluded from the analysis.