Developmental processes exert their influence on the evolution of comp
lex morphologies through the genetic correlations they engender betwee
n traits. Butterfly wing color patterns provide a model system to exam
ine this connection between development and evolution. In butterflies,
the nymphalid groundplan is a framework used to decompose complex win
g patterns into their component pattern elements. The first goal of th
is work has been to determine whether the components of the nymphalid
groundplan are the products of independent developmental processes. To
test this hypothesis, the genetic correlation matrices for two specie
s of butterflies, Precis coenia and Precis evarete, were estimated for
27 wing pattern characters. The second purpose was to test the hypoth
esis that the differentiation of serial homologs lowers their genetic
correlations. The ''eyespots'' found serially repeated across the fore
- and hindwing and on the dorsal and ventral wing surfaces provided an
opportunity to test this hypothesis. The genetic correlation matrices
of both species were very similar. The pattern of genetic correlation
measured between the different types of pattern elements and between
the homologous repeats of a pattern element supported the first hypoth
esis of developmental independence among the elements of the groundpla
n. The correlation pattern among the differentiated serial homologs wa
s similarly found to support the second hypothesis: pairs of eyespots
that had differentiated had lower genetic correlations than pairs that
were similar in morphology. The implications of this study are twofol
d: First, the apparent developmental independence among the distinct e
lements of wing pattern has facilitated the vast diversification in mo
rphology found in butterflies. Second, the lower genetic correlations
between differentiated homologs demonstrates that developmental constr
aints can in fact be broken. The extent to which genetic correlations
readily change, however, remains unknown. (C) 1994 Wiley-Liss, Inc.