ISSN:
1573-8477
Keywords:
Heliconius numata
;
Melinaea
;
Ithomiinae
;
aposematism
;
Müllerian mimicry
;
polymorphism
;
spatial heterogeneity
;
frequency-dependent selection
;
population genetic structure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Polymorphism in aposematic animals and coexistence of multiple mimicry rings within a habitat are not predicted by classical Müllerian mimicry. The butterfly Heliconius numata Cramer (Lepidoptera: Nymphalidae; Heliconiinae) is both polymorphic and aposematic. The polymorphism is due to variation at a single locus (or `supergene') which determines colour patterns involved in Müllerian mimicry. We sampled 11 sites in a small area (approx. 60×30km) of North-eastern Peru for H. numata and its co-mimics in the genus Melinaea and Athyrtis (Ithomiinae), and examined the role of temporal and spatial heterogeneity in the maintenance of polymorphism. Colour-patterns of Melinaea communities, which constitute the likely `mimetic environment' for H. numata, are differentiated on a more local scale than morphs of H. numata, but the latter do show a strong and significant response to local selection for colour-pattern. In contrast, analysis of enzyme polymorphism in H. numata across the region revealed no spatial structure, which is consistent with a high mobility of this species. Differences in spatial variability in the two taxa may have caused H. numata to become polymorphic, while temporal variability, not significant in this study, probably has a lesser effect. The mimetic polymorphism is therefore explained by means of multiple selection-migration clines at a single locus, a similar process to that which explains narrow hybrid zones between geographic races of other Heliconius butterflies.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1010875213123
Permalink
