Related Experiment Videos
Chromosome evolution in Neotropical Danainae and Ithomiinae (Lepidoptera)
Keith S Brown1, Barbara Von Schoultz, Esko Suomalainen
1Museu de História Natural, Departamento de Zoologia, Universidade Estadual de Campinas, São Paulo, Brazil.
Hereditas
|February 11, 2005
Summary
The study reveals diverse chromosome numbers in Neotropical Ithomiinae butterflies, with most species showing variation from the typical butterfly karyotype. This chromosomal diversity may reflect their evolutionary adaptability and ecological strategies.
Area of Science:
- * Evolutionary Biology
- * Genetics
- * Entomology
Background:
- * The Neotropical butterfly subfamily Ithomiinae is known for its role in mimicry rings.
- * Understanding karyotype evolution is crucial for comprehending speciation and adaptation in insects.
Purpose of the Study:
- * To document chromosome numbers across a wide range of Ithomiinae taxa.
- * To investigate the patterns of karyotype evolution within the subfamily.
- * To correlate chromosomal changes with the subfamily's ecological and behavioral traits.
Main Methods:
- * Chromosome counts were performed on 1011 populations of 242 Ithomiinae species.
- * Comparative analysis included Neotropical Danainae and Australian Tellervo as sister groups.
- * Karyotype data were superimposed on a cladistic phylogeny of the Ithomiinae.
Main Results:
- * Chromosome numbers ranged from n=5 to n=120, with modal values at n=12-18, deviating from the typical butterfly modal number (n=30-31).
- * An early halving of the chromosome complement to approximately n=14-15 is suggested, followed by significant variation within genera and tribes.
- * At least 40 species exhibited substantial geographical variation in chromosome number, with minimal evidence of reduced fertility or incipient speciation.
Conclusions:
- * Ithomiinae butterflies display remarkable karyotype diversity, suggesting significant evolutionary flexibility.
- * Chromosomal variation appears to be a common phenomenon within the subfamily, often without apparent negative fitness consequences.
- * The observed karyotype evolution likely contributes to the subfamily's ecological opportunism, gregarious behavior, and migratory patterns.