A recent study unveils that the chromosomes of butterflies and moths have stayed nearly the same for over 250 million years, dating back to their common ancestor.
This stability persists despite the vast diversity observed in wing patterns, sizes, and caterpillar shapes across more than 160,000 species globally.
Investigating Evolutionary History
Researchers from the Wellcome Sanger Institute and the University of Edinburgh delved into the evolutionary history of butterflies and moths by analyzing over 200 high-quality chromosome-level genomes.
This comprehensive study aimed to understand the genetic makeup of these insects.
Genetic Exceptions
The study identified rare cases where certain species defied genetic norms, experiencing chromosomal fusions and fissions.
These genetic rearrangements, where chromosomes merge or split, deviate from the usual stability observed in the majority of butterfly and moth species.
Implications for Conservation
Published in Nature Ecology and Evolution, the findings provide valuable insights into the strict constraints governing genome evolution in these ecologically crucial insects.
Understanding these genetic dynamics can enhance conservation efforts by informing targeted strategies, monitoring ecosystem health, adapting to climate change, and incorporating genetic information into broader conservation initiatives.
Contribution to Larger Projects
This research aligns with the Darwin Tree of Life Project, aiming to sequence all 70,000 species in Britain and Ireland. It also contributes to the broader Earth BioGenome Project, seeking to sequence the 1.6 million cataloged species worldwide.
Chromosomal Changes and Biodiversity
The study prompts broader questions about how chromosomal changes influence biodiversity over time.
Ongoing efforts, such as Project Psyche, focus on sequencing all 11,000 European species of butterflies and moths to deepen our understanding of these processes.
Importance of Lepidoptera
Butterflies and moths, collectively known as Lepidoptera, constitute 10 percent of all described animal species. They play crucial roles as pollinators and herbivores in various ecosystems.
Insights into Chromosome Evolution
Researchers identified 32 ancestral chromosome building blocks, named “Merian elements,” that have remained unchanged in most butterfly and moth species for over 250 million years.
Despite minor changes in some species, the chromosomes and gene order remained remarkably stable.
Exceptional Species and Genetic Diversity
Certain species, like blue butterflies (Lysandra) and cabbage white butterflies (Pieris), exhibited significant chromosomal rearrangements, challenging the typical genome structure constraints.
Understanding these exceptions enhances our knowledge of the factors driving genetic diversity and aids in the protection of species facing unique challenges due to environmental changes and climate change.
Charlotte Wright, the study’s first author at the Wellcome Sanger Institute, expressed surprise at the remarkable chromosome stability despite species diversification.
This challenges the notion that stable chromosomes limit species diversification and suggests that such stability could be the foundation for building diversity. The hope is to find clues in rare groups that have deviated from these genetic rules.