Fossils, genomes provide conflicting data in debate on mosquitoes’ origins, PgII

Key Highlights:

• A recent study suggests mosquitoes originated around 106 million years ago, challenging the long-held belief of 220 million years.
• The study, led by Tommy Lam at the University of Hong Kong, analyzed large-scale genome data to rebuild mosquito evolution.
• Conflicting evidence arises from fossil records, with the oldest mosquito fossil dating back about 100 million years.
• The research indicates a possible co-evolution of mosquitoes and Plasmodium, the malaria parasite, around 43-46 million years ago.

Detailed Insights:

• The traditional view of mosquito evolution, placing their origin in the Triassic Period, is based on limited fossil evidence and potentially skewed molecular studies.
• The new study addresses branch attraction bias in previous analyses, which may have made unrelated mosquito groups appear more closely related.
• The research proposes an alternative evolutionary tree, suggesting that Anophelinae mosquitoes are closely related to the Culex group, challenging the two-subfamily hypothesis.
• Experts highlight limitations of the new study, including a sampling bias towards Anopheles and the difficulty in accurately determining the root of evolutionary trees.
• The co-evolution theory suggests that the diversification of mosquitoes and Plasmodium influenced each other's biology, but this is debated due to conflicting fossil evidence.

Scientific/Technical Concepts Involved:

• Benchmarking universal single-copy orthologs: Conserved genetic markers that change very little over time, used to rebuild evolutionary relationships.
• Ultraconserved elements: Highly conserved regions of the genome that are similar across diverse species, useful for evolutionary studies.
• Branch attraction bias: A phenomenon that skews phylogenetic analyses, making unrelated groups appear more closely related due to similar genetic changes.
• Phylogenetic dating: A method used to estimate the timing of evolutionary events based on genetic data and fossil records.