iiinova — where your digital self keeps evolving

Justin Merondun @merondun.bsky.social · 30/10/2025

This was the product of a decade of work, led by Jochen Wolf @jochenwolflab.bsky.social) and kick-started by @frodefossoy.bsky.social & Bård Stokke, made possible by field teams from dozens of countries! @rytikerttunen.bsky.social @biosulc.bsky.social @btobirds.bsky.social @gregowens.bsky.social

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Justin Merondun @merondun.bsky.social · 30/10/2025

This explains how cuckoos can evolve diverse eggs yet remain one species. Mothers control egg color, while patterning reflects biparental variation tied to geographic and host context. This dual system stabilizes mimicry without necessarily driving speciation. 5/6

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Justin Merondun @merondun.bsky.social · 30/10/2025

Egg patterning instead appears to be controlled by many biparentally inherited genes. These nuclear loci allow local adaptation to hosts and geography, but they don’t drive full genomic separation between cuckoo host races. 4/6

autosomal polygenic basis of egg patterning variation

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Justin Merondun @merondun.bsky.social · 30/10/2025

In common cuckoos, egg color follows maternal lineages. A candidate gene involved in eggshell coloration shows evidence of an ancient autosome-to-W translocation, while other nearby loci tie coloration to mitochondrial function and the heme pathway that produces pigments. 3/6

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Justin Merondun @merondun.bsky.social · 30/10/2025

Common and Oriental cuckoos sneak their eggs into other birds’ nests. Common cuckoos parasitize over 100 host species, fueling an evolutionary arms race: hosts are under pressure to detect foreign eggs, while cuckoos refine their mimicry to escape detection. 2/6

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Justin Merondun @merondun.bsky.social · 30/10/2025

Our new @science.org paper is out! Cuckoos and hosts are locked in a coevolutionary arms race over egg mimicry. But how are these egg types inherited, and could this drive speciation? We sequenced hundreds of genomes to find out! doi.org/10.1126/scie... 🧵1/6

doi.org

Genomic architecture of egg mimicry and its consequences for speciation in parasitic cuckoos

Host-parasite arms races facilitate rapid evolution and can fuel speciation. Cuculus cuckoos are deceptive egg mimics that exhibit a broad diversity of counterfeit egg phenotypes, representing host-ad...

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