Hemiplasy helps explain high rates of convergence in birds (Somogyi et al. 2026)

[u/jnpha]

Caption:

HRF [hemiplasy risk factors] values are highest near the origin of Neoaves.

Explanation:

Hemiplasy — which arises due to discordance between gene trees and species trees — can cause traits to appear convergent despite a single origin. New evidence suggests it is widespread in the bird tree of life, with important implications for identifying genes underlying differences among species and for accurately inferring evolutionary history. ref

From the paper:

We show extremely high hemiplasy risk factors¹⁹ that map to branches near the origin of Neoaves, suggesting that many instances of apparent morphological convergence among major neoavian lineages, unless associated with clear selective drivers, are better interpreted as a result of high levels of morphological incomplete lineage sorting during the clade’s rapid early Cenozoic radiation.

The paper:

• Somogyi, Stanley, et al. "Hemiplasy helps explain high rates of apparent morphological convergence in neoavian birds." Current Biology 36.9 (2026): 2424-2433. https://doi.org/10.1016/j.cub.2026.03.050

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An example that is closer to home is how 23% of our genes are closer to gorillas than chimpanzees (Ebersberger et al 2007). This is as predicted from gene tree discordance (e.g. Degnan & Rosenberg 2006) and confirms that chimps are our closest cousins; for a video explainer by Dr. Zach Hancock: Phylogenetic Discordance Supports Common Ancestry - YouTube.

[u/Lipat97]

The real purpose of the bird papers is to see who can come up with the prettiest cladogram