New research by the Milner Centre for Evolution academics in collaboration with Sun Yat-sen University in Guangzhou (China) shows that Southern and Northern breeding populations of plovers in China are in fact two distinct species: Kentish plover (Charadrius alexandrinus) in the North and white-faced plover (Charadrius dealbatus) in the South.
Using state-of-the-art genomics analysis, the team revealed that the Kentish plover and white-faced plover diverged approximately half a million years ago due to cycling sea level changes between the Eastern and Southern China Sea causing intermittent isolation of the two regional populations.
The results show that despite looking very similar, the two plover species have high levels of genetic divergence on their sex chromosomes, (Z chromosome) than on other chromosomes, indicating that sexual selection might play a role to in the evolution of the two species.
Dr Yang Liu, a visiting scholar from Sun Yat-sen University at the Milner Centre for Evolution, led the work. He said: “The initial divergence of the two plovers was probably triggered by the geographical isolation.
“However, other factors, such as ecological specialisations, behavioural divergence, and sexual selection could also contribute to the speciation of the two species. Paper. (open access) – Xuejing Wang, Kathryn H. Maher, Nan Zhang, Pinjia Que, Chenqing Zheng, Simin Liu, Biao Wang, Qin Huang, De Chen, Xu Yang, Zhengwang Zhang, Tamás Székely, Araxi O. Urrutia, Yang Liu. Demographic Histories and Genome-Wide Patterns of Divergence in Incipient Species of Shorebirds. Frontiers in Genetics, 2019; 10 DOI: 10.3389/fgene.2019.00919 More.
So different sets of genes can result in identical looking birds? This is getting as complicated as the butterflies.
From Jonathan Martinez at Eurekalert:
See also: A physicist looks at biology’s problem of “speciation” in humans