Andy Adcock
Worst person on Birdforum
I hope this isn't breaking any protocols, apologies if it is, I'll remove if so advised.
A quote from the paper, no idea if anyone can glean anything from this, most of this way over my head.
Clade 3: western subalpine warbler
At the high end of genetic divergence, clade 3 is isolated from all other lineages in both mitochondrial and nuclear markers. Mitochondrial distances from the other clades are high (3.3–4.1 and 4.4–5.2% for Cytb and COI genes, respectively) and comparable to those observed between full species (Helbig et al., 1995; Hebert et al., 2004; Pons et al., 2016). The substantial lack of shared nuclear alleles is evident in the single intron and in the multilocus networks, and the inferred lack of gene flow with the other lineages supports the recognition of clade 3 as a full species-level group
Genetic analyses of our small North African sample size (one breeding bird from Tunisia and five breeding birds from Morocco) suggest that the populations from the entire Maghreb belong to the same lineage, which is closely related to western European populations from Portugal, Spain, France and north-west Italy. Gene flow between European and North African populations probably followed a western route acrossthe Strait of Gibraltar rather than the Strait of Sicily.This interesting result would need to be confirmedusing more individuals.
Many species belonging to diverse zoological groups occur on both sides of theStrait of Gibraltar, whereas Italian–North African endemics shared across the Strait of Sicily are muchrarer (Husemann et al., 2014). Considering birds,the biogeographical importance of the Strait ofGibraltar as a link between Europe and North Africa has been pointed out by several studies dealing with different species [e.g. Galerida cristata (Linnaeus,1758), Guillaumet et al., 2008; Muscicapa striata(Pallas, 1764), Pons et al., 2016].
Unlike the European population, we did not detect any sign of population expansion for the North African population. Such a difference suggests that these populations do not share the same demographic history. From a biogeographical perspective, it would be interesting to test whether the Maghreb could have played a role as a glacial refugium for the western subalpine warbler.
