These results suggest a potential historical hybrid zone between these two species as islands were successively colonized, which parallels a hypothesis for whistlers in Fiji by Ernst Mayr in 1932. @ethanofthegulls addressed this w/ whistler 🧬 .

Explicit tests of gene flow with ABBA-BABA support this. Moreover, across the whole tree, we see signatures of ancient introgression between clades earlier in the evolution of the group.

What's also interesting is that these T. sacer taxa are endemic to single islands that do not overlap with the non-breeding range of T. sanctus. Not all of each of these island-endemic sacer taxa had the mismatched mtDNA either.

What I didn't expect was that some, but not all, taxa within the Pacific Kingfisher (T. sacer) would also have mtDNA of a different species, Sacred Kingfisher (t. sanctus).

Incomplete lineage sorting was highlighted as a major with a subset of these species previously, with it being shown as a contributor to mitochondrial discordance in this group. @Dev_Der .

Site and gene concordance factors between major topologies suggest that incomplete lineage sorting is a deeply problematic issue, which was expected.

And found that, for some relationships they agree but others (bolded) that have different relationships or have no statistical support. Overall, we did not find a single well supported tree that matched between datasets or analyses.

From these data, we extracted four types of molecular markers. This ranged from 13 mitochondrial genes with 11,000 base pairs to 8,012 protein coding genes comprising 5 million amino acid sites.

To do so, we relied on vouchered museum samples, including bits of tissue taken from toepads of museum specimens--the oldest of which is from the 1880s

And nearly half of these have never been sequenced for any molecular systematics project.

For my dissertation, I wanted to investigate this interesting result and incorporate the entirety of the diversity of this genus into a molecular phylogeny. There might be 28 species but many are polytypic species complexes than span the Indo-Pacific (w/ 93 sp/ssp).

As some background, I worked on the systematics of kingfishers and their allies for my master's thesis. Clearly, this clade of (mostly) island endemic kingfishers was diversifying at a faster rate than the rest of the order Coraciiformes.

The first chapter of my dissertation is available on @biorxivpreprint. We resequenced genomes of all species (& subspecies) of rapidly radiating genus of Indo-pacific kingfishers.

Morning commute to #Evolution2024 is an absolute delight!

RT @jfnacl: For the past few years I've been obsessed with the question of where Cuban bobwhites came - are they native or introduced, wher….

It also included learning a substantial amount about tarsal scuttelation patterns of Eurocephalus, which has long confused taxonomists. Even Mayr wrote a bit on the subject of what family Eurocephalus belongs to (at that point, the genus was allied closely with helmet-shrikes)

When first described as a member of Corvidae, Smith (1836) noted ―[Eurocephalus anguitimens] true place may be found in another family, and the resemblances, particularly as regards its habits, may be those of analogy and not affinity.".

One fun aspect of this project was doing a deep dive into the modern and historical literature about these birds. These include: ."Of the genera considered to form Laniidae, Eurocephalus is the least shrike-like" --Harris & Franklin 2000

So we added more samples with genome-scale data and found instead that Eurocephalus was more closely related to crows and jays than shrikes.

We wanted to follow up on a peculiar relationship we found in the McCullough et al. 2022 study: that 1 shrike genus, Eurocephalus (green), was not within shrikes (blue). But this relied on a handful of genes & 1/2 Eurocephalus species.