Ethan Gyllenhaal
@ethanofthegulls.bsky.social
NSF Postdoc at Texas Tech and Cornell studying the evolution of south Pacific birds with genomics, museums, and simulations. Birder. SLiM enjoyer. He/him.
I'm not familiar with the precise tree, but there is enough variation in mask extent and crown color that one has to wonder about ILS/ancient gene flow! Wonder what ASIP's doing....
November 21, 2025 at 6:39 PM
I'm not familiar with the precise tree, but there is enough variation in mask extent and crown color that one has to wonder about ILS/ancient gene flow! Wonder what ASIP's doing....
Look forward to more about Solomon Island phylogeography in the future, but in the mean time, @lukemusher.bsky.social and I have a pre-print that highlights how a similar phenomenon can occur on continents (with bias in both topology and branch lengths): doi.org/10.1101/2025...
November 21, 2025 at 6:29 PM
Look forward to more about Solomon Island phylogeography in the future, but in the mean time, @lukemusher.bsky.social and I have a pre-print that highlights how a similar phenomenon can occur on continents (with bias in both topology and branch lengths): doi.org/10.1101/2025...
One big question that still lingers is when this gene flow occurs. Theory suggests that dispersal start high and declines over time in island birds, but it is hard to observe modern inter-island migration. But we found a lucky breadcrumb: an F1 inter-island hybrid (formerly intergrade, now split).
November 21, 2025 at 6:29 PM
One big question that still lingers is when this gene flow occurs. Theory suggests that dispersal start high and declines over time in island birds, but it is hard to observe modern inter-island migration. But we found a lucky breadcrumb: an F1 inter-island hybrid (formerly intergrade, now split).
Although we have some evidence suggesting biased inference in this system, we wanted to generalize these findings using coalescent simulations with gene flow based on island biogeographic theory. For a wide parameter space, the Makira-sister pattern dominated regardless of the split history.
November 21, 2025 at 6:29 PM
Although we have some evidence suggesting biased inference in this system, we wanted to generalize these findings using coalescent simulations with gene flow based on island biogeographic theory. For a wide parameter space, the Makira-sister pattern dominated regardless of the split history.
So what could explain the dominance of this topology? Well, it turns out the island most isolated from propagules is also most isolated from gene flow from the central Bukida group. This was both true in theory and with tests of gene flow.
November 21, 2025 at 6:29 PM
So what could explain the dominance of this topology? Well, it turns out the island most isolated from propagules is also most isolated from gene flow from the central Bukida group. This was both true in theory and with tests of gene flow.
Indeed, when we ran simulations of colonization history with SLiM, we found that only ~1% of simulations produced a colonization history consistent with this topology. Note that the GIF has very low population size/dispersal rate for visualization.
November 21, 2025 at 6:29 PM
Indeed, when we ran simulations of colonization history with SLiM, we found that only ~1% of simulations produced a colonization history consistent with this topology. Note that the GIF has very low population size/dispersal rate for visualization.
However, the island of Makira was most isolated from lineages moving between island from their source population to the west, but was also inferred as sister to all other populations. This was counter-intuitive as first, especially because the genus doesn't make it east of the Solomons.
November 21, 2025 at 6:29 PM
However, the island of Makira was most isolated from lineages moving between island from their source population to the west, but was also inferred as sister to all other populations. This was counter-intuitive as first, especially because the genus doesn't make it east of the Solomons.
Awesome!! Super interesting about the per-patch carotenoid result, the pairing slipped past me when @jlwilliamson.bsky.social and I picked out pairings with differing carotenoids. So did COYE x KEWA, but more overlap the putative pix are more complicated: media.ebird.org/catalog?bird...
Kentucky Warbler x Common Yellowthroat (hybrid) - Geothlypis formosa x trichas - Media Search - Macaulay Library and eBird
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November 21, 2025 at 5:02 PM
Awesome!! Super interesting about the per-patch carotenoid result, the pairing slipped past me when @jlwilliamson.bsky.social and I picked out pairings with differing carotenoids. So did COYE x KEWA, but more overlap the putative pix are more complicated: media.ebird.org/catalog?bird...
It’s because they couldn’t stop staring at the bird’s clown face.
October 29, 2025 at 2:51 AM
It’s because they couldn’t stop staring at the bird’s clown face.