Zosteropidae (2 Viewers)

[Peter Kovalik]

Babbington, J., Boland, C.R.J., Kirwan, G.M. et al. Morphological differences between ‘Mangrove White-eye’ and montane Abyssinian White-eye (Zosterops abyssinicus arabs) in Arabia despite no differentiation in mitochondrial DNA: incipient speciation via niche divergence?. J Ornithol (2020). https://doi.org/10.1007/s10336-020-01788-3

Abstract:

The Arabian population of the Abyssinian White-eye Zosterops abyssinicus arabs occurs in the Asir Mountains in southwest Saudi Arabia, the highlands of Yemen, and southwest Oman. In Saudi Arabia, a recently discovered, very small, and enigmatic population of white-eyes Zosterops sp. indet. occurs in stands of mature mangroves on the Kingdom’s southern Red Sea coast 80–100 km west of the nearest locality of Z. a. arabs in the Asir Mountains. We obtained biometric data and blood samples from individuals of both populations, in the Asir Mountains and the Red Sea mangroves, complemented by measurements from museum specimens from throughout the range of Z. a. arabs. The mangrove-dwelling white-eyes were found to differ in morphometrics and several plumage characters from montane Abyssinian White-eyes Z. a. arabs. However, no differences were revealed by one mitochondrial marker between four ‘Mangrove White-eyes’ and five Z. a. arabs from the Asir Mountains. ‘Mangrove White-eyes’ might thus represent the result of a recent colonization followed by niche divergence, and a putative case of incipient speciation in one of the fastest-radiating vertebrate lineages. A review of the scant available literature and our own surveys indicate that the ‘Mangrove White-eye’ is very scarce within a highly restricted and threatened range, and presumably at risk of extinction.

 

[Peter Kovalik]

Maëva Gabrielli, Benoit Nabholz, Thibault Leroy, Borja Milá and Christophe Thébaud. Within-island diversification in a passerine bird. Proc Biol Sci Published:18 March 2020Article ID:20192999 https://doi.org/10.1098/rspb.2019.2999

Abstract:

The presence of congeneric taxa on the same island suggests the possibility of in situ divergence, but can also result from multiple colonizations of previously diverged lineages. Here, using genome-wide data from a large population sample, we test the hypothesis that intra-island divergence explains the occurrence of four geographical forms meeting at hybrid zones in the Reunion grey white-eye (Zosterops borbonicus), a species complex endemic to the small volcanic island of Reunion. Using population genomic and phylogenetic analyses, we reconstructed the population history of the different forms. We confirmed the monophyly of the complex and found that one of the lowland forms is paraphyletic and basal relative to others, a pattern highly consistent with in situ divergence. Our results suggest initial colonization of the island through the lowlands, followed by expansion into the highlands, which led to the evolution of a distinct geographical form, genetically and ecologically different from the lowland ones. Lowland forms seem to have experienced periods of geographical isolation, but they diverged from one another by sexual selection rather than niche change. Overall, low dispersal capabilities in this island bird combined with both geographical and ecological opportunities seem to explain how divergence occurred at such a small spatial scale.

 

[Peter Kovalik]

Joseph D. Manthey, Carl H. Oliveros, Michael J. Andersen, Christopher E. Filardi & Robert G. Moyle. Gene flow and rapid differentiation characterize a rapid insular radiation in the southwest Pacific (Aves: Zosterops ). Evolution. First published:14 June 2020 https://doi.org/10.1111/evo.14043

Abstract:

As a dispersive lineage expands its distribution across a heterogeneous landscape, it leaves behind allopatric populations with varying degrees of geographic isolation that often differentiate rapidly. In the case of oceanic islands, even narrowly separated populations often differentiate, which seems contrary to the highly dispersive nature of the founding lineage. This pattern of highly dispersive lineages differentiating across narrow sea barriers has perplexed biologists for more than a century. We used two reduced‐representation genomic datasets to examine the diversification of a recent, rapid geographic radiation, the white‐eyes (Aves: Zosterops ) of the Solomon Islands. We incorporated methods that targeted phylogenetic structure, population structure, and explicit tests for gene flow. Both data sets showed evidence of gene flow among species, but not involving the closely spaced islands in the New Georgia Group. Instead, gene flow has occurred among the larger islands in the archipelago, including those recently connected by land bridges as well as those isolated by large expanses of deep ocean. Populations separated by shallow seas, and connected by land bridges during glacial cycles, ranged from no differentiation to both phenotypic and genomic differentiation. These complex patterns of gene flow and divergence support a model of rapid geographic radiation in which lineages differentially evolve dispersal disparity and phenotypic differences.

 

[JustinJansen]

Phylogenomics of white-eyes, a 'great speciator', reveals Indonesian archipelago as the center of lineage diversity​

Abstract​

Archipelagoes serve as important 'natural laboratories' which facilitate the study of island radiations and contribute to the understanding of evolutionary processes. The white-eye genus Zosterops is a classical example of a 'great speciator', comprising c. 100 species from across the Old World, most of them insular. We achieved an extensive geographic DNA sampling of Zosterops by using historical specimens and recently collected samples. Using over 700 genome-wide loci in conjunction with coalescent species tree methods and gene flow detection approaches, we untangled the reticulated evolutionary history of Zosterops, which comprises three main clades centered in Indo-Africa, Asia, and Australasia, respectively. Genetic introgression between species permeates the Zosterops phylogeny, regardless of how distantly related species are. Crucially, we identified the Indonesian archipelago, and specifically Borneo, as the major center of diversity and the only area where all three main clades overlap, attesting to the evolutionary importance of this region.

 

[MJB]

Phylogenomics of white-eyes, a 'great speciator', reveals Indonesian archipelago as the center of lineage diversity​

Abstract​

Archipelagoes serve as important 'natural laboratories' which facilitate the study of island radiations and contribute to the understanding of evolutionary processes. The white-eye genus Zosterops is a classical example of a 'great speciator', comprising c. 100 species from across the Old World, most of them insular. We achieved an extensive geographic DNA sampling of Zosterops by using historical specimens and recently collected samples. Using over 700 genome-wide loci in conjunction with coalescent species tree methods and gene flow detection approaches, we untangled the reticulated evolutionary history of Zosterops, which comprises three main clades centered in Indo-Africa, Asia, and Australasia, respectively. Genetic introgression between species permeates the Zosterops phylogeny, regardless of how distantly related species are. Crucially, we identified the Indonesian archipelago, and specifically Borneo, as the major center of diversity and the only area where all three main clades overlap, attesting to the evolutionary importance of this region.

Happy New Year, JJFJJ!

Supplementary File 2 lists only one new split from this study, two species comprising Z. chloris, but gives no detail.

I was hoping for a possible explanation of two very different Zosterops I saw in Borneo close to the coast between Seria and Bandar Seri Bagawan in 1984, but no such luck!
MJB

 

[Jim LeNomenclatoriste]

Supplementary File 2

Where are they?

 

[MJB]

Where are they?

I can send you the two files - they're in draft form in Word, but I haven't worked out on this new BF if I can do that as if in a PM. Indeed, I haven't worked out if there is a PM system.
MJB

 

[njlarsen]

The PM system is now called Conversations. If you, while on a PC, mouse over another users avitar, a popup appears with the option of "starting conversation" as one part.

Niels

 

[delia todd]

I can send you the two files - they're in draft form in Word, but I haven't worked out on this new BF if I can do that as if in a PM. Indeed, I haven't worked out if there is a PM system.
MJB

.... and you'll find all your old PM's in the "Envelope" on the top row, beside your name. You can start 'conversations' there as well, if you know the member's username.

 

[awiner]

Happy New Year, JJFJJ!

Supplementary File 2 lists only one new split from this study, two species comprising Z. chloris, but gives no detail.

I was hoping for a possible explanation of two very different Zosterops I saw in Borneo close to the coast between Seria and Bandar Seri Bagawan in 1984, but no such luck!
MJB

I'm assuming the spit is Wakatobi White-eye.

The two white-eyes in Brunei (as treated today) should be Hume's and Swinhoe's, with Swinhoe's strictly coastal. (Though apparently there's thought that the ssp. in coastal western Borneo - now "erwini" - might deserve its own taxa, so there's at least some mystery left.)

 

[MJB]

I'm assuming the spit is Wakatobi White-eye.

The two white-eyes in Brunei (as treated today) should be Hume's and Swinhoe's, with Swinhoe's strictly coastal. (Though apparently there's thought that the ssp. in coastal western Borneo - now "erwini" - might deserve its own taxa, so there's at least some mystery left.)

My recollection was that the coastal taxon, easily found and numerous, was the more prevalent; the other was scarce and on 3 visits we saw it only twice, a maximum of 2 birds. The behaviour was different, too, the scarce taxon keeping below the bush and scrub tops, forging lower down. They were too distant for useful images, but thanks for the information. At least there is a plausible answer to something that's puzzled me for 36 years!
MJB

 

[Jim LeNomenclatoriste]

I'm assuming the spit is Wakatobi White-eye.

Nope, flavissimus is sampled and close to chloris. It's an other subspecies

 

[viator]

Nope, flavissimus is sampled and close to chloris. It's an other subspecies

What does that mean then in terms of IOC already having Wakatobi split off?

 

[Peter Kovalik]

IOC Updates Diary Feb 6

Post proposed split of Bougainville White-eye and Guadalcanal White-eye from Grey-throated White-eye.

Post proposed split of Oya Tabu White-eye from Capped White-eye

Post proposed split of Green-fronted White-eye from Black-fronted White-eye.

 

[albertonykus]

Sendell‐Price, A.T., K.C. Ruegg, B.C. Robertson, and S.M. Clegg (2021)
An island‐hopping bird reveals how founder events shape genome‐wide divergence
Molecular Ecology (advance online publication)
doi: 10.1111/mec.15898
https://onlinelibrary.wiley.com/doi/10.1111/mec.15898

When populations colonise new areas, both strong selection and strong drift can be experienced due to novel environments and small founding populations, respectively. Empirical studies have predominantly focused on the phenotype when assessing the role of selection, and limited neutral‐loci when assessing founder‐induced loss of diversity. Consequently, the extent to which processes interact to influence evolutionary trajectories is difficult to assess. Genomic‐level approaches provide the opportunity to simultaneously consider these processes. Here, we examine the roles of selection and drift in shaping genomic diversity and divergence in historically documented sequential island colonisations by the silvereye bird (Zosterops lateralis). We provide the first empirical demonstration of the rapid appearance of highly diverged genomic regions following population founding, the position of which are highly idiosyncratic. As these regions rarely contained loci putatively under selection, it is most likely that these differences arise via the stochastic nature of the founding process. However, selection is required to explain rapid evolution of larger body size in insular silvereyes. Reconciling our genomic data with these phenotypic patterns suggests there may be many genomic routes to the island phenotype, that vary across populations. Finally, we show that accelerated divergence associated with multiple founding steps is the product of genome‐wide rather than localised differences, and that diversity erodes due to loss of rare alleles. However even multiple founder events do not result in divergence and diversity levels seen in evolutionary older subspecies, and therefore do not provide a shortcut to speciation as proposed by founder‐effect speciation models.

 

[njlarsen]

Without access to the full paper, I find it difficult to discern what they mean by the last couple of sentences.

Niels

 

[l_raty]

The paper is open access, actually.

 

[njlarsen]

The paper is open access, actually.

Thanks, did not realize that.
Niels

 

[Peter Kovalik]

Carl H. Oliveros, Michael J. Andersen, Robert G. Moyle. A phylogeny of white-eyes based on ultraconserved elements. Molecular Phylogenetics and Evolution,
In Press, Journal Pre-proof, Available online 29 July 2021. https://doi.org/10.1016/j.ympev.2021.107273

Abstract:

White-eyes are an iconic radiation of passerine birds that have been the subject of studies in evolutionary biology, biogeography, and speciation theory. Zosterops white-eyes in particular are thought to have radiated rapidly across continental and insular regions of the Afro- and Indo-Pacific tropics, yet, their phylogenetic history remains equivocal. Here, we sampled 77% of the genera and 47% of known white-eye species and sequenced thousands of ultraconserved elements to infer the phylogeny of the avian family Zosteropidae. We used concatenated maximum likelihood and species tree methods and found strong support for seven clades of white-eyes and three clades within the species-rich Zosterops radiation.

 

[Jim LeNomenclatoriste]

Carl H. Oliveros, Michael J. Andersen, Robert G. Moyle. A phylogeny of white-eyes based on ultraconserved elements. Molecular Phylogenetics and Evolution,
In Press, Journal Pre-proof, Available online 29 July 2021. https://doi.org/10.1016/j.ympev.2021.107273

Abstract:

White-eyes are an iconic radiation of passerine birds that have been the subject of studies in evolutionary biology, biogeography, and speciation theory. Zosterops white-eyes in particular are thought to have radiated rapidly across continental and insular regions of the Afro- and Indo-Pacific tropics, yet, their phylogenetic history remains equivocal. Here, we sampled 77% of the genera and 47% of known white-eye species and sequenced thousands of ultraconserved elements to infer the phylogeny of the avian family Zosteropidae. We used concatenated maximum likelihood and species tree methods and found strong support for seven clades of white-eyes and three clades within the species-rich Zosterops radiation.

I want it