Tags:
Evolutionary biology,
Speciation,
Hybridization,
Birds,
Sexual selection,
Sex chromosomes,
Population genetics
Publications
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Fawthrop, Ruth; Cerca, José; Pacheco, George Antunes; Sætre, Glenn-Peter; Scordato, Elizabeth S.C. & Ravinet, Mark
[Show all 7 contributors for this article]
(2024).
Understanding human-commensalism through an ecological and evolutionary framework.
Trends in Ecology & Evolution.
ISSN 0169-5347.
3368.
doi:
10.1016/j.tree.2024.10.006.
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Human-commensalism has been used to broadly describe interactions in which non-human partners benefit from tight associations with humans and their environments. Human-commensal status has often been intuitively assigned, and the term has been applied without first being clearly defined. This has led to inconsistencies in application across different fields and confusion with other ecologically distinct descriptors of human association. We propose a clear definition of human-commensalism rooted within an ecological and evolutionary framework. Such framing enables exploration of the potential origins of human-commensalism and has implications for the study of biogeography and demography, the pace and form of adaptation to an anthropogenic niche, and predictions of future evolutionary change in response to anthropogenic pressures.
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Gholamhosseini, Ali; Aliabadian, Mansour; Töpfer, Till & Sætre, Glenn-Peter
(2023).
Morphology and morphometry of two hybridizing buntings at their hybrid zone in northern Iran reveal intermediate and transgressive morphotypes.
Avian Research.
14,
p. 1–10.
doi:
10.1016/j.avrs.2023.100150.
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The closely related Black-headed Bunting (Emberiza melanocephala, a western Palearctic lineage) and Red-headed Bunting (Emberiza bruniceps, an eastern Palearctic lineage) hybridize and replace each other south of the Caspian Sea. The parental species have distinct phenotypes and therefore morphology is useful for assessing hybridization in the contact zone. In the years of 1940 and 1977, quite a few hybrids were collected and studied morphologically. Since then, the hybrid zone appears to have expanded westwards, but there has been a time gap in the collection of morphological data. Here we reanalyze bunting specimens morphologically and compare the historical data with recent data. Morphometric and phenotypic traits from three time periods (1940, 1977 and recent) were studied to assess phenotypic variation of hybrids, pattern of hybridization, and transgressive traits in the hybrid zone. Our results show that most of the birds in the hybrid zone exhibit intermediate phenotypes (both colors and morphometric characters), ranging from the pure phenotype of either of the parental species. However, hybridization has also produced novel phenotypes not seen in any of the parents. Using a canonical discriminant function analysis, the morphometric characters separated each parental species and the hybrids quite well. Our results showed morphometric intermediacy of hybrids in accordance with phenotypes. We observe a time trend in which recent hybrids are more similar to Red-headed Buntings phenotypically compared to historical samples. This pattern is likely a signature of a westward expansion of the Red-headed Bunting into the breeding range of the Black-headed Bunting.
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Yazdi, Homa Papoli; Ravinet, Mark; Rowe, Melissah; Sætre, Glenn-Peter; Guldvog, Caroline Øien & Eroukhmanoff, Fabrice
[Show all 9 contributors for this article]
(2022).
Extensive transgressive gene expression in testis but not ovary in the homoploid hybrid Italian sparrow.
Molecular Ecology.
ISSN 0962-1083.
31(15),
p. 4067–4077.
doi:
10.1111/mec.16572.
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Hybridization can result in novel allelic combinations which can impact the hybrid phenotype through changes in gene expression. While misexpression in F1 hybrids is well documented, how gene expression evolves in stabilized hybrid taxa remains an open question. As gene expression evolves in a stabilizing manner, break-up of co-evolved cis- and trans-regulatory elements could lead to transgressive patterns of gene expression in hybrids. Here, we address to what extent gonad gene expression has evolved in an established and stable homoploid hybrid, the Italian sparrow (Passer italiae). Through comparison of gene expression in gonads from individuals of the two parental species (i.e., house and Spanish sparrow) to that of Italian sparrows, we find evidence for strongly transgressive expression in male Italian sparrows—2530 genes (22% of testis genes tested for inheritance) exhibit expression patterns outside the range of both parent species. In contrast, Italian sparrow ovary expression was similar to that of one of the parent species, the house sparrow (Passer domesticus). Moreover, the Italian sparrow testis transcriptome is 26 times as diverged from those of the parent species as the parental transcriptomes are from each other, despite being genetically intermediate. This highlights the potential for regulation of gene expression to produce novel variation following hybridization. Genes involved in mitochondrial respiratory chain complexes and protein synthesis are enriched in the subset that is over-dominantly expressed in Italian sparrow testis, suggesting that selection on key functions has moulded the hybrid Italian sparrow transcriptome.
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Cuevas, Angelica; Eroukhmanoff, Fabrice; Ravinet, Mark; Sætre, Glenn-Peter & Runemark, Anna
(2022).
Predictors of genomic differentiation within a hybrid taxon.
PLoS Genetics.
ISSN 1553-7390.
18(2).
doi:
10.1371/journal.pgen.1010027.
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Hybridization is increasingly recognized as an important evolutionary force. Novel genetic methods now enable us to address how the genomes of parental species are combined in hybrid lineages. However, we still do not know the relative importance of admixed proportions, genome architecture and local selection in shaping hybrid genomes. Here, we take advantage of the genetically divergent island populations of Italian sparrow on Crete, Corsica and Sicily to investigate the predictors of genomic variation within a hybrid taxon. We test if differentiation is affected by recombination rate, selection, or variation in ancestry proportions. We find that the relationship between recombination rate and differentiation is less pronounced within hybrid lineages than between the parent species, as expected if purging of minor parent ancestry in low recombination regions reduces the variation available for differentiation. In addition, we find that differentiation between islands is correlated with differences in signatures of selection in two out of three comparisons. Signatures of selection within islands are correlated across all islands, suggesting that shared selection may mould genomic differentiation. The best predictor of strong differentiation within islands is the degree of differentiation from house sparrow, and hence loci with Spanish sparrow ancestry may vary more freely. Jointly, this suggests that constraints and selection interact in shaping the genomic landscape of differentiation in this hybrid species.
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Warmuth, Vera; Burgess, Malcolm; Laaksonen, Toni; Manica, Andrea; Mägi, Marko & Nord, Andreas
[Show all 10 contributors for this article]
(2021).
Major population splits coincide with episodes of rapid climate change in a forest-dependent bird.
Proceedings of the Royal Society of London. Biological Sciences.
ISSN 0962-8452.
288(1962),
p. 1–10.
doi:
10.1098/rspb.2021.1066.
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Climate change influences population demography by altering patterns of gene flow and reproductive isolation. Direct mutation rates offer the possibility for accurate dating on the within-species level but are currently only available for a handful of vertebrate species. Here, we use the first directly estimated mutation rate in birds to study the evolutionary history of pied flycatchers ( Ficedula hypoleuca ). Using a combination of demographic inference and species distribution modelling, we show that all major population splits in this forest-dependent system occurred during periods of increased climate instability and rapid global temperature change. We show that the divergent Spanish subspecies originated during the Eemian–Weichselian transition 115–104 thousand years ago (kya), and not during the last glacial maximum (26.5–19 kya), as previously suggested. The magnitude and rates of climate change during the glacial–interglacial transitions that preceded population splits in pied flycatchers were similar to, or exceeded, those predicted to occur in the course of the current, human-induced climate crisis. As such, our results provide a timely reminder of the strong impact that episodes of climate instability and rapid temperature changes can have on species' evolutionary trajectories, with important implications for the natural world in the Anthropocene.
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Cuevas, Angelica; Ravinet, Mark; Sætre, Glenn-Peter & Eroukhmanoff, Fabrice
(2020).
Intraspecific genomic variation and local adaptation in a young hybrid species.
Molecular Ecology.
ISSN 0962-1083.
00,
p. 791–809.
doi:
10.1111/mec.15760.
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Hybridization increases genetic variation, hence hybrid species may have greater evolutionary potential once their admixed genomes have stabilized and incompatibilities have been purged. Yet, little is known about how such hybrid lineages evolve at the genomic level following their formation, in particular their adaptive potential. Here we investigate how the Italian sparrow (Passer italiae), a homoploid hybrid species, has evolved and locally adapted to its variable environment. Using restriction site‐associated DNA sequencing (RAD‐seq) on several populations across the Italian peninsula, we evaluate how genomic constraints and novel genetic variation have influenced population divergence and adaptation. We show that population divergence within this hybrid species has evolved in response to climatic variation, suggesting ongoing local adaptation. As found previously in other nonhybrid species, climatic differences appear to increase population differentiation. We also report strong population divergence in a gene known to affect beak morphology. Most of the strongly divergent loci among Italian sparrow populations do not seem to be differentiated between its parent species, the house and Spanish sparrows. Unlike in the hybrid, population divergence within each of the parental taxa has occurred mostly at loci with high allele frequency difference between the parental species, suggesting that novel combinations of parental alleles in the hybrid have not necessarily enhanced its evolutionary potential. Rather, our study suggests that constraints linked to incompatibilities may have restricted the evolution of this admixed genome, both during and after hybrid species formation.
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Hagen, Ingerid Julie; Lien, Sigbjørn; Billing, Anna Maria; Elgvin, Tore Oldeide; Trier, Cassandra Nicole & Niskanen, Alina Katariina
[Show all 10 contributors for this article]
(2020).
A genome-wide linkage map for the house sparrow (Passer domesticus) provides insights into the evolutionary history of the avian genome.
Molecular Ecology Resources.
ISSN 1755-098X.
20(2),
p. 544–559.
doi:
10.1111/1755-0998.13134.
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The house sparrow is an important model species for studying physiological, ecological and evolutionary processes in wild populations. Here, we present a medium density, genome wide linkage map for house sparrow (Passer domesticus) that has aided the assembly of the house sparrow reference genome, and that will provide an important resource for ongoing mapping of genes controlling important traits in the ecology and evolution of this species. Using a custom house sparrow 10 K iSelect Illumina SNP chip we have assigned 6,498 SNPs to 29 autosomal linkage groups, based on a mean of 430 informative meioses per SNP. The map was constructed by combining the information from linkage with that of the physical position of SNPs within scaffold sequences in an iterative process. Averaged between the sexes; the linkage map had a total length of 2,004 cM, with a longer map for females (2,240 cM) than males (1,801 cM). Additionally, recombination rates also varied along the chromosomes. Comparison of the linkage map to the reference genomes of zebra finch, collared flycatcher and chicken, showed a chromosome fusion of the two avian chromosomes 8 and 4A in house sparrow. Lastly, information from the linkage map was utilized to conduct analysis of linkage disequilibrium (LD) in eight populations with different effective population sizes (Ne) in order to quantify the background level LD. Together, these results aid the design of future association studies, facilitate the development of new genomic tools and support the body of research that describes the evolution of the avian genome.
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Cramer, Emily Rebecca A; Rowe, Melissah; Eroukhmanoff, Fabrice; Lifjeld, Jan Terje; Sætre, Glenn-Peter & Johnsen, Arild
(2019).
Measuring sperm swimming performance in birds: effects of dilution, suspension medium, mechanical agitation, and sperm number.
Journal of Ornithology = Journal fur Ornithologie.
ISSN 0021-8375.
p. 1–11.
doi:
10.1007/s10336-019-01672-9.
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Sperm swimming performance, including swimming speed and the proportion of motile cells, may strongly affect fertilization success. However, little is known about how methodological factors affect in vitro measurement of these parameters. We compare the swimming performance of sperm from House Sparrows (Passer domesticus) and Spanish Sparrows (Passer hispaniolensis) in two standard suspension media, at two different dilutions, and with different degrees of cell agitation. Further, we conduct a resampling analysis to investigate sample size effects. Sperm performance was generally reduced when sperm were diluted, or when suspended in phosphate-buffered saline (PBS) rather than a medium containing additional nutrients. Sperm performance was particularly low when they were diluted more and suspended in PBS, suggesting that seminal fluid may provide compounds that enhance performance but that these are less available following dilution. Mechanical agitation of the cells by vigorous pipetting increased the proportion of motile cells. Between-male repeatability, assessed on a single sample measured in multiple conditions, was moderate and significant, suggesting that similar results may be obtained regardless of the methodology used to assess sperm motion. We found no evidence of biased results when low numbers of cells per male were used in analysis, though precision increased substantially as sample size increased from five to 20 or more cells per male. We recommend using the same suspension media and similar sperm concentrations and levels of agitation, to the greatest degree possible, and including as many individuals as possible in analyses, even when some individuals are represented by few sperm cells.
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Rowe, Melissah; Whittington, Emma; Borziak, Kirill; Ravinet, Mark; Eroukhmanoff, Fabrice & Sætre, Glenn-Peter
[Show all 7 contributors for this article]
(2019).
Molecular diversification of the seminal fluid proteome in a recently diverged passerine species pair.
Molecular Biology and Evolution (MBE).
ISSN 0737-4038.
37(2),
p. 488–506.
doi:
10.1093/molbev/msz235.
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Seminal fluid proteins (SFPs) mediate an array of postmating reproductive processes that influence fertilization and fertility. As such, it is widely held that SFPs may contribute to postmating, prezygotic reproductive barriers between closely related taxa. We investigated seminal fluid (SF) diversification in a recently diverged passerine species pair (Passer domesticus and Passer hispaniolensis) using a combination of proteomic and comparative evolutionary genomic approaches. First, we characterized and compared the SF proteome of the two species, revealing consistencies with known aspects of SFP biology and function in other taxa, including the presence and diversification of proteins involved in immunity and sperm maturation. Second, using whole-genome resequencing data, we assessed patterns of genomic differentiation between house and Spanish sparrows. These analyses detected divergent selection on immunity-related SF genes and positive selective sweeps in regions containing a number of SF genes that also exhibited protein abundance diversification between species. Finally, we analyzed the molecular evolution of SFPs across 11 passerine species and found a significantly higher rate of positive selection in SFPs compared with the rest of the genome, as well as significant enrichments for functional pathways related to immunity in the set of positively selected SF genes. Our results suggest that selection on immunity pathways is an important determinant of passerine SF composition and evolution. Assessing the role of immunity genes in speciation in other recently diverged taxa should be prioritized given the potential role for immunity-related proteins in reproductive incompatibilities in Passer sparrows.
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Runemark, Anna; Fernández, Laura Piñeiro; Eroukhmanoff, Fabrice & Sætre, Glenn-Peter
(2018).
Genomic contingencies and the potential for local adaptation in a hybrid species.
The American Naturalist.
ISSN 0003-0147.
192(1),
p. 10–22.
doi:
10.1086/697563.
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Hybridization is increasingly recognized as a potent evolutionary force. Although additive genetic variation and novel combinations of parental genes theoretically increase the potential for hybrid species to adapt, few empirical studies have investigated the adaptive potential within a hybrid species. Here, we address whether genomic contingencies, adaptation to climate, or diet best explain divergence in beak morphology using genomically diverged island populations of the homoploid hybrid Italian sparrow Passer italiae from Crete, Corsica, and Sicily. Populations vary significantly in beak morphology both between and within islands of origin. Temperature seasonality best explains population divergence in beak size. Interestingly, beak shape along all significant dimensions of variation was best explained by annual precipitation, genomic composition, and their interaction, suggesting a role for contingencies. Moreover, beak shape similarity to a parent species correlates with proportion of the genome inherited from that species, consistent with the presence of contingencies. In conclusion, adaptation to local conditions and genomic contingencies arising from putatively independent hybridization events jointly explain beak morphology in the Italian sparrow. Hence, hybridization may induce contingencies and restrict evolution in certain directions dependent on the genetic background.
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Ravinet, Mark; Elgvin, Tore Oldeide; Trier, Cassandra Nicole; Aliabadian, Mansour; Gavrilov, Andrey & Sætre, Glenn-Peter
(2018).
Signatures of human-commensalism in the house sparrow genome.
Proceedings of the Royal Society of London. Biological Sciences.
ISSN 0962-8452.
285(1884),
p. 1–10.
doi:
10.1098/rspb.2018.1246.
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House sparrows (Passer domesticus) are a hugely successful anthrodependent species; occurring on nearly every continent. Yet, despite their ubiquity and familiarity to humans, surprisingly little is known about their origins. We sought to investigate the evolutionary history of the house sparrow and identify the processes involved in its transition to a human-commensal niche. We used a whole genome resequencing dataset of 120 individuals from three Eurasian species, including three populations of Bactrianus sparrows, a non-commensal, divergent house sparrow lineage occurring in the Near East. Coalescent modelling supports a split between house and Bactrianus sparrow 11 Kya and an expansion in the house sparrow at 6 Kya, consistent with the spread of agriculture following the Neolithic revolution. Commensal house sparrows therefore likely moved into Europe with the spread of agriculture following this period. Using the Bactrianus sparrow as a proxy for a pre-commensal, ancestral house population, we performed a comparative genome scan to identify genes potentially involved with adaptation to an anthropogenic niche. We identified potential signatures of recent, positive selection in the genome of the commensal house sparrow that are absent in Bactrianus populations. The strongest selected region encompasses two major candidate genes; COL11A—which regulates craniofacial and skull development and AMY2A, part of the amylase gene family which has previously been linked to adaptation to high-starch diets in humans and dogs. Our work examines human-commensalism in an evolutionary framework, identifies genomic regions likely involved in rapid adaptation to this new niche and ties the evolution of this species to the development of modern human civilization.
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Yeh, D Justin; Boughman, Janette W.; Sætre, Glenn-Peter & Servedio, Maria R
(2018).
The evolution of sexual imprinting through reinforcement.
Evolution.
ISSN 0014-3820.
72(7),
p. 1336–1349.
doi:
10.1111/evo.13500.
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Sætre, Glenn-Peter; Pulido, Angelica Maria Cuevas; Hermansen, Jo Skeie; Elgvin, Tore Oldeide; Fernández, Laura Piñeiro & Sæther, Stein Are
[Show all 8 contributors for this article]
(2017).
Rapid polygenic response to secondary contact in a hybrid species.
Proceedings of the Royal Society of London. Biological Sciences.
ISSN 0962-8452.
284(1853).
doi:
10.1098/rspb.2017.0365.
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Secondary contact between closely related species can have genetic consequences.
Competition for essential resources may lead to divergence in
heritable traits that reduces interspecific competition leading to increased rate of genetic divergence. Conversely, hybridization and backcrossing can lead to genetic convergence. Here, we study a population of a hybrid
species, the Italian sparrow (Passer italiae), before and after it came into secondary contact with one of its parent species, the Spanish sparrow (P. hispaniolensis), in 2013. We demonstrate strong consequences of interspecific
competition: Italian sparrows were kept away from a popular
feeding site by its parent species, resulting in poorer body condition and a significant drop in population size. Although no significant morphological change could be detected, after only 3 years of sympatry, the Italian sparrows had diverged significantly from the Spanish sparrows across a set of 81 protein-coding genes. These temporal genetic changes are mirrored by genetic divergence observed in older sympatric Italian sparrow populations
within the same area of contact. Compared with microallopatric birds, sympatric ones are genetically more diverged from Spanish sparrows. Six significant outlier genes in the temporal and spatial comparison (i.e. showing
the greatest displacement) have all been found to be associated with learning and neural development in other bird species.
character displacement, interspecific
competition, Passer, hybrid species,
cognition, learning
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Gholamhosseini, Ali; Aliabadian, Mansour; Darvish, Jamshid; Topfer, Till & Sætre, Glenn-Peter
(2017).
An Expanding Hybrid Zone between Black-Headed and Red-Headed Buntings in Northern Iran.
Ardea.
ISSN 0373-2266.
105(1),
p. 27–36.
doi:
10.5253/arde.v105i1.a5.
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Elgvin, Tore Oldeide; Trier, Cassandra Nicole; Tørresen, Ole Kristian; Hagen, Ingerid; Lien, Sigbjørn & Nederbragt, Alexander Johan
[Show all 9 contributors for this article]
(2017).
The genomic mosaicism of hybrid speciation.
Science Advances.
3,
p. 1–16.
doi:
10.1126/sciadv.1602996.
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Hybridization is widespread in nature and, in some instances, can result in the formation of a new hybrid species. We investigate the genetic foundation of this poorly understood process through whole-genome analysis of the hybrid Italian sparrow and its progenitors. We find overall balanced yet heterogeneous levels of contribution from each parent species throughout the hybrid genome and identify areas of novel divergence in the hybrid species exhibiting signals consistent with balancing selection. High-divergence areas are disproportionately located on the Z chromosome and overrepresented in gene networks relating to key traits separating the focal species, which are likely involved in reproductive barriers and/or species-specific adaptations. Of special interest are genes and functional groups known to affect body patterning, beak morphology, and the immune system, which are important features of diversification and fitness. We show that a combination of mosaic parental inheritance and novel divergence within the hybrid lineage has facilitated the origin and maintenance of an avian hybrid species.
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Sætre, Camilla Lo Cascio; Coleiro, Charles; Austad, Martin; Gauci, Mark; Sætre, Glenn-Peter & Voje, Kjetil L.
[Show all 7 contributors for this article]
(2017).
Rapid adaptive phenotypic change following colonization of a newly restored habitat.
Nature Communications.
8(14159),
p. 1–6.
doi:
10.1038/ncomms14159.
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Real-time observation of adaptive evolution in the wild is rare and limited to cases of marked, often anthropogenic, environmental change. Here we present the case of a small population of reed warblers (Acrocephalus scirpaceus) over a period of 19 years (1996–2014) after colonizing a restored wetland habitat in Malta. Our data show a population decrease in body mass, following a trajectory consistent with a population ascending an adaptive peak, a so-called Ornstein–Uhlenbeck process. We corroborate these findings with genetic and ecological data, revealing that individual survival is correlated with body mass, and more than half of the variation in mean population fitness is explained by variation in body mass. Despite a small effective population size, an adaptive response has taken place within a decade. A founder event from a large, genetically variable source population to the southern range margin of the reed warbler distribution likely facilitated this process.
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Eroukhmanoff, Fabrice; Rowe, Melissah; Cramer, Emily Rebecca A; Haas, Fredrik; Hermansen, Jo Skeie & Runemark, Anna
[Show all 8 contributors for this article]
(2016).
Experimental evidence for ovarian hypofunction in sparrow hybrids.
Avian Research.
7.
doi:
10.1186/s40657-016-0038-1.
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Background Postzygotic isolation in the form of reduced viability and/or fertility of hybrids may help maintain species boundaries in the face of interspecific gene flow. Past hybridization events between house sparrows (Passer domesticus) and Spanish sparrows (P. hispaniolensis) have given rise to a homoploid hybrid species, the Italian sparrow (P. italiae). Although genetic incompatibilities are known to isolate these three species, the biological consequences of these incompatibilities are still unknown in early generation hybrids. Methods We investigated whether F1 hybrids between house and Spanish sparrows experience reduced viability or fertility. More specifically, we generated hybrids through controlled crosses in aviaries, and compared ovaries of female hybrids with female of pure-species sparrows. Results We found that overall, hybrid ovaries were underdeveloped and that half of all female hybrids exhibited symptoms of ovarian hypofunction (ovarian atrophy and complete absence of developed follicles). Conclusions Fertility in hybrids is a common consequence or post-zygotic barriers between species. We discuss these results in light of previous findings on genetic incompatibilities between the parent species and the potential role of incompatibilities in hybrid speciation, a rare evolutionary process in birds.
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Burri, Reto; Nater, Alexander; Kawakami, Takeshi; Mugal, Carina F.; Olason, Pall I. & Smeds, Linnea
[Show all 18 contributors for this article]
(2015).
Linked selection and recombination rate variation drive the evolution of the genomic landscape of differentiation across the speciation continuum of Ficedula flycatchers.
Genome Research.
ISSN 1088-9051.
25(11),
p. 1656–1665.
doi:
10.1101/gr.196485.115.
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Speciation is a continuous process during which genetic changes gradually accumulate in the genomes of diverging species. Recent studies have documented highly heterogeneous differentiation landscapes, with distinct regions of elevated differentiation ('differentiation islands') widespread across genomes. However, it remains unclear which processes drive the evolution of differentiation islands, how the differentiation landscape evolves as speciation advances, and ultimately how differentiation islands are related to speciation. Here, we addressed these questions based on population genetic analyses of 200 re-sequenced genomes from 10 populations of four Ficedula flycatcher sister species. We show that a heterogeneous differentiation landscape starts emerging among populations within species and that differentiation islands evolve recurrently in the very same genomic regions among independent lineages. Contrary to expectations from models that interpret differentiation islands as genomic regions involved in reproductive isolation that are shielded from gene flow, patterns of sequence divergence (dxy and relative node depth) do not support a major role of gene flow in the evolution of the differentiation landscape in these species. Instead, as predicted by models of linked selection, genome-wide variation in diversity and differentiation can be explained by variation in recombination rate and the density of targets for selection. We thus conclude that the heterogeneous landscape of differentiation in Ficedula flycatchers evolves mainly as the result of background selection and selective sweeps in genomic regions of low recombination. Our results emphasize the necessity of incorporating linked selection as a null model to identify genome regions involved in adaptation and speciation.
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Smeds, Linnea; Warmuth, Vera; Bolivar, Paulina; Uebbing, Severin; Burri, Reto & Suh, Alexander
[Show all 17 contributors for this article]
(2015).
Evolutionary analysis of the female-specific avian
W chromosome.
Nature Communications.
6,
p. 1–10.
doi:
10.1038/ncomms8330.
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The typically repetitive nature of the sex-limited chromosome means that it is often excluded
from or poorly covered in genome assemblies, hindering studies of evolutionary and
population genomic processes in non-recombining chromosomes. Here, we present a draft
assembly of the non-recombining region of the collared flycatcher W chromosome,
containing 46 genes without evidence of female-specific functional differentiation. Survival of
genes during Wchromosome degeneration has been highly non-random and expression data
suggest that this can be attributed to selection for maintaining gene dose and ancestral
expression levels of essential genes. Re-sequencing of large population samples revealed
dramatically reduced levels of within-species diversity and elevated rates of between-species
differentiation (lineage sorting), consistent with low effective population size. Concordance
between W chromosome and mitochondrial DNA phylogenetic trees demonstrates
evolutionary stable matrilineal inheritance of this nuclear–cytonuclear pair of chromosomes.
Our results show both commonalities and differences between W chromosome and
Y chromosome evolution.
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Bailey, Richard Ian; Tesaker, Maria Rundhaugen; Trier, Cassandra Nicole & Sætre, Glenn-Peter
(2015).
Strong selection on male plumage in a hybrid zone between a hybrid bird species and one of its parents.
Journal of Evolutionary Biology.
ISSN 1010-061X.
28(6),
p. 1257–1269.
doi:
10.1111/jeb.12652.
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Trier, Cassandra Nicole; Hermansen, Jo Skeie; Sætre, Glenn-Peter & Bailey, Richard Ian
(2014).
Evidence for Mito-Nuclear and Sex-Linked Reproductive Barriers between the Hybrid Italian Sparrow and Its Parent Species.
PLoS Genetics.
ISSN 1553-7390.
10(1).
doi:
10.1371/journal.pgen.1004075.
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Studies of reproductive isolation between homoploid hybrid species and their parent species have rarely been carried out. Here we investigate reproductive barriers between a recently recognized hybrid bird species, the Italian sparrow Passer italiae and its parent species, the house sparrow P. domesticus and Spanish sparrow P. hispaniolensis. Reproductive barriers can be difficult to study in hybrid species due to lack of geographical contact between taxa. However, the Italian sparrow lives parapatrically with the house sparrow and both sympatrically and parapatrically with the Spanish sparrow. Through whole-transcriptome sequencing of six individuals of each of the two parent species we identified a set of putatively parent species-diagnostic single nucleotide polymorphism (SNP) markers. After filtering for coverage, genotyping success (>97%) and multiple SNPs per gene, we retained 86 species-informative, genic, nuclear and mitochondrial SNP markers from 84 genes for analysis of 612 male individuals. We show that a disproportionately large number of sex-linked genes, as well as the mitochondria and nuclear genes with mitochondrial function, exhibit sharp clines at the boundaries between the hybrid and the parent species, suggesting a role for mito-nuclear and sex-linked incompatibilities in forming reproductive barriers. We suggest that genomic conflict via interactions between mitochondria and sex-linked genes with mitochondrial function (“mother's curse”) at one boundary and centromeric drive at the other may best explain our findings. Hybrid speciation in the Italian sparrow may therefore be influenced by mechanisms similar to those involved in non-hybrid speciation, but with the formation of two geographically separated species boundaries instead of one. Spanish sparrow alleles at some loci have spread north to form reproductive barriers with house sparrows, while house sparrow alleles at different loci, including some on the same chromosome, have spread in the opposite direction to form barriers against Spanish sparrows.
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Eroukhmanoff, Fabrice; Elgvin, Tore Oldeide; Rojas, Maria Fernanda Gonzales; Haas, Fredrik; Hermansen, Jo Skeie & Sætre, Glenn-Peter
(2014).
Effect of Species Interaction on Beak Integration in an Avian Hybrid Species Complex.
Evolutionary Biology.
ISSN 0071-3260.
41(3),
p. 452–458.
doi:
10.1007/s11692-014-9278-3.
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Roberts, Aubrey Jane; Druckenmiller, Patrick Scott; Sætre, Glenn-Peter & Hurum, Jørn Harald
(2014).
A new upper jurassic ophthalmosaurid ichthyosaur from the Slottsmøya Member, Agardhfjellet Formation of central Spitsbergen.
PLOS ONE.
9(8).
doi:
10.1371/journal.pone.0103152.
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Abundant new ichthyosaur material has recently been documented in the Slottsmøya Member of the Agardhfjellet Formation from the Svalbard archipelago of Norway. Here we describe a partial skeleton of a new taxon, Janusaurus lundi, that includes much of the skull and representative portions of the postcranium. The new taxon is diagnosed by a suite of cranial character states including a very gracile stapedial shaft, the presence of a dorsal process on the prearticular and autapomorphic postcranial features such as the presence of an interclavicular trough and a conspicuous anterodorsal process of the ilium. The peculiar morphology of the ilia indicates a previously unrecognized degree of morphological variation in the pelvic girdle of ophthalmosaurids. We also present a large species level phylogenetic analysis of ophthalmosaurids including new and undescribed ichthyosaur material from the Upper Jurassic of Svalbard. Our results recover all Svalbard taxa in a single unresolved polytomy nested within Ophthalmosaurinae, which considerably increases the taxonomic composition of this clade. The paleobiogeographical implications of this result suggest the presence of a single clade of Boreal ophthalmosaurid ichthyosaurs that existed during the latest Jurassic, a pattern also reflected in the high degree of endemicity among some Boreal invertebrates, particularly ammonoids. Recent and ongoing descriptions of marine reptiles from the Slottsmøya Member Lagerstätte provide important new data to test hypotheses of marine amniote faunal turnover at the Jurassic-Cretaceous boundary. This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
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Sætre, Glenn-Peter
(2014).
Genome scans and elusive candidate genes: Detecting the variation that matters for speciation.
Molecular Ecology.
ISSN 0962-1083.
23(19),
p. 4677–4678.
doi:
10.1111/mec.12905.
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Riyahi, Sepand; Hammer, Øyvind; Arbabi, Tayebeh; Sanchez, Antonio; Roselaar, Cees S & Aliabadian, Mansour
[Show all 7 contributors for this article]
(2013).
Beak and skull shapes of human commensal and non-commensal house sparrows Passer domestics.
BMC Evolutionary Biology.
13.
doi:
10.1186/1471-2148-13-200.
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Background The granivorous house sparrow Passer domesticus is thought to have developed its commensal relationship with humans with the rise of agriculture in the Middle East some 10,000 years ago, and to have expanded with the spread of agriculture in Eurasia during the last few thousand years. One subspecies, P. d. bactrianus, residing in Central Asia, has apparently maintained the ancestral ecology, however. This subspecies is not associated with human settlements; it is migratory and lives in natural grass- and wetland habitats feeding on wild grass seeds. It is well documented that the agricultural revolution was associated with an increase in grain size and changes in seed structure in cultivated cereals, the preferred food source of commensal house sparrow. Accordingly, we hypothesize that correlated changes may have occurred in beak and skull morphology as adaptive responses to the change in diet. Here, we test this hypothesis by comparing the skull shapes of 101 house sparrows from Iran, belonging to five different subspecies, including the non-commensal P. d. bactrianus, using geometric morphometrics. Results The various commensal house sparrow subspecies share subtle but consistent skeletal features that differ significantly from those of the non-commensal P. d. bactrianus. Although there is a marked overall size allometry in the data set, the shape difference between the ecologically differentiated sparrows cannot be explained by differences in size alone. Relative to the size allometry commensal house sparrows exhibit a skull shape consistent with accelerated development (heterochrony), resulting in a more robust facial cranium and a larger, more pointed beak. Conclusion The difference in skull shape and robustness of the beak between commensal and non-commensal house sparrows is consistent with adaptations to process the larger and rachis encapsulated seeds of domesticated cereals among human associated populations.
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Backström, Niclas; Sætre, Glenn-Peter & Ellegren, Hans
(2013).
Inferring the demographic history of European Ficedula flycatcher populations.
BMC Evolutionary Biology.
13(2).
doi:
10.1186/1471-2148-13-2.
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Background Inference of population and species histories and population stratification using genetic data is important for discriminating between different speciation scenarios and for correct interpretation of genome scans for signs of adaptive evolution and trait association. Here we use data from 24 intronic loci re-sequenced in population samples of two closely related species, the pied flycatcher and the collared flycatcher. Results We applied Isolation-Migration models, assignment analyses and estimated the genetic differentiation and diversity between species and between populations within species. The data indicate a divergence time between the species of <1 million years, significantly shorter than previous estimates using mtDNA, point to a scenario with unidirectional gene-flow from the pied flycatcher into the collared flycatcher and imply that barriers to hybridisation are still permeable in a recently established hybrid zone. Furthermore, we detect significant population stratification, predominantly between the Spanish population and other pied flycatcher populations. Conclusions Our results provide further evidence for a divergence process where different genomic regions may be at different stages of speciation. We also conclude that forthcoming analyses of genotype-phenotype relations in these ecological model species should be designed to take population stratification into account.
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Eroukhmanoff, Fabrice; Hermansen, Jo Skeie; Bailey, Richard Ian; Sæther, Stein Are & Sætre, Glenn-Peter
(2013).
Local adaptation within a hybrid species.
Heredity.
ISSN 0018-067X.
111(4),
p. 286–292.
doi:
10.1038/hdy.2013.47.
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Bailey, Richard Ian; Eroukhmanoff, Fabrice & Sætre, Glenn-Peter
(2013).
Hybridization and genome evolution II: Mechanisms of species divergence and their effects on evolution in hybrids.
Current Zoology.
ISSN 1674-5507.
59(5),
p. 675–685.
doi:
10.1093/czoolo/59.5.675.
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Eroukhmanoff, Fabrice; Bailey, Richard Ian & Sætre, Glenn-Peter
(2013).
Hybridization and genome evolution I: The role of contingency during hybrid speciation.
Current Zoology.
ISSN 1674-5507.
59(5),
p. 667–674.
doi:
10.1093/czoolo/59.5.667.
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Seierstad, Kristian S.; Carlsen, Tor; Sætre, Glenn-Peter; Hofton, Tom Hellik; Miettinen, Otto & Kauserud, Håvard
(2013).
A phylogeographic survey of a circumboreal polypore indicates introgression among ecologically differentiated cryptic lineages.
Fungal ecology.
ISSN 1754-5048.
6(1),
p. 119–128.
doi:
10.1016/j.funeco.2012.09.001.
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Hogner, Silje; Sæther, Stein Are; Borge, Thomas; Bruvik, Torbjørn; Johnsen, Arild & Sætre, Glenn-Peter
(2012).
Increased divergence but reduced variation on the Z chromosome relative to autosomes in Ficedula flycatchers: differential introgression or the faster-Z effect?
Ecology and Evolution.
2(2),
p. 379–396.
doi:
10.1002/ece3.92.
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Recent multilocus studies of congeneric birds have shown a pattern of elevated interspecific divergence on the Z chromosome compared to the autosomes. In contrast, intraspecifically, birds exhibit less polymorphism on the Z chromosome relative to the autosomes. We show that the four black-and-white Ficedula flycatcher species show greater genetic divergence on the Z chromosome than on the autosomes, and that the ratios of intraspecific polymorphism at Z-linked versus autosomal markers are below the neutral expectation of 75%. In all species pairs, we found more fixed substitutions and fewer shared polymorphisms on the Z chromosome than on the autosomes. Finally, using isolation with migration (IMa) models we estimated gene flow among the four closely related flycatcher species. The results suggest that different pattern of evolution of Z chromosomes and autosomes is best explained by the faster-Z hypothesis, since the estimated long-term gene flow parameters were close to zero in all comparisons.
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Bonnet, Timothee; Slagsvold, Per Kristian & Sætre, Glenn-Peter
(2011).
Genetic species identification of a Collared Pied Flycatcher from Norway.
Journal of Ornithology = Journal fur Ornithologie.
ISSN 0021-8375.
152(4),
p. 1069–1073.
doi:
10.1007/s10336-011-0703-4.
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Hermansen, Jo Skeie; Sæther, Stein Are; Elgvin, Tore Oldeide; Borge, Thomas; Hjelle, Elin & Sætre, Glenn-Peter
(2011).
Hybrid speciation in sparrows I: phenotypic intermediacy, genetic admixture and barriers to gene flow.
Molecular Ecology.
ISSN 0962-1083.
20(18),
p. 3812–3822.
doi:
10.1111/j.1365-294X.2011.05183.x.
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Junge, Claudia; Vøllestad, Leif Asbjørn; Barson, Nicola Jane; Haugen, Thrond; Villar, Jaime Otero & Sætre, Glenn-Peter
[Show all 8 contributors for this article]
(2011).
Strong gene flow and lack of stable population structure in the face of rapid adaptation to local temperature in a spring-spawning salmonid, the European grayling (Thymallus thymallus).
Heredity.
ISSN 0018-067X.
106(3),
p. 460–471.
doi:
10.1038/hdy.2010.160.
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Veen, Thor; Sheldon, Ben C; Weissing, Franz J.; Visser, Marcel E.; Qvarnström, Anna & Sætre, Glenn-Peter
(2010).
Temporal differences in food abundance promote coexistence between two congeneric passerines.
Oecologia.
ISSN 0029-8549.
162(4),
p. 873–884.
doi:
10.1007/s00442-009-1544-1.
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Engh, Ingeborg Bjorvand; Skrede, Inger; Sætre, Glenn-Peter & Kauserud, Håvard
(2010).
High variability in a mating type linked region in the dry rot fungus Serpula lacrymans caused by frequency-dependent selection?
BMC Genetics.
11.
doi:
10.1186/1471-2156-11-64.
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Background The mating type loci that govern the mating process in fungi are thought to be influenced by negative frequency-dependent selection due to rare allele advantage. In this study we used a mating type linked DNA marker as a proxy to indirectly study the allelic richness and geographic distribution of mating types of one mating type locus (MAT A) in worldwide populations of the dry rot fungus Serpula lacrymans. This fungus, which causes serious destruction to wooden constructions in temperate regions worldwide, has recently expanded its geographic range with a concomitant genetic bottleneck. Results High allelic richness and molecular variation was detected in the mating type linked marker as compared to other presumably neutral markers. Comparable amounts of genetic variation appeared in the mating type linked marker in populations from nature and buildings, which contrast the pattern observed with neutral genetic markers where natural populations were far more variable. Some geographic structuring of the allelic variation in the mating type linked marker appeared, but far less than that observed with neutral markers. In founder populations of S. lacrymans, alleles co-occurring in heterokaryotic individuals were more divergent than expected by chance, which agrees with the expectation for populations where few mating alleles exists. The analyzed DNA marker displays trans-species polymorphism wherein some alleles from the closely related species S. himantoides are more similar to those of S. lacrymans than other alleles from S. himantoides. Conclusions Our results support the idea that strong negative frequency-dependent selection maintains high levels of genetic variation in MAT-linked genomic regions, even in recently bottlenecked populations of S. lacrymans.
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Engh, Ingeborg Bjorvand; Carlsen, Tor; Sætre, Glenn-Peter; Högberg, Nils; Doi, S & Kauserud, Håvard
(2010).
Two invasive populations of the dry rot fungus Serpula lacrymans show divergent population genetic structures.
Molecular Ecology.
ISSN 0962-1083.
19(4),
p. 706–715.
doi:
10.1111/j.1365-294X.2009.04505.x.
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Wiley, Chris; Qvarnström, A.; Anderson, Gunilla; Borge, Thomas & Sætre, Glenn-Peter
(2009).
POSTZYGOTIC ISOLATION OVER MULTIPLE GENERATIONS OF HYBRID DESCENDENTS IN A NATURAL HYBRID ZONE: HOW WELL DO SINGLE-GENERATION ESTIMATES REFLECT REPRODUCTIVE ISOLATION?
Evolution.
ISSN 0014-3820.
63(7),
p. 1731–1739.
doi:
10.1111/j.1558-5646.2009.00674.x.
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Normann, Ben David; Bolsø, Agnes; Kalvig, Anne Kathrine; Sætre, Glenn-Peter & Benestad, Esben Esther Pirelli
(2023).
Nyans — Hvordan bør vi prate om kjønn?
[Internet].
YouTube.
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Brattgjerd, Marianne; Aslaksen, Kamilla; Suren, Pål & Sætre, Glenn-Peter
(2022).
Kjønnsaktivisme med svake grupper som gisler.
Klassekampen.
ISSN 0805-3839.
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Vogt, Henrik & Sætre, Glenn-Peter
(2020).
En massiv medikalisering av friske kropper.
Aftenposten (morgenutg. : trykt utg.).
ISSN 0804-3116.
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Vogt, Henrik & Sætre, Glenn-Peter
(2020).
Kjønn, verdighet og vitenskap.
Aftenposten (morgenutg. : trykt utg.).
ISSN 0804-3116.
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Vogt, Henrik & Sætre, Glenn-Peter
(2020).
Kjønnsideologien kan føre til en stor medisinsk-etisk skandale.
Aftenposten (morgenutg. : trykt utg.).
ISSN 0804-3116.
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Gadmar, Tone Charlotte; Bøhn, Einar Duenger; Sætre, Glenn-Peter & Jemterud, Torkild
(2014).
Abels Tårn.
[Radio].
EKKO, NRK P2.
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Bache-Mathiesen, Lena; Sætre, Glenn-Peter; Runemark, Anna & Bailey, Richard Ian
(2014).
Investigating constraints on male plumage evolution in a hybrid species.
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Fernández, Laura Piñeiro; Sætre, Glenn-Peter; Eroukhmanoff, Fabrice & Runemark, Anna
(2014).
Beak shape variation in a homoploid hybrid species: effects of ecology, genetic composition and species interactions.
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Elgvin, Tore Oldeide; Trier, Cassandra Nicole; Tørresen, Ole Kristian; Lien, Sigbjørn; Jensen, Henrik & Sætre, Glenn-Peter
(2014).
Sparrows, scaffolds and pseudo-chromosomes.
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Eroukhmanoff, Fabrice; Hermansen, Jo Skeie; Elgvin, Tore Oldeide; Sæther, Stein Are & Sætre, Glenn-Peter
(2014).
Genome wide signature of character displacement in a hybrid species.
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Bache-Mathiesen, Lena & Sætre, Glenn-Peter
(2013).
Investigating the genetic basis of sexually selected male plumage traits involved in reproductive isolation.
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Fernandez-Celemin, Laura & Sætre, Glenn-Peter
(2013).
Geographic variation in beak morphology and the role of hybridization.
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Sætre, Glenn-Peter
(2013).
Snublet over "urspurven" nær grensen til Turkmenistan.
Aftenposten (morgenutg. : trykt utg.).
ISSN 0804-3116.
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Sætre, Glenn-Peter
(2013).
Hybrid speciation through discordant cline movement of mito-nuclear and sex-linked incompatibilities.
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Roberts, Aubrey Jane; Hurum, Jørn Harald & Sætre, Glenn-Peter
(2013).
Characterization of a new Ophthalmosaurid ichthyosaur from the Upper Jurassic of Spitsbergen.
NGF Abstracts and Proceedings of the Geological Society of Norway.
p. 110–110.
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Hermansen, Jo Skeie; Elgvin, Tore Oldeide; Sæther, Stein Are; Borge, Thomas; Hjelle, Elin & Sætre, Glenn-Peter
(2010).
Hybrid speciation in sparrows.
Full text in Research Archive
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Junge, Claudia; Barson, Nicola J.; Haugen, Thrond O.; Leder, Erica H.; Primmer, Craig R. & Sætre, Glenn-Peter
[Show all 7 contributors for this article]
(2009).
Assessing the implications of metapopulation dynamics for selection in recently established grayling populations.
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Adaptation to local environmental conditions is strongly affected by the level of gene flow among subpopulations. Many studies on local adaptation have been conducted on salmonids, and although metapopulation structuring in salmonids seems intuitive, it is nevertheless rarely tested. A metapopulation is broadly defined as a collection of local populations inhabiting discrete patches of suitable habitat, interacting through dispersal and persisting in a balance between stochastic extinctions and recolonizations. Metapopulation dynamics, especially the nature of extinction-recolonization dynamics have profound implications for the outcome of selection in subdivided populations. Here, subpopulations of European grayling (Thymallus thymallus) in a recently colonized Norwegian lake system, Lesjaskogsvatnet, were investigated. A founder bottleneck has resulted in reduced neutral variation; nevertheless, there is evidence for local adaptation in early life history traits to varying temperature regimes. The aim of this study was to explicitly test for metapopulation dynamics based on three proposed conditions; (i) discrete habitats, (ii) asynchronic dynamics, and (iii) dispersal. Habitats suitable for spawning are only found in the discrete tributaries or at discrete patches in the lake, separated in both cases by the habitat matrix. The latter two criteria were tested via a genetic approach using microsatellites. Asynchrony in the subpopulation dynamics was tested for by estimating effective population sizes (Ne) using different temporal methods, and searching for bottleneck signatures. Furthermore, indirect methods were applied to investigate the dispersal rates and the level of gene flow within the lake system. Preliminary analysis suggests that the grayling in Lesjaskogsvatnet belong to a large metapopulation.
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Published
Nov. 3, 2010 3:34 PM
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Oct. 15, 2026 11:20 AM
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