scholarly journals INTROGRESSION IN THE DROSOPHILA SUBOBSCURA — D. MADEIRENSIS SISTER SPECIES: EVIDENCE OF GENE FLOW IN NUCLEAR GENES DESPITE MITOCHONDRIAL DIFFERENTIATION

Evolution ◽  
2013 ◽  
Vol 68 (3) ◽  
pp. 705-719 ◽  
Author(s):  
Danielle K. Herrig ◽  
Alec J. Modrick ◽  
Evgeny Brud ◽  
Ana Llopart
Keyword(s):  
Gene Flow ◽  
Drosophila Subobscura ◽  
Nuclear Genes ◽  
Sister Species

Introgression between non-sister species of honeyeaters (Aves: Meliphagidae) several million years after speciation

2019 ◽  
Vol 128 (3) ◽  
pp. 583-591
Author(s):  
Leo Joseph ◽  
Alex Drew ◽  
Ian J Mason ◽  
Jeffrey L Peters
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sex Chromosomes ◽  
Common Ancestor ◽  
Sister Species ◽  
Species Boundaries ◽  
North Eastern ◽  
The City

Abstract We reassessed whether two parapatric non-sister Australian honeyeater species (Aves: Meliphagidae), varied and mangrove honeyeaters (Gavicalis versicolor and G. fasciogularis, respectively), that diverged from a common ancestor c. 2.5 Mya intergrade in the Townsville area of north-eastern Queensland. Consistent with a previous specimen-based study, by using genomics methods we show one-way gene flow for autosomal but not Z-linked markers from varied into mangrove honeyeaters. Introgression barely extends south of the area of parapatry in and around the city of Townsville. While demonstrating the long-term porosity of species boundaries over several million years, our data also suggest a clear role of sex chromosomes in maintaining reproductive isolation.

scholarly journals Gene flow and gene flux shape evolutionary patterns of variation in Drosophila subobscura

Heredity ◽  
2013 ◽  
Vol 110 (6) ◽  
pp. 520-529 ◽  
Author(s):  
C Pegueroles ◽  
C F Aquadro ◽  
F Mestres ◽  
M Pascual
Keyword(s):  
Gene Flow ◽  
Drosophila Subobscura ◽  
Evolutionary Patterns

Peninsular Malaysia’s first limbless lizard: a new species of skink of the genus Larutia (Böhme) from Pulau Pinang with a phylogeny of the genus

Zootaxa ◽  
2011 ◽  
Vol 2799 (1) ◽  
pp. 29 ◽  
Author(s):  
L. LEE GRISMER ◽  
EVAN QUAH SENG HUAT ◽  
CAMERON D. SILER ◽  
K. O. CHAN ◽  
PERRY L. WOOD, JR. ◽  
...  
Keyword(s):  
New Species ◽  
Molecular Phylogeny ◽  
Large Body ◽  
Peninsular Malaysia ◽  
Nuclear Genes ◽  
Sister Species ◽  
Unique Combination ◽  
A New Species

A new species of the scincid genus Larutia, L. penangensis sp. nov., from Pulau Pinang, Peninsular Malaysia is separated from all other congeners by having the unique characteristics of the complete absence of limbs, four supralabials, large body scales, and no banding or striping pattern. Additionally, it has the following unique combination of characters that further separates it from all congeners: a single presubocular; separated nasals; paired frontoparietals; small, widely separated prefrontals; no supranasals or postnasal; two postsupralabials; and large, posterior chinshields that contact the infralabials. A molecular phylogeny based on one mitochondrial and two nuclear genes from all species of Larutia from Peninsular Malaysia indicates L. penangensis sp. nov. is most basal and that L. seribuatensis is the sister lineage to a clade containing L. miodactyla and the sister species L. trifasciata and L. larutensis. Consistencies and inconsistencies between this phylogeny and a previously proposed morphological phylogeny are discussed.

scholarly journals Extraordinarily rapid life-history divergence between Cryptasterina sea star species

2012 ◽  
Vol 279 (1744) ◽  
pp. 3914-3922 ◽  
Author(s):  
Jonathan B. Puritz ◽  
Carson C. Keever ◽  
Jason A. Addison ◽  
Maria Byrne ◽  
Michael W. Hart ◽  
...  
Keyword(s):  
Life History ◽  
Gene Flow ◽  
Critical Role ◽  
Divergence Time ◽  
Sister Species ◽  
Disruptive Selection ◽  
Sea Star ◽  
Posterior Density ◽  
Sea Stars ◽  
Highest Posterior Density

Life history plays a critical role in governing microevolutionary processes such as gene flow and adaptation, as well as macroevolutionary processes such speciation. Here, we use multilocus phylogeographic analyses to examine a speciation event involving spectacular life-history differences between sister species of sea stars. Cryptasterina hystera has evolved a suite of derived life-history traits (including internal self-fertilization and brood protection) that differ from its sister species Cryptasterina pentagona , a gonochoric broadcast spawner . We show that these species have only been reproductively isolated for approximately 6000 years (95% highest posterior density of 905–22 628), and that this life-history change may be responsible for dramatic genetic consequences, including low nucleotide diversity, zero heterozygosity and no gene flow. The rapid divergence of these species rules out some mechanisms of isolation such as adaptation to microhabitats in sympatry, or slow divergence by genetic drift during prolonged isolation. We hypothesize that the large phenotypic differences between species relative to the short divergence time suggests that the life-history differences observed may be direct responses to disruptive selection between populations. We speculate that local environmental or demographic differences at the southern range margin are possible mechanisms of selection driving one of the fastest known marine speciation events.

scholarly journals Effects of Colonization Processes on Genetic Diversity: Differences Between Annual Plants and Tree Species

Genetics ◽  
2000 ◽  
Vol 154 (3) ◽  
pp. 1309-1321 ◽  
Author(s):  
Frédéric Austerlitz ◽  
Stéphanie Mariette ◽  
Nathalie Machon ◽  
Pierre-Henri Gouyon ◽  
Bernard Godelle
Keyword(s):  
Genetic Diversity ◽  
Life Cycle ◽  
Gene Flow ◽  
Tree Species ◽  
Population Diversity ◽  
Pollen Flow ◽  
Nuclear Genes ◽  
Annual Plants ◽  
High Level ◽  
The Impact

Abstract Tree species are striking for their high within-population diversity and low among-population differentiation for nuclear genes. In contrast, annual plants show much more differentiation for nuclear genes but much less diversity than trees. The usual explanation for this difference is that pollen flow, and therefore gene flow, is much higher for trees. This explanation is problematic because it relies on equilibrium hypotheses. Because trees have very recently recolonized temperate areas, they have experienced many foundation events, which usually reduce within-population diversity and increase differentiation. Only extremely high levels of gene flow could counterbalance these successive founder effects. We develop a model to study the impact of life cycle of forest trees, in particular of the length of their juvenile phase, on genetic diversity and differentiation during the glacial period and the following colonization period. We show that both a reasonably high level of pollen flow and the life-cycle characteristics of trees are needed to explain the observed structure of genetic diversity. We also show that gene flow and life cycle both have an impact on maternally inherited cytoplasmic genes, which are characterized both in trees and annual species by much less diversity and much more differentiation than nuclear genes.

scholarly journals Ancient and recent introgression shape the evolutionary history of pollinator adaptation and speciation in a model monkeyflower radiation (Mimulus section Erythranthe)

2020 ◽  
Author(s):  
Thomas C. Nelson ◽  
Angela M. Stathos ◽  
Daniel D. Vanderpool ◽  
Findley R. Finseth ◽  
Yao-wu Yuan ◽  
...  
Keyword(s):  
Gene Flow ◽  
Evolutionary History ◽  
Species Tree ◽  
Sister Species ◽  
Pollination Syndrome ◽  
Gene Trees ◽  
Trait Evolution ◽  
Genome Wide ◽  
Hummingbird Pollination ◽  
History Of

AbstractInferences about past processes of adaptation and speciation require a gene-scale and genome-wide understanding of the evolutionary history of diverging taxa. In this study, we use genome-wide capture of nuclear gene sequences, plus skimming of organellar sequences, to investigate the phylogenomics of monkeyflowers in Mimulus section Erythranthe (27 accessions from seven species). Taxa within Erythranthe, particularly the parapatric and putatively sister species M. lewisii (bee-pollinated) and M. cardinalis (hummingbird-pollinated), have been a model system for investigating the ecological genetics of speciation and adaptation for over five decades. Across >8000 nuclear loci, multiple methods resolve a predominant species tree in which M. cardinalis groups with other hummingbird-pollinated taxa (37% of gene trees), rather than being sister to M. lewisii (32% of gene trees). We independently corroborate a single evolution of hummingbird pollination syndrome in Erythranthe by demonstrating functional redundancy in genetic complementation tests of floral traits in hybrids; together, these analyses overturn a textbook case of pollination-syndrome convergence. Strong asymmetries in allele-sharing (Patterson’s D-statistic and related tests) indicate that gene-tree discordance reflects ancient and recent introgression rather than incomplete lineage sorting. Consistent with abundant introgression blurring the history of divergence, low-recombination and adaptation-associated regions support the new species tree, while high-recombination regions generate phylogenetic evidence for sister status for M. lewisii and M. cardinalis. Population-level sampling of core taxa also revealed two instances of chloroplast capture, with Sierran M. lewisii and Southern Californian M. parishii each carrying organelle genomes nested within respective sympatric M. cardinalis clades. A recent organellar transfer from M. cardinalis, an outcrosser where selfish cytonuclear dynamics are more likely, may account for the unexpected cytoplasmic male sterility effects of selfer M. parishii organelles in hybrids with M. lewisii. Overall, our phylogenomic results reveal extensive reticulation throughout the evolutionary history of a classic monkeyflower radiation, suggesting that natural selection (re-)assembles and maintains species-diagnostic traits and barriers in the face of gene flow. Our findings further underline the challenges, even in reproductively isolated species, in distinguishing re-use of adaptive alleles from true convergence and emphasize the value of a phylogenomic framework for reconstructing the evolutionary genetics of adaptation and speciation.Author SummaryAdaptive radiations, which involve both divergent evolution of new traits and recurrent trait evolution, provide insight into the processes that generate and maintain organismal diversity. However, rapid radiations also generate particular challenges for inferring the evolutionary history and mechanistic basis of adaptation and speciation, as multiple processes can cause different parts of the genome to have distinct phylogenetic trees. Thus, inferences about the mode and timing of divergence and the causes of parallel trait evolution require a fine-grained understanding of the flow of genomic variation through time. In this study, we used genome-wide sampling of thousands of genes to re-construct the evolutionary histories of a model plant radiation, the monkeyflowers of Mimulus section Erythranthe. Work over the past half-century has established the parapatric and putatively sister species M. lewisii (bee-pollinated) and M. cardinalis (hummingbird-pollinated, as are three other species in the section) as textbook examples of both rapid speciation via shifts in pollination syndrome and convergent evolution of floral syndromes. Our phylogenomic analyses re-write both of these stories, placing M. cardinalis in a clade with other hummingbird-pollinated taxa and demonstrating that abundant introgression between ancestral lineages as well as in areas of current sympatry contributes to the real (but misleading) affinities between M. cardinalis and M. lewisii. This work illustrates the pervasive influence of gene flow and introgression during adaptive radiation and speciation, and underlines the necessity of a gene-scale and genome-wide phylogenomics framework for understanding trait divergence, even among well-established species.

scholarly journals Prevalence of disruptive selection predicts extent of species differentiation in Lake Victoria cichlids

2018 ◽  
Vol 285 (1871) ◽  
pp. 20172630 ◽  
Author(s):  
Jacco C. van Rijssel ◽  
Florian N. Moser ◽  
David Frei ◽  
Ole Seehausen
Keyword(s):  
Gene Flow ◽  
Natural Selection ◽  
Genetic Differentiation ◽  
Lake Victoria ◽  
Sister Species ◽  
Disruptive Selection ◽  
Nuptial Coloration ◽  
Ecological Selection ◽  
Evolutionary Response ◽  
Species Pairs

Theory suggests that speciation with gene flow is most likely when both sexual and ecological selection are divergent or disruptive. Divergent sexual and natural selection on the visual system have been demonstrated before in sympatric, morphologically similar sister species of Lake Victoria cichlids, but this does not explain the subtle morphological differences between them. To investigate the significance of natural selection on morphology during speciation, we here ask whether the prevalence of disruptive ecological selection differs between sympatric sister species that are at different stages of speciation. Some of our species pairs do ( Pundamilia ) and others do not ( Neochromis ) differ distinctively in sexually selected male nuptial coloration. We find that (i) evidence for disruptive selection, and for evolutionary response to it, is prevalent in traits that are differentiated between sister species; (ii) prevalence of both predicts the extent of genetic differentiation; and (iii) genetic differentiation is weaker in species pairs with conserved male nuptial coloration. Our results speak to the existence of two different mechanisms of speciation with gene flow: speciation mainly by sexual selection tightly followed by ecological character displacement in some cases and speciation mainly by divergent ecological selection in others.

scholarly journals The Pleistocene species pump past its prime: evidence from European butterfly sister species

2020 ◽  
Author(s):  
Sam Ebdon ◽  
Dominik R. Laetsch ◽  
Leonardo Dapporto ◽  
Alexander Hayward ◽  
Michael G. Ritchie ◽  
...  
Keyword(s):  
Gene Flow ◽  
Contact Zone ◽  
Sister Species ◽  
Transcriptome Data ◽  
Last Interglacial ◽  
Species Divergence ◽  
Glacial Cycles ◽  
Contact Zones ◽  
Genome Wide ◽  
Species Pairs

AbstractThe Pleistocene glacial cycles had a profound impact on the ranges and genetic make-up of organisms. Whilst it is clear that the contact zones that have been described for many sister taxa are secondary and have formed during the last interglacial, it is unclear when the taxa involved began to diverge. Previous estimates based on small numbers of loci are unreliable given the stochasticity of genetic drift and the contrasting effects of incomplete lineage sorting and gene flow on gene divergence. Here we use genome-wide transcriptome data to estimate divergence for 18 sister species pairs of European butterflies showing either sympatric or contact zone distributions. We find that in most cases species divergence predates the mid-Pleistocene transition or even the entire Pleistocene period. We also show that although post divergence gene flow is restricted to contact zone pairs, they are not systematically younger than sympatric pairs. This suggests that contact zones are not limited to the embryonic stages of the speciation process, but can involve notably old taxa. Finally, we show that mitochondrial and nuclear divergence are only weakly correlated and mitochondrial divergence is higher for contact-zone pairs. This suggests a possible role of selective sweeps affecting mitochondrial variation in maintaining contact zones.Impact SummaryThe influence of the Pleistocene glacial cycles on structuring species and genetic diversity in temperate taxa has permeated biogeographic and phylogeographic thinking for decades. Although phylogeographic studies have repeatedly claimed that the Pleistocene acted as a species pump, systematic tests of this idea based on robust estimates of species divergence are lacking. Here we estimate divergence times for all sister species pairs of European butterfly using genome-wide transcriptome data. We find that most species pairs are substantially older than the onset of Pleistocene glacial cycling. We also show that post divergence gene flow is restricted to pairs that form contact-zones. However, in contrast to expectations under a null model of allopatric speciation contract zone pairs are not necessarily younger than sympatric pairs.

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