1 / 17

N.I. Abramson

Supraspecies phylogenetic relationships in the subfamily Arvicolinae (voles and lemmings): nuclear versus mitochondrial genes. Could hard polytomies be resolved?. N.I. Abramson. Zooological Institute, Russian Academy of Sciences. Overview of the talk.

wlawson
Télécharger la présentation

N.I. Abramson

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Supraspecies phylogenetic relationships in the subfamily Arvicolinae (voles and lemmings): nuclear versus mitochondrial genes. Could hard polytomies be resolved? N.I. Abramson Zooological Institute, Russian Academy of Sciences

  2. Overview of the talk What are arvicolids and why they present an excellent model to test evolutionary and phylogenetic hypotheses and approaches to phylogeny recovery Brief historical background Material and methods Unexpected results of molecular research in phylogeny reconstruction Mitochondrial versus nuclear genes Could hard polytomies be resolved? Molecular data in paleontological context

  3. Subfamily Arvicolinae(voles and lemmings)

  4. Arvicolinae as a model one of the most young and species rich groups of Muroidea (over 100 known species). widely distributed in all landscape types in the temperate and arctic zones of the Northern Hemisphere unprecedented paleontological record, rapid evolution rate, and continuous diversification morphological, cytogenetic, biochemical and molecular data sets available

  5. BRIEF HISTORICAL BACKGROUND

  6. BRIEF HISTORICAL BACKGROUND

  7. BRIEF HISTORICAL BACKGROUND Journal of Mammalian Evolution, Vol. 6, No. 3, 1999 MtDNA Evidence for Repeated Pulses of SpeciationWithin Arvicoline and Murid Rodents Chris J. Conroy and Joseph A. Cook1 The evolutionary radiation of Arvicolinae rodents (voles and lemmings): relative contribution of nuclear and mitochondrial DNA Phylogenies Thomas Galewski et al. Mitochondrial phylogeny of Arvicolinae using comprehensive taxonomic sampling yields new insights ELENA V. BUZAN, BORIS KRYSTUFEK, BERND HÄNFLING2 and WILLIAM F. HUTCHINSON

  8. Objective To separate the phyletic lineages that divergedduring the basal (first) radiation wave from the groupsarising at the later steps of the evolution of Arvicolinae

  9. Material and methods The sample includes: • 21 vole speciesbelonging to 14 (out of 28) genera of eight (out of ten) tribes • Vole tribesEllobiusini and Lagurini, which were not examined before, and whose phylogenetic positions are questionable • Akodon(Sigmodontinae),Peromyscus(Neotominae), and • Cricetulus(Cricetinae), used asan outgroup • Molecular markers: • GHR , 10 exon, 921 bp; • LCAT, 612 bp: exons 2-5; introns, 330 bp • Phylogenetic analysis: • MP for both the concatenated matrix and the two separate genes • ML for exons for both genes • Bayesian analysis • Relaxed molecular clock, using the Bayesian algorithm of the Multidivtime package( BRCA1, RAG1,IRBP,and cmyc)

  10. Results III I I wave II wave III wave

  11. Results Myodini Lagurini Ellobiusini Arvicolini Chronogram of radiation in the subfamily Arvicolinae. The divergence time corresponds to the mean a posteriori estimateof the age. Gray bars show the confidence intervals of the nodes.

  12. Mitochondrial versus nuclear genes Cyt b Buzan et al., 2008

  13. Possible evolutionary scenario

  14. Morphological and paleontological evidence

  15. Molecular data in paleontological context • The first radiation waveOur results suggest that basalsubfamily radiation occurred in the late Miocene,which is in accordance with paleontological data indicating that the most primitive undoubted members ofthe group appeared about 7.0 million years ago in Pontic deposits of eastern Europe • The second radiationwave. This step correspondsto the divergence of the ancestors of modernMyodini. The divergence time corresponds to the LateMiocene–Early Pliocene according to molecular data.Our findings indicate that Myodini diverged from thecommon branch of Arvicolinae after the first (basal)radiation wave but before Lagurini/Ellobiusini/Arvicoliniradiation. The distribution of modern speciesand paleontological findings indicate that the grouporiginates from East Asia and that level and highlandforests were its initial habitats. • The third radiation waveof Arvicolinae includesthe divergence of Lagurini/Ellobiusini/Arvicolini.The divergence dates back to the Early Plioceneaccording to our results. This means that Palearcticvoles of a pro-Mimomys organization level might be acommon ancestor of the group. Lagurini and Arvicolinideveloped along the main evolutionarily pathwayof the subfamily, gradually adapting to eatingvegetative parts of grasses and colonizing predominantlymeadow (Arvicolini) and steppe (Lagurini)landscapes. Ellobiusini provide a remarkable exampleof rapid evolutionary changes associated with theadaptation to subterranean life; in particular, they preservedthe primitive molar structure, while their craniumand limbs were changed. Rapid adaptive evolutionexplains why it is difficult to infer the phylogennetic position of Ellobiusini from classical morphological data

  16. Aknowledgements • This work is coauthored by Vladimir Lebedev, Anna Bannikova and Alexei Tesakov • A.S. Smorktcheva provide invaluable material on yellow steppe vole • A.Kostygov, E.Rodchenkova, T.Petrova & S.Bodrov assist in the laboratory • Financial support was provided by RFFI grant 09-04-01330 and Programs of Fundamental Research RAS: “Biosphere Origin and Evolution” and “Biodiversity”

  17. Thank you for attention

More Related