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DR. MARCIAL ESCUDERO, POSTDOCTORAL RESEARCHER IN JUAN ARROYO'S GROUP AT UNIVERSITY OF SEVILLE.

EMAIL: AMESCLIR@GMAIL.COM

 

    My research interest is mainly focused in the study of biodiversity and diversification and evolution of flowering plants at different evolutionary scales.  Biodiversity is not evenly distributed , rather it varies greatly across space (e.g. latitudinal gradients, hotspots, etc.) and across the tree of life (e.g. shifts in diversification rates). My colleagues and I perform studies of molecular phylogenetics and biogeography, phylogeography, cytogenetics, herbarium study, phylogenetic comparative methods (i) to quantity the biodiversity (how many species there are and how they are delimited and related) and (ii) to disentangle the mechanisms that generate and maintain the observed biodiversity.

I welcome collaborations with researchers at the undergraduate, graduate or post graduate level in ongoing projects or developing new projects. Please email me if you have questions.

Follow me in the networks:



http://scholar.google.es/citations?user=NIVWYBUAAAAJ&hl=es

https://twitter.com/MEscudero_Carex



LAST NEWS!!!!!

*MARCH-12-2015

NEW ACCEPTED PUBLICATION ABOUT THE ORIGIN OF THE BIPOLAR DISJUNCTION.

ABSTRACT:


Aim: The bipolar disjunction, a biogeographical pattern defined by taxa with a distribution at very high latitudes in both hemispheres (> 61oN – > 54oS), is only known to occur in about 30 vascular plant species.  The aim of this study was to test the four classic hypotheses proposed to explain this exceptional disjunction in the bipolar species Carex arctogena: convergent evolution, vicariance, mountain-hopping and direct long-distance dispersal. Location: Arctic/boreal and temperate latitudes of both hemispheres. Methods: A combination of molecular and bioclimatic data was used to test phylogeographic hypotheses in C. arctogena. Three chloroplast markers (atp sequenced for all species in Carex sections Capituligerae and Longespicatae. Carex rupestris, C. obtusata and Uncinia triquetra were used as outrgroups. Phylogenetic relationships, divergence time estimates and biogeographical patterns were inferred using maximum likelihood, statistical parsimony and Bayesian inference. Results: Carex sections Capituligerae and Longespicatae formed a monophyletic group that diverged during the late Miocene. Two main lineages of C. arctogena were inferred. Southern Hemisphere populations of C. arctogena shared the same haplotype as a widespread circumboreal lineage. Bioclimatic data shows that Southern and Northern Hemisphere populations currently differ in their ecological regimes. Main conclusions: Two of the four hypotheses accounting for bipolar disjunctions may be rejected. Our results suggest that direct long-distance dispersal the bipolar distribution of C. arctogena.


TAMARA VILLAVERDE, MARCIAL ESCUDERO, SANTIAGO MARTÍN-BRAVO, LEO P. BRUEDERLE, MODESTO LUCEÑO & JULIAN STARR. 2015 IN PRESS. DIRECT LONG-DISTANCE DISPERSAL BEST EXPLAINS THE BIPOLAR DISJUNCTION OF CAREX ARTOGENA (CAREX SECT. CAPITULIGERAE, CYPERACEAE). JOURNAL OF BIOGEOGRAPHY, 000, 000-0000.



*DECEMBER-12-2014 

NEW ACCEPTED PUBLICATION ABOUT THE RELATIONSHIP BETWEEN CHROMOSOME NUMBER AND GENOME SIZE IN ORGANISMS WITH HOLOCENTRIC CHROMOSOMES.

ABSTRACT:

Premise of the study: In organisms with holocentric chromosomes like Carex species, chromosome number evolution has been hypothesized to be a result of fission, fusion and/or translocation events. Negative, positive or the absence of correlations have been found between chromosome number and genome size in Carex. Methods: Using the inferred diploid chromosome number and 80 genome size measurements from 26 individuals and 20 populations of Carex gr. laevigata, we have tested the null hypothesis of chromosome number evolution by duplication and deletion of whole chromosomes. Results: Our results show a significant positive correlation between genome size and chromosome number, but the slope of such correlation supports the hypothesis of proliferation and removal of repetitive DNA fragments to explain genome size variation rather than duplication and deletion of whole chromosomes. Conclusions: Our results refine the theory of the holokinetic drive: this mechanism is proposed to facilitate repetitive DNA removal (or any segmental deletion) when smaller homologous chromosomes are preferentially inherited or repetitive DNA proliferation (or any segmental duplication) when larger homologs are preferred. This study sheds light on how karyotype evolution plays an important role in the diversification of the species of the genus Carex.

MARCIAL ESCUDERO, ENRIQUE MAGUILLA, JOÃO LOUREIRO, MARIANA CASTRO, SILVIA CASTRO & MODESTO LUCEÑO. IN PRESS. GENOME SIZE STABILITY DESPITE HIGH CHROMOSOME NUMBER VARIATION IN CAREX GR. LAEVIGATA. AMERICAN JOURNAL OF BOTANY, 102, 233-238. LINK. PDF.

 

* NOVEMBER - 17 - 2014
LAST WEEK THE INTERNATIONAL CONFERENCE MODERN PHYLOGENETIC COMPARATIVE METHODS WAS CELEBRATED IN SEVILLA (NOVEMBER 11-15 2014).
The meeting was very successful and fulfilled the expectations.
Visit the WEBSITE. Photos are also available HERE.

* OCTOBER - 31 - 2014
NEW POSTDOCTORAL POSITION.
Today has been published the formal resolution for a two years postdoctoral position that I will enjoy at the University of Seville from April 1st 2015. During these two years I will be working on the evolution of hercogamy in flowering plants at Juan Arroyo's lab.
LINK TO RESOLUTION.

* OCTOBER- 3-2014.

50 YEARS DOÑANA BIOLOGICAL STATION.

This year Doñana Biological Station is 50 years old. You can enjoy this wonderful movie about the history of EBD: MOVIE LINK.




SELECTED PUBLICATIONS:


1. MARCIAL ESCUDERO, ENRIQUE MAGUILLA & MODESTO LUCEÑO. 2013. SELECTION BY CLIMATIC REGIME AND NEUTRAL EVOLUTIONARY PROCESSES IN HOLOCENTRIC CHROMOSOMES (CAREX GR. LAEVIGATA: CYPERACEAE): A MICROEVOLUTIONARY APPROACH. PERSPECTIVES IN PLANT ECOLOGY, EVOLUTION AND SYSTEMATICS, 15, 118-129. LINKPDF.



2. MARCIAL ESCUDERO, ANDREW HIPP, THOMAS HANSEN, KJETIL VOJE & MODESTO LUCEÑO. 2012. SELECTION AND INERTIA IN THE EVOLUTION OF HOLOCENTRIC CHROMOSOMES IN SEDGES (CAREX, CYPERACEAE). NEW PHYTOLOGIST, 195, 237-247. LINKPDF.

     



3. MARCIAL ESCUDERO, ANDREW HIPP, MARCIA WATERWAY & LUIS VALENTE. 2012. DIVERSIFICATION RATES AND CHROMOSOME EVOLUTION IN THE MOST DIVERSE ANGIOSPERM GENUS OF THE TEMPERATE ZONE (CAREX, CYPERACEAE). MOLECULAR PHYLOGENETICS AND EVOLUTION, 63, 650-655. LINK. PDF.




4. MARCIAL ESCUDERO, PABLO VARGAS, PAUL ARENS, JOOP OUBORG & MODESTO LUCEÑO. 2010. THE EAST-WEST-NORTH COLONIZATION HISTORY OF THE MEDITERRANEAN AND EUROPE BY THE COASTAL PLANT CAREX EXTENSA (CYPERACEAE). MOLECULAR ECOLOGY, 19, 352-370. LINKPDF.



5. MARCIAL ESCUDERO, PABLO VARGAS, VIRGINIA VALCÁRCEL & MODESTO LUCEÑO. 2008. STRAIT OF GIBRALTAR: AN EFFECTIVE GENE-FLOW BARRIER FOR WIND-POLLINATED CAREX HELODES (CYPERACEAE) AS REVEALED BY DNA SEQUENCES, AFLP, AND CYTOGENETIC VARIATION. AMERICAN JOURNAL OF BOTANY, 95, 745-755. LINKPDF.




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