Rapid speciation, cryptic divergence, and evolutionary convergence in the diversification of dark-eyed and yellow-eyed juncos

Transcription

1 Rapid speciation, cryptic divergence, and evolutionary convergence in the diversification of dark-eyed and yellow-eyed juncos Borja Milá Guillermo Friis Pau Aleixandre Museo Nacional de Ciencias Naturales CSIC Madrid

2 How do species form? Understanding the relative roles of: Natural selection Sexual selection Gene flow / isolation Galapagos finches Hawaii s depranidids Phenotype Genotype Morphology Coloration Song Genetics Phylogenomics Transcriptomics Paradiseidae Topography Ecological niche Paleoclimatology Dispersal Monarchidae Geography + Ecology

3 Phenotype and species limits in the genus Junco Dark-eyed junco (Junco hyemalis) Yellow-eyed junco (Junco phaeonotus) Junco vulcani Volcano junco (Costa Rica) Volcano junco (Junco vulcani)

4 Postglacial expansions in North American birds McGillivray s Warbler (Oporornis tolmiei) Chipping Sparrow (Spizella passerina) Yellow-rumped Warbler (Setophaga coronata) Cyt b CR n = 159 Milá et al. 2000, Proc. R. Soc. B Milá et al. 2006, Evolution Milá et al. 2007, Molecular Ecology

5 Rapid postglacial speciation in Junco AFLP mtdna (D-loop) Coalescence estimate of T (MDIV): years Milá et al. 2007, Proc. R. Soc. B

6 Geographically isolated Junco lineages Junco h. insularis Isla Guadalupe Junco p. bairdi Baja California Junco p. alticola Guatemala

7 mtdna variation across the junco range Pau Aleixandre FPU

8 Evolutionary history of Juncos: not about eye color Bayesian / ML ND2+COI+DL (1433 bp) USA Mexico Guatemala Guadalupe Island Baja California Costa Rica

9 Need for further resolution: Phylogenomics Next Generation Sequencing (Illumina Platforms) SNP discovery using Genotyping-by-sequencing (GBS) Genome-wide SNP loci Very large number loci Low $$ cost Non-model species (from Myles 2013, Trends in Genetics)

10 Genetic structure at the genome level GBS : 14,000 SNP loci Guillermo Friis FPI

11 PC1 Morphology and coloration: divergence and convergence PCA of morphological variables (wing, tail, tarsus, bill length, bill width, bill depth) DFA of color variables (brightness, hue and chroma, 6 body parts) PC2 J. insularis mearnsii insularis Bill length Bill depth Bill width Aleixandre et al. 2012, PLoS One Guillermo Friis, unpublised data

12 Morphological vs. color divergence in the junco radiation Morphology Genetics Color Genetics

13 The role of sexual selection: Sexual dimorphism increases with latitude DFA scores of brightness and chroma tristimulus variables, corrected by collection date. phaeonotus dorsalis caniceps Latitude Guillermo Friis, PhD student

14 Genetic basis of plumage color: Transcriptomics RNAseq of growing feather tissue to target color genes in ORJU and SCJU Diseño: 2 morfos x 4 individuos x 4 partes del cuerpo 30 librerías de cdna secuenciadas en 2 carriles de un Illumina HiSeq M de reads, 5000M de bp en total

15 Identification of target genes controling melanic color Melanin pathway genes within the top 25 up- or down-regulated transcripts Etienne Kornobis Postdoc

16 Junco colors: deposition of eumelanins and phaeomelanins

17 The role of ecology: Ecological niche models of junco forms Maxent 19 bioclim variables Qscat NDVI, NDVI SD Elevation Tree cover. Amanda Zelmer and Guillermo Friis, Unpublished data

18 Niche divergence among closely related forms caniceps dorsalis (23%) (47%)

19 Conclusions Speciation can happen within just 10,000 years. Old, isolated lineages are most genetically divergent: drift. Genome-wide divergence among morphs: multifarious selection. Ecological niche divergence among forms: natural selection. Color diversity and sexual dimorphism increase with latitude: sexual selection. Simple genetic architecture underlying color patterns? Taxonomic revision needed: some taxa severely threatened.

20 Acknowledgements Funding Ministerio de Ciencia e Innovación (MICINN) CSIC UC-Mexus, UCLA National Science Foundation Field work A. Alvarado, I. Arias, O. Espinosa, A. Gutiérrez, S. Larios, A. Lee, J. McCormack, A. Oliveras, L. Orozco, M. Ramírez, V. Rodríguez, E. Arbeláez. Collaborators A. Navarro, UNAM, México J. Hernández, Conservación de Islas, México R. Rodríguez Estrella, CIBNOR, BCS, México E. Ketterson & J. Atwell, Indiana Univ., USA J. McCormack, Occidental College, USA T. Smith & B. Wayne, UCLA, USA See the new science film on juncos at:

21 Song variation: consistent with genetics Dark-eyed juncos Yellow-eyed juncos Guadalupe junco Baird s junco