DNA Barcoding reveals recent speciation, extreme genus-level polyphyly and cryptic species in Neotropical birds

Transcription

1 Image from Ridgely and Tudor, Field Guide to the Songbirds of South America DNA Barcoding reveals recent speciation, extreme genus-level polyphyly and cryptic species in Neotropical birds Leonardo Campagna 1, Stephen C. Lougheed 2, Darío A. Lijtmaer 1, Pablo L. Tubaro 1. 1 División de Ornitología, Museo Argentino de Ciencias Naturales Bernardino Rivadavia. 2 Department of Biology, Queen s University, Canada.

2 > 700 Neotropical bird species specimen records. Collaboration between researchers from Argentina, Bolivia, Canada and the United States. Kerr et al PLoS ONE 4(2): e4379. Campagna et al Mol Ecol Resour. 10:

3 Cryptic species

4 Incipient species More cryptic species Genus-level polyphyly Sporophila Troglodytes Phrygilus

5 Sporophila Seedeaters

6 9 Sporophila species known colloquially as Southern capuchinos Sexually dimorphic. Little variation in size and shape. Migratory Sympatric or even syntopic. Males differ in coloration patterns and song. Females are mostly brown and olive and show cryptic coloration differences (UV). Campagna et al Proc Roy Soc B. In press.

7 Lack of reciprocal monophyly. Low interspecific genetic distances. Shared COI haplotypes. Campagna et al Mol Ecol Resour. 10:

8 5 nuclear DNA loci (here NUMT2) Mitochondrial Control Region + COI+ Cytochrome b 6 microsatellite DNA loci Campagna et al Proc Roy Soc B. In press.

9 Phenotypically diverse: highly diverged in male plumage patterns and song (suggesting a role for sexual selection). Shared genetic variation (neutral genes!) through: -Hybridization and introgression (evidence from coalescent Bayesian simulations). - Retention of ancestral polymorphisms. Evidence of demographic expansions from smaller ancestral populations. Radiated during the Mid Pleistocene ( within the last half million years). Campagna et al Proc Roy Soc B. In press.

10 Phrygilus Sierra-Finches

11 11 grassland species distributed from Venezuela to Argentina. Lowland species (<1800 m), Highland specialists (>4000 m) and generalists (0->4000 m). Some occur throughout the Andes while others have small ranges.

12 COI data suggests the following species are embedded in Phrygilus: -Melanodera melanodera -Haplospiza unicolor -Catamenia analis -Catamenia inornata -Sicalis flaveola -Sicalis luteola -Sicalis luteocephala -Sicalis olivascens -Diglossa cyanea -Diglossa sittoides Campagna et al Mol Phylogenet Evol. 61:

13 Data from Cytochrome b, control region and 3 nuclear loci confirm members from at least 10 genera make Phrygilus polyphyletic: -Melanodera -Rowettia -Sicalis -Idiopsar -Haplospiza -Acanthidops -Catamenia -Diglossa -Diglossopis -Xenodacnis The genus will be divided into 4 groups: -Idiopsar -Phrygilus -Rhopospina -Geospizopsis Campagna et al Mol Phylogenet Evol. 61:

14 Nine species from the Malvinas/Falkland Islands

15 Archipelago 450 km off the coast of Tierra del Fuego. Total surface of km 2. Several plant and invertebrate endemics. One endemic duck species and the extinct Falkland/Malvinas Island Wolf. Campagna et al. In revision.? 9 breeding passerine species: -Melanodera melanodera -Sturnella loyca -Turdus falcklandii -Troglodytes cobbi -Anthus correndera -Carduelis barbata -Cinclodes antarcticus -Cistothorus platensis -Muscisaxicola maclovianus

16 Shared haplotypes Deep divergence Shallow divergence Campagna et al. In revision.

17 Troglodytes aedon and Troglodytes cobbi Cobb s Wren Differences in habitat and ecology. Statistically significant differences in song. House Wren Show genetic differences in other mitochondrial (Cyt b) and nuclear loci (Fib5 and CHD1Z).

18 Conclusions A standardized mitochondrial survey like DNA barcoding can flag species worthy of deeper study. COI performs well as a marker for initial lineage discovery (both in cases of low and higher genetic divergence). So far multi-locus studies have confirmed COI patterns. The ongoing effort to barcode Neotropical birds will uncover many more interesting cases to evolutionary biologists.

19 Thanks to Picture credits: R Güller, A Ocampo, P Fenalti, J. St.Clair, R Moller Jensen, M López, PE Allasi, E Moebes, P Derennes, S Vitale, N Athanas, A Grosset, L Hegedus, K Stahl, F Piedrahita. Collaborators: A Barreira, P Benites, Y Davies, MD Eaton, K Geale, AG Di Giacomo, AS Di Giacomo, P Handford, PDN Hebert, S Imberti, KCR Kerr, JC Reboreda, J. St.Clair, Z Sun, R Woods. Provided tissue samples: Argentine Museum of Natural History; University of Kansas Museum of Natural History; British Museum of Natural History, Zoological Museum, University of Copenhagen; Louisiana State University Museum of Zoology; Smithsonian National Museum of Natural History; Museo de Ciencias y Tecnología de la Pontificia Universdad Católica de Río Grande do Sul; Smithsonian Tropical Research Institute (STRI). Funding agencies: