Só o mais apto sobrevive: a seleção natural em ação diante de nossos olhos nas Ilhas Galápagos

Natural colonization and adaptation of a mosquito species in Galápagos and its implications for disease threats to endemic wildlife

Arnaud Bataillea,b,c,1, Andrew A. Cunninghamb, Virna Cedeñod,e,f, Leandro Patiñod, Andreas Constantinoua, Laura D. Kramerg and Simon J. Goodmana,1

+Author Affiliations

aInstitute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, United Kingdom;

bInstitute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, United Kindom;

cNatural Environment Research Council Molecular Genetics Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom;

dGalápagos Genetics, Epidemiology and Pathology Laboratory, Galápagos National Park, Puerto Ayora, Galápagos Islands, Ecuador;

eBiotechnology Program, Universidad de Guayaquil, Guayaquil, Ecuador;

fConcepto Azul, Guayaquil, PO Box 09-02-142A, Ecuador; and

gWadsworth Center, New York State Department of Health, Albany, NY 12159

Edited by Francisco J. Ayala, University of California, Irvine, CA, and approved May 1, 2009 (received for review February 6, 2009)

Abstract

Emerging infectious diseases of wildlife have been recognized as a major threat to global biodiversity. Endemic species on isolated oceanic islands, such as the Galápagos, are particularly at risk in the face of introduced pathogens and disease vectors. The black salt-marsh mosquito (Aedes taeniorhynchus) is the only mosquito widely distributed across the Galápagos Archipelago. Here we show that this mosquito naturally colonized the Galápagos before the arrival of man, and since then it has evolved to represent a distinct evolutionary unit and has adapted to habitats unusual for its coastal progenitor. We also present evidence that A. taeniorhynchus feeds on reptiles in Galápagos in addition to previously reported mammal and bird hosts, highlighting the important role this mosquito might play as a bridge-vector in the transmission and spread of extant and newly introduced diseases in the Galápagos Islands. These findings are particularly pertinent for West Nile virus, which can cause significant morbidity and mortality in mammals (including humans), birds, and reptiles, and which recently has spread from an introductory focus in New York to much of the North and South American mainland and could soon reach the Galápagos Islands. Unlike Hawaii, there are likely to be no highland refugia free from invading mosquito-borne diseases in Galápagos, suggesting bleak outcomes to possible future pathogen introduction events.

Aedes disease vector phylogenetics West Nile virus

Footnotes

1To whom correspondence may be addressed. E-mail: bgyaba@leeds.ac.uk or s.j.goodman@leeds.ac.uk

Author contributions: A.B., A.A.C., V.C., and S.J.G. designed research; A.B. performed research; L.P. and L.D.K. contributed new reagents/analytic tools; A.B. and A.C. analyzed data; and A.B., A.A.C., and S.J.G. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

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