000			02715nab a22003497a 4500
003			EC-PaCDF
005			20171127141741.0
008			160905b20162016xxu|||||||||||||||||eng||
040			_aEC-PaCDF
041			_aeng
082	0	4	_221 _a578.65
100	1		_aKleindorfer, Sonia. _9404
245	1	0	_aNaris deformation in Darwin’s finches: _bExperimental and historical evidence for a post-1960s arrival of the parasite Philornis downsi.
520	0		_aThe rate of evolution depends on the strength of selection, which may be particularly strong for introduced parasites and their naive hosts. Because natural selection acts on phenotypes and because parasites can alter host phenotype, one fruitful starting point to measure the impact of novel pathogens is to quantify parasite-induced changes to host phenotype. Our study system is Darwin’s finches on Floreana Island, Galápagos Archipelago, and the virulent fly larvae of Philornis downsi that were first discovered in Darwin’s finch nests in 1997. We use an experimental approach and measure host phenotype in parasitized and parasite-free chicks in Darwin’s small ground finch (Geospiza fuliginosa). Beak size did not differ between the two treatment groups, but naris size was 106% larger in parasitized chicks (~3.3 mm) versus parasite-free chicks (~1.6 mm). To test if P. downsi was present prior to the 1960s, we compared naris size in historical (1899–1962) and contemporary birds (2004–2014) on Floreana Island in small ground finches (G. fuliginosa) and medium tree finches (Camarhynchus pauper). Contemporary Darwin’s finches had significantly larger naris size (including extreme deformation), whereas historical naris size was both smaller and less variable. These findings provide the first longitudinal analysis for the extent of P. downsi-induced change to host naris size and show that Darwin’s finches, prior to the 1960s, were not malformed. Thus natural selection on altered host phenotype as a consequence of P. downsi parasitism appears to be contemporary and novel.
546			_aEnglish
653			_aDarwin’s finches.
653			_aPinzones de Darwin.
653			_aNatural selection
653			_aSeleccion natural
653			_aNaris malformation
653			_aMalformación de Naris
653			_aHistorical colletions
653			_aColectas históricas
653			_aAdaptive divirgence
653			_aDivorcion adaptativa
653			_aGalapagos islands
653			_aIslas Galápagos
700	1		_aSulloway, Frank.
773	0		_gVol. 7 (May 2016), p. 122-131 _tGlobal Ecology and Conservación
856	4	0	_uhttp://dx.doi.org/10.1016/j.gecco.2016.05.006
942			_2ddc _cARTICLE
999			_c12836 _d12836