Comparative genetic structure and demographic history in endemic galapagos weevils.
J Hered
; 103(2): 206-20, 2012.
Article
em En
| MEDLINE
| ID: mdl-22174444
The challenge of maintaining genetic diversity within populations can be exacerbated for island endemics if they display population dynamics and behavioral attributes that expose them to genetic drift without the benefits of gene flow. We assess patterns of the genetic structure and demographic history in 27 populations of 9 species of flightless endemic Galápagos weevils from 9 of the islands and 1 winged introduced close relative. Analysis of mitochondrial DNA reveals a significant population structure and moderately variable, though demographically stable, populations for lowland endemics (F(ST) = 0.094-0.541; π: 0.014-0.042; Mismatch P = 0.003-0.026; and D((Tajima)) = -0.601 to 1.203), in contrast to signals of past contractions and expansions in highland specialists on 2 islands (Mismatch P = 0.003-0.026 and D((Tajima)) = -0.601 to 1.203). We interpret this series of variable and highly structured population groups as a system of long-established, independently founded island units, where structuring could be a signal of microallopatric differentiation due to patchy host plant distribution and poor dispersal abilities. We suggest that the severe reduction and subsequent increase of a suitably moist habitat that accompanied past climatic variation could have contributed to the observed population fluctuations in highland specialists. We propose the future exploration of hybridization between the introduced and highland endemic species on Santa Cruz, especially given the expansion of the introduced species into the highlands, the sensitivity to past climatic variation detected in highland populations, and the potentially threatened state of single-island endemics.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Variação Genética
/
Demografia
/
Ecossistema
/
Migração Animal
/
Gorgulhos
/
Genética Populacional
Aspecto:
Determinantes_sociais_saude
Limite:
Animals
País/Região como assunto:
America do sul
/
Ecuador
Idioma:
En
Revista:
J Hered
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
Estados Unidos