| comparative landscape genetics and the adaptive radiation of darwin's finches: the role of peripheral isolation. | we use genetic divergence at 16 microsatellite loci to investigate how geographical features of the galápagos landscape structure island populations of darwin's finches. we compare the three most genetically divergent groups of darwin's finches comprising morphologically and ecologically similar allopatric populations: the cactus finches (geospiza scandens and geospiza conirostris), the sharp-beaked ground finches (geospiza difficilis) and the warbler finches (certhidea olivacea and certhidea fu ... | 2005 | 16101765 |
| exploitation of opuntia cactus by birds on the galápagos. | (1) there is a close association between opuntia helleri (cactus) and geospiza conirostris (cactus finch) on isla genovesa, and between opuntia echios and geospiza scandens on isla daphne major. the two finch species consume nectar and pollen, pollinate the obligatorily out-crossing flowers, consume the aril around the seeds, crack the seeds and occasionally disperse them. (2) in the dry season the two finch species open opuntia flower buds, thereby gaining early access to pollen. but in the pro ... | 1981 | 28309307 |
| darwin's finches: population variation and sympatric speciation. | the classical model of the adaptive radiation of darwin's finches is one of repeated speciation in allopatry. evidence presented here suggests that sympatric specification may have contributed to the radiation. on isla genovesa geospiza conirostris displays several features that are consistent with a model of sympatric speciation. males are polymorphic in song type. those singing song a have significantly longer bills than those singing song b. the two groups of males forage in different ways th ... | 1979 | 16592654 |
| selection on bill characters in a population of darwin's finches: geospiza conirostris on isla genovesa, galápagos. | lande and arnold's (1983) technique for measuring selection on correlated quantitative traits was used to identify the targets of selection and to reveal the direction of selection on three bill dimensions, during different stages of the life cycle in a population of darwin's finches, geospiza conirostris, on isla genovesa, galápagos. there was a tendency towards disruptive selection during dry conditions, arising from differential survival. in terms of longevity and breeding success of females, ... | 1985 | 28561983 |
| niche shifts and competition in darwin's finches: geospiza conirostris and congeners. | | 1982 | 28568229 |