| isospora daphnensis n. sp. (apicomplexa: eimeriidae) from the medium ground finch (geospiza fortis) from the galapagos islands. | in march and april 1987 fecal samples from 237 nestling birds, including 199 from 85 nest sites of geospiza fortis, 23 from 12 nest sites of geospiza scandens, 6 from 2 nest sites of geospiza magnirostris, and 9 from 2 nest sites of hybrids involving geospiza fuliginosa and g. fortis, were collected from daphne major in the galapagos archipelago and examined for coccidia. only 3 of 4 nestlings from 1 nest site of g. fortis (1.5%) had oocysts in their feces. two of the 3 infected nestlings had co ... | 1990 | 2299524 |
| multilocus genotypes from charles darwin's finches: biodiversity lost since the voyage of the beagle. | genetic analysis of museum specimens offers a direct window into a past that can predate the loss of extinct forms. we genotyped 18 galápagos finches collected by charles darwin and companions during the voyage of the beagle in 1835, and 22 specimens collected in 1901. our goals were to determine if significant genetic diversity has been lost since the beagle voyage and to determine the genetic source of specimens for which the collection locale was not recorded. using 'ancient' dna techniques, ... | 2010 | 20194164 |
| divergence with gene flow as facilitated by ecological differences: within-island variation in darwin's finches. | divergence and speciation can sometimes proceed in the face of, and even be enhanced by, ongoing gene flow. we here study divergence with gene flow in darwin's finches, focusing on the role of ecological/adaptive differences in maintaining/promoting divergence and reproductive isolation. to this end, we survey allelic variation at 10 microsatellite loci for 989 medium ground finches (geospiza fortis) on santa cruz island, galápagos. we find only small genetic differences among g. fortis from dif ... | 2010 | 20194167 |
| songs of darwin's finches diverge when a new species enters the community. | bird species sing different songs and as a result rarely breed with each other. species are not static but can shift in acoustic and morphological space, yet maintain their distinctiveness. investigating such a situation in a community of darwin's finches sheds light on the origin and maintenance of premating barriers between species. explanations for songs divergence generally invoke morphological changes to the sound-producing apparatus, environmental changes influencing transmitting propertie ... | 2010 | 21048082 |
| sisyphean evolution in darwin's finches. | the trajectory of speciation involves geographic isolation of ancestral populations followed by divergence by natural selection, genetic drift or sexual selection. once started, the process may experience fits and starts, as sometimes diverging populations intermittently reconnect. in theory populations might cycle between stages of differentiation and never attain species status, a process we refer to as sisyphean evolution. we argue that the six putative ground finch species (genus geospiza) o ... | 2015 | 25040800 |
| insights into the evolution of darwin's finches from comparative analysis of the geospiza magnirostris genome sequence. | a classical example of repeated speciation coupled with ecological diversification is the evolution of 14 closely related species of darwin's (galápagos) finches (thraupidae, passeriformes). their adaptive radiation in the galápagos archipelago took place in the last 2-3 million years and some of the molecular mechanisms that led to their diversification are now being elucidated. here we report evolutionary analyses of genome of the large ground finch, geospiza magnirostris. | 2013 | 23402223 |
| a population founded by a single pair of individuals: establishment, expansion, and evolution. | events occurring at the founding of a population, and in the next few generations, are potentially of great importance for the future evolution of the population. this study reports demographic, genetic, and morphological changes that took place during and after the colonization of the small galápagos island of daphne major by three male and two female large ground finches, geospiza magnirostris, at the end of 1982. using assignment tests with microsatellite dna data we demonstrate heterogeneity ... | 2001 | 11838776 |
| the founding of a new population of darwin's finches. | we report the natural colonization of the small galápagos island daphne major by the large ground finch (geospiza magnirostris). immigrants of this species were present in every year of a 22-yr study, 1973-1994. typically they arrived after a breeding season and left at the beginning of the next one. geospiza magnirostris bred on the island for the first time in the exceptionally wet el niño year of 1982-1983, and bred in all subsequent years except drought years. in agreement with theoretical e ... | 1995 | 28565010 |