| natural selection on bill characters in the two bill morphs of the african finch pyrenestes ostrinus. | evidence for natural selection on seven bill and body characters is examined in the two bill morphs of the african estrildid finch pyrenestes ostrinus. two regression methods are used in examining natural selection in association with survivorship: a parametric (lande and arnold, 1983) and a non-parametric (schluter, 1988) method. selection was estimated in adult males, females and juveniles over a four-year period in a population in south-central cameroon. selection was common among groups but ... | 1990 | 28569017 |
| development of beak polymorphism in the african seedcracker, pyrenestes ostrinus. | the black-bellied african seedcracker, pyrenestes ostrinus, exhibits a non-sex-related polymorphism in beak size that enables the small-, large-, and mega-billed morphs to utilize different trophic niches. the bill polymorphism between small- and large-billed individuals was previously shown to be under genetic control of a single autosomal locus with the allele for a large bill being dominant. african seedcrackers offer a novel opportunity to study the genetic basis of an adaptive polymorphism ... | 2009 | 19878285 |
| growth factor gene igf1 is associated with bill size in the black-bellied seedcracker pyrenestes ostrinus. | pyrenestes finches are unique among birds in showing a non-sex-determined polymorphism in bill size and are considered a textbook example of disruptive selection. morphs breed randomly with respect to bill size, and differ in diet and feeding performance relative to seed hardness. previous breeding experiments are consistent with the polymorphism being controlled by a single genetic factor. here, we use genome-wide pooled sequencing to explore the underlying genetic basis of bill morphology and ... | 2018 | 30451848 |