Frequency of insularia during the decline in melanics in the peppered mothBiston betularia in Britain

Citation
Lm. Cook et Bs. Grant, Frequency of insularia during the decline in melanics in the peppered mothBiston betularia in Britain, HEREDITY, 85(6), 2000, pp. 580-585
Citations number
20
Categorie Soggetti
Biology,"Molecular Biology & Genetics
Journal title
HEREDITY
ISSN journal
0018067X → ACNP
Volume
85
Issue
6
Year of publication
2000
Pages
580 - 585
Database
ISI
SICI code
0018-067X(200012)85:6<580:FOIDTD>2.0.ZU;2-S
Abstract
Over the last three decades the frequency of the dark melanic form carbonar ia of the peppered moth Biston betularia has declined in Britain. Data have been examined which show the intermediate phenotype insularia, controlled by alleles at the same locus, to have increased or remained level in freque ncy. Phenotype frequency of insularia does not always track allele frequenc y accurately because it is recessive to its alternative when carbonaria is common but dominant to the alternative when typical is common. It is shown that if insularia fitness lies between that of carbonaria and typical, and melanics replace typicals or vice versa. there will be a rise and fall in i nsularia allele frequency during a transitory period. The path followed is strongly affected by initial gene frequencies, During the high melanic peri od in Britain, differences in insularia frequency between localities may ha ve been influenced by history of arrival of the novel morphs as well as by local selective conditions.