मेलानिक इसके अंग्रेजी अर्थ का उदाहरण

All of the group are in currently placed in the genus Cacicus, except the aberrant yellow-billed cacique (Amblycercus holosericeus), and the Mexican cacique (Cassiculus melanicterus) which constitute respective monotypic genera.

Mexican cacique, Cassiculus melanicterus.

Other explanations for the observed correlation with industrial pollution have been proposed, including strengthening the immune system in a polluted environment, absorbing heat more rapidly when sunlight is reduced by air pollution, and the ability to excrete trace elements into melanic scales and feathers.

In 1906, the geneticist Leonard Doncaster described the increase in frequency of the melanic forms of several moth species from about 1800 to 1850 in the heavily industrialised north-west region of England.

Among these, Apamea crenata (clouded border brindle moth) and Acronicta rumicis (knot grass moth) are always polymorphic, though the melanic forms are more common in cities and (like those of the peppered moth) are declining in frequency as those cities become less polluted.

The melanic phenotype of Biston betularia has been calculated to give a fitness advantage as great as 30 per cent.

betularia in Michigan and Pennsylvania were melanic.

In 1921, the evolutionary biologist Richard Goldschmidt argued that the observed increase in the melanic form of the black arches moth, Lymantria monacha, could not have been caused by mutation pressure alone, but required a selective advantage from an unknown cause: he did not consider camouflage as an explanation.

Autosomal suppressors of drive are known in Drosophila mediopunctata, Drosophila paramelanica, Drosophila quinaria, and Drosophila testacea, emphasizing the importance of these drive systems in natural populations.