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However, in birds and reptiles, this pairing is just the opposite: thus, in Lovebirds, it is the female which has an XY pairing and thus determines the sex of an offspring, depending on whether the mother passes an X gene or a Y gene. It is on the X gene that the genetic information for sex-linked recessive traits is passed.
The black-chinned hummingbird (Archilochus alexandri) is the bird species known to have the smallest genome among birds, which is only 0.91 Gb long.The genomic evolution of birds has come under scrutiny since the advent of rapid DNA sequencing, as birds have the smallest genomes of the amniotes despite acquiring highly derived phenotypic traits.
The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds, some fish and crustaceans such as the giant river prawn, some insects (including butterflies and moths), the schistosome family of flatworms, and some reptiles, e.g. majority of snakes, lacertid lizards and monitors, including Komodo dragons.
This is a result of the same genetic mutation as the genuine Blue genetic mutation in all typical parrot and parakeet species. Consequently, White-faced cockatiels are mainly grey with more or less white throughout their plumage. White-faced cocks display brilliant white faces while hens display basically grey faces with some white streaks.
Passerines, the "song birds". This is the largest order of birds and contains more than half of all birds. Family Acanthisittidae. Genus Acanthisitta - rifleman; Genus Xenicus - New Zealand wrens; Family Acanthizidae - scrubwrens, thornbills, and gerygones Genus Acanthiza – thornbill; Genus Acanthornis – scrubtit; Genus Aethomyias ...
The terms "primitive" and "advanced", etc., are not properly used in referring to a species or an organism as any species or organism is a mosaic of primitive and derived traits. Using "primitive" and "advanced" may lead to "ladder thinking" (compare the Latin term scala naturae 'ladder of nature'), [ 8 ] which is the thought that all species ...
Sexual selection in birds concerns how birds have evolved a variety of mating behaviors, with the peacock tail being perhaps the most famous example of sexual selection and the Fisherian runaway. Commonly occurring sexual dimorphisms such as size and color differences are energetically costly attributes that signal competitive breeding ...
The Sibley–Monroe checklist is a list of bird species based on a study conducted by Charles Sibley and Burt Monroe. It drew on extensive DNA–DNA hybridization studies to reassess the relationships between modern birds. It was considered a landmark in ornithology on its release. [1]