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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 evolution of birds began in the Jurassic Period, with the earliest birds derived from a clade of theropod dinosaurs named Paraves. [1] Birds are categorized as a biological class, Aves. For more than a century, the small theropod dinosaur Archaeopteryx lithographica from the Late Jurassic period was considered to have been the earliest bird.
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.
The Accipitridae (/ ˌ æ k s ɪ ˈ p ɪ t r ɪ d iː,-d eɪ /) is one of the four families within the order Accipitriformes, [2] and is a family of small to large birds of prey with strongly hooked bills and variable morphology based on diet.
The entire genome of the domestic fowl (Gallus gallus) was sequenced in 2004, and was followed in 2008 by the genome of the zebra finch (Taeniopygia guttata). [94] Such whole-genome sequencing projects allow for studies on evolutionary processes involved in speciation . [ 95 ]
Birds (except Falconidae) usually have karyotypes of approximately 80 chromosomes (2n = 80), with only a few being distinguishable macrochromosomes and an average of 60 being microchromosomes. [7] They are more abundant in birds than any other group of animals. Chickens (Gallus gallus) are an important model organism for studying ...
Bird Word Mahjongg. Solve mahjongg word puzzles in this solitaire word building game from the creators of Lost Island Mahjongg. With over 100 different puzzles and virtually unlimited letter ...
Genomic streamlining has been used to explain certain eukaryotic genome sizes as well, particularly bird genomes. Larger genomes require a larger nucleus, which typically translates to a larger cell size. [23] For this reason, many bird genomes have also been under selective pressure to decrease in size.