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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 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 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.
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 ...
The zebra finch genome was the second bird genome to be sequenced, in 2008, after that of the chicken. [32] The Australian zebra finch uses an acoustic signal to communicate to embryos. It gives an incubation call to its eggs when the weather is hot—above 26 °C (79 °F)—and when the end of their incubation period is near.
His paternity was confirmed by a DNA test, police said, WREG reports. If you or someone you know has been sexually assaulted, please contact the National Sexual Assault Hotline at 1-800-656-HOPE ...
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 ...
Oregon head coach Dan Lanning shared his solution to success for the 12-team College Football Playoff. "Just win. Just win," Lanning said to sports columnist John Canzano on his "The Bald Faced ...