在一个小岛上,25%的鸟都不会飞,失去飞行能力对于鸟类会造成一些影响,也有一些原因导致了这些能力的丧失: 主要是身体结构的不同。 相关词汇:flightless bird, muscle, relying, flying ancestors, ostrich, emu, cassowary, rhea, ki...
evolutionbirdsinsectsconstraintsThough most birds and insects are capable of flight ('volant') some species are flightless. In this paper I test the hypothesis that phylogenetic constraints have played a role in the...doi:10.1007/BF01237847Derek A. Roff...
The ability to fly has been lost in many groups of birds. A comparison of the wing structures and genomes of flighted and non-flighted species of steamer duck highlights a possible mechanism for the loss of flight. Genomes of flighted and flightless steamer ducks compared. Falkland Flightless...
A comparative test of the correlated evolution of flightlessness and relative brain size in birds. J. Zool. 263, 317-327.Iwaniuk, A.N., Nelson, J.E., James, H.F. & Olson, S.L. 2004. A comparative test of the correlated evolution of flightlessness and the relative brain size in ...
The best known of these changes are gigantism in small vertebrates and dwarfism in larger species, the so-called Island Rule [2]. In addition there are changes in body shape. Insular mammals often have reduced limb lengths and enlarged cheek teeth [3]. Many insular birds evolve flightlessness...
This study investigates the genetic basis of recent divergence in male wing size between species of the model parasitoid wasp Nasonia. The forewings of flightless Nasonia vitripennis males are 2.3 times smaller than males of their flighted sister species N. giraulti. We describe a major genetic ...
Important examples are vestiges of hindlimbs and pelvic girdles of pythons (Fig. 7.27) and greenland whales, (which show that snakes and whales originally evolved from four-footed ancestors), wings of flightless birds such as Ostrich; Emu, Cassowary, Kiwi, Rhea and Dodo (extinct), splint bone...
Birds exhibit an enormous diversity in adult skull shape (disparity), while their embryonic chondrocrania are considered to be conserved across species. However, there may be chondrocranial features that are diagnostic for bird clades or for Aves as a wh
Recently, paleontologists have unearthed many fossils of feathered, but flightless, dinosaurs (Norrell and Xu 2005). This suggests that feathers evolved long before birds did—in their dinosaur ancestors (Fig. 1). The very first feathers may have been nothing more than a downy fuzz that helped ...
Evolution of flightless land birds on southern continents: Transferrin comparison shows monophyletic origin of ratites 1976 . Evolution of flightless land birds on southern continents: transferrin comparison shows monophyletic origin of ratites . Journal of Molecular Evolution ... EM Prager,AC Wilson,ORE...