Search results
Results from the WOW.Com Content Network
Wing structure and colouration often vary with morphs, such as in the aphids, migratory phases of locusts and polymorphic butterflies. At rest, the wings may be held flat, or folded a number of times along specific patterns; most typically, it is the hindwings which are folded, but in a few groups such as the vespid wasps, it is the forewings.
Vestigial wings are those not fully developed and that have lost function. Since the discovery of the vestigial gene in Drosophila melanogaster, there have been many discoveries of the vestigial gene in other vertebrates and their functions within the vertebrates. [70] The vestigial gene is considered to be one of the most important genes for ...
In humans, the vermiform appendix is sometimes called a vestigial structure as it has lost much of its ancestral digestive function.. Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. [1]
Arrows show the vestigial structure called Darwin's tubercle. In the context of human evolution, vestigiality involves those traits occurring in humans that have lost all or most of their original function through evolution. Although structures called vestigial often appear functionless, they may retain lesser functions or develop minor new ones.
Vestigial eye in the extant Rhineura floridana and remnant jugal in the extinct Rhineura hatchery (reclassified as Protorhineura hatcherii). [91] [92] Functionless wings in flightless birds such as ostriches, kiwis, cassowaries, and emus. [93] [94] The presence of the plica semilunaris in the human eye—a vestigial remnant of the nictitating ...
Brachyptery is an anatomical condition in which an animal has very reduced wings. Such animals or their wings may be described as "brachypterous". Another descriptor for very small wings is microptery. Brachypterous wings generally are not functional as organs of flight and often seem to be totally functionless and vestigial.
The vestigial wings are so small that they are invisible under the bristly, hair-like, two-branched feathers. While most adult birds have bones with hollow insides to minimise weight and make flight practicable, kiwi have marrow, like mammals and the young of other birds. With no constraints on weight due to flight requirements, brown kiwi ...
During the pupal stage, many larval structures are broken down, and adult structures, including the discs, undergo rapid development. Each disc everts and elongates, with the central portion of the disc becoming the distal part of whichever appendage it is forming: the wing, leg, antenna, etc.