Search results
Results from the WOW.Com Content Network
Vestigial structures are often homologous to structures that are functioning normally in other species. Therefore, vestigial structures can be considered evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time. The existence of vestigial traits can be attributed to changes in ...
A dewclaw is a digit – vestigial in some animals – on the foot of many mammals, birds, and reptiles (including some extinct orders, like certain theropods). It commonly grows higher on the leg than the rest of the foot, such that in digitigrade or unguligrade species, it does not make contact with the ground when the animal is standing.
Remnant eyes (and eye structures) in animals that have lost sight such as blind cavefish (e.g. Astyanax mexicanus), [88] mole rats, snakes, spiders, salamanders, shrimp, crayfish, and beetles. [89] [90] Vestigial eye in the extant Rhineura floridana and remnant jugal in the extinct Rhineura hatchery (reclassified as Protorhineura hatcherii ...
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.
That this vestigial response occurs even before becoming consciously aware of a startling noise would explain why the function of ear-perking had evolved in animals. The mechanism serves to give a split-second advantage to a startled animal – possibly an animal being stalked and hunted.
A so-called "cathedral" mound produced by a termite colony. Structures built by non-human animals, often called animal architecture, [1] are common in many species. Examples of animal structures include termite mounds, ant hills, wasp and beehives, burrow complexes, beaver dams, elaborate nests of birds, and webs of spiders.
In females, the mesonephros degenerates entirely, though vestigial structures such as Gartner's ducts, the epoophoron, and paroophoron are common. In males, a few of the more caudal tubules will survive and give rise to the efferent ductules of the testis , [ 1 ] the epididymis , vas deferens , seminal vesicle , as well as vestigial structures ...
A = Anapsid, B = Synapsid, C = Diapsid. It was traditionally assumed that first reptiles were anapsids, having a solid skull with holes only for the nose, eyes, spinal cord, etc.; [10] the discoveries of synapsid-like openings in the skull roof of the skulls of several members of Parareptilia, including lanthanosuchoids, millerettids, bolosaurids, some nycteroleterids, some procolophonoids and ...