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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 features may take various forms; for example, they may be patterns of behavior, anatomical structures, or biochemical processes. Like most other physical features, however functional, vestigial features in a given species may successively appear, develop, and persist or disappear at various stages within the life cycle of the organism ...
Evidence for common descent comes from the existence of vestigial structures. [72] These rudimentary structures are often homologous to structures that correspond in related or ancestral species. A wide range of structures exist such as mutated and non-functioning genes, parts of a flower, muscles, organs, and even behaviors.
Homologous structures - structures (body parts/anatomy) which are similar in different species because the species have common descent and have evolved, usually divergently, from a shared ancestor. They may or may not perform the same function. An example is the forelimb structure shared by cats and whales.
Pelvic spurs (also known as vestigial legs) are external protrusions found around the cloaca in certain superfamilies of snakes belonging to the greater infraorder Alethinophidia. [1] These spurs are made up of the remnants of the femur bone, which is then covered by a corneal spur, or claw-like structure. [ 1 ]
Hummingbirds and sunbirds, two nectarivorous bird lineages in the New and Old Worlds have parallelly evolved a suite of specialized behavioral and anatomical traits. These traits (bill shape, digestive enzymes, and flight) allow the birds to optimally fit the flower-feeding-and-pollination ecological niche they occupy, which is shaped by the birds' suites of parallel traits.
A vestigial response or vestigial reflex in a species is a response that has lost its original function. In humans, vestigial responses include ear perking, goose bumps and the hypnic jerk . In humans
Scorpion anatomy: 1 = prosoma; 2 = mesosoma; 3 = metasoma The metasoma is clearly visible on this ant: it is the posterior section, including the petiole. The metasoma is the posterior part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the mesosoma. [1]