vestigiality

An appendix with the vestigiality of ten men!

History written all over us (vestigiality and unintelligent design)

In the foregoing examples the vestigiality is generally the (sometimes incidental) result of adaptive evolution.

It is important to avoid confusion of the concept of vestigiality with that of exaptation.

Human vestigiality is related to human evolution, and includes a variety of characters occurring in the human species.

Whether they have any extant function or not, they have lost their former function and in that sense they do fit the definition of vestigiality.

The concept of vestigiality applies to genetically determined structures or attributes that have apparently lost most or all of its ancestral function in a given species.

"Linhenykus highlights the vestigiality of the outer fingers of advanced alvarezsaurids and underscores the complexity in evolution of these vestigial fingers."

However, there are many examples of vestigiality as the product of drastic mutation, and such vestigiality is usually harmful or counter-adaptive.

However, these findings do not imply vestigiality of arm swing, which appears to be debateful after the 2003 evidences on the function of arm swing in bipedal locomotion.

The term vestigiality is useful in referring to many genetically determined features, either morphological, behavioral, or physiological; in any such context however, it need not follow that a vestigial feature must be completely useless.

The emergence of vestigiality occurs by normal evolutionary processes, typically by loss of function of a feature that is no longer subject to positive selection pressures when it loses its value in a changing environment.

The flightless snow scorpionfly (snow scorpionfly) with its vestigiality wings seems to be close to the common ancestor of the 2000 or so currently known varieties of flea, which split off in many directions around 160 million years ago.

In the context of human evolution, human vestigiality involves those characters (such as organs or behaviors) occurring in the human species that are considered vestigial-in other words having lost all or most of their original function through evolution.

In this view, bipedality and other avian skeletal alterations were side effects of muscle hyperplasia, with further evolutionary modifications of the forelimbs, including adaptations for flight or swimming, and vestigiality, being secondary consequences of two-leggedness.

It makes sense of the geologic record, biogeography, parallels in embryonic development, biological homologies, vestigiality, cladistics, phylogenetics and other fields, with unrivalled explanatory power; it has also become essential to applied sciences such as medicine and agriculture.

Modern evolutionary theory, beginning with Darwin at least, poses no such presumption and the concept of evolutionary change is independent of either any increase in complexity of organisms sharing a gene pool, or any decrease, such as in vestigiality or in loss of genes.