What is the difference between a homologous structure and a analogous structure?

Answer 1

Homologous structures are different forms of animal anatomy which have come from the some origin (a common ancestor), these can be extremely different in appearance and function. For example a bats wing, a seals flipper and a human arm all have common bone and muscle structures suggesting that they all derived from a common ancestor.

Vestigial structures are parts of the anatomy which have lost their original function through the evolutionary process and no longer obtain a major functional role in that animals life. For example in human the appendix's original function was to break down cellulose in plant material, other vestigial functions in humans include the coccyx (tailbone) and ear muscles.

Answer 2

Homologous structures derive from a common ancestor (eg. the forelimbs of birds and mammals are homologous structures). Analogous structures are the result of convergent evolution (eg. various features of the wings of birds and bats are analogous structures).

Answer 3

Homologous structures: It applies to biochemistry, physical structure, and physiology; as well as to the behavior and often, function. It is the assumption that similar structures stem from the common ancestry of all living things. Darwinists have defined homology as correspondence of structure derived from a common primitive origin; which assumes speciation to be true (from the book - Of People and Pandas).

Analogous structures: A very similar structure may not be considered homologous, although they perform the same function. Structures having a similar appearance and function in unrelated groups are said to be analogous. In other words, Darwinian mechanisms have arrived at similar solutions to the same physiological problem using very different raw material. (from the book - Of People and Pandas).

Answer 4

A Vestigial organ is a functionless or rudimentary version of a trait that has a function in a close relative.

Homologous structures are characteristics that are derived from a common ancestor. (similar strucutre, different function)

There are also analogous structures which are apparently similar (usually in function) yet phylogenetically independent.

Answer 5

Homologous structures are shared by related species and have been inherited from a common ancestor while vestigial structures are inherited form common ancestors but have lost much or all of their original function due to different selection pressures acting on the descendant.

Answer 6

Homologous structures are similar in structure and origin but may have different functions, indicating common ancestry. Analogous structures have similar functions but different origins and structures, suggesting they evolved independently in response to similar environmental pressures.

Answer 7

Homologous structures features that two different species have in common due to common ancestors. Vestigial structure is useless features that once served a purpose but are now evolving away.

Answer 8

Homologous st. Are those st which are similer in origin and vestigial st are those st which is non essential for the organism and there is no use