Search results
Results From The WOW.Com Content Network
The smelling organs of the terrestrial coconut crab are similar to those of insects. [ 141 ] In an odd cross-phyla example, an insect, the hummingbird hawk-moth ( Macroglossum stellatarum ), also feeds by hovering in front of flowers and drinking their nectar in the same way as hummingbirds and sunbirds .
The opposite of homologous organs are analogous organs which do similar jobs in two taxa that were not present in their most recent common ancestor but rather evolved separately. For example, the wings of insects and birds evolved independently in widely separated groups , and converged functionally to support powered flight , so they are ...
Ileum, caecum and colon of rabbit, showing Appendix vermiformis on fully functional caecum The human vermiform appendix on the vestigial caecum. The appendix was once believed to be a vestige of a redundant organ that in ancestral species had digestive functions, much as it still does in extant species in which intestinal flora hydrolyze cellulose and similar indigestible plant materials. [10]
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]
Functionally similar features that have arisen through convergent evolution are analogous, whereas homologous structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions.
An interesting observation made by some of these physicians was the presence of homologous structures in a wide variety of animals, even including humans. These observations were later used by Darwin as he formed his theory of Natural Selection. [8] Edward Tyson is regarded as the founder of modern comparative anatomy.
Many scientists have found the evolution of the eye attractive to study because the eye distinctively exemplifies an analogous organ found in many animal forms. Simple light detection is found in bacteria, single-celled organisms, plants and animals. Complex, image-forming eyes have evolved independently several times. [1]
The endostyle is an organ found in invertebrate chordate species of tunicates, lancelets, and in the larval stage of vertebrate lampreys.It assists in filter-feeding. [1] It has evolved into the thyroid in vertebrate chordates.