Search results
Results From The WOW.Com Content Network
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 analogous.
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.
Convergent evolution—the repeated evolution of similar traits in multiple lineages which all ancestrally lack the trait—is rife in nature, as illustrated by the examples below. The ultimate cause of convergence is usually a similar evolutionary biome , as similar environments will select for similar traits in any species occupying the same ...
Pseudoplesiomorphy – a trait that cannot be identified as either a plesiomorphy or an apomorphy that is a reversal. [15] Reversal – a loss of derived trait present in ancestor and the reestablishment of a plesiomorphic trait. Convergence – independent evolution of a similar trait in two or more taxa. Apomorphy – a derived trait.
Bottom: in a separate species , a gene has a similar function (histone-like nucleoid-structuring protein) but has a separate evolutionary origin and so is an analog. Sequence homology is the biological homology between DNA , RNA , or protein sequences , defined in terms of shared ancestry in the evolutionary history of life .
It differs from divergent evolution as the species involved do not descend from a closely related common ancestor and the traits accumulated are similar. [4] An example of convergent evolution is the development of flight in birds, bats, and insects, all of which are not closely related but share analogous structures allowing for flight. [8]
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.
Analogous structures - structures similar in different organisms because, in convergent evolution, they evolved in a similar environment, rather than were inherited from a recent common ancestor. They usually serve the same or similar purposes. An example is the streamlined torpedo body shape of porpoises and sharks. So even though they evolved ...