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Crescentin was discovered in 2009 by Christine Jacobs-Wagner in Caulobacter crescentus (now vibrioides), an aquatic bacterium which uses its crescent-shaped cells for enhanced motility. [1] The crescentin protein is located on the concave face of these cells and appears to be necessary for their shape, as mutants lacking the protein form rod ...
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 ...
[2] [1] One measure is to use the difference between the average and maximum fitness values, as used by Patnaik & Srinivas, to then vary the crossover and mutation probabilities. [6] Population diversity is another measure which has been extensively used in studies to measure premature convergence. However, although it has been widely accepted ...
The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. 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.
For example, Agrobacterium tumefaciens is a plant pathogen, Brucella abortus is an animal pathogen, and Sinorhizobium meliloti is a soil bacterium that invades, and becomes a symbiont in, plant root nodules that fix nitrogen yet most of the proteins of the Caulobacter cell cycle control are also found in these species. The specific coupling ...
A common example of homologous structures is the forelimbs of vertebrates, where the wings of bats and birds, the arms of primates, the front flippers of whales, and the forelegs of four-legged vertebrates like horses and crocodilians are all derived from the same ancestral tetrapod structure.
This is even more obvious in some species of dogs, such as malamutes and huskies, who appear even more physically and behaviorally similar. [17] There is a divergent genomic sequence of the mitochondrial DNA of wolves and dogs dated to over 100,000 years ago, which further supports the theory that dogs and wolves have diverged from shared ancestry.
It also assists scientists in classifying organisms based on similar characteristics of their anatomical structures. A common example of comparative anatomy is the similar bone structures in forelimbs of cats, whales, bats, and humans. All of these appendages consist of the same basic parts; yet, they serve completely different functions.