There are a variety of different modes of coevolution

There are a variety of different modes of coevolution -...

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There are a variety of different modes of coevolution. In some cases coevolution is quite specific such as those between two cellular functions. The endosymbiont theory proposes that current day mitochondria and chloroplasts were once free-living unicellular individuals. These cells entered the cytoplasm of other cells, an example of the general phenomenon of endosymbiosis . Current-day mitochondrial and chloroplast genomes are much smaller than the genome sizes of their presumed free-living ancestors. Some of this reduction in genome size is due to the transfer of genes from organelle genomes to the nuclear genome. Thus, being in the cellular environment has influenced the evolution of organelle genomes. There is evidence that the faster rate of evolution of animal mitochondrial DNA has accelerated the rate of evolution of some of the nuclear genes that function in the mitochondria. Thus there is some evidence for reciprocal phenomena Other modes of coevolution involve competitive interaction between two specific
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Unformatted text preview: species. The Plethodon salamander study is a good example: two species are competing: in the Great Smoky mountains the two species compete strongly as evidenced by the fact that each species will increase population size if the other is removed. Here there is a clear reciprocal interaction between the two populations (species), each affecting the other. [The role of competition between species, the coevolutionary responses to this competition and the consequences for the evolution of communities is illustrated in the Anolis lizard fauna of the Caribbean. There is coevolution because the competitive interactions between resident and invading species of Anolis involve reciprocal responses in the evolution of body size. These affect the structure of the lizard community as evidenced by the general pattern of there being a single species of lizard on each island.]...
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