![]() For example, the question of how many parallel changes are required to be recognized as an instance of concerted change is naturally dealt with in our model: the statistical signature of concerted or regular change is that the multiple parallel events are more probable if treated as a single coordinated change than as a collection of independent changes ( Box 1).Ī conventional sporadic change model would count the 34 transitions from q to x as 34 independent events. This places concerted evolution in a statistical setting that allows for formal hypothesis testing about the nature and rates of concerted changes. Ĭan events of concerted change be detected statistically in sequence data, and do they improve the characterization of evolution and the inference of evolutionary histories? Although previous researchers working in a linguistic setting have used the concept of regular changes to build algorithms for automatically inferring cognacy, to our knowledge the model we report here is the first probabilistic description of concerted change. ![]() Linguists have proposed several explanations for the regularity of changes grounded in a number of basic processes, including speech production, perception, and cognition. ![]() These multiple instances of one phoneme changing to the same other phoneme yield regular sound correspondences between pairs or groups of languages. A well-known example is the ∗ p> f sound change in the Germanic languages wherein an older Indo-European p sound was replaced by an f sound, such as in ∗ pater>father, or ∗ pes, ∗pedis>foot (linguistic convention is to use the “>” symbol to indicate a transition from one sound to another, and here the ∗ symbol denotes a reconstructed ancestral form). Linguists have long recognized concerted change that affects copies of the same sound (or phoneme) appearing in different words as a central feature of linguistic evolution. It might arise from several mechanisms, including homologous recombination, that allow certain favorable elements to spread or damaging elements to be neutralized. ![]() Concerted evolutionary change is widespread in genetic systems, being implicated in the genome-wide control of repetitive elements, the evolution of gene families, and homogenization of Y chromosome sequences and as a means by which asexual organisms might escape the debilitating consequences of Muller’s ratchet. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |