5,220 Matching Annotations
  1. Jul 2015
    1. coalescence

      Coalescence is a merging of two units. For example, here the authors consider that Middle East or China are unlikely centers of dog origin because such a scenario would require that ancient wolves and dogs from these areas are united by a common ancestor.

    2. two-phase bottleneck

      A population bottleneck is the reduction of the population size, followed by an expansion, e.g. a small group leaves the first population and immigrates elsewhere.

      This reduction often leads to the loss of genetic diversity in the population; it is called the founder effect.

    3. tochastic effects

      Stochasticity is randomness; in this context, the fact that several lineages mixed resulted in different offspring but each did not recapitulate all the characteristics of its ancestors.

    4. phylogenetically

      A phylogeny is the method to resolve the evolutionary history of a group of species. The relationship between these species can be inferred from various statistical analyses that estimate the genetic relatedness of each species to one another, depending on their differences either in DNA or protein material.

    5. mitochondrialgenomes

      DNA located in the mitochondria. All animal mitochondrial genomes, with a few exceptions, contain the same 37 genes, making them useful as a model for genome evolution.

      Specifically, the comparison of mitochondrial gene arrangements in animals has been critical to inferring ancient evolutionary relationships.

    1. tochastic effects

      Stochasticity is randomness; in this context, the fact that several lineages mixed resulted in different offspring but each did not recapitulate all the characteristics of its ancestors.

    2. Molecular dating

      Molecular dating is a technique that allows biologists to determine the divergence time for two genes or for two species. It is based on the theory of the molecular clock stating that mutations accumulate in organisms at a stable speed.

      Thus, if you compare genes or protein sequences in different species, you can, assuming you know the speed of variation for these sequences, estimate the age of the last common ancestor.

    3. phylogenetically

      A phylogeny is the method to resolve the evolutionary history of a group of species. The relationship between these species can be inferred from various statistical analyses that estimate the genetic relatedness of each species to one another, depending on their differences either in DNA or protein material.

    4. mitochondrial genomes

      DNA located in the mitochondria. All animal mitochondrial genomes, with a few exceptions, contain the same 37 genes, making them useful as a model for genome evolution.

      Specifically, the comparison of mitochondrial gene arrangements in animals has been critical to inferring ancient evolutionary relationships.

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  2. Feb 2014