Sökning: "ancestral sequences"

Visar resultat 1 - 5 av 28 avhandlingar innehållade orden ancestral sequences.

1. 1. Computational problems in evolution : Multiple alignment, genome rearrangements, and tree reconstruction

   Författare :Isaac Elias; Jens Lagergren; Lior Pachter; KTH; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Distance Methods; Tree reconstruction; Sorting by Transpositions; multiple alignment; ancestral sequences; Computer science; Datavetenskap;

   Sammanfattning : Reconstructing the evolutionary history of a set of species is a fundamental problem in biology. This thesis concerns computational problems that arise in different settings and stages of phylogenetic tree reconstruction, but also in other contexts. LÄS MER

3. 2. The Dawn of a New Age : Interrelationships of Acoela and Nemertodermatida and the Early Evolution of Bilateria

   Författare :Andreas Wallberg; Ulf Jondelius; Mikael Thollesson; Graham Budd; Gonzalo Giribet; Uppsala universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Acoela; Nemertodermatida; Bilateria; Metazoa; evolution; phylogenetic inferrence; ancestral reconstruction; taxon sampling; microRNA; Systematics and phylogenetics; Systematik och fylogeni; systematisk zoologi; Systematic Zoology;

   Sammanfattning : Deciphering the rapid emergence of bilaterian animals around the time of the Cambrian Explosion and reconstructing the interrelationships of animal groups have long been two of the most elusive problems in Zoology. This thesis concerns the phylogenetic interrelationships within and among Acoela and Nemertodermatida, two groups of small worms that are believed to be basal bilaterians and which may provide important clues for understanding the early evolution of animals. LÄS MER

4. 3. The evolution of sex chromosomes and sex-linked sequences in birds

   Författare :Homa Papoli Yazdi; Hans Professor; Bengt Hansson; Uppsala universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; sex chromosomes; female heterogamety; recombination suppression; genetic map; inversions; genetic diversity; pseudoautosomal region; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

   Sammanfattning : Identifying the processes involved in the evolution of suppressed recombination between sex chromosomes and understanding their consequences for the evolutionary dynamics of sex-linked loci have been major topics of research during the last century. In this thesis, I used the avian ZW system, where females are the heterogametic sex, to investigate the underlying processes in sex chromosome evolution in birds. LÄS MER

5. 4. An evolutionary view of the taxonomy and ecology of Inocybe (Agaricales) with new perspectives gleaned from GenBank metadata

   Författare :Martin Ryberg; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
   Nyckelord :Inocybe; Inocybaceae; emerencia; GenBank; Insufficiently identified sequences IIS ;

   Sammanfattning : Inocybe (Inocybaceae) is one of the most speciose genera among the gilled mushrooms (Agaricales) but large parts of its taxonomy and evolutionary history remain poorly explored. The present thesis sho... LÄS MER

7. 5. Autolytinae: molecules, morphology, and reproduction

   Författare :Arne Nygren; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Phylogeny; systematics; revision; new taxa; PhyloCode; reconstruction of ancestral states.;

   Sammanfattning : Autolytines constitute a well delineated group of syllid polychaetes, separated from other syllids by the presence of a sinuous pharynx, lack of ventral cirri and reproduction with dimorphic sexes. The group comprises c. 170 nominal species distributed worldwide, mostly inhabiting hard substrates restricted to the continental shelf. LÄS MER