Evolutionary History of Chromosome 20

The evolutionary history of human chromosome

We report on a comparative molecular cytogenetic and in silico study on evolutionary changes in human chromosome 7 homologs in all major primate lineages. The ancestral mammalian homologs comprise two chromosomes (7a and 7b/16p) and are conserved in carnivores. The subchromosomal organization of the ancestral primate segment 7a shared by a lemur and higher Old World monkeys is the result of a p...

Evolutionary History of Behavior

History of Evolutionary Theory

The term "evolution" is linked to the idea of development in the sciences of life, and only subsequently did it acquire the present meaning of diversification and origin of new species. The dominant image of the scala naturae, strictly related to the creationist, static and essentialistic positions, was substituted by the image of the tree that characterizes the transformist theories, and that ...

Chromosome number in South American species of Bothriochloa (Poaceae: Andropogoneae) and evolutionary history of the genus.

Mitotic chromosome number of 14 taxa of Bothriochloa native to Argentina, Brazil and Uruguay were surveyed. Chromosome numbers of B. eurylemma, B. meridionalis and B. velutina are reported for the first time, with 2n = 6x = 60, and this ploidy level is the most common among the studied taxa. In addition, new cytotypes were found for B. alta (2n = 60), B. barbinodis (2n = 60), B. exaristata (2n ...

Evolutionary history of the genus Capra (Mammalia, Artiodactyla): discordance between mitochondrial DNA and Y-chromosome phylogenies.

The systematics of the genus Capra remain controversial in spite of studies conducted using morphology, mtDNA, and allozymes. Here, we assess the evolutionary history of Capra (i) using phylogenetic analysis of two nuclear genes located on the Y-chromosome and (ii) previously published and new cytochrome b sequences. For the Y-chromosome phylogeny, we sequenced segments from the amelogenin (AME...