Question

what are some of the important biological concepts that might be learned from studying size diversification in dogs?

Answer 1

Q Answer: Evolutionary change in morphological traits can be very rapid, as has been documented by a range of studies. Most of the changes found in natural populations are at a relatively small scale, how-ever, and therefore the question is raised as to whether there are inherent limits to the amounts of change that can occur by micro evolutionary mechanisms or whether special   macro evolutionary   processes   are   required   to achieve large-scale change. The domestic dogs 'descended from several wild species. Phylogenetic analyses derived from molecular markers support an origin of the domestic dog from one ancestor, the wolf thus refuting Darwin's hypothesis. The unresolved issue relates to whether or not all lineages of dogs originated from a single wolf stock or multiple stocks of wolves. Most studies of variation at the mitochondrial control region suggest that patterns of relationship among dog and wolf mitochondrial lineages is the result of multiple origins of dogs from different wolf stocks followed by introgressive hybridization between dogs and wolves.

Despite the high level of phenotypic variation among breeds, genetic divergence within the domestic dog and between most species of the genus Canis is quite low. All species of Canis have identical karyotypes and genetic comparisons based on mitochondrial and nuclear genes reveal low levels of divergence between members of this genus.