DNA footprints of livestock domestication and evolutionary history

Abstract

The observation of animal and plant breeding greatly influenced Darwin's thought. During the maturation of his theory of evolution, he realised that anthropogenic selection was the driving force shaping domestic animal phenotypes to meet human needs. A concept that was transferred to natural species after the reading of Malthus’ book on the struggle for existence. After the definition of his theory, Darwin continuously searched in domestic plant and animals confirmation of his hypotheses on the transmission of traits and evolution of species. He also observed that some morphological and physiological traits were shared among unrelated domestic animal species but were absent in the wild ancestors. The Russian scientist Dmitri Belyaev proved that these traits emerged as a consequence of domestication by recording their appearance in silver fox selected for tame behaviour, an experiment that is ongoing since about 50 years. Nowadays, genomic technologies allow scientists to explore the molecular basis of these traits and to reconstruct the evolutionary history of domestic animals. The availability of high-density single nucleotide polymorphisms panels permits the detection of signatures left by natural and artificial selection along the genome of domestic animals. The analysis of genomic and mitochondrial DNA contributes substantial information for the identification of sites of primary domestication, Neolithic routes of world colonisation and later voyages linked to human migration events. The understanding of all changes occurring following domestication and anthropogenic selection may help in understanding natural selection and molecular evolution occurring in all living organisms.