Genetic study reveals shared history of man and dog

The new work documents several times when human movement contributed to dog expansion, building on previous research by others.

Washington: Much of the diversity seen in modern dog populations was already present around the time the last Ice Age had ended 11,000 years ago, a global study of ancient DNA.
The paper, published in Science, showed how our canine companions spread across the world with their masters, but also found intriguing periods when our shared history was decoupled.

A research team led by the Francis Crick Institute sequenced the genomes of 27 dogs, some of which lived nearly 11,000 years ago, across Europe, the Near East and Siberia.They found that by this time, well before the domestication of any other animal, there were already at least five different types of dog with distinct genetic ancestries.

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“By the end of this period, dogs were already widespread across the northern hemisphere.” When and where dogs first diverged from wolves is a contentious matter — analyses of genetic data indicates a window of roughly 25,000-40,000 years ago.

Evolutionary pathways between our two species have at times followed similar routes.

Humans, for example, have more copies than chimpanzees of a gene that creates a digestive enzyme called salivary amylase, which helps us break down high-starch diets.
Likewise, the paper demonstrated that early dogs carried extra copies of these genes compared to wolves, and this trend only increased over time as their diets adapted to agricultural life.

The new work documents several times when human movement contributed to dog expansion, building on previous research by others.