Is the Tibetan Mastiff the ancestor of all flock guarding dogs?

Most sources state that the ancestor of large flock guarding and mastiff (molossus)-type dogs is the Tibetan Mastiff. However, there is no genetic research to support this claim.
 

Tibet

Tibet is an autonomous region connected to China. It is 1.2 million kilometres in area, with a population of approximately 3 million. Its borders are defined by the Karanlik Mountains in the north and the peaks of the Himalayas in the south. To the west are the Karakurum Mountains. Tibet is known as the 'roof of the world'. Average height above sea level is over 4000 metres. For this reason the average temperature is -5 degrees centigrade. No other country has such harsh natural and climatic conditions.
Life in Tibet depends entirely on the yak (Bos grunniens). These long haired cattle are accustomed to living in extremely low temperatures at heights of up to 6000 metres above sea level. The staple food of the country is all provided by the yak - meat, milk and butter. Clothing and tents are made from the long hair of the yak. Yak dung is used for fuel. For thousands of years Tibet has been a closed society ruled by priests. Up to the present day they have been able to establish neither a significant civilization, nor a significant presence in the world. Sheep farming is a minor form of animal husbandry. In such a country there is a large breed like the Tibetan mastiff.

The Yak (Bos grunnies). Ankara Zoo, Turkey. Photo by Orhan Yılmaz.

Some questions

Here we need to ask some questions.

1. Up to the present time, Tibet has not reached a significant population size. The Tibetans are Buddhists and there is no warlike or expansionist tradition in their religion. The country is bounded by the world's highest mountains in the north, south and west. Living in such a situation, to where have the Tibetan people migrated, made expeditions, taken their culture, or taken their Tibetan Mastiffs to become the ancestors of all the other large flock guarding dogs?

2. Nowadays the Tibetan Mastiff is rarely found even in Tibet. There are more Tibetan Mastiffs in the USA than in Tibet. How could such a breed, rare even in its own country, spread across the whole world?
3. The main colour of the Tibetan Mastiff is black. Upon this black ground there may be bright yellowish brown or gold patches. White is never found. However, the most common colours in large flock guarding dogs are light shades such as pure white, ivory and cream. The most notable white dog breeds are Akbash, Kuvasz, Komondor, Maremma, Great Pyrenean, Pyrenean Mastiff, Carpathian, Armenian Sheep, South Russian Shepherd, Spanish Mastiff, Mioritic, Slovak Chuvach and the Polish Tatra. How can the predominantly black Tibetan Mastiff be the ancestor and gene source for all the large flock guarding dogs?

Tibetan Mastiff. Photo by www.bod.com.

The contrary thesis and supporting evidence

My view on this subject is that all the large flock guarding dogs are derived from the shepherd dogs of the Central Asian Turks, rather than from the mastiff.

To number just the first few:

1. Either as a result of prolonged drought, or because of rapid population growth causing overcrowding, or from a desire to conquer new lands, the Turks in the past repeatedly left their homelands. They founded 16 empires, not states. From China to Spain there is no place in Europe or Asia on which they did not set foot and disseminate their culture. They must have taken their dogs everywhere they went.

2. Even today large flock guarding dogs are found in large numbers in all the Turkic republics of Central Asia.

3. In the Turkic republics dogs of all colours exist. This gene variation may be the cause of colour variations in all the other large flock guarding dogs.

The common features of shepherd dogs in this group are large size, great strength and generally a whitish coat. The following are the shepherd dog breeds recognised by respected dog clubs world wide.