LINKING BIOGEOGRAPHY TO ANCESTRY
Environmental Setting of My Genetic Ancestors


Researchers have found the skeleton remains of prehistoric Asians who lived in the Stone Age during the time of the Last Glacial Maximum of the Ice age.

Figure 5
The Stone Age

Stone Age Timeline


As early as 200,000 years ago modern humans are estimated to have lived in China. Much is being learned of their cultural patterns, lifestyles, and population migratory patterns.

Life in the Paleolithic period meant my earliest ancestors had to contend with thick year-round ice sheets, frigid climate, and dwindling hunting and foraging spaces. To keep warm in the cold climate, they would be wrappped in animal skin. They would take shelter in the warmth of caves, staying near the mouth of the cave where it would be lighter for better vision. Where no caves existed, they built temporary shelters from branches, leaves, and animal skins. As hunter-gatherers, they sought food by hunting and fishing. They also gathered edible plants, fruit, and collected eggs from bird nests. A single kill of a woolly mammoth would provide a clan with food for months. These ancient Paleolithic people were also the first to leave behind art. They used combinations of minerals, ochres, burnt bone meal and charcoal mixed into water, blood, animal fats and tree saps to etch humans, animals and signs. They also carved small figurines from stones, clay, bones and antlers.

Both my maternal and paternal ancestral lines stem from such Paleolithic environs.

My maternal ancestry stems from the woman who gave rise to haplogroup B in mainland China ~50,000 years ago. Her descendants carried the haplogroup B marker B4b1 eastward into Southeast Asia. The B4b1 marker has been found mainly in populations of southern China and Southeast Asia, especially the Philippines and the Austronesian speakers of eastern Indonesia and the aborigines of Taiwan and Hainan, China. Moreover, the B4b1 marker also gave rise to the B2 marker, my present maternal marker, ~15,000 years ago which spread into the Americas.

My paternal genetic ancestry stems from the man who gave rise to haplogroup O in China ~45,000 years ago. For thousands of generations, his descendants stayed in east Asia where they have become the majority of the Han Chinese, Japanese, and Taiwanese. That said, he and his offspring family of markers over the ages have lived in different places in the centuries following his genetic origin but have remained in Asia.

That said, my effort involves pinpointing the geographic origin of ancestors based on Caitlin Dempsey's belief that when a marker is formed it can be linked to a geographic location and to group populations with the same marker by point of origin.

Figure 6
The Paternal Haplogroup O

Haplogroup O Map

Haplogroup O, known by its defining genetic marker O-M175, is mostly found among populations in East and Southeast Asia and mostly associated with the Chinese people and the main Han Chinese lineage of which I am a part. Moreover, Haplogroup O is also marked, along with its corresponding DNA markers, by Sino-Austronesian languages

As the largest and most dominant component of the East Asian Y chromosome gene pool, Haplogroup O accounts for 75% of the total paternal lineages of Chinese. Yet, it is almost nonexistent in Western Siberia, Western Asia, Europe, and Africa and is completely absent from the Americas.

Hereafter, for reading ease, I will refer to genetic ancestors as just ancestors and as stated, my earliest ancestors lived in the Ice Age when glaciers were at their thickest and living was harsh.

Figure 7
Animation of Ice Age Coverage


Ice Age image

The dimension of the world of my early ancestors included living among other types of human beings, which is relevant to my genome. At some point, my ancestors encountered these other archaic humans and not unexpectedly, interacted with them. Both Neanderthal and Denisovan DNA markers are present in modern Asian populations, including mine. My genome includes 1.4% Neanderthal and 1.8% Denisovan.

Figure 8
Neanderthal-Denisovan


Neandertal-Denisovan image

Neanderthals and other humanids, such as the Denisovans had long interbred with Asians as noted in this video. Deniovans wandered Asia for hundreds of thousands of years and remained in existence as recent as the time of my ancestors. Their genes are found in modern East Asian populations and the Oceanic islands and records show Denisovans interbred with early modern humans in Southeast Asia, particularly among the modern residents of the Pacific islands, including the Philippines and New Guinea. "As a result of ancient interbreeding, people living today on islands of Southeast Asia and Oceania have genomes with up to 6 percent Denisovan DNA." Furthermore, Clare Wilson points out "Our species may have been interbreeding with Denisovans as recently as 15,000 years ago." To that end, genetic analysis uncovered a direct descendant of two different groups of early humans with the now proven existance of humans with a Neanderthal mother and a Denisovan father.

A report of the other hominids living along side Neanderthals and Denisovans in southeast Asia can be viewed in this video. A research team led by David Reich discovered at least three major waves of human migration into the South Asia over the past 50,000 years and during that time the anatomically modern hunter-gatherers in Southeast Asia interacted with the ancient human Homo erectus, Homo floresiensis, and Denisovan " populations. Moreover, in addition to (Homo floresiensis) in Fores in indonesia, other hominids lived in the area as well, such as in present day Luzon in the Philippines with (Homo luzonensis). Current evidence suggests that Southeast Asia was occupied by Hoabinhian hunter-gatherers until about 4000 years ago.

Figure 9
Homo luzonensis


My early ancestors also lived in a time when many of today's Southeast Asia islands were still above sea level. They were connected to the Asian mainland to form the continent of Sundaland. It was twice the size of India and it stretched east to west from Burma to Borneo and included present-day Malaysia and Indonesia. In essence, Sundaland joined the islands of today's Southeast Asia into a single great landmass, extending all the way to the Philippines.

Figure 10
Ice Age Asia
with Sundaland above sea level


Ice Age Asia

Figure11
Animation of Sundaland
Slowly Sinking Below Sea Level


Sundaland in Asia Sinking

While the extensive savanna of Sundaland remained above sea level my ancestors would have adapted to this environment and likely settle on the broad riverine flood plains and, in time, integrate with the existing communities.

But, ~29,400 years ago things changed for my earlies ancestor. My O-M175 ancestral lineage experienced a genetic variation which resulted in an offspring acquiring a genetic trait his ancestor didn't have, in essence, a new genetic marker. The new offspring of the O-M175 ancestor had formed a new haplogroup O genetic marker O-M122. As such, the new ancestor with the O-M122 marker is known by the acronym Most Recent Common Ancestor (MRCA).As such, he is the most recent man from which all the men in my O-M122 haplogroup branch are directly descended. The O-M122 marker is the main sublineage of O-M175 and is the predominant sub-group in China. Specifically, O-M122 is also found at high levels amongst Han Chinese, Tibeto-Burman populations (including many of those in Yunnan, Tibet, Myanmar, Northeast India, and Nepal), Manchu, Mongolians, Koreans, Vietnamese, Malays, Filipinos, Thailand, Polynesians, Naiman tribe of Kazakhs,[5] and Kazakhs in the Altai Republic.

I know when this O-M122 MRCA lived, but only generally where. He lived about 24,700 years ago, during the Paleolithic Period when my ancestors would have crafted stone tools and weapons attached to wood shafts to serve as spears and likely lived as a nomad staying near rivers and lakes.

As the ethnic ancestor of the Han Chinese, he reached the upper and middle Yellow River basin. Continuous migrations of the O-M122 ancestral line makes the specific geographical location of my O-M122 ancestor ambivalent. Possibly he existed along the 600 mile stretch of the Yangtze River believed to be the cradle of ancient civilizations. The Yangtze River plays an important role in China's culture and long history of civilization and it forms the boundary between present day northern and southern China. To that point, my O-M122 ancestor may have lived in the river section known as the Middle Reach and in the general vicinity of the present day Hubei Province of China where the famous Three Gorges are located.

With the passage of time,my haplogroup O lineage would again evolve. About 23,200 years ago in China's Yangtze River Delta my O-M122 ancestor gave rise to an ancestor bearing the DNA Marker O-P201 around present day Chongqing. The O-P201 marker is a major branch of haploroup O in Asia.

It might have been the harshness of ice age weather or global cooling that drove both animals and man south and prompted my O-P201 ancestor's continued southern migration. In any case, it resulted in the emergence of an O-P164 ancestor ~19,200 years ago. Interestingly, with the advent of the Neolithic Period 18,000 years ago the matriarchal clan society existed in China. It was a social system in which the mother was head of the family and descent was traced through the mother's side of the family.

A pattern of genetic variation among my subsequent ancestors would be largely shaped by continued human migration into Southeast Asia. Their journey may have even been overland into the continent of Sundaland, which would not wholly sink under the sea until ~12,000 years ago.

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