Plate Tectonics of Japan
The Japanese Shintoism (Holy Kojiki) asserts that Japan was created by a divine female being, Amaterasu-o-mi-kami (天照大神), whose parents lassoed the Japanese islands with humongous ropes and brought them together to their present location. Japan's emperors are said to be descendents of this goddess - the founding mother of Japan. Amaterasu was born from the left eye of the creator god Izanagi and a grandson of hers, Ninigi, was sent to Kyushu to wed a princess. Ninigi's great-grandson Jimmu became the first emperor of Japan in 660 BC. (Diamond 1998)

The myth of roping the islands has some elements of truth in plate tectonics. Geological evidence suggests that the Japanese islands were created when the Eurasian, the Pacific and the Philippines plates collided some 10-20 millions of year ago (Taira 2001). The physical Universe is believed to have originated in a Big Bang about 15 billion years ago. The Sun was formed from cosmic dusts and debris about 5 billion years ago. During the formative years of the Sun, millions of small planets - planetesimals - revolved around it, and these collided with each other and accreted into larger planets, one of which being the Earth.

The Earth is about 4.7 billion years old. During the first billion years, the Earth was under constant bombardment by planetesimals and it was essentially a molten rock, spinning and revolving around the Sun. As celestial collisions dropped off, the surface of the Earth cooled and rocks were formed. The oldest rock on earth is about 3.8 billion years old. It is probable that rocked formed much earlier but plate tectonics and collisions would have destroyed the older rocks. This period is called the Hadean Era (4.5 - 3.8 billion years ago).

Life began about 3.6 billion years ago. The oldest Hominid fossil is about 10 million years old, and it is believed that hominids inhabited much of the continents of Africa and Eurasia. Geological evidence indicates that the continents have been floating all over the Earth's surface. About 750 million years ago, Rodinia, a super continent, began to break up into tectonic plates. The plates got stuck together and formed a new super-continent of Gondwanaland surrounded by several island continents about 350 million years ago. The island continents formed Pangaea, the last supercontinent, about 200 million years ago.

It is clear from plate tectonics that Japan, Korea, Siberia, and Manchuria were cut from the same tectonic plates millions of years ago and that they had much in common in terms of fauna and flora, including hominids.

The Ice Ages
About 30 million years ago, the Earth cooled down and extensive glaciations lowered the sea level. (Smith 2004) The Earth warmed and the sea level rose until the next Ice Age hit the Earth about three million years ago. It is believed the ice-age cycle is related to the Earth's spin precession and its orbit around the Sun that changes its eccentricity in 100,000 to 400,000 years. When the Earth's orbit around the Sun is less circular, its temperature drops and glaciations occur. Ice reflects solar energy and the cooling process accelerates. The Earth's spin axis wobbles with a period of 19,000 to 23,000 years. The spin axis tilts the Earth is irradiated unevenly and one or the other hemisphere freezes.

Major glaciations during the past 450,000 years wrecked havoc with plants and animals alike. Species were wiped out en masse during ice ages. Some hominids in the coastal regions and at isolated hot spots managed to survive the cold spells, and this process of selective survivals gave rise to diversification in genetics, culture, and languages.

According to Smith (2004):

The present Ice Age began when the Isthmus of Panama emerged to block the Atlantic-Pacific connection, creating a conveyor belt of cold salty water that sinks near the Arctic 0cean and goes back south, instead of carrying heat to the Arctic Ocean. Australopithecus lived in transitional woodlands near trees, because with no stone weapons and no fire, trees were the only way Australopithecus could avoid the lions. The ice age killed the trees, and with the trees gone, the lions killed Australopithecus. Homo, smart enough to defend itself with fire and stone, could live on the ground. Homo's intelligence required a large brain, which meant difficult childbirth and a long dangerous childhood. Homo's survival required couples to mate for life to care for their few children over a long childhood.

About 11,600 years ago, the earth's temperatures dropped suddenly about 14 degrees C below present-day average temperature due to the Toba volcano eruption that covered the Earth with ashes. This cold snap lowered the sea level by about 100 meters and reconnected several land masses. The Sea of Coree became an inland lake and the Japanese islands became reconnected to the Eurasian continent. About 11,600 years ago, this cold snap was broken in a short time span of about 50 years and the last ice age came to an sudden end, ushering in the Holocene Era of the present epoch.

The Ice Age Civilization of Japan

As the glaciers melted and sea level rose about 35 meters to its present level in a time span of about 4,000 years, the northern Sunda Shelf near China, Korea, and Japan began to flood. The coastal inhabitants were forced to move to higher grounds and became stranded on islands or merged with humans indigenous to the inlands.

Archeological evidence suggest that the Japanese islands were inhabited by Paleolithic people as far back as some 40,000 years ago. An American zoologist, Edward S. Mores, discovered archeological evidence of the Jomon people in the 1800's. Jomon refers to the pottery made by the ancient people of Japan. It is believed that the Jomon culture thrived in Japan from about 10,000 years ago to about 2,400 years ago. (Crystal 2004)

The Jomon people were part of the Sunda coastal inhabitants, the Oceanic proto-types, that populated southern parts of Korea, Chinese coastal areas, Indochina, India, Malaysia, and other Pacific islands. The proto-Oceanic people were Negroid and their descendants inhabit Japan as Ainus, India as Dravidians, Filipinos, Fijis, Australian aborigines, and so on.

It should be noted that the oldest Jomon pottery, about 12,700 years old, was discovered on Kyushu, the island closest to Korea. Jomon pottery spread north and reached Tokyo around 9,500 years ago and Hokkaido around 7,000 years ago. It is significant that the art of wet rice cultivation followed the same pattern, suggesting Jomon pottery and other tools of civilization came from Korea. (Diamond 1998). In about 250 BC, floods of immigrants from Korea began to arrive in Japan and exterminate the Jomon people.