Note Japanese archaeological studies have been advanced by amateurs as well as professional scholars.

General Definitions of Geologic Time Periods:
    Cenozoic Era (shinseidai): from 70 million yrs bp;
        Tertiary (daisanki): Paleocene, Eocene, Oligocene, Miocene, Pliocene
        Quaternary (daiyonki): from 1.7 million yrs bp; four ice age cycles
            Pleistocene (kooshinsei): Glacial Age; humans appear
            Holocene (kanshinsei, chuusekisei): from 10,000 yrs bp; Recent Age;
Geological & Climate Transformations relating to Japan:
    2,000,000 ybp: Okhotsk Sea and East China Sea were inland: i.e., completely surrounded by land.
        Continental Bridge (rikkyoo): from Ryuukyuus (south) to Chishima Islands (north)
    500,000 ybp: Chishima and Ryuukyuu arcs connected to mainland with some breaks.
        vocanic activity leaves rich loam plains on central area of Continental Bridge (now Japan).
    300,000 ybp: end of inter-ice age two, beginning of ice age three.
        Chishima arc (north) and Ryuukyuu arc (south) become semi-submerged (i.e. islands).
Flora & Fauna Transformations:
    Pleistocene: large mammals from south:
        Stegodon elephant; Nauman elephant;
    Late Pleistocene: large mammals from north:
        Ootsunojika (very large deer): late Pleistocene ~ extinct 8,000 ybp;
        Mammoth elephant: late Pleistocene ~ extinct
        Tonakai (caribou): from late Pleistocene;
        Jakoojika (musk deer): from late Pleistocene;
    40,000 ~ 30,000 ybp: climate and flora become similar to present
        in north: cold; forest, tundra
        in east: fir (needle) trees
        in west: combination of evergreen needle trees and broad-leaf deciduous trees.
General Definitions of Stone Ages: (as outlined by Christian Jurgensen Thomsen, Danish 1788-1865)
    Old stone age: chipped stone tools; usu. Pleistocene;
    Middle stone age: finely worked stone; polished stones; bows&arrows; early pottery;
        hunting, fishing; shell mounds.
    New stone age: usu. Holocene; plants&animals same as present; cultivation, livestock;
        shift from hunting-gathering to production;
Early Evidence of Humans outside of Japan:
   100ky (=100,000 yrs ago) at Skhul, Israel: evidence of anatomically modern humans.
        = physically, but not neurologically/behaviorally modern.
        = perhaps migration out of Africa at this time was blocked by Neanderthals in Europe.
   50ky (=50,000 yrs ago) initial modern human migration from Africa (NYT 99.12.7)
        = (R.G.Klein, The Human Career, 1999) 50ky Aurignacian stone tools indicate modern neurological evolution.
        = (A.S.Santachiara-Benerecetti, Nature Genetics, 99.12) mitochondrial DNA indicate 50ky migration
           from Africa to India and S.E.Asia, along southern route.
        = (M.Feldman, 99) Y chromosomes indicate common male ancestor, circa 40ky, and narrowest population of 2,000.
        = (L.Cavalli-Sforza) boats and navigation were probably used c. 50ky.
   27-20ky ﾒVenusﾓ figurines of stone age women, exaggerated features (?not in Japan, though).
        = (Olga Soffer) new technologies of fine weaving, hide&seek fashion.
   12ky extinction of large mammals in North America (135 species); in 4 centuries
        = (P.S.Martin) hypothesis that the animals were killed by human hunters.
        = (E.L.Lundelius) harsh climate change was dominant factor.
        = (R.D.E.MacPhee) human-accompanied pathogens explain extinction.
Earliest Evidence of Human Habitation in Japan:
    500ky (=kilo-years before present)
        = homo erectus widespread on northeast mainland (now Siberia, Mongolia, China)
        = homo erectus probably lived on Continental Bridge: evidence of hand axes (early stone age).
   350ky: Chichibu, Saitama: small stone tools, ground holes: to store food? (2000.07)
   40-30ky: evidence of late stone age implements indicate humans all over Cont. Bridge.
        =  homo sapiens: Yamashita-choo doojin, Mikkabi-jin (found in Shizuoka coal field, old stone age?),
        =  lived in caves and tents, hunted with spears, used stone blades.
        =  stone implements differ between north and south, indicating different groups (Amino-4).
        =  knife shapes appear to be related to climate and vegetation differences.
   18-14ky: latter half of Fourth (Ulm) Ice Age:
        = Major shift in body types: due to climate or population? (Matsuura Hidenao, Ochanomizu U.)
        = "Hamakita-jin": found 1962 in Shizuoka; 18~14ky based on flourine, C14.
                bones indicate slender body;
        = "Minatogawa-jin" complete skeleton found in Okinawa; 17~16ky; head like Joomon, but body slender
        = Pottery shards (16.5ky) found at Oodaiyama, in Kanita, in Aomori (Asahi 99.04.17)
Tracing the Genetic Roots of Contemporary Populations:
    Early hypothesized migrations: 15,000ybp mongoloid from north; 12,000bp melanesian from south
    DNA tree by Omoto Kaishi & Saitoo Naruya (Kokusai bunka kenkyuujo) (Asahi shinbun 98.5.22eve)
        Ainu: came from N.E.Asia earlier than Mainland population; probably descend from Joomon.
        Mainland (Yayoi) genetically closest to Koreans, then Tibetans, then Mongols, then Ainu.
    HLA (white blood cell dna) trees by Tokunaga Shooshi (Tokyo U) et al. (Asahi 98.5.29 eve).
        Yayoi route 1: North China > Korea > North Kyuushuu > Kinki
        Yayoi route 2: Korea > Hokuriku > Japan Sea coastline
        Yayoi route 3: South China > Ryuukyuu Islands > South Kyuushuu > Shikoku > Honshu pacific coast
        Yayoi route 4: South China > Korea / North Kyuushuu
    Virus studies (HTLV, JCV[MY, CY]) by Tajima (Aichi Cancer Research C.), Yogoo (Tokyo U.):
        HTLV, CY: Jomon? = (Kyuushuu, Hokkaidoo) same as Peru, Andes, etc. (and Korean peninsula)
        MY: Yayoi? = (central Japan) same as N. China.  (Asahi 98.6.5eve)
    Bone studies (Nakahashi Takahiro, Kyushu U): small initial Yayoi influx, grew steadily on mainland. (Asahi98.6.12)
        Yayoi population went from 0% to 80+% within 200 years: had slightly higher pop. growth rate,
        (Koyama Shuzo, Kokuritsu minzoku hakubutsukan): total pop. increase in 200 yrs. from 80,000 to 600,000.
        (Suzuki Takahiro, Tokyo Ctr. for Rsrch on Elderly): Yayoi brought tuberculosis; hurt Joomon population.
Joomon Culture (7,500ybp ~ 300bc): Middle-stone age, occurred later than European New Stone Age.
        refined use of stone, wood
        rope-imprinted clay pottery for cooking and storage
        advanced use of bows and arrows
        hunter-gatherer society subject to natural phenomena
        indications of other-worldly attentions
        Kurohama kaizuka: early Joomon shell-mound, in s. Saitama. 10,000 shells
    = Wheat cultivation (6,000ybp) evidence at Asabane, in Okayama (Mainichi 99.04.27)