The species variants out of which 20th century humanity will ultimately evolve largely consist of nomadic hunter-gatherers using stone tools (homo habilis), fire, and caves for survival during this period. In the latter millennia these variants are exhibiting faith in magic and the supernatural, participating in communal hunting, and constructing artificial shelters. They are also doing rock carving and paintings.
-- page 789, "Stone Age", The Concise Columbia Encyclopedia, Second Edition, 1989, Columbia University Press
-- Milestones in Technology, February 26, 1999, The Knoxville News-Sentinel ["http://www.knoxnews.com/"]
A bit of aggressive behavior in males may be encouraged by improved immune systems around this time or before.
Aggression may bolster the immune systems of men. Throughout the evolution of humanity, warriors and hunters likely required stronger immune systems than other family/tribal members, since they were more likely to suffer injuries and exposure to new disease than others.
This effect seems to have continued into the modern day.
Moderate aggressiveness seemed to provide the best immune system benefits, with the effect plateauing after that, in terms of aggressive tendencies spurring further immune advantages.
-- Aggression helps men fight off illness By Amy Norton, Reuters Health/Yahoo! Health Headlines, August 23, 2000; SOURCE: Psychosomatic Medicine 2000;62:583-590
Note that humanity's use of fire remains extremely fragile over most of this time-- for they cannot start a fire from scratch.
Rather, someone from a group must either capture a flame from a natural forest fire ignited by lightning, then the group must do their best to maintain the flame into perpetuity, or else the group must try to steal or trade for a flame from another group in possession of such.
The lack of fire-starting technology and the relative rarity of local natural fires (perhaps occuring only once in a generation) combine with the usefulness of fire to make it one of the rarest and most valuable commodities known to early man.
|-- lamp; Encyclopedia Britannica ["http://www.britannica.com/bcom/eb/article/printable/4/0,5722,46974,00.html"], found on or about 2-16-2000, and fire; Encyclopedia Britannica ["http://www.britannica.com/bcom/eb/article/8/0,5716,34938+1,00.html"], found on or about 2-16-2000|
Notice the presence of supply and demand here for a mysterious, rare, and valuable commodity: fire. A commodity which can not be produced unless one already possesses it-- in which case it can be indefinitely recreated at no more cost than supplying dry wood or brush for consumption. A commodity which can help the old live longer and the feeding of babies be eased, due to cooking. A commodity which can help protect against animals and other beings, as well as the cold. A commodity which magically brings a bit of sunlight to the darkness, allowing work and exploration to proceed despite nightfall or subterranean environs. A commodity which is difficult to store and maintain, and is easily lost through accident or sabotage. A commodity that is dangerous, capable of inflicting severely painful injuries and death, in a multitude of ways.
People with fire and the knowledge to use it possess enormous advantages over those without.
Are there not the makings of a market economy here? Some of the conditions above would make fire-related theft and sabotage or conquest exceedingly problem-prone, compared to more friendly barter and trade. The problems of fire maintenance would also seem to encourage groups to remain on good terms with neighbors-- as any might need to request a 'light' refresher from the other at any time.
Could the hazards and requirements of fire mark the earliest beginnings of a bartering system in the making?
Anthropologist D. Falk suggests that one advantage human predecessors enjoy now over competing hominids is better cooling systems for the brain. William R. Corliss questions if this advantage will be expanded upon later by the development of male pattern baldness.
|-- COOLER HEADS, BIGGER BRAINS? From Science Frontiers Digest of Scientific Anomalies ["http://www.knowledge.co.uk/frontiers/"] #77, SEP-OCT 1991 by William R. Corliss, citing Pat Shipman; "Hotheads," Discover, 12:18, April 1991|