NO. 1 CULTURAL DEVELOPMENT IN LATIN AMERICA 31 
remains, there have been discovered no surely Archaic sites, although 
obsidian projectile points occur in private Guatemalan collections which 
typologically, at least, should be ascribed to this period. But one thing 
is certain: the Maya area was definitely marginal to the initial de- 
velopment of agriculture in Mesoamerica, contrary to what has been 
claimed by earlier writers, most of them misled by the supposed der- 
ivation of maize from teosinte. 
We cannot yet answer the question, Why was central or southern 
Mexico the region in which the really important food plants of Nu- 
clear America were first domesticated? Desert Culture-like peoples 
were found everywhere from Oregon to Chiapas during the Hypsi- 
thermal climatic interval, all very much interested in the collection of 
wild-plant foods, but apparently only in the highlands of Mexico 
were found the ecological niches that exactly suited the wild ances- 
tors of maize, beans, squashes, pumpkin, and other potential culti- 
gens. Thus it was purely a matter of biological good fortune that the 
peoples of Mexico were the first New World Indians to advance to- 
ward a settled life, a head start which gave them a considerable ad- 
vantage over their less fortunate contemporaries. 
The Formative Period can be defined rather loosely, and unsatis- 
factorily it seems to us, as all of that time span beginning with the 
first production of ceramics and ending with the earliest Long Count 
inscription in the Maya area. As a classificatory unit, does this mean 
anything? In a purely developmental sense, it would be most useful 
to confine the term "Formative" to mean that period during which 
farming became sufficiently effective to permit the growth of villages 
all over Mesoamerica, including our area. But we now realize that 
within the span usually alloted to the Formative, namely from about 
1500 B.C. to about a.d. 300, some unusually advanced civilizations 
appeared, head and shoulders above the tribal village cultures with 
which they were contemporary. Then as now in Mesoamerica, cultural 
evolution has been mosaic rather than unitary, and it is fruitless to 
attempt to outline broad developmental stages here with any great 
rigor. Let us therefore consider the Formative merely as a time period, 
to be used or discarded as we see fit. 
The sudden spread of villages all over Mesoamerica at this time 
implies some drastic improvement in food supplies, that is, in the 
maize plant. What probably happened was the appearance of teosinte 
as the result of a cross between maize and its close relative, Zea 
tripsacum; subsequent introgression, or backcrossing, with teosinte 
resulted in a stronger maize stalk with greatly enlarged ears — that is, 
in a tremendous jump in available food energy (cf. Mangelsdorf, 
