C. Earle Smith

Archeological evidence for selection in avocado

SummaryA series of avocado seeds recovered from the deposits in El Riego, Purrón and Coxeatlán Caves of the Tehuaeán area show gradual increase in size and a change in shape from oldest to youngest. The oldest cotyledon from Zone XXIV of the Coxcatlán Cave deposit is dated at least 7000 B. C. It was probably brought into the Cave from a native tree growing in mesic forest in one of the barrancas in the mountainside to the east. The quantity of avocado seeds and the presence of other undoubtedly cultivated plants indicates that avocados probably were being planted on nearby streamsides by 6500 B. C. The dramatic increase in the figure obtained by multiplying the length by the width of the largest avocado cotyledons proves that selection for larger fruit was markedly effective by 900 B. C. Since avocados are a long-lived tree crop and the results of selection are not readily apparent, the increase in size is particularly significant.While the average size of the avocado cotyledons increases from older to younger cultural horizons, the smaller seeds remain abundant. Evidently trees that bore small or poor fruit were not eliminated and they probably slowed the process of selection materially for trees that bore larger and better fruit.

Critical identification of Mexican archaeological cotton remains

SummaryMeasurements of cotton boll segments from caves near Mitla, Oaxaca, Mexico, datable between 700 and 1300 A.D., indicate that the archaeological material is more closely related to the modern racespunctatum andlatifolium ofG. hirsutum than it is to other races. This is supported by the shape of the bolls and, particularly, by the high percentage of tufted seeds found in the archaeological cotton.That the material isG. hirsutum has now been confirmed by examination of an archaeological peduncle which clearly shows the fringe of hairs above the true floral nectary, virtually a hallmark of the species. The external extra-floral nectaries completely eliminate the possibility that this could be an Asiatic cultivated cotton.All of the Mexican archaeological cotton known so far is completely domesticated. We have no evidence as to where cotton originated as a cultigen. It was introduced into the Tehuacán and Oaxaca Valleys as a cultivated plant.

Early Sedentary Communities of the Basin of Mexico

Abstract Excavations and survey since 1970 have produced data on many aspects of human occupation in the Basin of Mexico between 1200 B.C. and 500 B.C. (un calibrated radiocarbon dates). We attempt here to summarize our current understanding of the communities of that period in the Basin, with respect to chronology, stylistic affinities of their material remains, subsistence patterns, craft production, trade relationships, socio-political aspects, and the possible religious beliefs of their inhabitants. We urge in conclusion that even-handed attention be provided to both the historical and the processual aspects of the evidence in the interest of a more complete understanding of the past in our region.

Additional notes on Pre-Conquest avocados in Mexico

SummaryA total of 118 measured cotyledons from the archaeological deposits in the Oaxaca Valley show an average length of 2.9 cm and an average width of 1.6 cm. Average 1 × w =4.63. The majority of the cotyledons are elongate and have a convex base. Among the cotyledons found are eight in which the outer seed coats are intact. Assuming that the outer seed coats are relatively free from shrinkage, they show that the original size of the avocado cotyledons was about 36% greater than the size of the fully desiccated cotyledons. The average length of the intact seeds coats is 3.8 cm, average width is 2.0 cm and the average 1 × w =7.26.By applying the 36% differential to the Tehuacán Valley avocado cotyledons of the same time period, we find that the largest cotyledon had a length of 4.4 cm and a width of 4.8 cm which compare favorably with the size of modern cultivated avocado seeds.The Tehuacán Valley people practised selection for large fruit which was presumably of better quality than the wild-type fruit from which they were derived. while we have no old series with which to compare sizes in the Oaxaca Valley, it appears that the people of this area did little to improve the size of the avocado fruit which they were growing. If it is correct to assume that the two cotyledons found in Zone B-1 of Guila Nacquitz Cave are in their correct position (they could be instrusive) and they came originally from the same stock as those of the Tehuacán Valley where most of the archaeological cotyledons are of similar size and shape, it is obvious that the Oaxaca Valley people did not take advantage of the opportunity for improving avocados.

Plant Remains from Guitarrero Cave

Publisher Summary This chapter discusses the plant remains from the Guitarrero Cave. The archaeological plant remains from the Guitarrero Cave provide a partial record of the vegetational history of the area. The deposit from which they were removed apparently spans a time range from 10,000 B.C., until early ceramic times. However, the margins and deeper parts of the deposit disclosed a stratigraphie record divisible into four complexes. The chapter describes a survey in which the plants that were recognized as having potential as fiber sources were collected with sufficient material to extract fiber for comparison with archaeological samples. This proved to be particularly valuable because the early people of the Guitarrero Cave used a number of species of Tillandsia. When reduced to leaf fragments such as the ones that were recovered from the cave, only cross sections of the leaves enabled them to be identified. Collections were also made of extra parts of edible and medicinal plants in case these should be needed for comparison.

Ethnobotany in the Puuc, Yucatan

Ethnobotanical observations made in 4 weeks during the summer of 1970 are reported. Cooperation of a number of students participating in a University of Alabama summer class made the collection of information more complete, because the students lived in Ticul where many of the observations were made.Cultivation in this part of Yucatan is easily divided into the staple crops, corn, beans, squash, sometimes chili, jicama or sweet potato, grown in milpas and fruits and herbs grown in dooryard gardens. Milpas are usually cultivated for no more than two seasons before they are moved to a new area which has been fallowed for 7 to 10 years. This allows recovery of soil fertility in the very thin soils of the area. Dooryard gardens furnish items for the kitchen and, frequently, a surplus which can be sold for cash.Ticul market is the retail market of the area where both permanent and casual vendors sell produce and other items. The butchers and some of the vegetable and fruit vendors rent the same stall daily while many rural householders with only a small surplus sell a few items during Sunday market from a cloth spread on the ground. The local government fixes stall rental, settles disputes and assumes responsibility for market sanitation.Oxkutxcab market is a wholesale market, reportedly for the whole southern half of Yucatan. The butcher and a very few stall holders sell retail. Produce is largely offered by the basin, burlap bag or other quantity, but never by a single piece. Fruit was the principle commodity during the period of observation. Local government exercises the same control for the Oxkutxcab market as the Ticul government does.Commercial production in the area includes hennequen plantations, many of which are now abandoned, and fruit orchards. Among the local industries involving plant material are manufacturers of rope from hennequen fiber and hats from guano(Sabal mayarum) leaves.

Plant fibers and civilization— cotton, a case in point

-~s first te(hnical invention was probably a knot. Natural weapons were close at hand, and our forebears rarely worried about the latest clothing styles. Man had little incentive to improve weapons or make clothes. Mans upright stance, though, enables him to gather a number of objects for t ransport in his arms. Ear ly man must have soon found that he could carry the weight of far nmre small objects th.an his arms could conveniently hold. His solution was to tie the small objects into one large bundle with fibers. Plant fibers have always offered several advantages. Not the least of these adv.anrages to primitive people is the wide distribution of fiber-producing seed plants. Another advantage lies in p lant immobility; plants do not have to be caught before they e.an be used. A further advantage is the ease with which plant fibers can be used; for rough tying, the fibers need not be taken from the stem or leaf in which they originally grew, but the whole structure can be used as a cord. The structure of plants is mechanical|y bolstered by fiber cells which may be extracted for use in many ways. Furthermore, hairs which are suitable for fiber use aid in the dispersal of some seeds. I know of plants in 44 different families which are used for fiber, and I am sure that there are many which I have missed. Hill (1937, 1952) notes that over 750 species of plants are used for fibers in the Phil ippine Islands alone. Primitive people employ almost every fiber plant which occurs in their environment. Through the areheological record, there is

Pre-conquest plant fibers from the tehuacan valley, mexico

SummaryAltogether, a total of 46 samples, selected by the archeologists as cotton, were examined. of these, more than half (32 samples) are cotton or largely cotton. The cotton grown and used in the Tehuacán area varies widely in color from pure white to rich brown. The bulk of the cotton was an off-white or tan color. In three instances, cotton yarns which had apparently been specially coated were found. Several samples of yarn had been dyed red or blue.The remaining samples of fiber include pochote orCeiba seed fiber, leaf fiber (includingAgave leaf fiber), bast fiber, and one sample of urticaceous fiber (probablyBoehmeria). In several instances, the bast fibers are fine and soft, and had been made into yarn or textile. One of these yarns was dyed red.In five samples, abundant animal hair was found with the cotton fiber. All of these samples were found in El Riego Cave. Probably, animal hair was spun into the cotton yarns deliberately.

Archeological evidence for selection of chupandilla and cosahuico under cultivation in Mexico

SummaryFrom four caves in the Tehuacan Valley, excavated by the Proyecto ArqueológicoBotánico Tehuacán, seeds of ehupandilla (Cyrtocarpa procera) and cosahuico (Sideroxylon) cf.tempisque) were recovered. Measurements of these show that a definite increase in size took place. Chupandilla seeds showed little increase in the lower levels (ea. 6500 to 2300 B. C.) but from ca. 900 B. C. to A. D. 1500 there was a constant increase in size. During this period, chupandilla showed no significant change in fruit proportions. Cosahuico, on the other hand, showed an increase in size beginning in levels whose earliest date is ca. 4800 B. C. and the increase continued to the top at ca. A. D. 1500. Furthermore, cosahuico seeds became proportionally more elongate from ca. 4800 to 200 B. C, less elongate from ca 200 B. C. to A. D. 700 and then again more elongate from ca. A. D. 700 to 1500. Especially notable size increases in the seeds of both fruits from Purrón Cave (TC 272) can be associated with the building of a dam and extensive irrigation system near that cave. Undoubtedly, these changes in size and shape are attributable to cultivation of the trees and active selection of seeds from large fruit for the propagation of new trees. This datum further strengthens the premises previously established by a study of avocado cotyledons from the same area (6).

Vegetation and man in the Basin of Mexico

The Basin of Mexico (Fig. 1) lies at an elevation of about 2,000 m. Surrounded by mountains on the east, south and west, it receives drainage from all directions, but drainage from the north is less. As a consequence of continued input and no outlet from the Basin, water accumulated in the past in the valley to form 5 large, shallow lakes during the dry seasons. During the period of historical observation, these at least partially coalesced, particularly during heavy rainy seasons. Generally, the level of the lakes at the time of Spanish Conquest is stated to have been 2,240 m. In the historic period, a drain was opened to the north to reduce the lakes to their present condition. Colonial period accounts (Rojas et al., 1974) indicate that various causeways constructed prehistorically were still functional in providing overwater access to Tenochtitlan (Mexico City) and in separating the waters of Lake Texcoco (Fig. 1) into an eastern saline body and a western fresh water area as well as separating lakes Xochimilco and Chalco. Fresh water from the mountains to the west and south provided a flow which made possible the utilization of the lake water for intensive farming with the development of the unique chinampa system (Armillas, 1971). The lakes of the Basin of Mexico made the area very attractive to prehistoric people who found game animals plentiful and useful plants from a number of different associations within easy reach (Lorenzo et al., 1975). With development of cultivation, undoubtedly around the margins of the lakes initially, the Basin became the site of one of the earliest urban populations in the Americas. However, in order to understand the development of a burgeoning population it is necessary to provide the biological background in which this developed.