Economic Botany

, Volume 20, Issue 2, pp 169–175 | Cite as

Archeological evidence for selection in avocado

  • C. Earle Smith
Article

Summary

A 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.

Keywords

Archeological Evidence Valley Floor Catl Mesic Forest Cave Deposit 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Anderson, E., 1950. Variation in avocados at the Rodiles plantation. Ceiba1: 50–55.Google Scholar
  2. Blake, S. F. 1920. A preliminary revision of the North American and West Indian avocados(Persea spp.) 3. Wash. Acad. Sci.10: 9–21.Google Scholar
  3. Coit, J. E. 1948. Mexican explorations of 1948. Calif. Avocado Soc. Yrbk.1948: 59–62.Google Scholar
  4. Contreras, A. A. 1942. Mapa de las Provincias Climatologicas de la Republica Mexicana.Google Scholar
  5. Griswold, H. B. 1946. Primitive avocados of Central America and Mexico. Calif. Avocado Soc. Yrbk.1946: 103–105.Google Scholar
  6. Kopp, Lucille E. 1966. A taxonomic revision of the genusPersea in the western hemisphere (Persea Lauraceae). Mem. N. Y. Bot. Gard.14 (1): 1–120.Google Scholar
  7. MacNeish, R. S. 1964. Ancient mesoamerican civilization. Science143: 531–537.PubMedCrossRefGoogle Scholar
  8. Popenoe, W. 1941. The avocado—a horticultural problem. Calif. Avocado Soc. Yrbk.1941: 79–85.Google Scholar
  9. — and Williams, L. O. 1947. The expedition to Mexico of October, 1947. Calif. Avocado Soc. Yrbk.1947: 22–28.Google Scholar
  10. — and Williams, L. O. 1948. Mexican explorations of 1948. Calif. Avocado Soc. Yrbk.1948: 54–58.Google Scholar
  11. Schroeder, C. A. 1947. The expedition to Mexico of May, 1947. Calif. Avocado Soc. Yrbk.1947: 29–33.Google Scholar
  12. Shamel, A. D. 1938. Avocado studies in Mexico in 1938. Calif. Avocado Soc. Yrbk.1938: 67–85.Google Scholar
  13. Smith, C. E., 1965. Flora, Tehuacán Valley. Fieldiana. Bot.31: 107–143.Google Scholar

Copyright information

© The New York Botanical Garden 1966

Authors and Affiliations

  • C. Earle Smith
    • 1
  1. 1.Crops Research Division, Agricultural Research ServiceUnited States Department of AgricultureBeltsville

Personalised recommendations