PLB143: Lecture 01


What is crop evolution?


We are what we eat: Changes in diet over space and time

© Paul Gepts 2011




Arcimboldo: Fruithead'

(G. Arcimboldo: 1527-1593)

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Readings

Presentation slides


How is crop evolution different from natural evolution?

  • Same evolutionary processes:
    • mutation
    • selection
    • drift
    • migration
    • recombination
    • reproductive mode
  • Human intervention:
    • at which stages?
    • what consequences?

Some related sites of interest


Schematic representation of the main factors of crop evolution

Gepts 2004

Domestication triangle

Contemporary California Diet

Salad and Vegetable Recipes from Worthington (1983)

Vegetable

Number of
times cited 

Vegetable

Number of
times cited 

Aragula 

Jícama  

3

Avocado 

Lettuce 

Beans 

Mushrooms

Beets 

Onions

Bell peppers 

Peanut 

Brassica spp.

Peas 

Carrots 

Radicchio 

Celery 

Radish

Belgian endives

Spinach

Cucumber 

Tomato

Fennel 

Zucchini 

Jerusalem artichoke

 


Original California Native American Diet

Example of the Coahuilla Indians (Prescott-Barrows 1900)

  • chenopodium Chenopodium or Lamb's Quarters (from Martin-Luther-Universität Halle-Wittenberg, Landwirtschaftliche Fakultät, Institut für Acker- und Pflanzenbau, Germany)

  • agave   Yucca mohavensis   (from "Landscape Plants for Western Regions", ISBN 0-9605988-3-9, © Robert C. Perry 1992)
  • Juniper (Juniperus occidentalis)

  • Pine or piñon nut (Pinus spp.): sugar pine, digger pine, Mexican or Nevada nut pine

Other sites of interest


Census (2000): Data for California

Race/ethnic group 

1990

2000

 

Proportion (%) 

Proportion (%) 

White 

69 

47

Black 

6

Asian & Pacific Islander 

10 

11

American Indian, Inuit, Aleut 

0.5

Hispanic

25  (any race) 

32

Two or more races

--

3


Contemporary Italian cooking:  

Salad recipes of Caggiano (1992)

Vegetable 

Number of
times cited 

Vegetable 

Number of
times cited 

Arugula 

Fennel 

Asparagus 

Lentils 

Bean 

Lettuce 

Beet 

Onion 

10 

Bell peppers 

Pea 

Brassica spp. 

Potato 

Carrots 

Radicchio 

2

Celery 

Spinach 

Chicory

Tomato 

10 

Eggplant 

Zucchini



Cooking during Imperial Rome

The Art of Cooking by Apicius (± 50 AD)

Pisam Vitellianam sive fabam: pisam coques, lias. teres piper, ligusticum, zingiber, et super condimenta mittis vitella ovorum, quae dura coxeris, mellis unc. III, liquamen, vinum, et acetum. haec omnium mittis in caccabum et condimenta quae trivisti. adiecto oleao ponis ut ferveat. condies pisam, lias si aspera fuerit. mel mittis et inferes.

Peas or beans à la Vitellius  (image from Classics Program at Skidmore College ): Boil the peas (or beans), stir until smooth. Pound pepper, lovage, ginger; and over the spices put yolks of hard-boiled eggs, 3 oz. honey, liquamen, wine, and vinegar. Put all this, including the spices which you have pounded, in the saucepan. Add oil, and bring to the boil. Season the peas with this. Stir until smooth if lumpy. Add honey and serve.

Some related sites of interest

Lovage (Levisticum officinale, Umbelliferae or Apiaceae, Dicots)

Gernot Katzer's Spice Pages

Ginger (Zingiber officinale, Zingiberaceae, Monocots)

Gernot Katzer's Spice Pages



Vegetables 

Number of
times cited 

Vegetables

Number of
times cited 

Artichoke 

Fennel 

Asparagus 

Leeks 

6

Beets 

Lettuce 

Brassica spp. 

Melon

Carrots 

Mushrooms 

Celery 

Olives 

Chicory 

Onions 

Cucumber 

Radish 

Dates 

2

Stinging nettle 



Wild tomato in Mexico

wild tomato     Wild tomato



Pre-Columbian Civilizations

Other sites of interest

  Tikal Maya ruins at Tikal, Guatemala

  Machu Picchu Machu Picchu, Peru (from 1492 - An Ongoing Voyage - Electronic Exhibit )

A recent archaeological excavation: the ancient city of Caral in Peru (Solis et al. 2001)

Guila Naquitz, Mexico

  • Oldest remains: Squash seeds: 10,000 yrs; Maize seeds: 6,250 yrs
Maya chocolate beaker Maya pot   (from "Trésors du Nouveau Monde", ISBN 2 9600039 0 X, © asbl "Trésors du Nouveau Monde, Brussels , Belgium 1992): from El Petén , Guatemala ; AD 350-550; called " Yuchib'il" or "drinking cup" (20 cm high, 30 cm wide).

Borgia Codex Borgia, 16th century (from IBM Digital Library: Scriptorium or Manuscript Collection): The work is made of four parts: the first three discuss the art of predicting the future (each containing a 260-day calendar); the fourth is on cult. The exact interpretation of this text remains unclear. (C Borg.Mess.1 fol.56)

Codex Mendoza (16th cent. AD)

Codex Magliabechianus (16th cent. AD)

Codex Mendoza Title page : This manuscript provides information on taxes levied by the Aztec emperors, among other topics. It mentions specifically maize, beans, chili peppers, and cacao. Presumably, these foodstuffs, as well as other items such as ornemantal bird feathers, were used to support the large court of the emperor in Tenochtitlán (now Mexico City ).

Tlaloc, the Aztec god of fertility, rain, and agriculture (from Codex Magliabechiano facsimile, University of California Press 1903). This Codex describes in quite some detail, and not always in politically correct terms, the various deities of the Aztecs. Among them is Tlaloc, seen here with a maize plant and a pitcher of beans. 

"Book of the life of the ancient Indians and the superstitions and evil rites that they had and observed"

Foods of the Aztecs

Códice Florentino (16th century) (Estrada Lugo 1989)



In general: Plant uses listed by the Códice Florentino

This particular example shows several plants, including in the upper left corner mushrooms (with the assorted ill effects!) and in the lower right corner agave ( see also a current photo ).

Specifically, food plants of the Aztecs

Agave (Agave spp.) 

Maize (Zea mays

Amaranth (Amaranthus)

Peanut (Arachis hypogea

Avocado (Persea)

"Prickly pear"

Beans (Phaseolus spp.) 

Sunflower (Helianthus annuus)

Bell peppers (Capsicum sp.) 

Sweet potato (Ipomea sp) 

Cacao (Theobroma cacao

Squash, pumpkin ( sp.) 

Chia (Salvia sp.)  

Tomato (Lycopersicon , Physalis

Huauzontle (Chenopodium sp.) 

 

Jícama (Pachyrrhizus sp.)

 

Plant Species Used by the Mixtecs of GuerreroMexico (Caballero 1994)

  •   A figure illustrating that:
    • The majority of plants used by the Mixtecs are wild-growing plants
    • There is a full range of plants ranging from the wild to fully domesticated, with also semi-domesticated plants

Plant use by the Mixtec Indians (© Paul Gepts).


Conclusion: A comparison of salad or vegetable ingredients

The foods we eat in California have been introduced from a wide variety of sources. One of the goals of the study of crop evolution is to unravel this history.


Distrib. pattern

CA current

CA native

Italian

Roman

Aztec and Maya

Number

1

Present

Absent

Present

Present

Absent

17

2

Present

Absent

Present

Absent

Present

4

3

Absent

Present

Absent

Absent

Present

4

4

Present

Absent

Absent

Absent

Present

4



Features of Crop Evolution

  • Domestication: Selection of wild plants for adaptation to cultivation and human use
  • Long-range dissemination through:
    • human migration
    • trade
    • conquest, etc.
  • Not all plants used by humans were domesticated; varying degrees of domestication
  • Large range of uses; multiple uses per plant
  • Questions:
    • where? how? why?
    • methods of analysis?
    • effect on plants?
    • famous scientists in the field and their contributions?

Importance of Crop Evolution Studies

  • Basic:
    • Agricultural revolution: introduction of a technology that represents a quantum change for humans - anthropology, archaeology
    • Evolution: experimental system - population genetics, molecular evolution, developmental genetics, coevolution
  • Applied: foundation for
    • Plant germplasm conservation: what to conserve?
    • Plant breeding: where to get genetic diversity and how to introduce into improved cultivars?

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