Food: An Ecosystem Perspective

Food: An Ecosystem Perspective

Biology 101 Laboratory

Biology and Society

Laboratory Exercise 10

Objectives

When you have completed this lab, you will be able to:

Identify a wide range of plant foods that are eaten worldwide

Understand the geographic origin of major food species

Understand the biodiversity available in our crop plants

Stump the Instructor

What food plant did you bring in?

Where does it come from?

Where is it grown now?

Any interesting uses besides food?

HW Review:

The Plants We Eat

potatoescassavasweet potatoyam

soybeanspeanuts, groundnutsbeanspeas

grassesgrasses

roots &tubersroots &tubers

legumeslegumes

ricewheatcorn, maizebarleyoatsryemilletsorghum

Geographic Origin

Food species have been spread by humans for thousands of years

Often crops that are minor in their native range become major crops in different locations

Class Exercise: Geographic Origin

Common processed foods labels:

• What species are on the ingredients list?

• Online, find natural origin of each species/ingredient

• How many different species; from how many continents?

Crop Biodiversity

Many varieties selected from crop species

Selection by humans can result in varieties of the same plant that look like separate species

Species or Variety?

Different name but same species:• Broccoli • Collard greens• Cabbage

All are Brassica oleracea

Species or Variety?

Same name but different species:• Cabbage: Brassica oleracea• Chinese Cabbage: Brassica

campestris • Mustard Cabbage: Brassica juncea

Brassica campestris

Brassica oleracea

Brassica juncea

Mustard cabbage

CropWheatRiceCornSorghumSoybeansPotatoesCassavaTomatoes

The Crop Gene Bank

Accessions850,000420,000262,000168,500176,000

31,00028,00077,500

Percent9090958070

80-903590

HW: Biodiversity in Our Diet

Go to a food store selling fresh produce:• Survey the fruits and vegetables• Identify the species in which you can

find the most varieties in this store• Choose 5 species with the most

varieties• Report the total number of “varieties” in

each of these high-diversity species and list each variety

ApplesApples

Note the signsNote the signs

HintsOnly look at the five species with the highest diversity

Note that some species come in very different (and unexpected) forms [Cabbage, broccoli, Brussels sprouts, etc.; all the kinds of lettuce]

The whole idea is for you to look critically at the entire produce section, not just at things you usually buy

Ethical Discussion

Fig. 2. The abundance of fishes decreases as the populations of humans increase. This indicates that humans adversely affect the fish populations, probably by overfishing. The human populations are represented as per km2 of reef.

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Metric tons per hectare

• Designating 25% of the coastal zone a no-take marine reserve.

• Restrict fishing to only people of Hawaiian descent

• Keep things as they are where everyone can fish when and where they want.

Three scenarios to cope with diminishing fish stocks

Which do you support, and why?