Transcript Slide 1

Food and agriculture
Major topic not covered in biology courses
Habitat loss – conservation issues
Nutrition – body maintinence and disease
Human population
Thomas Malthus
Food production is arithmetic, population
growth in geometric = too many people not
enough food.
• Under nutrition – not enough calories
• Malnutrition – missing some vital
Note: nobody dies of either one – you die of something else due to
weakend body.
Why has the population bomb not gone off ??? What got better?
nutritional needs
food crops
malnutrition and undernutrition
food production
green revolution
new methods
3 molecular food types
4 calories/gm
- free in blood, first used
Fat (lipid)
9 calories/gm
- stored – 2nd used
4 calories/gm
- last used – first protein used is in blood =
Body needs
energy - see next page
vitamins – enzymes and enzyme helpers the body can’t make
minerals – calcium – rickets, vitamin c – scurvy, Vit A – night blindness
Iron – anemia (2/3 of college women deficient
8 essential amino acids – 8 of 21 the body can’t make
One ¼ pounder = all you need for protein
In talking about food, we need only talk about three major crops = most food
especially in underdeveloped countries.
Note: embryo contains vitamins, minerals, amino acids
body of seed = starch (energy only)
husk = ruffage.
(white flour – enriched!!)
Rice, wheat and corn barely have enough protein, and not the right kind.
Note: in undeveloped countries protein sources =
Bush meat – africa / fish - Asia
Traditional Diets
• Corn - low in essential amino acids – add
• Rice – low in essential amino acids – add
• Wheat – better, but add beans, etc.
History of Agriculture
• Permanent crop – fertile crescent; flood
plains (natural fertilizer, irrigation)
• Slash and burn – poor soils – fallow period
• Continuous cropping = fertilizer, irrigation
• Mechanization ;Multi- croping
Why the 1980 increase in yield? = genetics!!!
Note also the basis of rural to urban migration in U.S.
Green revolution -
Father of the Green Revolution; During the mid-20th century, Borlaug led
the introduction of these high-yielding varieties combined with modern
agricultural production techniques to Mexico, Pakistan, and India. As a
result, Mexico became a net exporter of wheat by 1963. Between 1965
and 1970, wheat yields nearly doubled in Pakistan and India, greatly
improving the food security in those nations.[4]
Later applied to rice – Rockefeller foundation support
? = why no increase in production in developed world??
Basis of rural to urban migration???
Other agriculture issues
Overuse of fertilizer: how much should you add???
Monoculture issues
Banana wilt rots the fruit before harvest and eventually kills
the tree
Almost all bananas in the world are cavendish strain – ripens slow –
Has decimated banana production in Africa, now affecting S. America
Effect on exports to Europe?
Solution: find a resistant strain.
Kills wheat – effect on Ethiopia – major food crop. Etc. A wind borne fungus
Potato blight
In Ireland, the Great Famine was a period of mass starvation, disease
and emigration between 1845 and 1852.[1] It is also known, mostly
outside of Ireland, as the Irish Potato Famine
During the Famine, Ireland's population fell by between 20 and 25%.[3]
Approximately 1 million people died and a million more emigrated from
Ireland.[4] The proximate cause of famine was a potato disease
commonly known as potato blight.[5] Although blight ravaged potato
crops throughout Europe during the 1840s, the impact and human cost in
Ireland — where a ⅓ of the population was entirely dependent on the
potato for food
Irish potato famine – millions left for U.S., Australia, etc.
Major advantage of transgenic
Crops – can develop quickly
compared to traditional breeding
Add golden rice = vitamin A.
A new – green revolution \
Transgenic crops
Some for economics
Some for production increase
Some for health.
• Issues today – food distribution vs food
• Weather patterns and water availability.
• Extreme weather – frost and heat. –
survival of worst conditions
If certain areas get drier, or more severe weather (spring floods, etc.) effect on
corn production ?
Drier summer – move corn to Canada.